APPARATUS AND METHODS FOR ELECTROCHEMICAL PROCESSSING OF MICROELECTRONIC WORKPIECES
An apparatus and method for electrochemical processing of microelectronic workpieces in a reaction vessel. In one embodiment, the reaction vessel includes: an outer container having an outer wall; a distributor coupled to the outer container, the distributor having a first outlet configured to introduce a primary flow into the outer container and at least one second outlet configured to introduce a secondary flow into the outer container separate from the primary flow; a primary flow guide in the outer container coupled to the distributor to receive the primary flow from the first outlet and direct it to a workpiece processing site; a dielectric field shaping unit in the outer container coupled to the distributor to receive the secondary flow from the second outlet, the field shaping unit being configured to contain the secondary flow separate from the primary flow through at least a portion of the outer container, and the field shaping unit having at least one electrode compartment through which the secondary flow can pass while the secondary flow is separate from the primary flow; an electrode in the electrode compartment; and an interface member carried by the field shaping unit downstream from the electrode, the interface member being in fluid communication with the secondary flow in the electrode compartment, and the interface member being configured to prevent selected matter of the secondary flow from passing to the primary flow.
This application is a continuation-in-part of U.S. application Ser. No. 09/804,697, entitled “SYSTEM FOR ELECTROCHEMICALLY PROCESSING A WORKPIECE,” filed on Mar. 12, 2001; which is a continuation of International Application No. PCT/US00/10120, filed on Apr. 13, 2000, in the English language and published in the English language as International Publication No. WO00/61498, which claims the benefit of Provisional Application No. 60/129,055, filed on Apr. 13, 1999, all of which are herein incorporated by reference. Additionally, this application is related to the following:
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- (a) U.S. patent application entitled “TRANSFER DEVICES FOR HANDLING MICROELECTRONIC WORKPIECES WITHIN AN ENVIRONMENT OF A PROCESSING MACHINE AND METHODS OF MANUFACTURING AND USING SUCH DEVICES IN THE PROCESSING OF MICROELECTRONIC WORKPIECES,” filed on Jun. 1, 2001, and identified by Perkins Coie LLP Docket No. 29195.8153US00;
- (b) U.S. patent application entitled “INTEGRATED TOOLS WITH TRANSFER DEVICES FOR HANDLING MICROELECTRONIC WORKPIECES,” filed on Jun. 1, 2001, and identified by Perkins Coie Docket No. 29195.8153US01;
- (c) U.S. patent application entitled “DISTRIBUTED POWER SUPPLIES FOR MICROELECTRONIC WORKPIECE PROCESSING TOOLS,” filed on Jun. 1, 2001, and identified by Perkins Coie Docket No. 29195.8155US00;
- (d) U.S. patent application entitled “ADAPTABLE ELECTROCHEMICAL PROCESSING CHAMBER,” filed on Jun. 1, 2001, and identified by Perkins Coie LLP Docket No. 29195.8156US00;
- (e) U.S. patent application entitled “LIFT AND ROTATE ASSEMBLY FOR USE IN A WORKPIECE PROCESSING STATION AND A METHOD OF ATTACHING THE SAME,” filed on Jun. 1, 2001, and identified by Perkins Coie Docket No. 29195.8154US00;
- (f) U.S. patent applications entitled “TUNING ELECTRODES USED IN A REACTOR FOR ELECTROCHEMICALLY PROCESSING A MICROELECTRONIC WORKPIECE,” one filed on May 4, 2001, and identified by U.S. application Ser. No. 09/849,505, and two additional applications filed on May 24, 2001, and identified separately by Perkins Coie Docket Nos. 29195.8157US02 and 29195.8157US03.
All of the foregoing U.S. patent applications in paragraphs (a)-(f) above are herein incorporated by reference.
TECHNICAL FIELDThis application relates to reaction vessels and methods of making and using such vessels in electrochemical processing of microelectronic workpieces.
BACKGROUNDMicroelectronic devices, such as semiconductor devices and field emission displays, are generally fabricated on and/or in microelectronic workpieces using several different types of machines (“tools”). Many such processing machines have a single processing station that performs one or more procedures on the workpieces. Other processing machines have a plurality of processing stations that perform a series of different procedures on individual workpieces or batches of workpieces. In a typical fabrication process, one or more layers of conductive materials are formed on the workpieces during deposition stages. The workpieces are then typically subject to etching and/or polishing procedures (i.e., planarization) to remove a portion of the deposited conductive layers for forming electrically isolated contacts and/or conductive lines.
Plating tools that plate metals or other materials on the workpieces are becoming an increasingly useful type of processing machine. Electroplating and electroless plating techniques can be used to deposit copper, solder, permalloy, gold, silver, platinum and other metals onto workpieces for forming blanket layers or patterned layers. A typical copper plating process involves depositing a copper seed layer onto the surface of the workpiece using chemical vapor deposition (CVD), physical vapor deposition (PVD), electroless plating processes, or other suitable methods. After forming the seed layer, a blanket layer or patterned layer of copper is plated onto the workpiece by applying an appropriate electrical potential between the seed layer and an anode in the presence of an electroprocessing solution. The workpiece is then cleaned, etched and/or annealed in subsequent procedures before transferring the workpiece to another processing machine.
The plating machines used in fabricating microelectronic devices must meet many specific performance criteria. For example, many processes must be able to form small contacts in vias that are less than 0.5 μm wide, and are desirably less than 0.1 μm wide. The plated metal layers accordingly often need to fill vias or trenches that are on the order of 0.1 μm wide, and the layer of plated material should also be deposited to a desired, uniform thickness across the surface of the workpiece 5. One factor that influences the uniformity of the plated layer is the mass transfer of electroplating solution at the surface of the workpiece. This parameter is generally influenced by the velocity of the flow of the electroplating solution perpendicular to the surface of the workpiece. Another factor that influences the uniformity of the plated layer is the current density of the electrical field across the surface of the wafer.
One concern of existing electroplating equipment is providing a uniform mass transfer at the surface of the workpiece. Referring to
Another concern of existing plating tools is that the diffusion layer in the electroplating solution adjacent to the surface of the workpiece 5 can be disrupted by gas bubbles or particles. For example, bubbles can be introduced to the plating solution by the plumbing and pumping system of the processing equipment, or they can evolve from inert anodes. Consumable anodes are often used to prevent or reduce the evolvement of gas bubbles in the electroplating solution, but these anodes erode and they can form a passivated film surface that must be maintained. Consumable anodes, moreover, often generate particles that can be carried in the plating solution. As a result, gas bubbles and/or particles can flow to the surface of the workpiece 5, which disrupts the uniformity and affects the quality of the plated layer.
Still another challenge of plating uniform layers is providing a desired electrical field at the surface of the workpiece 5. The distribution of electrical current in the plating solution is a function of the uniformity of the seed layer across the contact surface, the configuration/condition of the anode, and the configuration of the chamber. However, the current density profile on the plating surface can change. For example, the current density profile typically changes during a plating cycle because plating material covers the seed layer, or it can change over a longer period of time because the shape of consumable anodes changes as they erode and the concentration of constituents in the plating solution can change. Therefore, it can be difficult to maintain a desired current density at the surface of the workpiece 5.
SUMMARYThe present invention is directed toward reaction vessels for electrochemical processing of microelectronic workpieces, processing stations including such reaction vessels, and methods for using these devices. Several embodiments of reaction vessels in accordance with the invention solve the problem of providing a desired mass transfer at the workpiece by configuring the electrodes so that a primary flow guide and/or a field shaping unit in the reaction vessel direct a substantially uniform primary fluid flow toward the workpiece. Additionally, field shaping units in accordance with several embodiments of the invention create virtual electrodes such that the workpiece is shielded from the electrodes. This allows for the use of larger electrodes to increase electrode life, eliminates the need to “burn-in” electrodes to decrease downtime, and/or provides the capability of manipulating the electrical field by merely controlling the electrical current to one or more of the electrodes in the vessel. Furthermore, additional embodiments of the invention include interface members in the reaction vessel that inhibit particulates, bubbles and other undesirable matter in the reaction vessel from contacting the workpiece to enhance the uniformity and the quality of the finished surface on the workpieces. The interface members can also allow two different types of fluids to be used in the reaction vessel, such as a catholyte and an anolyte, to reduce the need to replenish additives as often and to add more flexibility to designing electrodes and other components in the reaction vessel.
In one embodiment of the invention, a reaction vessel includes an outer container having an outer wall, a first outlet configured to introduce a primary fluid flow into the outer container, and at least one second outlet configured to introduce a secondary fluid flow into the outer container separate from the primary fluid flow. The reaction vessel can also include a field shaping unit in the outer container and at least one electrode. The field shaping unit can be a dielectric assembly coupled to the second outlet to receive the secondary flow and configured to contain the secondary flow separate from the primary flow through at least a portion of the outer container. The field shaping unit also has at least one electrode compartment through which the secondary flow can pass separately from the primary flow. The electrode is positioned in the electrode compartment.
In a particular embodiment, the field shaping unit has a compartment assembly having a plurality of electrode compartments and a virtual electrode unit. The compartment assembly can include a plurality of annular walls including an inner or first annular wall centered on a common axis and an outer or second annular wall concentric with the first annular wall and spaced radially outward. The annular walls of the field shaping unit can be positioned inside of outer wall of the outer container so that an annular space between the first and second walls defines a first electrode compartment and an annular space between the second wall and the outer wall defines a second electrode compartment. The reaction vessel of this particular embodiment can have a first annular electrode in the first electrode compartment and/or a second annular electrode in the second electrode compartment.
The virtual electrode unit can include a plurality of partitions that have lateral sections attached to corresponding annular walls of the electrode compartment and lips that project from the lateral sections. In one embodiment, the first partition has an annular first lip that defines a central opening, and the second partition has an annular second lip surrounding the first lip that defines an annular opening.
In additional embodiments, the reaction vessel can further include a distributor coupled to the outer container and a primary flow guide in the outer container. The distributor can include the first outlet and the second outlet such that the first outlet introduces the primary fluid flow into the primary flow guide and the second outlet introduces the secondary fluid flow into the field shaping unit separately from the primary flow. The primary flow guide can condition the primary flow for providing a desired fluid flow to a workpiece processing site. In one particular embodiment, the primary flow guide directs the primary flow through the central opening of the first annular lip of the first partition. The secondary flow is distributed to the electrode compartments of the field shaping unit to establish an electrical field in the reaction vessel.
In the operation of one embodiment, the primary flow can pass through a first flow channel defined, at least in part, by the primary flow guide and the lip of the first partition. The primary flow can be the dominant flow through the reaction vessel so that it controls the mass transfer at the workpiece. The secondary flow can generally be contained within the field shaping unit so that the electrical field(s) of the electrode(s) are shaped by the virtual electrode unit and the electrode compartments. For example, in the embodiment having first and second annular electrodes, the electrical effect of the first electrode can act as if it is placed in the central opening defined by the lip of the first partition, and the electrical effect of the second electrode can act as if it is placed in the annular opening between the first and second lips. The actual electrodes, however, can be shielded from the workpiece by the field shaping unit such that the size and shape of the actual electrodes does not affect the electrical field perceived by the workpiece.
One feature of several embodiments is that the field shaping unit shields the workpiece from the electrodes. As a result, the electrodes can be much larger than they could without the field shaping unit because the size and configuration of the actual electrodes does not appreciably affect the electrical field perceived by the workpiece. This is particularly useful when the electrodes are consumable anodes because the increased size of the anodes prolongs their life, which reduces downtime for servicing a tool. Additionally, this reduces the need to “burn-in” anodes because the field shaping element reduces the impact that films on the anodes have on the shape of the electrical field perceived by the workpiece. Both of these benefits significantly improve the operating efficiency of the reaction vessel.
Another feature of several embodiments of the invention is that they provide a uniform mass transfer at the surface of the workpiece. Because the field shaping unit separates the actual electrodes from the effective area where they are perceived by the workpiece, the actual electrodes can be configured to accommodate internal structure that guides the flow along a more desirable flow path. For example, this allows the primary flow to flow along a central path. Moreover, a particular embodiment includes a central primary flow guide that projects the primary flow radially inward along diametrically opposed vectors that create a highly uniform primary flow velocity in a direction perpendicular to the surface of the workpiece.
The reaction vessel can also include an interface member carried by the field shaping unit downstream from the electrode. The interface member can be in fluid communication with the secondary flow in the electrode compartment. The interface member, for example, can be a filter and/or an ion-membrane. In either case, the interface member can inhibit particulates (e.g., particles from an anode) and bubbles in the secondary flow from reaching the surface of the workpiece to reduce non-uniformities on the processed surface. This accordingly increases the quality of the surface of the workpiece. Additionally, in the case of an ion-membrane, the interface member can be configured to prevent fluids from passing between the secondary flow and the primary flow while allowing preferred ions to pass between the flows. This allows the primary flow and the secondary flow to be different types of fluids, such as a catholyte and an anolyte, which reduces the need to replenish additives as often and adds more flexibility to designing electrodes and other features of the reaction vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description discloses the details and features of several embodiments of electrochemical reaction vessels for use in electrochemical processing stations and integrated tools to process microelectronic workpieces. The term “microelectronic workpiece” is used throughout to include a workpiece formed from a substrate upon which and/or in which microelectronic circuits or components, data storage elements or layers, and/or micro-mechanical elements are fabricated. It will be appreciated that several of the details set forth below are provided to describe the following embodiments in a manner sufficient to enable a person skilled in the art to make and use the disclosed embodiments. Several of the details and advantages described below, however, may not be necessary to practice certain embodiments of the invention. Additionally, the invention can also include additional embodiments that are within the scope of the claims, but are not described in detail with respect to
The operation and features of electrochemical reaction vessels are best understood in light of the environment and equipment in which they can be used to electrochemically process workpieces (e.g., electroplate and/or electropolish). As such, embodiments of integrated tools with processing stations having the electrochemical reaction vessels are initially described with reference to
A. Selected Embodiments of Integrated Tools with Electrochemical Processing Stations
The load/unload station 110 can have two container supports 112 that are each housed in a protective shroud 113. The container supports 112 are configured to position workpiece containers 114 relative to the apertures 106 in the cabinet 102. The workpiece containers 114 can each house a plurality of microelectronic workpieces 101 in a “mini” clean environment for carrying a plurality of workpieces through other environments that are not at clean room standards. Each of the workpiece containers 114 is accessible from the interior region 104 of the cabinet 102 through the apertures 106.
The processing machine 100 can also include a plurality of electrochemical processing stations 120 and a transfer device 130 in the interior region 104 of the cabinet 102. The processing machine 100, for example, can be a plating tool that also includes clean/etch capsules 122, electroless plating stations, annealing stations, and/or metrology stations.
The transfer device 130 includes a linear track 132 extending in a lengthwise direction of the interior region 104 between the processing stations. The transfer device 130 can further include a robot unit 134 carried by the track 132. In the particular embodiment shown in
The processing chamber 200 includes an outer housing 202 (shown schematically in
In operation the head assembly 150 holds the workpiece at a workpiece-processing site of the reaction vessel 204 so that at least a plating surface of the workpiece engages the electroprocessing solution. An electrical field is established in the solution by applying an electrical potential between the plating surface of the workpiece via the contact assembly 160 and one or more electrodes in the reaction vessel 204. For example, the contact assembly 160 can be biased with a negative potential with respect to the electrode(s) in the reaction vessel 204 to plate materials onto the workpiece. On the other hand the contact assembly 160 can be biased with a positive potential with respect to the electrode(s) in the reaction vessel 204 to (a) de-plate or electropolish plated material from the workpiece or (b) deposit other materials (e.g., electrophoric resist). In general, therefore, materials can be deposited on or removed from the workpiece with the workpiece acting as a cathode or an anode depending upon the particular type of material used in the electrochemical process.
B. Selected Embodiments of Reaction Vessels for us in Electrochemical Processing Chambers
The particular embodiment of the reaction vessel 204 shown in
The particular embodiment of the channels 340-346 in
Referring again to
The outer baffle 420 can include an outer wall 422 with a plurality of apertures 424. In this embodiment, the apertures 424 are elongated slots extending in a direction transverse to the apertures 416 of the inner baffle 410. The primary flow Fp flows through (a) the first inlet 320, (b) the passageway 324 under the base 412 of the inner baffle 410, (c) the apertures 424 of the outer baffle 420, and then (d) the apertures 416 of the inner baffle 410. The combination of the outer baffle 420 and the inner baffle 410 conditions the direction of the flow at the exit of the apertures 416 in the inner baffle 410. The primary flow guide 400 can thus project the primary flow along diametrically opposed vectors that are inclined upward relative to the common axis to create a fluid flow that has a highly uniform velocity. In alternate embodiments, the apertures 416 do not slant upward relative to the common axis such that they can project the primary flow normal, or even downward, relative to the common axis.
The field shaping unit 500 can have at least one wall 510 outward from the primary flow guide 400 to prevent the primary flow Fp from contacting an electrode. In the particular embodiment shown in
The electrode compartments 520 provide electrically discrete compartments to house an electrode assembly having at least one electrode and generally two or more electrodes 600 (identified individually by reference numbers 600a-d). The electrodes 600 can be annular members (e.g., annular rings or arcuate sections) that are configured to fit within annular electrode compartments, or they can have other shapes appropriate for the particular workpiece (e.g., rectilinear). In the illustrated embodiment, for example, the electrode assembly includes a first annular electrode 600a in the first electrode compartment 520a, a second annular electrode 600b in the second electrode compartment 520b, a third annular electrode 600c in the third electrode compartment 520c, and a fourth annular electrode 600d in the fourth electrode compartment 520d. As explained in U.S. application Ser. Nos. 60/206,661, 09/845,505, and 09/804,697, all of which are incorporated herein by reference, each of the electrodes 600a-d can be biased with the same or different potentials with respect to the workpiece to control the current density across the surface of the workpiece. In alternate embodiments, the electrodes 600 can be non-circular shapes or sections of other shapes.
Embodiments of the reaction vessel 204 that include a plurality of electrodes provide several benefits for plating or electropolishing. In plating applications, for example, the electrodes 600 can be biased with respect to the workpiece at different potentials to provide uniform plating on different workpieces even though the seed layers vary from one another or the bath(s) of electroprocessing solution have different conductivities and/or concentrations of constituents. Additionally, another the benefit of having a multiple electrode design is that plating can be controlled to achieve different final fill thicknesses of plated layers or different plating rates during a plating cycle or in different plating cycles. Other benefits of particular embodiments are that the current density can be controlled to (a) provide a uniform current density during feature filling and/or (b) achieve plating to specific film profiles across a workpiece (e.g., concave, convex, flat). Accordingly, the multiple electrode configurations in which the electrodes are separate from one another provide several benefits for controlling the electrochemical process to (a) compensate for deficiencies or differences in seed layers between workpieces, (b) adjust for variances in baths of electroprocessing solutions, and/or (c) achieve predetermined feature filling or film profiles.
The field shaping unit 500 can also include a virtual electrode unit coupled to the walls 510 of the compartment assembly for individually shaping the electrical fields produced by the electrodes 600. In the particular embodiment illustrated in
The individual partitions 530a-d can be machined from or molded into a single piece of dielectric material, or they can be individual dielectric members that are welded together. In alternate embodiments, the individual partitions 530a-d are not attached to each other and/or they can have different configurations. In the particular embodiment shown in
The walls 510 and the partitions 530a-d are generally dielectric materials that contain the second flow F2 of the processing solution for shaping the electric fields generated by the electrodes 600a-d. The second flow F2, for example, can pass (a) through each of the electrode compartments 520a-d, (b) between the individual partitions 530a-d, and then (c) upward through the annular openings between the lips 536a-d. In this embodiment, the secondary flow F2 through the first electrode compartment 520a can join the primary flow Fp in an antechamber just before the primary flow guide 400, and the secondary flow through the second-fourth electrode compartments 520b-d can join the primary flow Fp beyond the top edges of the lips 536a-d. The flow of electroprocessing solution then flows over a shield weir attached at rim 538 and into the gap between the housing 202 and the outer wall 222 of the container 220 as disclosed in International Application No. PCT/US00/10120. The fluid in the secondary flow F2 can be prevented from flowing out of the electrode compartments 520a-d to join the primary flow Fp while still allowing electrical current to pass from the electrodes 600 to the primary flow. In this alternate embodiment, the secondary flow F2 can exit the reaction vessel 204 through the holes 522 in the walls 510 and the hole 525 in the outer wall 222. In still additional embodiments in which the fluid of the secondary flow does not join the primary flow, a duct can be coupled to the exit hole 525 in the outer wall 222 so that a return flow of the secondary flow passing out of the field shaping unit 500 does not mix with the return flow of the primary flow passing down the spiral ramp outside of the outer wall 222. The field shaping unit 500 can have other configurations that are different than the embodiment shown in
An embodiment of reaction vessel 204 shown in
The second conduit system, for example, can include the plenum 330 and the channels 340-346 of the distributor 300, the walls 510 of the field shaping unit 500, and the partitions 530 of the field shaping unit 500. The secondary flow F2 contacts the electrodes 600 to establish individual electrical fields in the field shaping unit 500 that are electrically coupled to the primary flow Fp. The field shaping unit 500, for example, separates the individual electrical fields created by the electrodes 600a-d to create “virtual electrodes” at the top of the openings defined by the lips 536a-d of the partitions. In this particular embodiment, the central opening inside the first lip 536a defines a first virtual electrode, the annular opening between the first and second lips 536a-b defines a second virtual electrode, the annular opening between the second and third lips 536b-c defines a third virtual electrode, and the annular opening between the third and fourth lips 536c-d defines a fourth virtual electrode. These are “virtual electrodes” because the field shaping unit 500 shapes the individual electrical fields of the actual electrodes 600a-d so that the effect of the electrodes 600a-d acts as if they are placed between the top edges of the lips 536a-d. This allows the actual electrodes 600a-d to be isolated from the primary fluid flow, which can provide several benefits as explained in more detail below.
An additional embodiment of the processing chamber 200 includes at least one interface member 700 (identified individually by reference numbers 700a-d) for further conditioning the secondary flow F2 of electroprocessing solution. The interface members 700, for example, can be filters that capture particles in the secondary flow that were generated by the electrodes (i.e., anodes) or other sources of particles. The filter-type interface members 700 can also inhibit bubbles in the secondary flow F2 from passing into the primary flow Fp of electroprocessing solution. This effectively forces the bubbles to pass radially outwardly through the holes 522 in the walls 510 of the field shaping unit 500. In alternate embodiments, the interface members 700 can be ion-membranes that allow ions in the secondary flow F2 to pass through the interface members 700. The ion-membrane interface members 700 can be selected to (a) allow the fluid of the electroprocessing solution and ions to pass through the interface member 700, or (b) allow only the desired ions to pass through the interface member such that the fluid itself is prevented from passing beyond the ion-membrane.
When the interface members 700a-d are filters or ion-membranes that allow the fluid in the secondary flow F2 to pass through the interface members 700a-d, the secondary flow F2 joins the primary fluid flow Fp. The portion of the secondary flow F2 in the first electrode compartment 520a can pass through the opening 535 in the skirt 534 and the first interface member 700a, and then into a plenum between the first wall 510a and the outer wall 422 of the baffle 420. This portion of the secondary flow F2 accordingly joins the primary flow Fp and passes through the primary flow guide 400. The other portions of the secondary flow F2 in this particular embodiment pass through the second-fourth electrode compartments 520b-d and then through the annular openings between the lips 536a-d. The second-fourth interface members 700b-d can accordingly be attached to the field shaping unit 500 downstream from the second-fourth electrodes 600b-d.
In the particular embodiment shown in
When the interface member 700 is a filter material that allows the secondary flow F2 of electroprocessing solution to pass through the holes 732 in the first frame 730, the post-filtered portion of the solution continues along a path (arrow Q) to join the primary fluid flow Fp as described above. One suitable material for a filter-type interface member 700 is POREX®, which is a porous plastic that filters particles to prevent them from passing through the interface member. In plating systems that use consumable anodes (e.g., phosphorized copper or nickel sulfamate), the interface member 700 can prevent the particles generated by the anodes from reaching the plating surface of the workpiece.
In alternate embodiments in which the interface member 700 is an ion-membrane, the interface member 700 can be permeable to preferred ions to allow these ions to pass through the interface member 700 and into the primary fluid flow Fp. One suitable ion-membrane is NAFION® perfluorinated membranes manufactured by DuPont®. In one application for copper plating, a NAFION 450 on-selective membrane is used. Other suitable types of ion-membranes for plating can be polymers that are permeable to many cations, but reject anions and non-polar species. It will be appreciated that in electropolishing applications, the interface member 700 may be selected to be permeable to anions, but reject cations and non-polar species. The preferred ions can be transferred through the ion-membrane interface member 700 by a driving force, such as a difference in concentration of ions on either side of the membrane, a difference in electrical potential, or hydrostatic pressure.
Using an ion-membrane that prevents the fluid of the electroprocessing solution from passing through the interface member 700 allows the electrical current to pass through the interface member while filtering out particles, organic additives and bubbles in the fluid. For example, in plating applications in which the interface member 700 is permeable to cations, the primary fluid flow Fp that contacts the workpiece can be a catholyte and the secondary fluid flow F2 that does not contact the workpiece can be a separate anolyte because these fluids do not mix in this embodiment. A benefit of having separate anolyte and catholyte fluid flows is that it eliminates the consumption of additives at the anodes and thus the need to replenish the additives as often. Additionally, this feature combined with the “virtual electrode” aspect of the reaction vessel 204 reduces the need to “burn-in” anodes for insuring a consistent black film over the anodes for predictable current distribution because the current distribution is controlled by the configuration of the field shaping unit 500. Another advantage is that it also eliminates the need to have a predictable consumption of additives in the secondary flow F2 because the additives to the secondary flow F2 do not effect the primary fluid flow Fp when the two fluids are separated from each other.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
Claims
1-90. (canceled)
91. A reactor for electrochemical processing of microelectronic workpieces, comprising:
- a reaction vessel;
- a first electrode compartment and a second electrode compartment concentric with the first electrode compartment, wherein the first and second electrode compartments are in the reaction vessel;
- a first electrode in the first electrode compartment and a second electrode in the second electrode compartment;
- a dielectric section extending laterally inward into the reaction vessel to shield at least a portion of a workpiece from an electrical field produced by at least one of the electrodes; and
- an interface member in the reaction vessel between the dielectric section and at least one of the first and second electrodes, wherein the interface member is configured to prevent selected matter in the processing fluid from passing to the workpiece.
92. The reactor of claim 91 wherein the interface member comprises an ion-membrane through which selected ions can pass.
93. The reactor of claim 92 wherein the ion-membrane comprises a perfluoronated membrane.
94. The reactor of claim 91 wherein the interface member comprises a filter.
95. The reactor of claim 94 wherein the filter comprises a porous member.
96. The reactor of claim 91 wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member, and wherein the first annular conductive member is the innermost electrode in the reaction vessel.
97. The reactor of claim 91 wherein the dielectric section comprises a first lateral dielectric section of a field shaping unit in the reaction vessel, and the first lateral dielectric section of the field shaping unit is positioned over the first electrode.
98. The reactor of claim 97 wherein the field shaping unit further comprises a second lateral dielectric section positioned over the second electrode.
99. The reactor of claim 91 wherein the dielectric section is positioned over an outer concentric electrode.
100. A reactor for electrochemically processing a microelectronic workpiece, comprising:
- a reaction vessel having a workpiece processing zone;
- a first electrode compartment in the reaction vessel below the processing zone;
- a second electrode compartment in the reaction vessel below the processing zone and concentric with the first electrode compartment;
- a dielectric section extending radially inward into the reaction vessel;
- an interface member in the reaction vessel configured to prevent selected matter from passing from the electrode compartments to the processing zone; and
- a first electrode in the first electrode compartment and a second electrode in the second electrode compartment.
101. The reactor of claim 100 wherein the interface member comprises an ion-membrane through which selected ions can pass.
102. The reactor of claim 101 wherein the ion-membrane comprises a perfluoronated membrane.
103. The reactor of claim 100 wherein the interface member comprises a filter.
104. The reactor of claim 103 wherein the filter comprises a porous member.
105. The reactor of claim 100 wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member, and wherein the first annular conductive member is the innermost electrode in the reaction vessel.
106. The reactor of claim 100 wherein the dielectric section comprises a first lateral dielectric section of a field shaping unit in the reaction vessel, and the first lateral dielectric section of the field shaping unit is positioned over the first electrode.
107. The reactor of claim 106 wherein the field shaping unit further comprises a second lateral dielectric section positioned over the second electrode.
108. The reactor of claim 100 wherein the dielectric section is positioned over an outer concentric electrode.
109. A reactor for electrochemical processing of microelectronic workpieces, comprising:
- a reaction vessel having a workpiece processing zone;
- a first electrode compartment in the reaction vessel located below the processing zone;
- a second electrode compartment in the reaction vessel located below the processing zone and concentric with the first electrode compartment;
- a first electrode in the first electrode compartment and a second electrode in the second electrode compartment;
- a dielectric section extending laterally inward into the reaction vessel; and
- an ion-membrane in the reaction vessel between the processing zone and at least one of the first and second electrodes, wherein the ion-membrane is configured such that selected ions can pass through the ion-membrane.
110. The reactor of claim 109 wherein the ion-membrane comprises a perfluorinated membrane that is permeable to copper ions.
111. The reactor of claim 109 wherein the ion-membrane is impermeable to processing fluid.
112. A reactor for electrochemically processing microelectronic workpieces, comprising:
- a reaction vessel having a weir;
- a first electrode compartment and a second electrode compartment concentric with the first electrode compartment, wherein the first and second electrode compartments are in the reaction vessel and below the weir;
- a first electrode in the first electrode compartment and a second electrode in the second electrode compartment;
- a field shaping unit in the reaction vessel configured to obstruct at least a portion of a workpiece at the weir from at least a portion of at least one of the first and second electrodes; and
- an interface member in the reaction vessel between the weir and at least one of the first and second electrodes, wherein the interface member is configured to prevent selected matter in the processing fluid from passing to the weir.
113. A reactor for electrochemically processing microelectronic workpieces, comprising:
- a reaction vessel having a workpiece processing zone;
- a plurality of electrode compartments in the reaction vessel and below the processing zone;
- a first electrode in one of the electrode compartments and a second electrode in another of the electrode compartments;
- means for shaping an electrical field in the reaction vessel by shielding at least a portion of a workpiece at the workpiece processing zone from at least a portion of an electrical field generated by at least one of first electrode and/or the second electrode; and
- means for preventing selected matter in the processing fluid from passing from the first and second electrodes to the processing zone.
Type: Application
Filed: Mar 29, 2005
Publication Date: Sep 11, 2008
Inventors: Kyle Hanson (Kalispell, MT), Thomas Ritzdorf (Bigfork, MT), Gregory Wilson (Kalispell, MT), Paul McHugh (Kalispell, MT)
Application Number: 11/096,495
International Classification: C25C 7/00 (20060101);