Plating apparatus, plating method, and method for manufacturing semiconductor device

Abstract

A plating apparatus according to the present invention is provided with a plating tank 100 in which an anode electrode 5 is provided, the plating apparatus performing the plating by (i) streaming a plating solution and an electrolytic liquid into the plating tank 100, (ii) emitting a jet of the plating solution to the plating-target face W of the semiconductor wafer 1 from the underneath of the semiconductor wafer 1, and (iii) streaming the electrolytic liquid to the anode electrode 5 while electrically conducting between the semiconductor wafer 1 and the anode electrode 5, the plating tank including a partition in between the semiconductor wafer 1 and the anode electrode 5, and the partition (i) separating the semiconductor wafer 1 and the anode electrode 5 and (ii) dividing the plating tank 100 into a plating-target substrate room and an anode electrode room. Thus, in a face-down type fountain plating apparatus, the plating quality would not be degraded by micro foreign solid particles originated from, for example, a black film while maintaining the operability of the apparatus.

Description

This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Applications (i) No. 112888/2005 filed in Japan on Apr. 8, 2005 and (ii) No. 202283/2005 filed in Japan on Jul. 11, 2005, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to (i) a plating apparatus, (ii) a plating method, and (iii) a method for manufacturing a semiconductor device, all of which are excellent for finely plating a plating-target face of, for example, a semiconductor wafer in order to form wiring.

BACKGROUND OF THE INVENTION

In the recent years, metal plating has been utilized for forming a wiring on, for example, a semiconductor wafer. Known conventional apparatuses utilized for metal plating include a face-down type fountain plating apparatus, a rack-method vertical plating apparatus, and a face-up type fountain plating apparatus.

The face-down type fountain plating apparatus, as illustrated in FIG. 11, is provided with: a wafer holder 2′ that holds a semiconductor wafer 1′; a cup 3′; a plating solution jet tube 4′ for supplying plating solution to the cup 3′; and an anode electrode 5′. The anode electrode 5′ is normally made of copper mixed with phosphorus. The anode electrode 5′ is provided in the cup 3′. The wafer holder 2′ is provided to the cup 3′. The semiconductor wafer 1′ is held on top of the cup 3′ by the wafer holder 2′. In the face-down type fountain plating apparatus, the plating solution jet tube 4′ is disposed underneath of the semiconductor wafer 1′. With this structure, jets of plating solution emitted from the plating solution jet tube 4′ is applied on the semiconductor wafer 1′ from the underneath so as to plate the plating-target face (face to be plated).

The face-down type fountain plating apparatus is provided with the following components, although these components are not illustrated in FIG. 11: a plating solution tank disposed in such a way as to surround the cup 3′; a plating solution storage tank that functions as a supply source of plating solution; a pump utilized for circulating the plating solution within the plating apparatus; a filter that filters off foreign solid particles contained in the plating solution; and a pipe that connects the above components.

With the face-down type fountain plating apparatus, the pump conveys the plating solution from the plating solution storage tank to the bottom of the cup 3′ via the filter. Then, the plating solution streams into the cup 3′ from the underneath of the cup 3′ through the plating solution jet tube 4′, passes by the anode electrode 5′, and finally reaches the plating-target face of the semiconductor wafer 1. Subsequently, the plating solution is drained out of the cup 3′ from an upper edge of the cup 3′ (the plating solution is drained through a gap between the wafer holder 2′ and the cup 3′). Finally, the plating solution is collected by the plating solution tank and returned to the plating solution storage tank.

In the face-down type fountain plating apparatus is provided an “outlet opening through which the plating solution streamed into the plating tank is partially drained out of the plating tank from (i) a through hole made through the anode electrode or (ii) a vicinity of the anode electrode.” Another known plating apparatus is that adopting an inert electrode, a typical example of which includes platinum, as an anode electrode.

The rack-method vertical plating apparatus, as illustrated in FIG. 12, is provided with an anode electrode 6″, a rack 24, and a plating tank 12. The anode electrode 6″ is normally disposed in an anode bag 13 made of cloth having a raised back. As the anode electrode 6″, (i) a ball-shaped copper mixed with phosphorus that is placed in a bascket made of titanium or (ii) a copper plate made of copper mixed with phosphorus is used. The rack 24 is a plate-shaped jig provided with a power source for supplying the semiconductor wafer 1 with power. Through the jig is made a hole having an inner diameter slightly smaller than that of the semiconductor wafer 1. Finally, the plating tank 12 is provided with a wafer holder 25 and a squeegee (not illustrated). The wafer holder 25 stabilizes the semiconductor wafer 1 on the rack 24, and insulates the rear face of the semiconductor wafer 1. The squeegee agitates the plating solution.

The rack-method vertical plating apparatus is provided with the following components, although these components are not illustrated in FIG. 12: a plating solution tank; a plating solution storage tank that functions as a supply source of the plating solution; a pump utilized for circulating the plating solution within the plating apparatus; a filter that filters off foreign solid particles contained in the plating solution; a pipe that connects the above components; and accessory units.

The pump conveys the plating solution from the storage tank to an inlet opening 14 via the filter. Then, the plating solution streams in the vicinity of the anode bag 13, which covers the anode electrode 6, in the plating tank 12. Subsequently, the plating solution reaches the plating-target face of the semiconductor wafer 1. Then, the plating solution is drained out from the upper edge of the plating tank 12, and streams into the dam 15. Finally, the plating solution is returned to the plating solution storage tank via the return tube that constitutes a part of the dam 15. Such rack-method vertical plating apparatus is disclosed in Document 1: Janapese Unexamined Patent Publication 2000-87299 (published on Mar. 28, 2000).

Further, in the face-up type fountain plating apparatus, the plating-target face of a semiconductor wafer faces upward, and an anode electrode is so disposed as to face the plating-target face. Therefore, the plating solution is supplied onto the upper face of the semiconductor wafer. Such face-up type fountain plating apparatus is disclosed in, for example, Document 2: Japanese Unexamined Patent Publication No. 2001-49498 (published on Feb. 20, 2001) or Document 3: Japanese Unexamined Patent Publication no. 2001-24303 (published on Jan. 26, 2001).

The face-down type fountain plating apparatus has a problem in that micro foreign solid particles adhere to the plating-target face, and therefore the plating quality is degraded. This problem is originated from the surface of the anode electrode in the path through which the plating solution streams; the plating solution supplied from the plating solution storage tank by the pump is filtrated by the filter, is supplied to the cup from the underneath thereof, passes by the vicinity of the anode electrode, and reaches the plating-target face of the semiconductor wafer. If the anode electrode includes copper mixed with phosphorus then a film in black called black film is formed on the surface of the anode electrode. The black film is made of copper complex (Cu⁺) with one valence electron, which copper complex contains chlorine (Cl) or phosphorus (P). The black film is formed by a chemical combination with copper ion having one valence electron, which copper ion is dissolved from the anode electrode.

The black film suppresses a disproportionation reaction of copper according to formula (1) below, thereby preventing generation of slime.
2Cu⁺→Cu+Cu²⁺  (1)

However, the black film formed on the surface of the anode electrode is easily peeled off therefrom. A small piece of peeled black film is conveyed, along with a stream of the plating solution, to the plating-target face of the semiconductor wafer. This causes a problem in that the black film adheres to a plating-target face of the semiconductor wafer.

Such problem caused by the black film can be prevented by adopting an inert electrode as the anode electrode. In this case, however, an additive agent contained in the plating solution is oxidatively decomposed on the surface of the anode electrode. This causes a problem in that the consumption of the plating solution increases. Another problem is that the oxidative decomposition may generate a decomposition product, and the decomposition product would contaminate the plating solution.

In contrast, with the conventional rack-method vertical plating apparatus, the anode electrode containing copper mixed with phosphorus is disposed in the anode bag made of cloth having raised back. This prevents the foreign solid particles, which are generated from the black film, from adhering to the semiconductor wafer. However, in order to hold the semiconductor wafer in the plating tank, the vertical plating apparatus requires fixedly holding the semiconductor wafer on the rack. This causes problems in that (i) the operability is degraded, (ii) the plating quality is degraded, and (iii) automation of operation is made difficult.

Further, in the face-up type fountain plating apparatus according to Document 2, the bottom portion of the anode room includes an ion exchange resin or a porous neutral membrane to prevent the black film from peeling, which may be caused by dryness, and the anode room is filled with the plating solution. Further, in the face-up type fountain plating apparatus according to Document 3, the bottom face of the anode room includes a porous element having numerous thin holes.

Further, an apparatus having a different structure from the above plating apparatuses is disclosed in Document 4: Japanese Unexamined Patent Publication No. 2003-73889 (published on Mar. 12, 2003). Document 4 teaches a copper-plating apparatus that electrically plates a semiconductor wafer with copper, the copper-plating apparatus being configured such that (i) the plating tank is partitioned by an anion exchange membrane into a cathode room and an anode room, and (ii) an inert electrode is provided for functioning as the anode electrode. Further, in the plating apparatus according to Document 4, the cathode room and the anode room are separated by the anion exchange membrane, and a cathode liquid and an anode liquid are supplied to the cathode room and the anode room, respectively.

With regard to the face-down type fountain plating apparatus among the above conventional plating apparatuses, there has not been suggested a plating apparatus with which the plating solution would not be contaminated with micro foreign solid particles originated from, for example, a black film.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention has as an object to provide (i) a plating apparatus, especially a face-down type fountain plating apparatus, with which the plating quality would not be degraded by micro foreign solid particles originated from, for example, a black film, while maintaining the operability of the apparatus, (ii) a plating method, and (iii) a method for manufacturing a semiconductor device.

In order to solve the above problems, a plating apparatus according to the present invention is adapted so that, in a plating apparatus for plating a plating-target face of a plating-target substrate, the plating apparatus including a plating tank in which an anode electrode is provided, the plating apparatus performing the plating by (i) streaming a plating solution and an electrolytic liquid into the plating tank, (ii) emitting a jet of the plating solution to the plating-target face of the plating-target substrate from an underneath of the plating-target substrate, and (iii) streaming the electrolytic liquid to the anode electrode provided in the plating tank while electrically conducting between the plating-target substrate and the anode electrode, the plating tank including a partition in between the plating-target substrate and the anode electrode, and the partition (i) separating the plating-target substrate and the anode electrode and (ii) dividing the plating tank into a plating-target substrate room and an anode electrode room.

The plating apparatus according to the present invention performs the plating by streaming a plating solution and an electrolytic liquid into the plating tank, and electrically conducting between the anode electrode and the plating-target substrate. Further, the plating apparatus of the present invention adopts the face-up method in which jets of the plating solution are brought into contact with the plating-target face of the plating-target substrate from the underneath thereof. In this case, the electrolytic liquid streams into the anode electrode.

Note that the “plating-target substrate room” is the part of the space divided by the partition, which includes the plating-target substrate, whereas the “anode electrode room” is the part of the space divided by the partition, which part includes the anode electrode.

In the above structure, the anode electrode and the plating-target substrate are separated by the partition, and the plating tank is divided into the plating-target substrate room and the anode electrode room. This prevents the plating-target face from being contaminated with, for example, particles originated from the anode electrode.

As the foregoing described, with the above structure, it becomes possible to provide a plating apparatus with which the plating quality would not be degraded by the micro foreign solid particles originated from, for example, black film, while maintaining the operability of the apparatus. Further, with the above structure, it becomes possible to provide a high-density highly-precise semiconductor device having high-quality plating for wiring.

In the plating apparatus of the present invention, an exemplary structure in which “the plating solution is jet from an underneath of the plating-target substrate so that the plating solution is brought into contact with the plating-target face of the plating-target substrate, and a voltage is applied in between the plating-target substrate and the anode electrode while streaming the electrolytic liquid to the anode electrode” is that in which a plating solution jet tube for emitting a jet of the plating solution to the plating-target face of the plating-target substrate is provided in such a way that (i) the plating solution jet tube passes through the partition and (ii) the plating solution streams only into the plating-target substrate room.

This makes it possible to bring the plating solution into contact with the plating-target face of the plating-target substrate from the underneath thereof.

Another exemplary structure is that provided with an electrolytic liquid supply tube for streaming the electrolytic liquid only into the anode electrode room. This makes it possible to stream the electrolytic liquid into the anode electrode.

Normally, various additive agents are added to a plating solution used for plating. The additive agents are categorized into, roughly, (i) the substances that work in relation to the plating-target face of the plating-target substrate and (ii) the substances that work in relation to the surface of the anode electrode. The substances that work in relation to the plating-target face of the plating-target substrate generate, for example, a decomposition reaction on the surface of the anode electrode, generating a reaction product. This reaction product negatively affects the reactions in plating. The “electrolytic liquid” indicates a solution containing none of the substances that work in relation to the plating-target face of the plating-target substrate. In the above structure, the electrolytic liquid streams into the anode electrode room while the plating solution streams into the plating-target substrate room, and the anode electrode room and the plating-target substrate room are separated by the partition. Therefore, no decomposition reactions would be generated on the surface of the anode electrode, and the reactions in plating would not be negatively affected.

In order to solve the above problems, the method for manufacturing a semiconductor device, which method accords to the present invention, adapts the plating apparatus.

This makes it possible to provide a semiconductor device having high-quality plating for wiring without any adhering micro foreign solid particles originated from, for example, a black film on the surface of the anode electrode.

Further, in order to solve the above problems, the plating method of the present invention for plating a plating-target face of a plating-target substrate includes the plating steps of: (i) streaming a plating solution and an electrolytic liquid into a plating tank, (ii) emitting a jet of the plating solution to a plating-target substrate from an underneath of the plating-target substrate, and (iii) streaming the electrolytic liquid to an anode electrode provided in the plating tank while electrically conducting between the plating-target substrate and the anode electrode; and plating the plating-target substrate in the plating tank in which a plating-target substrate and an anode electrode are separated by a partition so that the plating tank is divided into a plating-target substrate room and an anode electrode room.

In the above configuration, the plating is performed by separating the anode electrode and the plating-target face in the plating tank, and dividing the plating tank into the plating-target substrate room and the anode electrode room. This prevents the plating-target face from being contaminated with particles originated from the anode electrode.

Additional objects, features, and strengths of the present invention will be made clear by the description below. Further, the advantages of the present invention will be evident from the following explanation in reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional diagram schematically illustrating a structure of a plating tank provided to a plating apparatus according to one embodiment of the present invention.

FIG. 2 is a cross sectional diagram illustrating an exemplary structure of a wafer holder of the plating tank.

FIG. 3 are a set of diagrams illustrating a structure of an area surrounded by an inner tube and a partition in the plating tank. The upper diagram is a diagram observing from a top of a plating-target face of a semiconductor wafer, and the lower diagram is a cross sectional diagram of the area.

FIG. 4 is an explanatory diagram illustrating a structure of an ion exchange membrane.

FIG. 5 is an explanatory diagram illustrating selective permeability of the ion exchange membrane.

FIG. 6 is a diagram schematically illustrating a structure of a plating apparatus according to one embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a structure of the semiconductor wafer.

FIG. 8(a) is a plane-view diagram schematically illustrating a semiconductor chip formed on the semiconductor wafer, at the time after a plating step is performed.

FIG. 8(b) is a cross sectional diagram schematically illustrating a semiconductor chip formed on the semiconductor wafer, at the time after the plating step is performed.

FIG. 9 is a cross sectional diagram schematically illustrating a plating tank provided to a plating apparatus according to another embodiment of the present invention.

FIG. 10 is a diagram schematically illustrating a structure of a plating apparatus according to another embodiment of the present invention.

FIG. 11 is a cross sectional diagram schematically illustrating a structure of a conventional face-down type fountain plating apparatus.

FIG. 12 is a cross sectional diagram schematically illustrating a structure of a conventional rack-method vertical plating apparatus.

FIG. 13(a) is a cross sectional diagram illustrating a process of a method for producing a semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of a semiconductor chip at the time before the step of forming a seed layer is performed.

FIG. 13(b) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the step of forming a seed layer is performed.

FIG. 13(c) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the step of applying a photoresist is performed.

FIG. 13(d) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the step of forming a pattern on the photoresist is performed.

FIG. 13(e) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the plating step is performed.

FIG. 13(f) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the step of removing is performed.

FIG. 13(g) is a cross sectional diagram illustrating the process of the method for producing the semiconductor wafer, which method accords to the present embodiment. The cross sectional diagram schematically illustrates a part of the semiconductor chip at the time after the step of etching is performed.

FIG. 14(a) is a cross sectional diagram illustrating a process of mounting an external connection terminal on a semiconductor wafer with a wiring plated-layer formed thereon. The cross sectional diagram schematically illustrates a part of the semiconductor chip with the wiring plated-layer, at the time before the step of forming an over coat layer is performed.

FIG. 14(b) is a cross sectional diagram illustrating the process of mounting the external connection terminal on the semiconductor wafer with a wiring plated-layer formed thereon. The cross sectional diagram schematically illustrates a part of the semiconductor chip after the step of forming an over coat layer is performed.

FIG. 14(c) is a cross sectional diagram illustrating the process of mounting the external connection terminal on the semiconductor wafer with a wiring plated-layer formed thereon. The cross sectional diagram schematically illustrates a part of the semiconductor chip after the step of forming a pattern on an over coat layer is performed.

FIG. 14(d) is a cross sectional diagram illustrating the process of mounting the external connection terminal on the semiconductor wafer with a wiring plated-layer formed thereon. The cross sectional diagram schematically illustrates a part of the semiconductor chip after the step of forming an external connection terminal is performed.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

The following describes one embodiment of the present invention, with reference to FIGS. 1 to 8(a) and 8(b).

FIG. 1 is a cross sectional diagram schematically illustrating a structure of a plating tank provided to a plating apparatus of the present embodiment. As illustrated in FIG. 1, a plating tank 100 is provided with: a wafer holder 2 that holds a semiconductor wafer (plating-target substrate (substrate to be plated)) 1; a cup 3; a plating solution supply nozzle (plating solution jet tube) 4; an anode electrode 5; a supporting member 6 that supports the anode electrode 5; a partition 7; and an electrolytic liquid supply tube 8. The cup 3 is provided with an inner tube 31 and an outer tube 32.

The inner tube (second cylinder cup) 31 and the outer tube (first cylinder cup) 32 are containers each having a substantially cylindrical shape with an opening top. The outer diameter of the inner tube 31 is so designed as to be smaller than that of the outer tube 32. The outer tube 32 has an opening bottom. At the center of the bottom part of the inner tube 31 is provided an electrolytic liquid supply tube 8 through which electrolytic liquid is supplied to the anode electrode 5.

Further, as illustrated in FIG. 1, the partition 7 having a doughnut-shape is formed on the inner wall of the outer tube 32. The partition 7 is disposed on the upper part of the outer tube 32 so as to form a partition in the inner tube 31 and in the outer tube 32. In other words, the partition 7 is so disposed as to keep the semiconductor wafer 1 separated from the anode electrode 5. This divides the plating tank 100 into a plating-target substrate room and an anode electrode room. The “plating-target substrate room” in the plating tank 100 is an area surrounded by the outer tube 32 and the partition 7, whereas the “anode electrode room” in the plating tank 100 is an area surrounded by the inner tube 31 and the partition 7. In the plating-target substrate room is disposed a plating-target face (face to be plated) W of the semiconductor wafer. Further, in the anode electrode room is disposed the anode electrode 5.

Further, as illustrated in FIG. 1, the plating solution supply nozzle 4 is provided. The plating solution supply nozzle 4 passes through a hole in a center portion of the partition 7. The supporting member 6 is connected to the inner tube 31, and allows electrolytic liquid to pass therethrough. On the supporting member 6, the anode electrode 5 is disposed. The anode electrode 5 is placed above the lower end of the plating solution supply nozzle 4.

The partition 7 includes a hydrocarbon type cation exchange membrane, but is not limited to a particular type of partition as long as the partition 7 includes a permeation member that is permeable to an ion of the electrolytic liquid around the anode electrode 5 and the supporting member 6, which electrolytic liquid has streamed into the anode electrode room through the electrolytic liquid supply tube 8. For example, the partition 7 may include an ion exchange membrane, a neutral membrane, a porous ceramics, or the like. Further, in the case in which the partition 7 includes a hydrocarbon type cation exchange membrane, either of the followings may be adopted as the hydrocarbon type cation exchange membrane: Selemion (registered trademark) (hydrocarbon type cation exchange membrane, manufactured by Asahi Glass Engineering Co., Ltd.), or Neosepta CM-1 (registered trademark) (hydrocarbon type cation exchange membrane, manufactured by Astom Corporation). A concrete structure of the partition 7 will be described later.

The inner tube 31 and the outer tube 32, both of which are components of the cup 3, the plating solution supply nozzle 4, and the supporting member 6 are all made of polypropylene. Further, the anode electrode 5 is a dissoluble anode electrode made of copper mixed with phosphorus. Thus, this anode electrode 5 is dissoluble. It should be noted that the member, which is made of propylene in the present embodiment by way of example, is not limited particularly, as long as the member has stable dimensions and is resistant to the plating solution and to the electrolytic liquid. For example, the inner tube 31, the outer tube 32, the plating solution supply nozzle 4, and the supporting member 6 may be made of hard vinyl chloride.

Meanwhile, the ion exchange membrane of Document 2 acts as a bottom covering member so as to have the anode electrode soaked in the plating solution, which anode electrode acts as a top covering member in the face-up type apparatus. The object of providing the ion exchange membrane is thus basically different from that of the present invention.

Further, in contrast to the plating apparatus according to Document 4, the plating apparatus of the present embodiment adopts the face-down method so that the operability of the plating apparatus improves significantly and mass-production of the apparatus is facilitated.

Further, with the plating apparatus according to Document 2 that adopts the face-up method, the sample (plating-target substrate) cannot be removed until the plating solution is completely drained out of the plating room. If the plating-target face is soaked in the plating solution while no voltage is applied, then the metal ion is dissolved again. On the other hand, with the plating apparatus of the present embodiment that adopts the face-down method, the sample (plating-target substrate) can be removed immediately after the plating is finished. This improves (i) productivity in mass-production and (ii) the plating quality.

Normally, various additive agents are added to a plating solution used for plating. The additive agents are categorized into, roughly, (i) the substances that work in relation to the plating-target face of the plating-target substrate and (ii) the substances that work in relation to the surface of the anode electrode. The substances that work in relation to the plating-target face of the plating-target substrate generate, for example, a decomposition reaction on the surface of the anode electrode, generating a reaction product. This reaction product negatively affects the reactions in plating.

Further, it is preferable that the plating solution contain copper. It is also preferable that the plating solution be a conductive liquid.

By using the plating solution containing copper as the plating solution, the plating-target face of the plating-target substrate is plated with copper. Further, the plating quality would be desirable especially when the plating is performed using a plating solution containing copper at the ratio of: 14 g to 40 g of copper with respect to 1 L of plating solution.

Further, it is preferable that the anode electrode be a dissoluble anode electrode made of copper containing phosphorus in a range of 0.04% to 0.06%.

If an anode electrode made of pure copper is used as the anode electrode, an increased amount of foreign particles is generated. However, in the above structure, the anode electrode is a dissoluble anode electrode made of copper mixed with phosphorus, and therefore a black membrane called a black film is formed on the surface of the anode electrode, which black film traps a copper complex ion (Cu⁺) that causes formation of the foreign particles.

Further, in order to prevent adhesion of micro foreign solid particles originated from, for example, a black film, the conventional structures are required to utilize an inert electrode. This causes a problem in that the consumption of additive agents increases due to oxidative decomposition of additive agent contained in the plating solution. Another problem is that the oxidative decomposition may generate a decomposition product, and the decomposition product would contaminate the plating solution. This degrades the plating quality.

The “electrolytic liquid” is a solution containing none of the substances that work in relation to the plating-target face of the plating-target substrate. In the above structure, the electrolytic liquid streams into the anode electrode room while the plating solution streams into the plating-target substrate room, and the anode electrode room and the plating-target substrate room are separated by the partition. Therefore, no decomposition reactions would be generated on the surface of the anode electrode, and the reactions in plating would not be negatively affected.

Even if a substance that negatively affects the plating is generated in the electrolytic liquid, the plating-target face would not be affected because the plating-target face is isolated by the partition.

Concretely, the electrolytic liquid is a solution containing no metal that is to be plated (for example, in the case of copper plating, the metal would be copper). On the other hand, the plating solution is a solution containing metal that is to be plated. Further, the electrolytic liquid and the plating solution are common in that both of them have a conductive properties.

More specifically, if a solution containing copper sulfate is used as the plating solution, then the electrolytic liquid is either sulfuric acid or an aqueous solution diluted with sulfuric acid.

Further, with the present invention, adhesion of micro foreign solid particles generated from, for example, a black film is prevented, even if the electrolytic liquid is either a solution containing metal that is the type of metal to be plated or a solution that is identical to the plating solution. Even if a substance that negatively affects the plating is generated, the plating-target face would not be affected because the plating-target face is isolated by the partition.

In other words, the electrolytic liquid may contain a copper. Further, the electrolytic liquid may be a conductive liquid.

Further, the electrolytic liquid may contain a copper at the ratio of: 14 g to 40 g of copper with respect to 1 L of electrolytic liquid.

The applicable dimensions of the semiconductor wafer 1 in the present embodiment may be set arbitrarily depending upon the dimensions of the members of the plating tank 100. In the following, exemplary dimensions applicable in the present embodiments are described. A semiconductor wafer with a diameter of approximately 100 mm to 300 mm may be used as the semiconductor wafer 1. More concretely, a semiconductor wafer with a diameter of approximately 150 mm may be used.

Further, the inner tube 31 has a cylindrical shape with an outer diameter of 130 mm, an inner diameter of 120 mm, a thickness of 5 mm, and a height of 110 mm.

Further, the supporting member 6 is disposed in between the inner tube 31 and the plating solution supply nozzle 4. The supporting member 6 is disposed 20 mm, or at least 5 mm, above the bottom face of the inner tube 31. Further, the supporting member 6 has numerous vertical through holes.

On an upper part of the outer tube 32, a partition 7 is closely and fixedly attached. Further, the height of the outer tube 32 may be 30 mm or longer. Further, in FIG. 1, the lower end of the outer tube 32 is positioned upper (i.e., closer to the plating-target substrate) than the lower end of the inner tube 31 is. The lower end of the outer tube 32, however, is not limited to the above case, and the lower end of the outer tube 32 may be lower than the lower end of the inner tube 31. Further, the inner diameter of the outer tube 32 is set, but not limited, to 140 mm.

Further, with the plating tank 100, the height of the inner tube 31 is set, but not limited, to 110 mm, and the width of a gap between the partition 7 and the upper end of the inner tube 31 is set, but not limited, to 5 mm. The height and the width are set so that the electrolytic liquid is sufficiently in contact with the periphery on the surface of the partition 7.

Further, the partition 7 has a doughnut-shape with an outer diameter of 140 mm and an inner diameter of 20 mm. The outer wall of the partition 7 is closely attached to the outer tube 32, while the plating solution supply nozzle 4 is closely attached to the inner wall. By this, the partition 7 is fixedly held. The dimensions of the partition 7 are not limited to the above dimensions. Further, in a case that the partition 7 is made of a product manufactured by Selemion, the thickness may be approximately 100 μm, or between 100 μm and 200 μm.

Further, the dimensions of the anode electrode 5 made of copper mixed with phosphorus are set, but not limited, to: 110 mm for the outer diameter, 30 mm for the inner diameter, and the 8 mm for the thickness. The dimensions of the anode electrode 5 may be set arbitrarily in such a way that the streams of the electrolytic liquid through the (i) gap between the supporting member 6 and the partition 7 and (ii) the gap between the inner tube 31 and the anode electrode 5 are not disturbed.

The plating solution supply nozzle 4 passes through the partition 7, and the top end of the plating solution supply nozzle 4 is set to be 2 mm above the partition 7. The plating solution supply nozzle 4 is not, however, limited to this structure and may be disposed arbitrarily, provided that the plating solution supply nozzle 4 reaches the partition 7 and is closely fixed on the partition 7.

The foregoing described the respective dimensions of the components of the plating tank 100, which components include the semiconductor wafer 1, the cup 3 (inner tube 31 and outer tube 32), the plating solution supply nozzle 4, the anode electrode 5, the supporting member 6, and the partition 7. The respective dimensions of the components of the plating tank 100, however, may be set arbitrarily depending upon (i) the dimensions of the plating tank 100 or (ii) the dimensions of a semiconductor wafer 1 to be used.

The following concretely describes the wafer holder 2 that holds the semiconductor wafer 1, with reference to FIG. 2. FIG. 2 is a cross sectional diagram illustrating a structure of the wafer holder 2 of the plating tank 100. As illustrated in FIG. 2, the wafer holder 2 is provided with an O-ring 21, a contact member 22, and a wafer holder ring 23. The wafer holder ring 23 is held by a holding member (not illustrated) with a certain distance between wafer holder ring 23 and the upper end of the outer tube 32. The O-ring 21 and the contact member 22 are provided on the wafer holder ring 23 so as to ensure close contact with the semiconductor wafer 1 being held.

Further, three contact members 22 are disposed on the edge of the semiconductor wafer 1. The three contact members 22 are equally distanced from each other. The number of the contact members 22, however, is not limited to three. Alternatively, four or more contact members 22 may be disposed on the edge of the semiconductor wafer 1 and may be equally distanced from each other. Further, a contact member 22 having that is in contact with the whole edge may be provided alternatively.

The inner diameter of the wafer holder ring 23 is set, but not limited, to 140 mm. The shape of the wafer holder ring 23, obviously, does not have to be a circle, and the wafer holder ring 23 may constitute a part of the casing of the apparatus. Further, the return tube 10 is provided on a part of the outer tube 32.

The following describes the respective members of the wafer holder 2.

The O-ring 21 is not limited particularly, as long as it ensures the close contact with the semiconductor wafer 1 and is resistant to the plating solution. For example, a silicone rubber may be used for the O-ring 21. A concrete example thereof is Viton (registered trademark) (manufactured by DuPont Dow Elastomers Japan).

Further, the contact member 22 is not limited particularly, as long as it (i) ensures the close contact with the semiconductor wafer 1, (ii) has a conductive property, and (iii) is resistant to the plating solution to be used. For example, a member that is made of titanium plated with metal may be used. Concrete examples of the contact member 22 include: a titanium plated with platinum; a titanium plated with gold; a resign plated with gold; and a combination of the above.

Furter, the wafer holder ring 23 is not limited particularly, as long as (i) the dimensions of the wafer holder ring 23 would not change and (ii) the wafer holder ring 23 is resistant to the plating solution to be used. Examples of the wafer holder ring 23 include: a ring made of hard vinyl chloride; and a ring made of polypropylene.

The following describes a structure of the partition 7 provided, to the plating tank 100, between (i) the plating-target face W of the semiconductor wafer 1 and (ii) the anode electrode 5, with reference to FIG. 3. FIG. 3 illustrates a structure of the area (plating-target substrate room) surrounded by the outer tube 32 and the partition 7 in the plating tank 100. The upper diagram of FIG. 3 is a diagram observing from the top of the plating-target face W of the semiconductor wafer 1, whereas the lower diagram of FIG. 3 is a cross sectional diagram thereof.

As illustrated in FIG. 3, the partition 7 has a doughnut-shape when observed from the plating-target face W. At the center portion of the partition 7, the plating solution supply nozzle 4 penetrates. Further, the outer edge of the partition 7 is fixed on the upper end portion of the outer tube 32.

Further, the partition 7 is provided with a semipermeable membrane (permeation member) 71 and semipermeable membrane supporting members 72 and 73. The partition 7 has such a structure that the semipermeable membrane supporting members 72 and 73 sandwich the semipermeable membrane 71. The semipermeable membrane supporting member 72 is disposed on the side that faces toward the anode electrode 5, while the semipermeable membrane supporting member 73 is disposed on the side that faces toward the plating-target face W of the semiconductor wafer 1.

Therefore, electrical conduction between the semiconductor wafer 1 and the anode electrode 5 causes the electrolytic liquid to pass through the semipermeable membrane supporting member 72, the electrolytic liquid having streamed to the anode electrode 5 (anode electrode room). Subsequently, an ion contained in the electrolytic liquid passes through the semipermeable membrane 71, and then pass through the semipermeable membrane supporting member 73. Consequently, the ion reaches to the plating-target face W (plating-target substrate room) of the semiconductor wafer 1. Note that the semipermeable membrane 71 is permeable to only the ion contained in the electrolytic liquid, but is not permeable to particles contained in the electrolytic liquid. This enables the partition 7 to separate the particles contained in the electrolytic liquid, and therefore prevents the plated face from being contaminated with the particles originated from the anode electrode 5.

The semipermeable membrane 71 is not limited particularly, as long as it is permeable to the ion of the electrolytic liquid when being soaked in the electrolytic liquid. Examples of the semipermeable membrane 71 include: a hydrocarbon type cation exchange membrane; a neutral membrane; and a porous ceramics. Further, concrete examples of the semipermeable membrane 71 in the case where the semipermeable membrane 71 is the hydrocarbon type cation exchange membrane include: Selemion (registered trademark) (hydrocarbon type cation exchange membrane, manufactured by Asahi Glass Engineering Co., Ltd.), and Neosepta CM-1 (registered trademark) (hydrocarbon type cation exchange membrane, manufactured by Astom Corporation).

The semipermeable membrane supporting members 72 and 73 are not limited particularly, as long as they (i) transmit the electrolytic liquid, (ii) ensures the stability of dimensions, and (iii) is resistant to the plating solution. The semipermeable membrane supporting members 72 and 73 may be made of polypropylene, or hard vinyl chloride, for example.

The following describes a structure of the semipermeable membrane 71, explaining, as an example, an ion exchange membrane including an ion exchange resin. FIG. 4 is an explanatory diagram illustrating a structure of the ion exchange membrane, and FIG. 5 is an explanatory diagram illustrating selective permeability of the ion exchange membrane.

As illustrated in FIG. 4, the “ion exchange membrane” is a membrane that is selectively permeable to an ion. The ion exchange membrane is categorized into, roughly, a cation exchange membrane and an anion exchange membrane. As illustrated in FIG. 4, when the electrolytic liquid is electrically conducted while the cation exchange membrane is soaked in the plating solution, the cation exchange membrane selectively passes cations (M+) therethrough but not anions (B−).

As illustrated in FIG. 5, an exchange group of negative electric charge is fixed in the cation exchange membrane. The exchange group of negative electric charge repels the anions (B−), and therefore the anions (B−) cannot pass through the cation exchange membrane. On the other hand, the exchange group of negative electric charge does not repel the cations (M+), and therefore the cations (M+) pass through the cation exchange membrane. In other words, only the cations (M+) can pass through the cation exchange membrane.

In contrast, the anion exchange membrane acts in an opposite manner as to the manner described above. In both cases, the ion exchange membranes conduct the selective permeation using a current power energy of an electrodialyzer.

The following describes a structure of a plating apparatus of the present embodiment, with reference to FIG. 6. FIG. 6 is a diagram schematically illustrating the structure of the plating apparatus of the present embodiment.

As illustrated in FIG. 6, the plating apparatus of the present embodiment is provided with: a plating tank 100 for plating the plating-target face W of the semiconductor wafer 1; a plating solution system 20 that circulates the plating solution within the plating apparatus; and an electrolytic liquid system 30 that circulates the electrolytic liquid within the plating apparatus.

The plating solution system 20 is provided with: a solution storage tank 9 that functions as a plating solution supply source; an outer tube 32; a return tube 10 connected to a part of the outer tube 32; a plating solution pump 101 for circulating the plating solution within the plating apparatus; a plating solution filter 111 that filters off foreign solid particles contained in the plating solution; and a pipe T that connects the above components.

The electrolytic liquid system 30 is provided with: an electrolytic liquid tank 22 including the members (wafer holder 2, cup 3, and members surrounded by the wafer holder 2 and the cup 3) provided in the plating tank 100; an electrolytic liquid storage tank 23 that functions as an electrolytic liquid supply source; an electrolytic liquid pump 102 that circulates the electrolytic liquid within the plating apparatus; an electrolytic liquid filter 112 that filters off the foreign solid particles contained in the electrolytic liquid; and a pipe T′ that connects these components.

The following describes (i) a stream path of the plating solution and (ii) a stream path of the electrolytic liquid, in the plating apparatus of the present embodiment.

In the plating solution system 20, the plating solution pump 101 conveys the plating solution stored in the plating solution storage tank 9 to the plating solution supply nozzle 4 of the plating tank 100 via the plating solution filter 111. The plating solution then streams into the plating-target substrate room (area surrounded by the partition 7 and the outer tube 32) of the plating tank 100, and reaches the plating-target face W of the semiconductor wafer 1. Subsequently, the plating solution streams into the return tube 10 provided on an upper edge of the outer tube 32. After that, the plating solution is returned to the plating solution storage tank 9.

In the electrolytic liquid system 30, the electrolytic liquid pump 102 conveys the electrolytic liquid stored in the electrolytic liquid storage tank 23 to the electrolytic liquid supply tube 8 of the plating tank 100 via the electrolytic liquid filter 112. The electrolytic liquid then streams into the anode electrode room (area surrounded by the partition 7 and the inner tube 31). Then, at the partition 7, an ion contained in the electrolytic liquid passes through the partition 7 and enters into the plating-target substrate room, whereas a black film that is originated from the anode electrode and contained in the electrolytic liquid does not pass through the partition and thus does not enter into the plating-target substrate room. As a result, a conduction state is realized, and the plating is performed.

The electrolytic liquid streamed into the anode electrode room is drained out of the plating tank 100 from an upper edge (gap between the inner tube 31 and the outer tube 32) of the inner tube 31. The electrolytic liquid then streams into the electrolytic liquid tank 22, and is returned to the plating solution storage tank 23.

The plating solution storage tank 9 and the pipe T in the plating solution system 20 are not limited to a particular type, as long as (i) the dimensions of the tank and the pipe would not change and (ii) the tank and the pipe are resistant to the plating solution to be used. The tank and the pipe may be made of, for example, hard vinyl chloride or polypropylene. Further, the electrolytic liquid tank 22, the electrolytic liquid storage tank 23, the electrolytic liquid filter 112, and the pipe T′ in the electrolytic liquid system 30 are not limited to particular types, as long as (i) the dimensions of the tank and the pipe would not change and (ii) the tank and the pipe are resistant to the plating solution to be used. These components may be made of, for example, hard vinyl chloride or polypropylene.

Further, the plating solution pump 101 in the plating solution system 20 is not limited to a particular pump, as long as the pump is (i) resistant to the plating solution to be used and is (ii) capable of conveying the plating solution without providing a negative influence thereon. Examples of the plating solution pump 101 include: Magnetic Pump MD-30R manufactured by IWAKI Co., Ltd.; and Magnetic Pump MD-6 to MD-70R manufactured by IWAKI Co., Ltd.

Further, the electrolytic liquid pump 102 in the electrolytic liquid system 30 is not limited to a particular pump, as long as the pump is (i) resistant to the electrolytic liquid to be used and is (ii) capable of conveying the electrolytic liquid without providing a negative influence thereon. Examples of the electrolytic liquid pump 102 include: Magnetic Pump MD-70R manufactured by IWAKI Co., Ltd.; and Magnetic Pump MD-30 to MD-100R manufactured by IWAKI Co., Ltd.

Further, the plating solution filter 111 and the electrolytic liquid filter 112 are not limited to a particular type of filter, as long as the filter (i) thoroughly (100%) filters off particles of diameters of approximately a half of a targeted minimum interval of a plating pattern, (ii) is resistant to the plating solution (or electrolytic liquid) to be used, and (iii) provides no negative influence on the plating solution (or electrolytic liquid). Examples of the plating solution filter 111 and the electrolytic liquid filter 112 include: a filter cartridge HDC (registered trademark) II made of polypropylene, manufactured by Nihon Pall Ltd. (J012; this thoroughly filters off all grains each having a diameter of 1.2 μm); a filter cartridge HDC (registered trademark) II made of polypropylene, manufactured by Nihon Pall Ltd. (J006; this thoroughly filters off all grains each having a diameter of 1.0 μm); a filter made of Teflon (registered trademark), and a hollow fiber membrane filter.

To the respective pipes T and T′, a valve, a flowmeter, and an air outlet tube are connected, although these components are not illustrated in FIG. 6. The stream of the plating solution can be controlled by a controller (not illustrated). A voltage can be applied in between the plating-target face and the anode electrode by a power source (not illustrated) so that the plating is performed.

The following describes the semiconductor wafer 1, which functions as the plating-target substrate in the present embodiment, with reference to FIG. 7. FIG. 7 is a schematic diagram illustrating a structure of the semiconductor wafer 1 used in the present embodiment. Further, FIG. 8(a) is a plane view and 8(b) is a cross sectional view, both illustrating a structure of a semiconductor chip 41 formed on the semiconductor wafer 1 at the time after the plating step is performed.

As illustrated in FIG. 7, on the surface of the semiconductor wafer 1 are formed a plurality of semiconductor chips 41. Further, along the edge of the semiconductor wafer 1 is disposed a contact section 42. Via the contact section 42 a plating seed layer (not illustrated) is exposed. The contact section 42 is for establishing a contact with the contact member 22 illustrated in FIG. 2, so that electricity is supplied therethrough.

As illustrated in FIG. 8(a), on the semiconductor chip 41 is formed the photoresist layer 18 with an arbitrary shape. Further, as illustrated in FIG. 8(b), a seed layer 19 is formed on the surface of the semiconductor chip 41 at the time after the plating step is performed. On the surface of the seed layer 19 are formed a wiring plated-layer 16 and a photoresist layer 18. A pad 17 is disposed on a face of the seed layer 19, which face is opposite to the face on which the wiring plated-layer 16 and the photoresist layer 18 are formed. In the semiconductor chip 41, the wiring plated-layer 16 and the pad 17 are electrically connected to each other.

Second Embodiment

The following describes another embodiment according to the present invention, with reference to FIGS. 9 and 10. In the present embodiment, the differences between the present embodiment and the first embodiment described above will be explained. Therefore, for the purpose of convenience, the members having the same functions as those explained in the first embodiment are given the same reference numerals, and explanations thereof are omitted.

FIG. 9 is a cross sectional diagram schematically illustrating a structure of a plating tank provided to the plating apparatus of the present embodiment. As illustrated in FIG. 9, the plating tank 200 is provided with: a wafer holder 2 that holds a semiconductor wafer (plating-target substrate (face to be plated)) 1; a cup 3; a plating solution supply nozzle 4; an anode electrode 5; a supporting member 6 that supports the anode electrode 5; a partition 7; an electrolytic liquid supply tube 8; an upper covering member 28; and an O-ring 29. The cup 3 is provided with an inner tube 31 and an outer tube 32.

As illustrated in FIG. 9, the plating tank 200 of the plating apparatus of the present embodiment has the same structure as that of the first embodiment except that an upper covering member 28 and an O-ring 29 are provided. The upper covering member 28 and the O-ring 29 function as means for closing the plating-target substrate room. The following explains the upper covering member 28 and the O-ring 29. Description of the dimensions and structures of the following components provided to the plating tank 200 is omitted because they are the same as those of the first embodiment: a semiconductor wafer 1; a wafer holder 2; a cup 3 (inner tube 31 and outer tube 32); a plating solution supply nozzle 4; an anode electrode 5; a supporting member 6; a partition 7; and an electrolytic liquid supply tube 8.

As illustrated in FIG. 9, the upper covering member 28 is disposed along the edge of the outer tube 32. The O-ring 29 is disposed in between the outer tube 32 and the upper covering member 28 so as to ensure the close contact with the outer tube 32.

The plating solution supplied to the plating solution supply nozzle 4 reaches the plating-target face (face to be plated) W of the semiconductor wafer 1. In the plating tank 200, the O-ring 29 ensures the close contact of the upper covering member 28 and the outer tube 32. In other words, the plating-target substrate room is closed (closed system). Therefore, after reaching the plating-target face W of the semiconductor wafer 1, the plating solution streams into the return tube 10, instead of draining out of the plating tank 200. Because the plating-target substrate room is closed, the plating solution that has streamed into the plating-target substrate room is shielded from the atmosphere outside of the plating tank 200. Accordingly, with the plating tank 200, the plating solution would not go out of the plating tank 200. This prevents the atmosphere from being contaminated with, for example, evaporated plating solution or a mist of the plating solution. Further, a fluctuation in the ion concentration due to evaporation of the plating solution is also prevented.

The dimensions of the upper covering member 28 are not limited to particular dimensions, as long as the plating-target substrate room can be closed. Further, the dimensions of the upper covering member 28 may be set arbitrarily depending upon the dimensions of the outer tube 32.

Further, the upper covering member 28 is made of polypropylene. The material of the upper covering member 28, however, is not limited to a particular material, as long as (i) the dimensions of the material would not change and (ii) the material is resistant to the plating solution. For example, the upper covering member 28 may be made of hard vinyl chloride.

Further, the material of the O-ring 29 is not limited to a particular material, as long as the material (i) allows the O-ring 29 to closely attach to the outer tube 32 and (ii) is resistant to the plating solution to be used. For example, the O-ring 29 may be made of silicone rubber, or more concretely, Viton (registered trademark).

The following describes a structure of the plating apparatus of the present embodiment, with reference to FIG. 10. FIG. 10 is a diagram schematically illustrating a structure of the plating apparatus of the present embodiment.

As illustrated in FIG. 10, the plating apparatus of the present embodiment is provided with: a plating tank 100 for plating the plating-target face W of the semiconductor wafer 1; a plating solution system 20′ that circulates the plating solution within the plating apparatus; an electrolytic liquid system 30′ that circulates the electrolytic liquid within the plating apparatus; and a replenishing liquid system 40 for (i) monitoring a concentration of the circulating plating solution and (ii) replenishing a replenishing liquid depending upon the concentration of the ion in the plating solution.

The plating solution system 20′ is provided with: a plating solution storage tank 9′ that functions as a plating solution supply source; a plating solution supply nozzle 4; a return tube 10 connected to a part of the outer tube 32; a plating solution pump 101 that circulates the plating solution within the plating apparatus; a plating solution filter 111 that filters off the foreign solid particles contained in the plating solution; and a pipe T that connects the above components. The plating solution system 20′ is different from the plating solution system 20 of the plating apparatus of the first embodiment in that the plating solution storage tank 9′ has a covering member and is covered (closed system).

Further, the electrolytic liquid system 30′ is provided with: an electrolytic liquid tank 22′ in which the members (the wafer holder 2, the cup 3, and a member surrounding them, and the upper covering member 28) surrounded by the plating tank 200 are included; an electrolytic liquid storage tank 23′ that functions as an electrolytic liquid supply source; an electrolytic liquid pump 102 that circulates the electrolytic liquid within the plating apparatus; an electrolytic liquid filter 112 that filters off the foreign solid particles contained in the electrolytic liquid; and a pipe T′ that connects the above components. The electrolytic liquid system 30′ is different from the electrolytic liquid system 30 of the plating apparatus of the first embodiment in that the electrolytic liquid storage tank 23′ has a covering member and is closed (closed system). Further, in the electrolytic liquid system 30′, the outer tube 32 is closely attached to the electrolytic liquid tank 22′ in such a way as to completely close the opening of the electrolytic liquid tank 22′. In other words, the electrolytic liquid tank 22′ is covered (closed system).

Further, the replenishing liquid system 40 is provided with: a replenishment unit 24; a supply pump 25; a replenishing liquid tank 26 having a covering member a sensor 27; and a pipe T″ that connects the above components. The pipe T″ is connected to the plating solution storage tank 9′ of the plating solution system 20′. Further, the sensor 27 detects an ion concentration of the plating solution stored in the plating solution storage tank 9′. Information of the ion concentration of the plating solution, which information is obtained by the sensor 27, is transmitted, in the form of an electric signal, to the supply pump 25 via the replenishment unit 24. The supply pump 25 replenishes, based upon an instruction according to the electric signal, the replenishing liquid from the replenishing liquid tank 26 to the plating solution storage tank 9′.

In FIG. 10, the replenishing liquid system 40 is illustrated as one system line. The replenishing liquid system 40, however, is not limited to the structure of the one system line. Alternatively, one system may be provided for respective kinds of liquids of which the plating solution is made, which liquid need to be controlled and replenished. Further, in place of the replenishing liquid tank 26 and the supply pump 25, (i) a replenishing pipe for pure water and (ii) a valve may be provided, which is controlled by the replenishment unit.

The following describes (i) a stream path of the plating solution and (ii) a stream path of the electrolytic liquid, in the plating apparatus of the present embodiment.

In the plating solution system 20′, the plating solution pump 101 conveys the plating solution stored in the plating solution storage tank 9′ to the plating solution supply nozzle 4 of the plating tank 200 via the plating solution filter 111. The plating solution then streams into the plating-target substrate room (area surrounded by the partition 7 and the outer tube 32) of the plating tank 200, and reaches the plating-target face W of the semiconductor wafer 1. Subsequently, the plating solution streams into the return tube 10 provided on an upper edge of the outer tube 32. After that, the plating solution is returned to the plating solution storage tank 9′.

At this time, the plating-target substrate room is in a closed state due to the upper covering member 28, and therefore the plating solution streamed into the plating-target substrate room is shielded from the atmosphere. This prevents the atmosphere from being contaminated with evaporated plating solution or a mist of the plating solution. Moreover, a fluctuation in the ion concentration due to evaporation of the plating solution is also prevented. Further, because the plating solution storage tank 9′ has a covering member and is covered, the plating solution streamed into the plating solution storage tank 9′ is shielded from the atmosphere. Therefore, with the plating apparatus, the atmosphere is prevented from being contaminated with evaporated plating solution or a mist of the plating solution. Further, a fluctuation in the ion concentration due to evaporation of the plating solution is also prevented.

In the electrolytic liquid system 30′, the electrolytic liquid pump 102 conveys the electrolytic liquid stored in the electrolytic liquid storage tank 23′ to the electrolytic liquid supply tube 8 of the plating tank 200 via the electrolytic liquid filter 112. The electrolytic liquid then streams into the anode electrode room (area surrounded by the partition 7 and the inner tube 31). Then, at the partition 7, an ion contained in the electrolytic liquid passes through the partition 7 and enters into the plating-target substrate room, whereas a black film that is originated from the anode electrode and contained in the electrolytic liquid does not pass through the partition and thus does not enter into the plating-target substrate room. As a result, a conduction state is realized, and the plating is performed.

The electrolytic liquid streamed into the anode electrode room is drained out of the plating tank 200 from an upper edge (gap between the inner tube 31 and the outer tube 32) of the inner tube 31. The electrolytic liquid then streams into the electrolytic liquid tank 22′, and is returned to the plating solution storage tank 23′.

At this time, because the electrolytic liquid tank 22′ and the electrolytic liquid storage tank 23′ are in a closed state, the electrolytic liquid streamed into (i) the electrolytic liquid tank 22′ and (ii) the electrolytic liquid storage tank 23′ are shielded from the atmosphere. This prevents the atmosphere from being contaminated with evaporated electrolytic liquid or a mist of the electrolytic liquid. Further, a fluctuation in the ion concentration due to evaporation of the electrolytic liquid is also prevented.

Description of the materials of the following components is omitted because they are the same as those of the first embodiment: the plating solution storage tank 9′; the plating solution pump 101; the plating solution filter 111; the pipe T; the electrolytic liquid tank 22; the electrolytic liquid storage tank 23; the electrolytic liquid pump 102; the electrolytic liquid filter 112; and the pipe T′.

The material of the pipe T″ of the replenishing liquid system 40 is not limited to a particular material, as long as the material (i) allows the dimensions of the pipe to remain unchanged and (ii) is resistant to the replenishing liquid to be used. For example, the pipe T″ may be made of hard vinyl chloride, polypropylene, or Teflon (registered trademark).

Further, the supply pump 25 is not limited particularly, as long as the pump is (i) resistant to the replenishing liquid to be used and (ii) capable of conveying the replenishing liquid to the plating solution storage tank 9′ without providing a negative influence on the plating solution. Examples of the supply pump 25 include: Peristaltic Pump MP-1000 manufactured by Tokyo Rikakikai Co.; and Peristaltic Pumps MP-1000A to MP-1000B manufactured by Tokyo Rikakikai Co.

To the respective pipes T, T′, and T″, for example a valve, a flowmeter, and an air outlet tube are connected, although these components are not illustrated in FIG. 10. The stream of the plating solution can be controlled by a controller (not illustrated). A voltage can be applied in between the plating-target face and the anode electrode by a power source (not illustrated) so that the plating is performed.

The plating apparatus according to the present invention can also be described in the following way.

The plating apparatus according to the invention is a plating apparatus for plating a substrate and is arranged such that (i) the electrolytic liquid system constituted by an anode electrode and an electrolytic liquid and (ii) the plating solution system constituted by a plating-target face and a plating solution are separated in the cup of the plating apparatus.

Further, in the plating apparatus, the plating solution streams into the area formed by the plating-target substrate and the partition provided in the outer tube 32 of the plating cup.

Further, in the plating apparatus, the electrolytic liquid streams into the area formed by the partition and the anode electrode provided in the inner tube 31 of the plating cup.

Further, the partition is provided so that the electrolytic liquid streamed into the inner tube 31 of the plating cup would not reach the plating-target substrate.

Further, the electrolytic liquid streamed into the inner tube 31 of the plating cup is drained out of the cup.

The structure (partition) that separates the anode electrode and the plating-target substrate in the plating cup is partially or wholly made of material that is permeable to an ion when soaked in the electrolytic liquid.

It is preferable that the material that (i) separates the anode electrode and the plating-target substrate in the plating cup and (ii) is permeable to an ion when soaked in the electrolytic liquid be a semipermeable membrane.

It is preferable that the material that (i) separates the anode electrode and the plating-target substrate in the plating cup and (ii) is permeable to an ion when soaked in the electrolytic liquid be an ion exchange membrane.

The plating apparatus according to the present invention is structured in such a way that the plating solution system and the electrolytic liquid system are separated so as to be independent from each other. Therefore, contamination of the plating-target face due to the anode electrode is prevented.

Further, the plating apparatus according to the present invention is structured in such a way that the plating solution system and the electrolytic liquid system are separated so as to be independent from each other. Therefore, the plating quality of the plating-target face would not be degraded by a decomposition of the additive agent in the plating solution due to the anode electrode.

Further, in the plating apparatus, the cup, the plating tank, the other tanks, and the pipes form a closed system so as to shield the plating solution and the electrolytic liquid from the atmosphere. This prevents the atmosphere from being contaminated with evaporated plating solution or evaporated electrolytic liquid.

Further, in the plating apparatus, the cup, the plating tank, the other tanks, and the pipes form a closed system so as to shield the plating solution and the electrolytic liquid from the atmosphere. This prevents a fluctuation in the concentration of the liquid due to evaporation of the liquids.

The plating solution is either a conductive liquid containing copper or a conductive liquid prepared by adding another substance to a conductive liquid containing copper.

Further, the plating solution contains copper metal, and the proportion of the copper metal in 1 L of the plating solution is 14 g to 40 g, inclusive.

The anode electrode is a dissoluble anode electrode plate made of copper mixed with phosphorus by 0.04% to 0.06%.

Further, the electrolytic liquid is (i) sulfuric acid or (ii) an aqueous solution in which sulfuric acid is diluted.

Further, the electrolytic liquid may be either a conductive liquid containing copper or a conductive liquid prepared by adding another substance to a conductive liquid containing copper.

Further, it is preferable that (i) the electrolytic liquid contain copper metal and (ii) the proportion of the copper in 1 L of electrolytic liquid be 14 g to 40 g, inclusive.

In a semiconductor device according to the present invention, (i) the electrolytic liquid system constituted by an anode electrode and an electrolytic liquid and (ii) the plating solution system constituted by the plating-target face and the plating solution are separated in the cup of the face-down type fountain plating apparatus utilized for plating a substrate.

Further, the plating solution is supplied to an area formed by (a) the partition in the outer tube 32 of the plating cup and (b) a substrate having a plating-target face. In the plating method including the steps of (i) streaming the plating solution into the area formed by (a) the partition in the outer tube 32 of the plating cup and (b) a substrate having a plating-target face, (ii) bringing the plating solution into contact with the plating-target face, (iii) electrically conducting between the plating-target face and the anode electrode provided in the plating cup, the partition prevents the electrolytic liquid streamed into the inner tube 31 of the plating cup from reaching the plating-target face. Therefore, the foreign solid particles contained in the electrolytic liquid would not adhere onto the plating-target face.

Further, in the plating method including the steps of (i) streaming the plating solution into the area formed by (a) the partition in the outer tube 32 of the plating cup and (b) the substrate having a plating-target face, (ii) bringing the plating solution into contact with the plating-target face, (iii) electrically conducting between the plating-target face and the anode electrode provided in the plating cup, the partition is permeable to only an ion contained in the electrolytic liquid streamed into the inner tube 31 of the plating cup. The rest of the electrolytic liquid is drained out of the cup.

The structure that separates the anode electrode and the plating-target face in the plating cup is partially or wholly made of material that is permeable to an ion when soaked in the electrolytic liquid.

The material that (i) separates the anode electrode and the plating-target face in the plating cup and (ii) is permeable to an ion when soaked in the electrolytic liquid is either a semipermeable membrane or an ion exchange membrane.

The plating apparatus is structured in such a way that the plating solution system and the electrolytic liquid system are separated so as to be independent from each other. Therefore, contamination of the plating-target face due to the anode electrode is prevented.

The plating apparatus is structured in such a way that the plating solution system and the electrolytic liquid system are separated so as to be independent from each other. Therefore, the plating quality would not be degraded by a decomposition of the additive agent contained in the plating solution due to the anode electrode.

The plating apparatus is adapted so that the cup, the plating tank, the other tanks, and pipes form a closed system so as to shield the plating solution and the electrolytic liquid from the atmosphere. This prevents (i) evaporation of the liquids, (ii) contamination of the atmosphere, and (iii) and fluctuation in the concentration of the liquids.

As a result, it becomes possible to provide (i) a semiconductor device with which the plating quality would not be degraded by micro foreign solid particles originated from, for example, a black film, while the operability of the face-down type fountain plating apparatus is maintained and (ii) a method for manufacturing the semiconductor device. It is also possible to prevent the plating solution, the electrolytic liquid, or the like from evaporating or generating a mist.

As the foregoing described, the present invention has the following effects.

Plating solution from which the foreign solid particles have been filtered off is brought into contact with the plating-target face. The plating-target face is separated, by the partition including an ion exchange membrane, from the electrolytic solution streamed into the vicinity of the anode electrode. Only copper ion passes through the partition, reaches the plating-target face, and is deposited. Therefore, it becomes possible to provide a high-density and highly-precise semiconductor device with a high-quality plating for wiring, without micro foreign solid particles being adhered on the surface of the anode electrode, which particles are originated from, for example, a black film.

Further, because it is not necessary to use an inert electrode, which has conventionally been adopted, to prevent micro foreign solid particles from adhering, which particles originate from, for example, a black film, an increase of the consumption of the additive agent due to oxidative decomposition of additive agent contained in the plating solution can be prevented. Further, the plating quality would not be degraded by a decomposition product contaminating the plating solution. Therefore, it becomes possible to provide a high-density and highly-precise semiconductor device with a high-quality plating for wiring. Further, because the plating is performed in the closed system, the plating solution and the electrolytic liquid neither evaporate nor generate mists, and the concentration remains unchanged and the clean surrounding environment is maintained.

Third Embodiment

In the present embodiment, a method for manufacturing a semiconductor chip using a plating apparatus according to one of the first or the second embodiments will be explained in detail, with reference to FIGS. 13(a) to 13(g), and FIGS. 14(a) to 14(d). FIG. 13 are cross sectional diagram illustrating the process of the method for manufacturing a semiconductor device according to the present embodiment. In the present embodiment, as one example of the method for manufacturing a semiconductor device, a method for manufacturing the semiconductor chip 41 illustrated in FIGS. 7, 8(a), and 8(b) will be explained.

As illustrated in FIGS. 13(a) to 13(g), the method for manufacturing the semiconductor device according to the present embodiment includes the steps of: forming a seed layer 19 on the surface of the semiconductor chip 41; applying a photoresist on the seed layer 19 thereby to form a photoresist layer 18 thereon; forming an arbitrary pattern on the photoresist layer 18; plating with metal according to the pattern thereby to form a wiring plated-layer; removing the photoresist layer 18; and etching the seed layer 19. FIG. 13(a) schematically illustrates a part of the semiconductor chip 41 at the time before the step of forming the seed layer is performed. FIG. 13(b) schematically illustrates a part of the semiconductor chip 41 at the time after the step of forming the seed layer is performed. FIG. 13(c) schematically illustrates a part of the semiconductor chip 41 at the time after the step of applying the photoresist is performed. FIG. 13(d) schematically illustrates a part of the semiconductor chip 41 at the time after the step of forming the photoresist pattern is performed. FIG. 13(e) schematically illustrates a part of the semiconductor chip 41 at the time after the step of plating is performed. FIG. 13(f) schematically illustrates a part of the semiconductor chip 41 at the time after the step of removing is performed. Finally, FIG. 13(g) schematically illustrates a part of the semiconductor chip 41 at the time after the step of etching is performed.

As illustrated in FIG. 13(a), a pad 17 that externally exchanges an electric signal is provided on the surface of the semiconductor chip 41 at the time before the seed layer is formed.

As illustrated in FIG. 13(b), in the step of forming a seed layer, the seed layer 19 is formed on the semiconductor chip 41. Specifically, a semiconductor wafer having the semiconductor chip 41 is placed in a spattering apparatus such that a seed layer is formed on the face where the pad is formed. Then, a titanium layer of 1000 Å thickness is formed on the surface of the semiconductor wafer, which titanium layer functions as a barrier metal. Subsequently, a copper layer of 300 Å thickness is formed. This copper layer functions as the seed layer 19 used for plating. The seed layer 19 is a first core that facilitates the growth of plating material (wiring plated-layer 16) in the plating step described below.

In the above example, in the step of forming the seed layer, the titanium layer is formed so as to function as the barrier metal. The layer to function as the barrier metal, however, is not limited to the titanium layer, and may be a chromium layer. Alternatively, a layer made of an alloy of titanium and tungsten may be used as the barrier metal. Any types of layer may function as the barrier metal, as long as the layer is made of metal that provides a barrier effect.

Further, in the above case, the thickness of the titanium layer is 1000 Å. The thickness, however, is not limited to that value, and the thickness may be 5000 Å or thicker, as long as the barrierness is ensured. Further, the thickness of the copper layer that functions as the seed layer 19 used for plating is 3000 Å, but the thickness is not limited to that value; the thickness of the copper layer may be 1000 Å or greater, as long as the thickness ensures that the electric current density is maintained at a constant level during the plating step.

As illustrated in FIG. 13(c), in the step of applying a photoresist, the photoresist is applied on the semiconductor wafer (including the semiconductor chip 41) thereby to form the photoresist layer 18, the semiconductor wafer having the seed layer 19 thereon. In the step of applying the photoresist, a spin-coating apparatus spins the semiconductor wafer 1 for 30 seconds at the velocity of 1500 spins per minute to coat the surface of the semiconductor wafer 1 with the photoresist (PMER P-LA900, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Then, the semiconductor wafer 1 is baked at 115° C. for 5 minutes.

In the above case, the PMER P-LA900 is used as the photoresist. The photoresist, however, is not limited to the product, as long as the photoresist is resistant to the processes performed during the plating step described below. For example, PMER N-CA3000, manufactured by Tokyo Ohka Kogyo Co., Ltd, may be used as the photoresist. Further, the method of coating the photoresist is not limited to the spin-coating. For example, the photoresist layer 18 may be formed on the semiconductor wafer 1 by applying a dry film (e.g., ORDYL MP100 Series, manufactured by Tokyo Ohka Kogyo Co., Ltd.) thereon.

Further, in the step of applying a photoresist application, the spin-coating apparatus spins the semiconductor wafer for 30 seconds at the velocity of 1500 spins/minute to coat the photoresist on the semiconductor wafer, and then the semiconductor wafer is baked at 115° C. for 5 minutes. The method of spin-coating, however, is not limited to the above method. For example, the semiconductor wafer may be spun at the velocity of 1000 spins to 3000 spins per minute until the thickness of the photoresist becomes sufficiently uniformed, and then the semiconductor wafer may be heated at 100° C. to 120° C. for approximately 5 minutes.

As illustrated in FIG. 13(d), in the step of forming a photoresist pattern, an arbitrary pattern is formed on the photoresist layer 18 that has been formed in the step of applying the photoresist. Specifically, after the step of applying the photoresist is performed, the semiconductor wafer having the semiconductor chip 41 is placed in an exposure device (not illustrated). Then, the photoresist layer 18 is illuminated with a g-line (436 nm). Subsequently, the photoresist layer 18 is developed by a development device (not illustrated) using 2.38%-TMAH aqueous solution. Then, a corresponding portion of the photoresist to the portion on which the plating for wiring is to be performed is removed.

In the above case, the photoresist layer 18 is illuminated with the g-line (436 nm). The light beam to be illuminated on the photoresist layer 18 during the exposure is not limited to a particular light beam, as long as the light beam can expose the photoresist. For example, an i-line (365 nm) or a deep UV (approximately 200 nm to 300 nm) may be illuminated on the photoresist layer 18. Further, in the step of forming the photoresist pattern, the photoresist layer 18 is developed using the 2.38%-TMAH aqueous solution. The concentration of the TMAH aqueous solution, however, is not limited to the value. For example, the concentration of the TMAH aqueous solution may be 1% to 3%. Alternatively, 25%-TMAH aqueous solution may be diluted with pure water to a concentration that is suitable for the development.

As illustrated in FIG. 13(e), in the plating step, an exposed portion of the seed layer 19 is plated, which portion is exposed as a result that the arbitrary pattern is formed on the photoresist layer 18 in the step of forming the photoresist pattern. In other words, after the step of forming a photoresist pattern is performed, the semiconductor wafer having the semiconductor chip 41 is placed in the plating apparatus illustrated in FIG. 1. Specifically, the semiconductor wafer 1 is placed on the wafer holder 2 of the plating apparatus. Then, the O-ring 21 and the contact member 22 are brought into close contact with the contact section 42 of the semiconductor chip 41 by a wafer holding member (not illustrated).

The plating step adopts, as a step of the method for manufacturing a semiconductor device, the plating method performed by the plating apparatus according to the first embodiment or to the second embodiment. In other words, the method for manufacturing a semiconductor device according to the present embodiment adopts the plating apparatus according to the first embodiment or to the second embodiment.

The following describes an exemplary plating step in which the plating apparatus illustrated in FIG. 6 is utilized. The plating apparatus to be utilized in the plating step is not limited to the plating apparatus illustrated in FIG. 6.

In the plating step, the electrolytic liquid pump 102 operated by a controller (not illustrated) transports dilute sulfuric acid (electrolytic liquid) to the electrolytic liquid filter 112 from the electrolytic liquid storage tank 23 where the dilute sulfuric acid is stored. The amount transported is approximately 20 L per minute, 10 L to 20 L per minute, or a sufficient amount for achieving the object. At this time, the electrolytic liquid stored in the electrolytic liquid storage tank 23 contains sulfuric acid by approximately 200 g/L or in a range of 150 g/L to 250 g/L.

The foreign solid particles that are contained in the electrolytic liquid and are larger than the diameter of the filter opening are filtered off and removed by the electrolytic liquid filter 112. Subsequently, the electrolytic liquid streams into the cup 3 via the pipe T′. Then, the electrolytic liquid entered from the bottom part of the inner tube 31 of the cup 3 streams into the area between the supporting member 5 and the bottom of the inner tube 31. The electrolytic liquid streamed into the area between the supporting member 5 and the bottom of the inner tube 31 (i) moves upward through the through holes of the supporting member and (ii) flows around the anode electrode. Then, the electrolytic liquid moves along the partition 7 toward the edge of the cup 3. Subsequently, the electrolytic liquid passes through the area between the inner tube 31 and the outer tube 32, is drained out of the cup to the electrolytic liquid tank 22, and is returned to the electrolytic liquid storage tank 23. Note that the anode electrode 6 is made of copper mixed with phosphorus by 0.04% to 0.06%.

On the other hand, the plating solution stored in the plating solution storage tank 9 is transported to the plating solution filter 111 by the plating solution pump 101 operated by a controller (not illustrated). The amount to be transported is approximately 2 L per minute, 1 L to 2 L per minute, or a sufficient amount for achieving the object. In the present embodiment by way of example, the plating solution stored in the plating solution storage tank 9 is a copper plating solution (microfab Cu200, manufactured by Electroplating Engineers of Japan Ltd.) containing copper and an additive agent (not illustrated) and copper. The ratio of copper contained is approximately 25 g/L in conversion of metallic copper.

The foreign solid particles that are contained in the plating solution and are larger than the diameter of the filter opening are filtered off by the plating solution filter 111. Then, the plating solution streams into the plating solution supply nozzle 4 via the pipe T. Subsequently, the plating solution streams into and fills in the area surrounded by the semiconductor wafer 1 and the partition 7. Consequently, the surface of the plating solution is brought into contact with the plating-target face W of the semiconductor wafer 1.

After being in contact with the plating-target face W of the semiconductor wafer 1, the plating solution is drained out of the cup 3 from the upper edge of the outer tube 32. Then, the plating solution passes through the return tube 10, which is provided on a part of the outer tube 32, and is returned to the plating solution storage tank 9.

At this time, if the plating-target face W of the semiconductor wafer 1 is a cathode electrode, and a power source (not illustrated) for plating applies a voltage in between the plating-target face W and the anode electrode 5 while controlling current, then a copper ion is generated on the surface of the anode electrode 5. In this case, the generated copper ion passes through the partition 7, and reaches, via the outer tube 32, the surface of the semiconductor wafer 1, which functions as the cathode electrode. Then, on the plating-target face W of the semiconductor wafer 1, the copper ion reacts, in a predefined way, with the additive agent contained in the plating solution, and is deposited as copper with the thickness of approximately 10 μm.

On the other hand, in the inner tube 31 is filled with the electrolytic liquid from which the foreign solid particles larger than the diameter of the filter opening have been removed by the electrolytic liquid filter 112. The electrolytic liquid that have streamed in the vicinity of the anode electrode 5 is blocked by the partition 7 and therefore cannot stream into the outer tube 32; only the copper ion passes through the partition 7 and streams into the outer tube 32. Thus, micro foreign solid particles originated from, for example, a black film on the surface of the anode electrode would not adhere to the plating-target W of the semiconductor wafer 1. Further, it is not necessary to use an inert electrode, which is used in a conventional apparatus in order to prevent the micro foreign solid particles originated from, for example, a black film from adhering. Therefore, (i) the consumption of the additive agent due to oxidative decomposition of the additive agent contained in the plating solution will not increase, and (ii) the plating solution will not be contaminated with a decomposition product and therefore the plating quality will not be degraded. Thus, high-quality plating is achieved.

Further, in the plating step, the electrolytic liquid is streamed into the anode electrode room (area surrounded by the partition 7 and the inner tube 31), while the plating solution is streamed into the plating-target substrate room (area surrounded by the partition 7 and the outer tube 32), thereby performing the plating process. Performing the plating process with the electrolytic liquid and the plating solution separated from one another allows reduction in the amount of necessary plating solution that is expensive. Further, in the case where the plating solution is decomposed or contaminated, the plating solution in the plating apparatus needs to be replaced. With the plating step (plating method) according to the present invention, only a few amount of the plating solution needs to be replaced when the plating solution is decomposed or contaminated.

The voltage to be applied in between the plating-target face W and the anode electrode 5 may be set arbitrarily depending upon the dimensions of the semiconductor wafer 1 or the dimensions of the plating tank. Further, the application time of the voltage can also be arbitrarily set depending upon the dimensions of the semiconductor wafer 1 or the dimensions of the plating tank. Specifically, the voltage is applied for 25 minutes while controlling the electric current density of the plating-target face W is maintained at 20 mA per square centimeters, or at an ampere in a range of 10 mA per square centimeters to 50 mA per square centimeters. The electric current density should be set to a sufficient value for achieving the object.

In the present embodiment, copper plating solution (microfab Cu200, manufactured by Electroplating Engineers of Japan Ltd.) is used as the plating solution. The plating solution, however, is not limited to the copper plating solution, and other plating solutions can also be used as long as the plating solutions can provide the required functions. For example, Levco Ex, manufactured by Uyemura & Co., Ltd, can also be used.

Further, in the step of removing, as illustrated in FIG. 13(f), the photoresist layer 18 formed on the semiconductor chip 41 after the plating step is removed. Specifically, the semiconductor wafer of FIG. 13(e), which semiconductor wafer contains the semiconductor chip 41, is placed in a removing apparatus (not illustrated). Then, the semiconductor wafer is soaked in a stripping solution (104 stripping solution, manufactured by Tokyo Ohka Kogyo Co., Ltd.) of 70° C. for 20 minutes, and is shaken occasionally. As a result, the photoresist layer 18 formed on the surface of the semiconductor wafer is removed.

The present invention is not limited to the step of removing, in which the semiconductor wafer 1 is soaked in the 104 stripping solution of 70° C. for 20 minutes, and is shaken occasionally. The soaking time is not limited to the above time, and the soaking time may be, for example, 15 minutes to 25 minutes. Further, R-100, manufactured by Mitsubishi Gas Chemical Company Inc., for example, may be used as the stripping solution, and the semiconductor wafer 1 may be soaked in R-100 of 50° C. for 8 minutes to 15 minutes, and be concussed occasionally. Alternatively, acetone may be used as the stripping solution.

Subsequently, in the step of etching, as illustrated in FIG. 13(g), the etching process is performed to remove the seed layer 19 on which no wiring plated-layer 16 is formed. Specifically, the semiconductor wafer 1 of FIG. 13(f), which semiconductor wafer 1 contains the semiconductor chip 41, is placed in an etching apparatus (not illustrated). Then, the semiconductor wafer 1 is soaked in 10%-persulfuric acid ammonium aqueous solution of 25° C. for one and a half minute, and is shaken, thereby to etch the seed layer 19 made of copper (Cu) other than the copper wiring plated section (wiring plated-layer 16), that is, the seed layer 19 on which no wiring plated-layer 16 is formed.

In the above case, during the step of etching, the semiconductor wafer is soaked in 10%-persulfuric acid ammonium aqueous solution of 25° C. for one and a half minute, and is shaken. The aqueous solution, however, is not limited to the above solution, and other aqueous solutions, for example 10%-sodium hydroxide aqueous solution or 40%-ferric chloride aqueous solution, may be used as the aqueous solution. Further, the temperature of the aqueous solution is not limited to the above temperature, and may be at a temperature in a range of 15° C. to 40° C.

Further, in the step of etching, subsequently, the semiconductor wafer is soaked in 25%-TMAH of 90° C. for one hour, and is shaken, thereby etching the titanium layer (not illustrated) other than the copper wiring plated-section (wiring plated-layer 16), which titanium layer functions as the barrier metal. In other words, the titanium layer on which no wiring plated-layer 16 is formed is etched.

In the above case, the etching is performed by soaking the titanium layer in 25%-TMAH of 90° C. for one hour with shaking. The aqueous solution used for etching the titanium layer, however, is not limited to the above aqueous solution. For example, (i) hydrochloric acid or (ii) a mixture of hydrofluoric acid and nitric acid.

On the semiconductor chip 41, on which the interconnect plated-layer 16 has been formed, of the semiconductor wafer, an external connection terminal is formed. The following describes the step of mounting an external connection terminal, with reference to FIGS. 14(a) to 14(d). FIGS. 14(a) to 14(d) are cross sectional diagrams illustrating the step of mounting an external connection terminal. In the step, the external connection terminal 34 is mounted on the semiconductor chip 41 on which the wiring plated-layer 16 has been formed.

The step of mounting an external connection terminal includes the steps of: forming an over coat layer on the surface of the semiconductor chip 41 where the wiring plated-layer 16 has been formed; forming an arbitrary pattern on the over coat layer; and forming an external connection terminal on the wiring plated-layer 16 according to the pattern on the over coat layer. FIG. 14(a) schematically illustrates a part of the semiconductor chip 41 on which the wiring plated-layer 16 at the time before the step of forming an over coat layer is performed. FIG. 14(b) schematically illustrates a part of the semiconductor chip 41 at the time after the step of forming an over coat layer is performed. FIG. 14(c) schematically illustrates a part of the semiconductor chip 41 at the time after the step of forming a pattern on the over coat layer is performed. Finally, FIG. 14(d) schematically illustrates a part of the semiconductor chip 41 at the time after the step of forming an external connection terminal.

As illustrated in FIG. 14(a), on the semiconductor chip 41 of the semiconductor wafer 1, the seed layer 19 is formed below the wiring plated-layer 16 (with respect to the wiring plated-layer 16, the seed layer 19 is formed on the side where the pad 17 is). The wiring plated-layer 16 is electrically connected, via the seed layer 19, to the pad 17 formed on the semiconductor chip 41.

As illustrated in FIG. 14(b), in the step of applying an over coat layer, an over coat layer 33 is formed on the semiconductor wafer including the semiconductor chip 41 on which the plating for wiring layer 16 has been formed. Specifically, the over coat layer 33 (CRC-8000 series, manufactured by Sumitomo Bakelite Company Limited) is spin-coated for 30 seconds at the speed of 1500 spins per minute by a spin-coating apparatus, and then is baked at 130° C. for five minutes.

In the step of applying an over coat layer, the CRC-8000 series is used as the over coat layer 33. The material to be used as the over coat layer 33, however, is not limited to the above material, and for example HD-8800 series, manufactured by Hitachi Chemical Co., Ltd., may also be used. Further, a photosensitive heat-resistant resin, such as HK-8000 series, may be used as the over coat layer 33.

Further, in the step of apply gin an over coat layer, the spin-coating apparatus performs the spin-coating for 30 seconds at the speed of 1500 spins per minute, and then the semiconductor wafer is baked at 130° C. for five minutes. The method of coating the over coat layer, however, is not limited to the above arrangement. For example, the semiconductor wafer may be spun at the speed of 1000 spins to 3000 spins per minute until the thickness becomes uniformed, and then may be heated at 120° C. to 140° C. for approximately five minutes.

As illustrated in FIG. 14(c), in the step of forming a pattern on the over coat layer, an arbitrary pattern is formed on the over coat layer 33. Specifically, after the step of applying an over coat layer is performed, the semiconductor wafer having the semiconductor chip 41 is placed in an exposure device (not illustrated). Then, the exposure device illuminates a g-line (436 nm) on the over coat layer 33. Subsequently, a development apparatus (not illustrated) develops the over coat layer 33 using 2.38%-TMAH aqueous solution, a portion of the over coat layer 33, on which portion the external connection terminal 34 is to be formed, is removed. Then, after the portion is removed, a curing process is performed for two hours under nitrogen atmosphere at 300° C. By the step of forming a pattern on the over coat layer, a part of the wiring plated-layer 16 on the semiconductor chip 41 is exposed, on which part the external connection terminal 34 is to be formed.

In the above case, during the step of forming a pattern on an over coat layer, the exposure device illuminates a g-line (436 nm) on the over coat layer 33. The light beam to be illuminated on the over coat layer 33, however, is not limited to a particular light beam, as long as the light beam can expose the over coat layer 33. For example, an i-line (365 nm) or a deep UV (approximately 200 nm to 300 nm) may be illuminated on the over coat layer 33.

Further, in the step of forming the pattern on the over coat layer, the over coat layer 33 is developed using the 2.38%-TMAH aqueous solution. The concentration of the TMAH aqueous solution, however, is not limited to the above value. For example, the concentration of the TMAH aqueous solution may be 1% to 3%. Further, 25%-TMAH aqueous solution may be diluted by pure water to a suitable concentration for the development.

Further, in the step of forming a pattern on an over coat layer, a part of the over coat layer 33 is removed, on which part an external connection terminal 34 is to be formed, and then the curing process is performed for two hours under the nitrogen atmosphere at 300° C. The step to be performed after the over coat layer is removed, however, is not limited to the above step. For example, after the over coat layer is removed, a step of providing a retention period for keeping the semiconductor wafer at 250° C. to 350° C. for 1.5 hours to 3 hours may be provided. Further, prior to or subsequent to the step of providing a retention period, a process for increasing the temperature and a process for reducing the temperature may be provided.

As illustrated in FIG. 14(d), in the step of forming the external connection terminal, the external connection terminal 34 is formed on the part of the over coat layer 33, which part of the over coat layer 33 was removed in the step of forming a pattern on an over coat layer. Specifically, the semiconductor wafer having the semiconductor chip 41 is placed in a ball mounting apparatus (not illustrated). Then, Flux (not illustrated) is applied on the portion where the wiring plated-layer 16 is exposed for forming the external connection terminal therein. Then, on the portion where the Flux is applied, a solder ball that is held by a tool (not illustrated) and functions as the external connection terminal 34 is mounted. Subsequently, the semiconductor wafer including the semiconductor chip 41 on which the solder ball is mounted is processed by a reflow oven with the temperature of 245° C. Specifically, the solder ball is melted again and cooled down so as to be connected, as the external connection terminal 34, to the wiring plated-layer 16.

In the above case, the solder ball that functions as the external connection terminal 34 is made of SnAg3.0Cu0.5 (M705, manufactured by Senju Metal Industry Co., Ltd.). The solder ball, however, is not limited to the above solder ball, and for example the solder ball may be made of Sn63Pb37. Alternatively, the solder ball may be made of other lead-free solder.

Further, in the step of forming an external connection terminal, the reflow oven heats at 245° C. The temperature at which the reflow oven heats, however, is not limited to the above temperature, and for example the temperature may be at 240° C. to 250° C.

As described above, a plating apparatus of the present invention for plating a plating-target face of a plating-target substrate, which plating apparatus includes a plating tank in which an anode electrode is provided, performs the plating by (i) streaming a plating solution and an electrolytic liquid into the plating tank, (ii) emitting a jet of the plating solution to the plating-target face of the plating-target substrate from an underneath of the plating-target substrate, and (iii) streaming the electrolytic liquid to the anode electrode provided in the plating tank while electrically conducting between the plating-target substrate and the anode electrode. The plating tank includes a partition in between the plating-target substrate and the anode electrode, and the partition (i) separates the plating-target substrate and the anode electrode and (ii) divides the plating tank into a plating-target substrate room and an anode electrode room.

This prevents the plating-target face from being contaminated with, for example, particles originated from the anode electrode, and therefore the plating quality would not be degraded by micro foreign solid particles originated from, for example, a black film, while maintaining the operability of the apparatus.

As described above, the method for manufacturing a semiconductor device, which method accords to the present invention, utilizes the above plating apparatus. Further, the method for manufacturing a semiconductor device, which method accords to the present invention, includes the above plating method.

Therefore, it becomes possible to provide a semiconductor device having high-quality plating for wiring but no micro foreign solid particles originated from, for example, a black film on the surface of the anode electrode.

Further, it is preferable in the plating apparatus of the present invention that the electrolytic liquid streaming into the anode electrode room does not reach the plating-target substrate room.

The electrolytic liquid streamed into the anode electrode room contains particles originated from the anode electrode as a result of the electric conduction between the anode electrode and the plating-target substrate. The particles are removed by passing the electrolytic liquid through the partition. Accordingly, with the above structure, the particles originated from the anode electrode would not reach the plating-target face. Therefore, the plating-target face is prevented from being contaminated with the particles.

Further, it is preferable that the plating apparatus according to the present invention has an electrolytic liquid outlet opening for draining the electrolytic liquid out of the plating tank, the electrolytic liquid having streamed into the anode electrode room.

In the above structure, the electrolytic liquid (i) is streaming to the anode electrode in the plating tank and (ii) is draining out of the plating tank through the electrolytic liquid outlet opening, while electrically conducting between the anode electrode and the plating-target substrate. Therefore, with the above structure, the particles originated from the anode electrode can be drained out of the plating tank, and therefore an electrolytic liquid with a reduced number of particles is constantly supplied to the anode electrode room.

Further, it is preferable in the plating apparatus of the present invention that (i) the plating apparatus has a partitioning portion including the partition and separating the anode electrode and the plating-target substrate in the plating tank, a part or a whole of the partitioning portion being made of a permeable member that, when being soaked in the electrolytic liquid, is permeable to an ion of the electrolytic liquid.

In the above structure, the permeable member is permeable to an ion in the electrolytic liquid when soaked in the electrolytic liquid. Therefore, when a voltage is applied to the electrolytic liquid, the ions in the electrolytic liquid transmit through the permeable member, while the particles originated from the anode electrode do not pass through the permeable member. Thus, with the above structure, the ions and the particles, both of which are contained in the electrolytic liquid streamed to the anode electrode, can be separated.

Further, the permeable member may be a semipermeable membrane.

Further, the permeable member may contain an ion exchange resin.

Further, it is preferable that the plating apparatus of the present invention be provided with plating-target substrate room closing means for closing the plating-target substrate.

In the above structure, the plating-target substrate room closing means closes the plating-target substrate room. Therefore, the plating solution streamed into the plating-target substrate room is shut off from the atmosphere outside of the plating tank. This (i) prevents the plating tank from being contaminated due to evaporation of the plating solution during the plating performed in the plating tank, and (ii) prevents a fluctuation in the concentration of the plating solution, which fluctuation may be caused by evaporation of the plating solution.

Further, it is preferable that the plating apparatus of the present invention further include: a plating solution supply source that stores plating solution to be supplied to the plating-target substrate room; a plating solution system for circulating the plating solution between the plating solution supply source and the plating-target substrate room; an electrolytic liquid supply source that stores electrolytic liquid to be supplied to the anode electrode room; and an electrolytic liquid system for circulating the electrolytic liquid between the electrolytic liquid supply source and the anode electrode room.

Further, it is preferable that the plating apparatus of the present invention further include a replenishing liquid system in which (i) a concentration of the plating solution circulating in the plating solution system, and (ii) replenishing liquid is replenished based upon concentration information of the plating solution.

The plating solution contains components necessary for metal plating. The “concentration information of plating solution” is concentration information regarding the components that are contained in the plating solution and are necessary for metal plating. Further, the “replenishing liquid” is a plating solution containing the components at high concentrations. The components of the plating solution may be sulfuric acid, copper, chlorine, additive agent, and/or the like, for example, in the case of copper plating.

With the above structure, in the replenishing liquid system, the replenishing liquid is replenished based upon the concentration information of the plating solution. Specifically, in the replenishing liquid system, the replenishing liquid is replenished when concentration of a component in the plating solution become lower than a predetermined managed level. Therefore, with the above structure, the plating solution with a constant level of concentration can be supplied to the plating tank.

Further, it is preferable in the plating apparatus of the present invention that each of the plating solution system and the electrolytic liquid system is a closed system.

This prevents the atmosphere from being contaminated with evaporation of the plating solution circulating in the plating solution system or evaporation of the electrolytic liquid circulating in the electrolytic liquid system. Further, a fluctuation in the concentrations of (i) the plating solution and (ii) the electrolytic liquid can be prevented, which fluctuation may be caused due to evaporation of the plating solution and evaporation of the electrolytic liquid.

Further, it is preferable that the plating solution (i) contain a copper and (ii) be conductive liquid.

There are a variety of plating solutions for forming various metal layers. With the above structure, a plating solution containing copper is used so that the plating-target face of the plating-target substrate is plated with copper. The “copper component” is metallic copper, copper ion, or a compound containing copper ion. Further, desirable plating is achieved in the case where the proportion of the copper in 1 L of the plating solution is 14 g to 40 g, inclusive.

Further, it is preferable that the anode electrode be a dissoluble anode electrode made of copper mixed with phosphorus.

If an anode electrode made of pure copper is used as the anode electrode, then the amount of foreign substances generated from the anode electrode increases. With the above structure, however, because the anode electrode is a dissoluble anode electrode made of copper mixed with phosphorus, a black membrane called black film is formed on the surface of the anode electrode. This traps copper complex ion (Cu+) that generates the foreign substances. It is preferable that the percentage of the phosphorus to be contained be 0.04% to 0.06%.

Further, conventionally, it is necessary to use an inert electrode in order to prevent adhesion of the micro foreign solid particles originated from, for example, a black film. This causes problems that (i) the consumption of the additive agent is increased due to oxidative decomposition of additive agent contained in plating solution and (ii) the plating quality is degraded due to plating solution contaminated with decomposition product.

With the present invention, even if a dissoluble anode electrode made of copper including phosphorus is used, because the particles originated from the anode electrode are removed by the partition, the micro foreign solid particles originated from, for example, black film is prevented from adhering.

As described above, the “electrolytic liquid” indicates a solution containing no substance that works in relation to the plating-target face of the plating-target substrate. Specifically, the electrolytic liquid is a solution containing no metal that is the type of metal to be plated in the plating process (for example, copper in the case of copper plating). On the other hand, the plating solution indicates a solution containing the metal to be plated. Both the electrolytic liquid and the plating solution have a conductive property.

Specifically, in the case where a solution containing copper sulfate is used as the plating solution, it is preferable that the electrolytic liquid be (i) sulfuric acid or (ii) an aqueous solution diluted with sulfuric acid.

Further, with the present invention, adhesion of the micro foreign particles originated from, for example, black film can be prevented even if the electrolytic liquid is (i) a solution containing metal that is the type of metal to be plated or (ii) a solution identical to the plating solution. Even if a substance that may cause a negative influence on the plating is generated on the surface of the anode electrode, because the plating-target face is separated by the partition, the plating-target face would not be affected by the substance.

Therefore, the electrolytic liquid may be a conductive liquid containing a copper.

Further, the electrolytic liquid may contain a copper at the ratio of 14 g to 40 g of copper with respect to 1 L of electrolytic liquid.

Further, in the plating apparatus of the present invention, the plating-target substrate may be a semiconductor wafer. Therefore, it becomes possible to provide, without spoiling the operability of the face-down type fountain plating apparatus, (i) a semiconductor device with which the plating quality would not be degraded by the micro foreign solid particles originated from, for example, black film and (ii) a method of producing the semiconductor device. Further, (i) evaporation of the plating solution and the electrolytic liquid can be prevented, and (ii) generation of mist can also be prevented.

Further, it is preferable in the plating method of the present invention that the electrolytic liquid streaming into the anode electrode room does not reach the plating-target substrate room.

Further, it is preferable that the plating method of the present invention include the step of draining the electrolytic liquid out of the plating tank, the electrolytic liquid having streamed into the anode electrode room.

Further, it is preferable in the plating method of the present invention that the partition that separates the anode electrode and the plating-target substrate includes a permeable member that, when soaked in the electrolytic liquid, is permeable to an ion contained in an electrolytic liquid.

Further, it is preferable that the plating method of the present invention include the step of closing the plating-target substrate room.

Further, it is preferable that the plating method of the present invention further include the steps of: circulating the plating solution plating solution between (i) the plating solution supply source that stores the plating solution and (ii) the plating-target substrate room; and circulating the electrolytic liquid between (i) the electrolytic liquid supply source that stores the electrolytic liquid and (ii) the anode electrode room.

Further, it is preferable in the plating method of the present invention that the step of circulating the plating solution includes the steps of (i) monitoring a concentration of the plating solution and (ii) replenishing a replenishing liquid based upon concentration information of the plating solution.

Further, in order to solve the above problems, it is preferable that the method for manufacturing a semiconductor device, which method accords to the present invention, include the plating method as its plating step.

Further, it is preferable that the method for manufacturing a semiconductor device, which method accords to the present invention, prior to the plating step, further include the steps of: forming a seed layer on a plating-target face of the plating-target substrate; applying a photoresist on a surface of the seed layer formed in the step of forming a seed layer; and forming a pattern by exposing and developing the photoresist.

As the foregoing described, with the plating apparatus of the present invention, the plating quality will not be degraded by the micro foreign solid particles originated from, for example, black film while maintaining its operability. Thus, the present invention is applicable to the semiconductor industries.

The present invention is not limited to the description of the embodiments above, but may be altered by a skilled person within the scope of the claims. An embodiment based on a proper combination of technical means disclosed in different embodiments is encompassed in the technical scope of the present invention.

The embodiments and concrete examples of implementation discussed in the foregoing detailed explanation serve solely to illustrate the technical details of the present invention, which should not be narrowly interpreted within the limits of such embodiments and concrete examples, but rather may be applied in many variations within the spirit of the present invention, provided such variations do not exceed the scope of the patent claims set forth below.

Claims

1. A plating apparatus for plating a plating-target face of a plating-target substrate, the plating apparatus comprising:

a plating tank in which an anode electrode is provided,

the plating apparatus performing the plating by (i) streaming a plating solution and an electrolytic liquid into the plating tank, (ii) emitting a jet of the plating solution to the plating-target face of the plating-target substrate from an underneath of the plating-target substrate, and (iii) streaming the electrolytic liquid to the anode electrode provided in the plating tank while electrically conducting between the plating-target substrate and the anode electrode,

the plating tank including a partition in between the plating-target substrate and the anode electrode, and

the partition (i) separating the plating-target substrate and the anode electrode and (ii) dividing the plating tank into a plating-target substrate room and an anode electrode room.

2. A plating apparatus as set forth in claim 1, further comprising:

a plating solution jet tube for emitting a jet of the plating solution to the plating-target face of the plating-target substrate,

the plating solution jet tube being provided in such a way that (i) the plating solution jet tube passes through the partition and (ii) the plating solution streams only into the plating-target substrate room.

3. A plating apparatus as set forth in claim 1, further comprising an electrolytic liquid supply tube for streaming the electrolytic liquid only into the anode electrode room.

4. A plating apparatus as set forth in claim 1, wherein the electrolytic liquid streaming into the anode electrode room does not reach the plating-target substrate room.

5. A plating apparatus as set forth in claim 1, further having an electrolytic liquid outlet opening for draining the electrolytic liquid out of the plating tank, the electrolytic liquid having streamed into the anode electrode room,.

6. A plating apparatus as set forth in claim 1, having a partitioning portion including the partition and separating the anode electrode and the plating-target substrate in the plating tank, a part or a whole of the partitioning portion being made of a permeable member that, when being soaked in the electrolytic liquid, is permeable to an ion of the electrolytic liquid.

7. A plating apparatus as set forth in claim 6, wherein the permeable member is a semipermeable membrane.

8. A plating apparatus as set forth in claim 6, wherein the permeable member contains ion exchange resin.

9. A plating apparatus as set forth in claim 1, further comprising a plating-target substrate room closing means for closing the plating-target substrate room.

10. A plating apparatus as set forth in claim 1, further comprising:

a plating solution supply source that stores plating solution to be supplied to the plating-target substrate room;

a plating solution system for circulating the plating solution between the plating solution supply source and the plating-target substrate room;

an electrolytic liquid supply source that stores electrolytic liquid to be supplied to the anode electrode room; and

an electrolytic liquid system for circulating the electrolytic liquid between the electrolytic liquid supply source and the anode electrode room.

11. A plating apparatus as set forth in claim 10, further comprising a replenishing liquid system for (i) monitoring a concentration of plating solution circulating within the plating solution system and (ii) replenishing a replenishing liquid based upon concentration information of the plating solution.

12. A plating apparatus as set forth in claim 10, wherein each of the plating solution system and the electrolytic liquid system is a closed system.

13. A plating apparatus as set forth in claim 1, wherein the plating solution is a conductive liquid containing copper.

14. A plating apparatus as set forth in claim 13, wherein the proportion of the copper in 1 L of the plating solution is 14 g to 40 g, inclusive.

15. A plating apparatus as set forth in claim 1, wherein the anode electrode is a dissoluble anode electrode made of copper mixed with phosphorus.

16. A plating apparatus as set forth in claim 1, wherein the electrolytic liquid is (i) sulfuric acid or (ii) an aqueous solution in which sulfuric acid is diluted.

17. A plating apparatus as set forth in claim 1, wherein the electrolytic liquid is a conductive liquid containing copper.

18. A plating apparatus as set forth in claim 17, wherein the proportion of the copper in 1 L of the electrolytic liquid is 14 g to 40 g, inclusive.

19. A plating apparatus as set forth in claim 1, wherein the plating-target substrate is a semiconductor wafer.

20. A plating method for plating a plating-target face of a plating-target substrate, the plating method comprising the plating steps of:

(i) streaming a plating solution and an electrolytic liquid into a plating tank, (ii) emitting a jet of the plating solution to a plating-target face of a plating-target substrate from an underneath of the plating-target substrate, and (iii) streaming the electrolytic liquid to an anode electrode provided in the plating tank while electrically conducting between the plating-target substrate and the anode electrode; and

plating the plating-target substrate in the plating tank in which a plating-target substrate and an anode electrode are separated by a partition so as to divide the plating tank into a plating-target substrate room and an anode electrode room.

21. A plating method as set forth in claim 20, comprising the plating step performed in such a way that the electrolytic liquid streamed into the anode electrode room does not reach the plating-target substrate room.

22. A plating method as set forth in claim 20, further comprising the step of draining the electrolytic liquid out of the plating tank, the electrolytic liquid having streamed into the anode electrode room,.

23. A plating method as set forth in claim 20, wherein:

the partition that separates the anode electrode and the plating-target substrate, includes a permeable member that, when being soaked in the electrolytic liquid, is permeable to an ion contained in an electrolytic liquid.

24. A plating method as set forth in claim 20, further comprising the step of closing the plating-target substrate room.

25. A plating method as set forth in claim 20, further comprising the steps of:

circulating the plating solution between (i) the plating solution supply source that stores the plating solution and (ii) the plating-target substrate room; and

circulating the electrolytic liquid between (i) the electrolytic liquid supply source that stores the electrolytic liquid and (ii) the anode electrode room.

26. A plating method as set forth in claim 25, wherein the step of circulating the plating solution includes the steps of:

(i) monitoring a concentration of the plating solution; and

(ii) replenishing a replenishing liquid based upon concentration information of the plating solution.

27. A method for manufacturing a semiconductor device, the method comprising the plating method set forth in claim 20 as its plating step.

28. The method as set forth in claim 27,

further comprising, prior to the plating step, the steps of:

forming a seed layer on a plating-target face of the plating-target substrate;

applying a photoresist on a surface of the seed layer formed in the step of forming a seed layer; and

forming a pattern by exposing and developing the photoresist.