PLATING APPARATUS AND PLATING SOLUTION DISCHARGING METHOD

An occurrence of a plating failure caused by gas bubbles generated from an anode is reduced and a structure relating to supply of a plating solution is simplified. A plating module 400 includes a plating tank 410 for housing a plating solution, an anode 430 disposed in the plating tank 410, a substrate holder 440 configured to hold a substrate Wf with a surface to be plated Wf-a facing downward, a membrane 420 partitioning an anode region 424 in which the anode 430 is disposed and a cathode region 422 in which the substrate Wf is disposed during a plating process, the membrane 420 having an inclined surface 423a opposed to the anode 430, a supply port 412 for supplying the plating solution to the anode region 424, and a gas-liquid pipe 470 having a first end portion 472 opening at proximity of an upper end of the inclined surface 423a of the membrane 420 and a second end portion 474 opening above the surface to be plated of the substrate during the plating process, the gas-liquid pipe 470 being configured to supply the plating solution supplied to the anode region 424 from the supply port 412 to the cathode region 422 via the second end portion 474.

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Description
TECHNICAL FIELD

The application relates to a plating apparatus and a plating solution discharging method.

BACKGROUND ART

There has been known a cup-type electroplating apparatus as one example of a plating apparatus. The cup-type electroplating apparatus immerses a substrate (for example, a semiconductor wafer) held onto a substrate holder with its surface to be plated facing downward in a plating solution, applies a voltage between the substrate (a cathode) and an anode, and thus, deposits a conductive film on a surface of the substrate.

PTL 1 discloses a plating apparatus of a cup type. This plating apparatus is provided with an inclined membrane between an anode and a cathode, and captures gas bubbles generated from the anode with the membrane and discharges them, thus being configured to reduce an occurrence of a plating failure caused by the gas bubbles.

CITATION LIST Patent Literature

    • PTL 1: US 6126798 A

SUMMARY OF INVENTION Technical Problem

While in the plating apparatus disclosed in PTL 1, reduction of occurrence of a plating failure caused by gas bubbles adhering to a surface to be plated of a substrate has been considered, a simplification of a structure relating to supplying a plating solution to a plating tank has not been considered.

That is, the plating apparatus disclosed in PTL 1 is provided with pipes for supplying a plating solution for each of an anode region and a cathode region, and therefore, the number of the pipes increases. As a result, the structure of the plating apparatus becomes complicated.

Therefore, it is one object of this application to reduce occurrence of a plating failure caused by gas bubbles generated from an anode and simplify a structure relating to supply of a plating solution.

Solution to Problem

According to one embodiment, a plating apparatus is disclosed. The plating apparatus includes a plating tank, an anode, a substrate holder, a membrane, a supply port, and a gas-liquid pipe. The plating tank is for housing a plating solution. The anode is disposed in the plating tank. The substrate holder is configured to hold a substrate with a surface to be plated facing downward. The membrane partitions an anode region in which the anode is disposed and a cathode region in which the substrate is disposed during a plating process. The membrane has an inclined surface opposed to the anode. The supply port is for supplying a plating solution to the anode region. The gas-liquid pipe has a first end portion opening at proximity of an upper end of the inclined surface of the membrane and a second end portion opening above the surface to be plated of the substrate during the plating process. The gas-liquid pipe is configured to supply the plating solution supplied to the anode region from the supply port to the cathode region via the second end portion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an overall configuration of a plating apparatus according to one embodiment.

FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus according to one embodiment.

FIG. 3 is a vertical cross-sectional view schematically illustrating a configuration of a plating module according to one embodiment.

FIG. 4 is a vertical cross-sectional view schematically illustrating a configuration of a check valve according to one embodiment.

FIG. 5 is a vertical cross-sectional view schematically illustrating a configuration of a gas-liquid pipe according to one embodiment.

FIG. 6 is a flowchart of a plating process method including a plating solution discharging method according to one embodiment.

 DESCRIPTION OF EMBODIMENTS

The following describes an embodiment of the present invention with reference to the drawings. In the drawings described below, the same or equivalent components are attached by the same reference numerals, and thus, overlapping descriptions are omitted.

<Overall Configuration of Plating Apparatus>

FIG. 1 is a perspective view illustrating the overall configuration of the plating apparatus of this embodiment. FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus of this embodiment. As illustrated in FIGS. 1 and 2, a plating apparatus 1000 includes load ports 100, a transfer robot 110, aligners 120, pre-wet modules 200, pre-soak modules 300, plating modules 400, cleaning modules 500, spin rinse dryers 600, a transfer device 700, and a control module 800.

The load port 100 is a module for loading a substrate housed in a cassette, such as a FOUP, (not illustrated) to the plating apparatus 1000 and unloading the substrate from the plating apparatus 1000 to the cassette. While the four load ports 100 are arranged in the horizontal direction in this embodiment, the number of load ports 100 and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring the substrate that is configured to grip or release the substrate between the load port 100, the aligner 120, the pre-wet module 200, and the spin rinse dryers 600. The transfer robot 110 and the transfer device 700 can perform delivery and receipt of the substrate via a temporary placement table (not illustrated) to grip or release the substrate between the transfer robot 110 and the transfer device 700.

The aligner 120 is a module for adjusting a position of an orientation flat, a notch, and the like of the substrate in a predetermined direction. While the two aligners 120 are disposed to be arranged in the horizontal direction in this embodiment, the number of aligners 120 and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 wets a surface to be plated of the substrate before a plating process with a process liquid, such as pure water or deaerated water, to replace air inside a pattern formed on the surface of the substrate with the process liquid. The pre-wet module 200 is configured to perform a pre-wet process to facilitate supplying the plating solution to the inside of the pattern by replacing the process liquid inside the pattern with a plating solution during plating. While the two pre-wet modules 200 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-wet modules 200 and arrangement of the pre-wet modules 200 are arbitrary.

For example, the pre-soak module 300 is configured to remove an oxidized film having a large electrical resistance present on a surface of a seed layer formed on the surface to be plated of the substrate before the plating process by etching with a process liquid, such as sulfuric acid and hydrochloric acid, and perform a pre-soak process that cleans or activates a surface of a plating base layer. While the two pre-soak modules 300 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-soak modules 300 and arrangement of the pre-soak modules 300 are arbitrary. The plating module 400 performs the plating process on the substrate. There are two sets of the 12 plating modules 400 arranged by three in the vertical direction and by four in the horizontal direction, and the total 24 plating modules 400 are disposed in this embodiment, but the number of plating modules 400 and arrangement of the plating modules 400 are arbitrary.

The cleaning module 500 is configured to perform a cleaning process on the substrate to remove the plating solution or the like left on the substrate after the plating process. While the two cleaning modules 500 are disposed to be arranged in the vertical direction in this embodiment, the number of cleaning modules 500 and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for rotating the substrate after the cleaning process at high speed and drying the substrate. While the two spin rinse dryers are disposed to be arranged in the vertical direction in this embodiment, the number of spin rinse dryers and arrangement of the spin rinse dryers are arbitrary. The transfer device 700 is a device for transferring the substrate between the plurality of modules inside the plating apparatus 1000.

The control module 800 is configured to control the plurality of modules in the plating apparatus 1000 and can be configured of, for example, a general computer including input/output interfaces with an operator or a dedicated computer.

An example of a sequence of the plating processes by the plating apparatus 1000 will be described. First, the substrate housed in the cassette is loaded on the load port 100. Subsequently, the transfer robot 110 grips the substrate from the cassette at the load port 100 and transfers the substrate to the aligners 120. The aligner 120 adjusts the position of the orientation flat, the notch, or the like of the substrate in the predetermined direction. The transfer robot 110 grips or releases the substrate whose direction is adjusted with the aligners 120 to the pre-wet module 200.

The pre-wet module 200 performs the pre-wet process on the substrate. The transfer device 700 transfers the substrate on which the pre-wet process has been performed to the pre-soak module 300. The pre-soak module 300 performs the pre-soak process on the substrate. The transfer device 700 transfers the substrate on which the pre-soak process has been performed to the plating module 400. The plating module 400 performs the plating process on the substrate.

The transfer device 700 transfers the substrate on which the plating process has been performed to the cleaning module 500. The cleaning module 500 performs the cleaning process on the substrate. The transfer device 700 transfers the substrate on which the cleaning process has been performed to the spin rinse dryer 600. The spin rinse dryer 600 performs the drying process on the substrate. The transfer robot 110 receives the substrate from the spin rinse dryer 600 and transfers the substrate, on which the drying process is performed, to the cassette at the load port 100. Finally, the cassette housing the substrate is unloaded from the load port 100.

<Configuration of Plating Module>

Next, a configuration of the plating module 400 will be described. Only one plating module 400 will be described as 24 plating modules 400 according to the embodiment are in the same configurations. FIG. 3 is a vertical cross-sectional view schematically illustrating a configuration of a plating module according to one embodiment.

As illustrated in FIG. 3, the plating module 400 includes a plating tank 410 for housing a plating solution. The plating tank 410 is configured to have a circular-plate-shaped bottom wall 411 and a cylindrical-shaped side wall 413 surrounding a peripheral edge portion of the bottom wall 411, and have an open upper surface. The side wall 413 is configured to include a cylindrical-shaped first side wall 413-1, which is connected to the peripheral edge portion of the bottom wall 411 and has a first thickness, and a cylindrical-shaped second side wall 413-2, which is disposed above the first side wall 413-1 and has a second thickness thinner than the first thickness.

The plating module 400 includes an anode 430 disposed in a bottom portion of the plating tank 410. The anode 430 may be a soluble anode or may be an insoluble anode. The plating module 400 includes a membrane 420 dividing an inside of the plating tank 410 in an up and down direction. The membrane 420 is a membrane partitioning an anode region 424, in which the anode 430 is disposed, and a cathode region 422, in which a substrate Wf is disposed during a plating process. An ionically resistive element 450 is disposed to be opposed to the membrane 420 in the cathode region 422. The ionically resistive element 450 is a member for achieving uniformity in a plating process on a surface to be plated Wf-a of the substrate Wf, and is configured of a plate-shaped member on which a great number of holes are formed.

The plating module 400 includes a substrate holder 440 for holding the substrate Wf (for example, a circular-plate-shaped substrate) with the surface to be plated Wf-a facing downward. The substrate holder 440 includes a power feeding contact point for power feeding to the substrate Wf from a power source, which is not illustrated. The substrate holder 440 includes a seal ring holder 442 for supporting an outer edge portion of the surface to be plated Wf-a of the substrate Wf and a frame 446 for holding the seal ring holder 442 onto a substrate holder main body, which is not illustrated. The substrate holder 440 includes a back plate 444 for pressing a back surface of the surface to be plated Wf-a of the substrate Wf and a shaft 448 attached to a back surface of a substrate pressing surface of the back plate 444.

The plating module 400 includes an elevating and lowering mechanism 443 for moving the substrate holder 440 up and down and a rotation mechanism 447 for rotating the substrate holder 440 such that the substrate Wf rotates about a virtual rotation axis (a virtual rotation axis extending perpendicularly in the center of the surface to be plated Wf-a) of the shaft 448. The elevating and lowering mechanism 443 and the rotation mechanism 447 are, for example, achievable by known mechanisms, such as a motor. The plating module 400 immerses the substrate Wf in a plating solution in the cathode region 422 using the elevating and lowering mechanism 443 and applies a voltage between the anode 430 and the substrate Wf, and thus, is configured to perform a plating process on the surface to be plated Wf-a of the substrate Wf.

The plating module 400 includes a paddle 460 disposed between the anode 430 and the substrate Wf, specifically, between the ionically resistive element 450 and the substrate Wf. The paddle 460 is disposed to be opposed to the surface to be plated Wf-a of the substrate Wf. The plating module 400 includes a driving mechanism 462 for reciprocating the paddle 460 along the surface to be plated Wf-a of the substrate Wf. The driving mechanism 462 is, for example, achievable by a known mechanism, such as a motor. The plating module 400 stirs the plating solution by reciprocating the paddle 460, and thus is allowed to enhance uniformity of plating formed on the surface to be plated.

The plating module 400 includes a supply port 412 for supplying the plating solution to the anode region 424. The supply port 412 is formed at the center of the bottom wall 411 of the plating tank 410. The plating module 400 includes a common pipe 414 connected to the supply port 412, and a supply pipe 414-1 and a discharge pipe 414-2 that branch from the common pipe 414. The supply pipe 414-1 is connected to a reserve tank 416 for storing the plating solution, a pump 417 for pressure feeding the plating solution stored in the reserve tank 416, and a supply valve 418 for opening and closing the supply pipe 414-1. The discharge pipe 414-2 is connected to a discharge valve 419 for opening and closing the discharge pipe 414-2.

The plating module 400 opens the supply valve 418, closes the discharge valve 419, and activates the pump 417, thus being allowed to supply the plating solution to the plating tank 410. Meanwhile, the plating module 400 stops the pump 417, closes the supply valve 418, and opens the discharge valve 419, thus being allowed to discharge the plating solution from the plating tank 410.

<Membrane>

The membrane 420 plays a role of capturing gas bubbles generated from the anode 430. The membrane 420 has a shape with an inclination for discharging the captured gas bubbles out of the plating module 400. Specifically, the membrane 420 is formed into an inverse cone shape having a central part 421 disposed at the center in a radial direction of the plating tank 410 and an inclined membrane 423 extending radially and obliquely upward from the central part 421. Thus, the membrane 420 has an inclined surface 423a opposed to the anode 430 on a bottom surface of the inclined membrane 423. The inclined surface herein indicates a surface that is inclined with respect to a horizontal surface. The membrane 420 is not limited to be in the inverse cone shape, but is only necessary to have the inclined surface 423a that is opposed to the anode 430. The inclined membrane 423 is only necessary to be a membrane of a material that allows capturing the gas bubbles generated from the anode 430.

With the plating module 400 according to the embodiment, the gas bubbles captured by the membrane 420 are allowed to move in a direction obliquely upward along the inclined surface 423a since the membrane 420 has the inclined surface 423a. As a result, the gas bubbles captured by the membrane 420 are allowed to move to an upper end of the inclined surface 423a.

<Check Valve>

The plating module 400 includes a check valve 425 disposed in the central part 421 of the membrane 420. FIG. 4 is a vertical cross-sectional view schematically illustrating a configuration of the check valve. FIG. 4 illustrates an enlarged region a in FIG. 3, and illustrates each of a state where the check valve 425 is “closed” (the left side), and a state where the check valve 425 is “opened” (the right side).

As illustrated in FIG. 4, the check valve 425 has a valve casing 426 forming a flow passage 426a that communicates the anode region 424 with the cathode region 422, a valve seat 426b disposed in the flow passage 426a, and a valve element 427 of a float type disposed below the valve seat 426b in the flow passage 426a and formed to be abuttable on the valve seat 426b. The valve element 427 is formed of a material having a specific gravity smaller than 1.

As soon as the plating solution is supplied to the anode region 424 from the supply port 412 when the plating process is started and the liquid surface rises up to the valve element 427, the valve element 427 is raised to abut on the valve seat 426b. This causes the check valve 425 to be “closed,” and therefore, the plating solution and the gas bubbles are not supplied to the cathode region 422 through the flow passage 426a from the anode region 424. Meanwhile, discharging the plating solution after the plating process lowers the liquid surface of the plating solution in the anode region 424 down to the valve element 427, and thus, the valve element 427 is lowered to be separated from the valve seat 426b. This causes the check valve 425 to be “opened,” and therefore, the plating solution flows from the cathode region 422 to the anode region 424 through the flow passage 426a.

<Gas-Liquid Pipe>

As illustrated in FIG. 3, the plating module 400 includes a gas-liquid pipe 470 for discharging the gas bubbles captured by the membrane 420 and supplying the plating solution to the cathode region 422. While the embodiment describes the example in which the plating module 400 includes two gas-liquid pipes 470 opposed to one another with the center of the plating tank 410 interposed therebetween, the example is not limited to this. The plating module 400 may include one gas-liquid pipe 470, or may include three or more gas-liquid pipes 470 disposed at equal intervals or at unequal intervals along a circumferential direction of the plating tank 410.

FIG. 5 is a vertical cross-sectional view schematically illustrating a configuration of a gas-liquid pipe according to one embodiment. FIG. 5 illustrates the enlarged region β in FIG. 3, and illustrates with members omitted as necessary. Two gas-liquid pipes 470 have similar configurations except for the different arrangement locations, and therefore, the description is given only for one gas-liquid pipe 470 in FIG. 5. As illustrated in FIG. 5, the gas-liquid pipe 470 has a first end portion 472 opening at the proximity of the upper end of the inclined surface 423a of the membrane 420 in the anode region 424.

In the embodiment, a gas bubble accumulation region BA in which the gas bubbles captured by the membrane 420 gather is formed at the proximity of the upper end of the inclined surface 423a. That is, an end portion 423b on the opposite side of the central part 421 of the inclined membrane 423 is connected to the peripheral edge portion of the bottom surface of the ionically resistive element 450 at a predetermined distance from the inner surface of the first side wall 413-1. This forms a circular flow passage surrounded by the end portion 423b of the inclined membrane 423, the peripheral edge portion of the bottom surface of the ionically resistive element 450, and the inner surface of the first side wall 413-1. The circular flow passage is formed of these three surfaces, and therefore, a constant amount of the gas bubbles are collectable in the gas bubble accumulation region BA. The first end portion 472 opens in the bottom surface of the ionically resistive element 450 toward the gas bubble accumulation region BA.

The gas-liquid pipe 470 has a second end portion 474 opening above the surface to be plated Wf-a of the substrate Wf during the plating process and inside the plating tank 410. The gas-liquid pipe 470 extends in an upward direction passing through the inside of the ionically resistive element 450 from the first end portion 472, thereafter, extends outward in a radial direction passing through the insides of the ionically resistive element 450 and the first side wall 413-1, and furthermore, extends in the upward direction inside the second side wall 413-2 to reach the second end portion 474. The gas bubbles having gathered in the gas bubble accumulation region BA are discharged from the second end portion 474 through the gas-liquid pipe 470. The second end portion 474 opens above the surface to be plated Wf-a, and thus, the gas bubbles discharged from the second end portion 474 can be inhibited from adhering to the surface to be plated Wf-a.

The gas-liquid pipe 470 is configured not only to discharge the gas bubbles, but also to supply the plating solution, which is supplied from the supply port 412 to the anode region 424, to the cathode region 422 via the second end portion 474. That is, as soon as the plating solution supplied from the supply port 412 fills the anode region 424, and furthermore, the plating solution is pressure-fed to the anode region 424 from the pump 417, the plating solution flows from the first end portion 472 to the gas-liquid pipe 470. This is because the membrane 420 has a large flow resistance against the plating solution while the first end portion 472 has a small flow resistance against the plating solution. Furthermore, as soon as the plating solution is pressure-fed to the anode region 424 from the pump 417, the plating solution that has flowed to the gas-liquid pipe 470 is supplied to the cathode region 422 via the second end portion 474. This fills the cathode region 422 with the plating solution.

In the embodiment, the second end portion 474 of the gas-liquid pipe 470 opens below a plating solution surface OF housed in the plating tank 410 during the plating process. That is, the plating module 400 is configured to perform the plating process while overflowing the plating solution supplied to the cathode region 422 over the second side wall 413-2. Accordingly, the plating solution surface OF is at a height position corresponding to an upper end of the second side wall 413-2. Opening the second end portion 474 below the plating solution surface OF enables causing an additive contained in the plating solution supplied from the second end portion 474 to contribute to the plating process.

However, not limited to this, the second end portion 474 of the gas-liquid pipe 470 may be opened above the plating solution surface OF housed in the plating tank 410 during the plating process. That is, “open to the inside of the plating tank 410” herein means that the second end portion 474 is inside the second side wall 413-2 of the plating tank 410 when the plating module 400 is viewed in plan view from above. Accordingly, the second end portion 474 may open in a region below an upper end portion (the plating solution surface OF) of the second side wall 413-2, or may open in a region above the upper end portion (the plating solution surface OF) of the second side wall 413-2. In any case, as long as the second end portion 474 opens to the inside of the plating tank 410, the plating solution that flows from the second end portion 474 is supplied to the cathode region 422.

With the plating module 400 according to the embodiment, the occurrence of the plating failure caused by the gas bubbles generated from the anode is reduced and the structure relating to the supply of the plating solution can be simplified. That is, the gas bubbles generated from the anode 430 are captured by the membrane 420 and can be discharged above the surface to be plated of the substrate by the gas-liquid pipe 470, and therefore, the occurrence of the plating failure caused by the gas bubbles adhering to the surface to be plated can be reduced. The plating solution can be supplied to the cathode region 422 via the gas-liquid pipe 470 from the anode region 424, and therefore, there is no need to dispose respective supply pipes for the anode region 424 and the cathode region 422, and thus, the structure relating to the supply of the plating solution can be simplified.

Furthermore, with the plating module 400 according to the embodiment, the plating solution can be fed from the cathode region 422 to the anode region 424 via the check valve 425, and can be discharged from the discharge pipe 414-2, and therefore, there is no need to dispose respective discharge pipes for the anode region 424 and the cathode region 422, and thus, the structure relating to the discharge of the plating solution can be simplified. Furthermore, with the plating module 400 according to the embodiment, the plating solution is dropped from the cathode region 422 to the anode region 424 via the check valve 425 to be discharged, and therefore, a larger amount of a by-product (sludge) adhering to a surface of the anode 430 can be washed away.

<Plating Process Method>

FIG. 6 is a flowchart of a plating process method including a plating solution discharging method according to one embodiment. The following plating process method is started with no plating solution stored in the plating tank 410 and the supply valve 418 and the discharge valve 419 closed.

The plating process method firstly executes a step (S101) of opening the supply valve 418 and operating the pump 417. This opens the supply pipe 414-1, and supplies the plating solution stored in the reserve tank 416 to the anode region 424 from the supply port 412.

Subsequently, the plating process method executes a step (S102) of raising the plating solution surface in the anode region 424 to close the check valve 425 by supplying the plating solution to the anode region 424. Specifically, S102 is executed in such a way that, once the plating solution surface in the anode region 424 rises up to the valve element 427, the valve element 427 is raised together with the rise of the plating solution surface, thereby abutting on the valve seat 426b to close the flow passage 426a.

Subsequently, the plating process method executes a step (S103) of supplying the plating solution to the cathode region 422 from the gas-liquid pipe 470 by increasing the flow resistance of the entire membrane 420 including the flow passage 426a by closing the check valve 425.

The plating process method executes a step (S104) of capturing the gas bubbles generated from the anode 430 with the membrane 420 and discharging the captured gas bubbles above the surface to be plated Wf-a of the substrate Wf via the gas-liquid pipe 470. Specifically, the gas bubbles captured by the membrane 420 move in an obliquely upward direction along the inclined surface 423a, gather in the gas bubble accumulation region BA at the proximity of the upper end of the inclined surface 423a, and are discharged above the surface to be plated Wf-a of the substrate Wf via the gas-liquid pipe 470.

As soon as the plating solution fills the plating tank 410, the plating process method executes the plating process by applying a voltage between the substrate Wf (the cathode) and the anode (Step S105). Once the plating process is completed, the plating process method executes a step (S106) of closing the supply valve 418 as well as stopping the pump 417.

Subsequently, the plating process method executes a step (S107) of discharging the plating solution from the anode region 424 by opening the discharge valve 419 to open the discharge pipe 414-2.

Subsequently, the plating process method executes a step (S108) of opening the check valve 425 disposed in the membrane 420, partitioning the anode region 424 and the cathode region 422, by discharging the plating solution from the anode region 424 and lowering the plating solution surface in the anode region 424. Specifically, S108 is executed in such a way that, once the plating solution surface in the anode region 424 lowers down to the valve element 427, the valve element 427 is lowered in association with the lowering of the plating solution surface, thereby being separated from the valve seat 426b, and thus, the flow passage 426a is opened.

Subsequently, the plating process method executes a step (S109) of feeding the plating solution in the cathode region 422 to the anode region 424 via the flow passage 426a and discharging the plating solution from the discharge pipe 414-2 by opening the check valve 425.

With the plating process method according to the embodiment, the gas bubbles generated from the anode 430 can be captured and discharged above the surface to be plated of the substrate, and therefore, the occurrence of the plating failure caused by the gas bubbles adhering to the surface to be plated can be reduced. With the plating process method according to the embodiment, the plating solution can be supplied to the cathode region 422 from the anode region 424 via the gas-liquid pipe 470, and therefore, there is no need to dispose respective supply pipes for the anode region 424 and the cathode region 422, and thus, a structure relating to the supply of the plating solution can be simplified. Furthermore, with the plating process method according to the embodiment, the plating solution can be fed from the cathode region 422 to the anode region 424 via the check valve 425, and can be discharged from the discharge pipe 414-2, and therefore, there is no need to dispose respective discharge pipes for the anode region 424 and the cathode region 422, and thus, a structure relating to the discharge of the plating solution can be simplified. Furthermore, with the plating process method according to the embodiment, the plating solution is dropped from the cathode region 422 to the anode region 424 via the check valve 425 to be discharged, and therefore, a larger amount of a by-product (sludge) adhering to the surface of the anode 430 can be washed away.

While several embodiments of the present invention have been described above, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be changed or improved without departing from the gist thereof, and of course, the equivalents of the present invention are included in the present invention. To the extent that at least part of the above-described problems can be solved, or at least part of the effect can be achieved, any combination or omission of each component described in the claims and specification is possible.

This application discloses, as one embodiment, a plating apparatus including a plating tank, an anode, a substrate holder, a membrane, a supply port, and a gas-liquid pipe. The plating tank is for housing a plating solution. The anode is disposed in the plating tank. The substrate holder is configured to hold a substrate with a surface to be plated facing downward. The membrane partitions an anode region in which the anode is disposed and a cathode region in which the substrate is disposed during a plating process. The membrane has an inclined surface opposed to the anode. The supply port is for supplying a plating solution to the anode region. The gas-liquid pipe has a first end portion opening at proximity of an upper end of the inclined surface of the membrane and a second end portion opening above the surface to be plated of the substrate during the plating process. The gas-liquid pipe is configured to supply the plating solution supplied to the anode region from the supply port to the cathode region via the second end portion.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the second end portion of the gas-liquid pipe is configured to open below a plating solution surface housed in the plating tank.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the membrane has a central part disposed at a center in a radial direction of the plating tank and an inclined membrane extending radially and obliquely upward from the central part.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which a check valve is arranged at the central part of the membrane and is configured to allow the plating solution to flow only in a direction from the cathode region to the anode region.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the check valve has a valve casing forming a flow passage communicating the anode region with the cathode region, a valve seat disposed in the flow passage, and a valve element of a floating type disposed below the valve seat in the flow passage and formed to be abuttable on the valve seat.

This application discloses, as one embodiment, a plating solution discharging method for discharging a plating solution housed in a plating tank of a cup-type plating apparatus. The method includes: a step of opening a discharge pipe communicated with an anode region of the plating tank to discharge a plating solution from the anode region; a step of opening a check valve disposed in a membrane partitioning the anode region and a cathode region by discharging the plating solution from the anode region to lower a plating solution surface of the anode region; and a step of feeding the plating solution in the cathode region to the anode region by opening the check valve to discharge the plating solution from the discharge pipe.

REFERENCE SIGNS LIST

    • 400 . . . plating module
    • 410 . . . plating tank
    • 412 . . . supply port
    • 420 . . . membrane
    • 421 . . . central part
    • 422 . . . cathode region
    • 423 . . . inclined membrane
    • 423a . . . inclined surface
    • 424 . . . anode region
    • 425 . . . check valve
    • 426 . . . valve casing
    • 426a . . . flow passage
    • 426b . . . valve seat
    • 427 . . . valve element
    • 430 . . . anode
    • 440 . . . substrate holder
    • 470 . . . gas-liquid pipe
    • 472 . . . first end portion
    • 474 . . . second end portion
    • Wf . . . substrate
    • Wf-a . . . surface to be plated

Claims

1. A plating apparatus comprising:

a plating tank for housing a plating solution;
an anode disposed in the plating tank;
a substrate holder configured to hold a substrate with a surface to be plated facing downward;
a membrane partitioning an anode region in which the anode is disposed and a cathode region in which the substrate is disposed during a plating process, the membrane having an inclined surface opposed to the anode;
a supply port for supplying a plating solution to the anode region; and
a gas-liquid pipe having a first end portion opening at proximity of an upper end of the inclined surface of the membrane and a second end portion opening above the surface to be plated of the substrate during the plating process, the gas-liquid pipe being configured to supply the plating solution supplied to the anode region from the supply port to the cathode region via the second end portion.

2. The plating apparatus according to claim 1, wherein

the second end portion of the gas-liquid pipe is configured to open below a plating solution surface housed in the plating tank.

3. The plating apparatus according to claim 2, wherein

the membrane has a central part disposed at a center in a radial direction of the plating tank and an inclined membrane extending radially and obliquely upward from the central part.

4. The plating apparatus according to claim 3, wherein

a check valve is arranged at the central part of the membrane and is configured to allow the plating solution to flow only in a direction from the cathode region to the anode region.

5. The plating apparatus according to claim 4, wherein

the check valve has a valve casing forming a flow passage communicating the anode region with the cathode region, a valve seat disposed in the flow passage, and a valve element of a floating type disposed below the valve seat in the flow passage and formed to be abuttable on the valve seat.

6. A plating solution discharging method for discharging a plating solution housed in a plating tank of a cup-type plating apparatus, the method comprising:

a step of opening a discharge pipe communicated with an anode region of the plating tank to discharge a plating solution from the anode region;
a step of opening a check valve disposed in a membrane partitioning the anode region and a cathode region by discharging the plating solution from the anode region to lower a plating solution surface of the anode region; and
a step of feeding the plating solution in the cathode region to the anode region by opening the check valve to discharge the plating solution from the discharge pipe.
Patent History
Publication number: 20260201600
Type: Application
Filed: Sep 25, 2023
Publication Date: Jul 16, 2026
Inventor: Masaki TOMITA (Tokyo)
Application Number: 18/865,642
Classifications
International Classification: C25D 21/14 (20060101); C25D 17/00 (20060101); C25D 17/06 (20060101);