JP2008546913A - Contact assembly for electrical processing of a workpiece and apparatus comprising a contact assembly for electrical processing of a workpiece - Google Patents

Abstract

  A contact assembly and an apparatus comprising the contact assembly for electrical processing of a workpiece are disclosed herein. The contact assembly includes a support member and a contact member combined with the support member. The support member includes an inner wall defining an opening configured to receive a workpiece. The contact member includes an attachment portion connected to the support member, and a plurality of contacts protruding from the attachment portion. Individual contacts project inward and upward to provide electrical contact with the centered workpiece, and cantilever segments projecting inward and downward for centering the workpiece It has a tip segment.

Description

  The following disclosure relates to a contact assembly for providing an electrical potential to a microfabricated workpiece for electrical processing of the workpiece.

  Electroprocessing of microelectronic / microfabricated workpieces such as silicon wafers (ie, electroplating or electropolishing / etching) typically uses a conductive surface on the device side of the workpiece as an electrolyte. It is necessary to establish a current path between the submerged electrode and the plurality of electrical contacts pressed against the conductive surface at the peripheral portion of the workpiece. As a result, by applying a potential difference between the electrical contact of the workpiece and the submerged electrode so that a current path extends through the electrolyte between the submerged electrode and the conductive surface, Selected species are deposited from the electrolyte on the workpiece (electroplating) or removed from the workpiece (electropolishing / etching).

  Today, the fabrication of semiconductor devices on the surface of a workpiece, such as a silicon wafer, deposits copper on the device surface of the workpiece to form interconnected copper wiring or vias, or Removing copper from selected portions of the work piece to isolate the interconnect copper interconnects or vias. Other microfabricated devices are produced on the surface of the workpiece without depositing copper, other metals, and other non-metallic materials in a similar manner, but without forming interconnect wiring or vias . During manufacturing, a number of such layers of wiring, vias, and other formations can be electroplated, or such layers can be electropolished / etched.

  As workpiece diameters increase (typically between 200 mm and 300 mm today), device sizes shrink, and wiring and via dimensions become more stringent, the device surface of the workpiece Electrical contact systems that provide electrical contact to the periphery must meet increasingly stringent specifications. In particular, the specifications for the uniformity of the plating film are becoming increasingly strict. Also, the peripheral surface area of the wafer that can be used to make electrical contact with the wafer is becoming increasingly smaller. These two in particular require the use of a larger number of electrical contact points around the periphery of the workpiece and the closer the contact points are to the edge of the workpiece. Workpieces such as silicon wafers do not have the same thickness or diameter (even if nominally the same), so the work piece is within a narrow band of perimeter that is not occupied by the device being manufactured It is becoming increasingly difficult to have an electrical contact system that contacts the peripheral parts of

  It is common for contact elements to be exposed to an electrolyte during an electrical processing cycle in order to make electrical contact in a narrow outer band. When such “wet contact” elements are used, as more and more contact points are provided, many of the contact elements that make electrical contact at each contact point are covered during electroplating. It tends to stick more and more to conductive surfaces for workpieces. This trend makes it difficult to remove the workpiece from the contact system after electroplating. This requires some means for removing the workpiece from the contact element after completion of electroplating.

  In the case of workpieces such as silicon wafers, the outer edge of the workpiece is rounded or chamfered, and the band allowed for the formation of electrical contact is located immediately radially inward of the outer edge. ing. As the specifications for the dimensions of the outer peripheral band of the workpiece surface are reduced, contact elements that form electrical contacts at the respective contact points (a) form contacts excessively radially inwardly, Erodes the area of the workpiece intended for the device, or (b) forms contact excessively radially outward, completely off the workpiece, or forms contact at the edge This may cause the band to come off. The workpiece mounting / holding system in which the electrical contact system is located must accommodate workpieces of various sizes within the limits of a particular workpiece, so everything around the workpiece It is difficult to form an electrical contact at this point. This requires some means for centering each workpiece against the contact elements of the electrical contact system.

Conventional electroprocessing systems rotate a workpiece in an electrolyte. As a result, electrical contact systems with “wet contact” elements produce flow turbulence and fluid turbulence as the work piece and “wet contact” elements rotate in the electrolyte during electrical processing. Let Electrolytic fluid turbulence adjacent to the workpiece surface being electroprocessed can cause bubbles and velocity boundary layer interruptions that adversely affect electroplating.
(Overview)

  The present invention provides a workpiece attachment / holding system that includes an electrical contact system designed to provide multiple electrical contacts to a workpiece in the area of a narrow band of perimeters. This electrical contact system centers the workpiece in precise alignment with the electrical contact. The electrical contact system can provide an electrical contact element that provides a drainage force to separate mechanical bonds that tend to form between the electrical contact element and the workpiece after electroplating. This electrical contact system can provide additional means of providing an evacuation force to separate such mechanical coupling as an aid to the force provided by the electrical contact element. The electrical contact element only occupies a thin strip around the periphery of the workpiece, and only projects a small distance into the electrolyte, reducing fluid turbulence.

  The electrical contact system includes a plurality of electrical contact elements, each having a cantilever segment protruding from the contact mounting segment and terminating at the contact tip segment. When the workpiece is inserted into the workpiece mounting / holding system for electroplating, the edge of the workpiece is pushed into contact with the cantilever segment of the respective contact element and along this segment Slide. The contact element is deformed by the force applied to move the workpiece along the cantilevered segment, resulting in the workpiece being brought into contact system for electrical processing. Oriented so that it tends to be centered and aligned with the contact system.

  The tip segment of the contact element is located at the end of the cantilevered segment so that it engages a point outside the tip segment when the workpiece is pushed to the final position for electrical processing in the contact system. Is directed to. When the workpiece reaches the final position, the points outside the tip segment are dragged across the workpiece over a short distance and deflected to be under deformation. As a result, when the work piece is released from the insertion force after electroprocessing, the flexing tip segment breaks the mechanical bond formed between the point outside the tip and the work piece, respectively. The contact element pivots around the joint with the cantilevered segment to return to an undeformed state. The relative configuration of the cantilever and tip segments is such that once the insertion force on the workpiece is removed and the mechanical connection is broken, the cantilever segment returns to its pre-deformation state. The work piece is pushed back and slid to the position where it entered the contact system. The tip segment of the contact element is short and is configured such that the protrusion to the electrolyte is only a short distance to reduce fluid disturbance.

  The electrical contact system includes a support member for an electrical contact element configured in the form of a mounting ring, and one or more electrical mounting members are secured to the mounting ring. The mounting member is a mounting segment of contacts forming a strip of conductive material, from which cantilevered segments of individual contact elements protrude. If more than one attachment member is provided, the attachment segments can abut each other end-to-end to provide a continuous conductive ring when secured to the attachment ring. Alternatively, a mounting segment can be electrically isolated from an adjacent mounting segment, but can also be secured to the mounting ring in an end-to-end manner.

  The attachment member can be manufactured from a thin sheet of conductive material while integrally forming a cantilever segment of a plurality of contact elements and a tip segment combined with each cantilever segment with the attachment segment. After the attachment member is formed into a contact attachment segment in which the cantilever segment and tip segment of the contact member are integrally formed, the cantilever segment and tip segment can be formed into their designed configuration. The tip segment can be formed to extend at an angle of approximately 90 degrees from the cantilevered segment. The cantilever segment can then be formed to extend at an obtuse angle from the attachment segment.

  The workpiece attachment / holding system includes a workpiece backing member designed to move the workpiece to a processing position within the electrical contact system and hold it in that position during electrical processing. When processing of the workpiece is complete, the backing member is retracted so that the workpiece can be removed from the mounting / holding system. The workpiece backing member can be provided with a vacuum system that can be operated upon completion of processing of the workpiece to hold the workpiece to the backing member when the backing member is retracted. The application of this vacuum system can be useful in moving the workpiece to break the mechanical bond formed between the tip segment of the electrical contact and the workpiece.

(Detailed explanation)
The following description discloses details and features of some embodiments for contact assemblies, electrochemical processing reactors, and integrated tools for processing microfabricated workpieces. The term “microfabricated workpiece” or “workpiece” refers to a substrate on which microdevices are formed on and / or within. Typical microdevices include microelectronic circuits or components, thin film recording heads, data storage elements, microfluidic devices, and other products. Micromachines or micromechanical devices are also included in this definition because they are manufactured in much the same way as integrated circuits. The substrate may be a semiconductor piece (eg, a silicon wafer or a gallium arsenide wafer), a non-conductive piece (eg, various ceramic substrates), or a conductive piece (eg, a doped wafer). The term electrochemical treatment or deposition also includes electroplating, electroetching, anodizing, and / or electroless plating. It can be appreciated that each of the details described below is presented to illustrate the following embodiments in a manner sufficient to enable those skilled in the art to make and use the embodiments. Will. However, each of the details and advantages described below may not be necessary to implement certain embodiments of the invention. The present invention may also include further embodiments that are encompassed within the scope of the claims but are not described in detail with respect to FIGS.

  The electrical contact system 100 schematically illustrated in FIGS. 1, 2A, and 2B includes a plurality of electrical contact elements 140 each having a cantilevered segment 142, a tip segment 144, and a mounting segment 130; And a support member 110 to which these contact elements 140 are attached. As will be described later in this specification, several contact elements 140 are integrated into a continuous band of material from which a plurality of contact elements 140 project without attachment segments 130 being separate and independent. It can be manufactured as a structure. The mounting surface 132 of the support member 110 may be conductive so that the contact element 140 becomes conductive when the support member 110 is connected to a power source. As shown in FIG. 1, the electrical contact system 100 is suitable for connection to a plating rotor 20 by a connecting member 22 that connects a support member 110 to the rotor structure. Further, the connection member 22 can provide power to the support member 110 through a rotor for plating. The connecting member 22 can also provide convenient attachment and removal to the plating rotor for the contact system 100.

  The support member 110 can be provided as a continuous ring, or as a series of segments arranged in a ring, and FIGS. 1, 5, and 6A show that the support member is in a circular workpiece. It is shown as a continuous annular ring that is considered suitable for use. The individual contact elements 140 travel around the support member 110 such that their cantilevered segments 142 project into the space 111 inside the support member ring defined by the support member ring, as seen in FIGS. 3 and 4A. Be placed. As shown in FIGS. 1, 2A, and 2B, when the contact system 100 is oriented to contact the workpiece in the processing position, with the surface to be processed of the workpiece directed downward, A cantilever segment 142 projects inward and downward, and a tip segment 144 projects inward and upward.

  As shown in FIG. 1, the plating rotor 20 includes a workpiece backing member 60 that extends and retracts with respect to the support member 110 along the path “T” in FIG. 1. When retracted, the backing member 60 can be removed from within the space 111 defined by the support member 110 and the workpiece can be inserted into or removed from the space 111. When the backing member 60 is stretched with the workpiece placed in a predetermined position in the space 111, the backing member contacts the back surface of the workpiece 101, and the workpiece is depicted in FIGS. 1 and 2A. Press to the processing position. As a result of the backing member 60 pushing the workpiece 101 into the processing position, the edge of the workpiece contacts the cantilevered segment 142 of the electrical contact 140, and the cantilevered segment is removed from the state shown in FIG. 2B. Bend to the state shown in FIG. 2A. Furthermore, when the workpiece is pushed to the processing position shown in FIG. 2A, the tip segment 144 of the electrical contact 140 contacts the surface of the workpiece 101 to be processed and makes electrical contact with this surface. Form.

  In the course of the movement of the workpiece 101 to the processing position shown in FIG. 2A, if the axis of the workpiece 101 is not centered in the space 111, the bending force applied to the cantilevered segment 142 is the contact system. As a result, the cantilevered segment 142 to which a greater burden is applied pushes the workpiece 101 and moves it so that the axis is positioned at the center. In addition, when the workpiece 101 is moved to the processing position shown in FIG. 2A and physical contact with the outer end of the tip segment 144 occurs, the contact of the workpiece with the cantilevered segment 142 ends, resulting in the workpiece being The only electrical contact with the workpiece 101 is at the outer end of the tip segment 144. This is described in more detail later with reference to FIGS. 3 and 4 herein.

3A-3C illustrate the individual contacts 140 for various stages when the workpiece 101 is loaded into the contact assembly 100. FIG. Referring to the orientations shown in FIGS. 3A-3C, when the backing member 60 (FIG. 1) pushes the workpiece 101 upward in the direction P ₁ , the edge 102 of the workpiece 101 cantilevered the individual contacts 140. Slide in contact with segment 142. The force applied to the cantilever segment 142 by an edge 102 of the workpiece 101, cantilevered segment 142 is bent, is diverted in the direction _{S 1.} If the work piece 101 is off-center at the opening 111 and thus the cantilever segment of the contact 140 is bent more greatly on one side of the contact assembly 100 than the other, the cantilever segment undergoes greater deformation 142 moves the workpiece 101 in the direction Y to align the workpiece 101 at the center. Because of the design of the contact system 100, the tip segment 144 extends only a small distance to the workpiece 101, so that all tip segment contacts are properly routed around the workpiece 101. In order to ensure, it is important that the workpiece 101 is accurately centered in the opening 111. Semiconductor wafers and other workpieces are manufactured within tolerance limits and are not uniformly the same diameter. Accordingly, the opening 111 must be dimensioned such that a workpiece having small dimensional variations can be inserted for processing. However, according to the contact system 100 of the present invention, due to the configuration of the cantilevered segment 142, workpieces of various dimensions within a given tolerance specification can be properly positioned. These cantilevered segments 142 have a sufficient acute angle (loading path P) to abut the workpiece edge 102 against the cantilevered segment 142 over a length that can cause alignment of the workpiece 101 axis in the opening 111. ₁ ) to the opening 111. A suitable acute angle does not exceed about 60 degrees at the point of initial contact with the workpiece as shown in FIG. 3A, or about the final deflection point as shown in FIG. 4C. as merely 30 degrees, and 30 degrees to 60 degrees with respect to the path P ₁ of the loading, the preferred acute angle when no load is applied is about 45 degrees.

The spring force accumulated in the cantilevered segment 142 is maximized at the point where the workpiece 101 contacts the tip segment 144 as seen in FIG. 3C. This situation is shown in greater detail in FIG. 4A. The spring force accumulated in the cantilevered segment 142 centers the workpiece 101 until the workpiece / contact situation shifts from contacting only the cantilevered segment 142 to just contacting the tip segment 144 only. Cause it to occur. As workpiece 101 further moves in direction P ₁ , cantilever segment 142 continues to bend and warps in direction S ₁ , and edge 102 of workpiece 101 moves away from cantilever segment 142 of contact 140.

As the workpiece 101 continues to advance from the position shown in FIG. 4A to the position shown in FIG. 4C, the transient segment (curve 143) of the contact 140 widens and the tip segment 144 moves between the tip segment 144 and the cantilevered segment 142. the angle β between pivots in the direction S ₂ to increase from about 90 degrees to an obtuse angle. When the work piece 101 moves to the position shown in FIG. 4C, the cantilevered segment 142 continues to bend around the fixed point 138. As a result, the tip segment edges 145 of the individual contacts 140 slide laterally across the surface of the work piece 101 to conveniently remove oxides that may be present on the work piece 101 surface, and the tip segment edges. When 145 reaches the final position as shown in FIG. 4C, it ensures good electrical contact with the surface of the workpiece.

  5A and 5B illustrate a method for forming a contact assembly 100 according to the present invention. For example, FIG. 5A is a top view of a sheet 228 of conductive material having a first portion 230a and a second portion 230b. Sheet 228 is embossed to form first and second portions 230a, 230b or cut using a suitable technique. The illustrated first and second portions 230 a and 230 b are mirror images of each other and each include a trapezoidal portion 240.

  FIG. 5B is a top view of the first portion 230a after separating the second portion 230b. Next, portion 240 is bent along line AA to form tip segment 144 and transient segment (bend 143) of contact 140, and first portion 230a is bent along line BB. The cantilevered segment 142 of the contact 140 protruding from the mounting portion 132 at an obtuse angle is formed. The first portion 230a is then bent along the line CC to contour the mounting segment 130 to generally match the configuration of the mounting surface 132 of the support member 110.

  Sheet portions 230a and 230b formed in this manner can be secured to support member 110 by spot welding, screws, or other techniques. As shown in FIGS. 5A and 5B, attachment holes 239 are provided in the portions 230a and 230b so that the ends of the portions formed in this way can be aligned and welded or screwed to the support member 110. The half holes 241 are provided at both ends of the portions 230a and 230b. This end-to-end attachment of the portion of the sheet thus formed is shown in FIG. 7B.

  The operation and characteristics of the contact assemblies are best understood in light of the environment and equipment in which they can be used for electrical processing (eg, electroplating and / or electropolishing / electroetching) of workpieces. Accordingly, the following description includes the following sections: (A) a reactor head with a contact assembly, (B) an electrochemical processing station with a contact assembly, and (C) an integrated tool and electrical processing. Divided into reactors.

A. Reactor Head with Contact Assembly FIG. 1 is a schematic side cross-sectional view of an electrical processing system 10 according to the present invention for applying a potential to a workpiece 101. The electrical processing system 10 includes a head assembly 20 for holding a workpiece 101 and a reaction vessel 90 for containing a processing fluid. The head assembly 20 includes a driving member 30 for rotating the workpiece 101 in the direction R, a backing member 60 for arranging the workpiece 101 in the head assembly 20, and a potential applied to the workpiece 101. A contact assembly 100 for adding. During electrical processing, the backing member 60 and the contact assembly 100 ensure that the workpiece 101 is in the workpiece processing position in the reaction vessel 90 and at least the processing surface of the workpiece 101 is in contact with the processing fluid. Hold.

  FIG. 2A is a side cross-sectional view of a portion of the contact assembly 100 with the workpiece 101 loaded in the processing position, and FIG. 2B is the portion of the contact assembly 100 with no workpiece loaded. FIG. As shown in FIG. 8, the head assembly can be rotated so that the contact assembly can be rotated from the “downward” position shown in FIG. 1 to the “upward” position shown in FIG. May be mounted to pivot about a horizontal axis. In the embodiment of FIG. 8, when the contact assembly is in the “upward” position shown and the backing member is retracted, the workpiece 101 having the surface to be processed is It can be loaded into the contact assembly in the “upward” state. After the workpiece is loaded and the backing member is extended to position the workpiece in a stable state within the head assembly shown in FIGS. 1 and 2A, the head assembly is shown in FIG. It can be pivoted to a “down” position and lowered into the reaction vessel 90 for processing. FIG. 6 is an isometric view of the contact assembly 100 inverted to the “upward” position shown in FIG.

  As already mentioned, with reference to FIGS. 2A, 2B, and 7, the contact assembly 100 includes a support member 110 and a plurality of contacts 140. FIG. Each contact 140 protrudes generally inward in a first direction at an angle with respect to the loading path P (FIG. 7), and a second cantilever segment 142 from the cantilevered segment 142 to the loading path P. And a tip segment 144 projecting generally inward in the direction of. As shown in FIG. 7B, the “first direction” is downward and the “second direction” is upward. However, according to the embodiment of FIG. 8 in which the workpiece is loaded into the head assembly when the head assembly is inverted to the “upward” position shown, the “first direction” is upward. Yes, the “second direction” is downward.

  Contact 140 is flexible: (a) a deflected first position (shown in FIG. 2A) when work piece 101 is fully loaded into contact assembly 100; and (b) work piece. The object 101 moves between a second position (shown in FIG. 2B) when it is not loaded into the contact assembly 100. Due to the flexibility of the contacts 140 and the orientation of the cantilevered segments 142 of the individual contacts 140, the workpiece 101 can be accurately centered. Specifically, the axis of the workpiece 101 is usually not centered in the contact assembly 100. The workpiece diameter is not uniform (even if within specified tolerance limits) and the opening 111 must be large enough to accept a reasonable range of workpiece diameters. The workpiece 101 often contacts the cantilevered segment 142 of the contact 140 in a “center-off” state. In addition to being flexible, the cantilevered segment 142 must be sufficiently rigid to push the workpiece 101 so that the axis is centered as described above. As the workpiece 101 moves along the loading path P toward the tip segment 144, the cantilevered segment 142 of the contact 140 that is subject to greater deformation due to the off-center workpiece 101 is The workpiece 101 is pushed toward the contact 140 on the opposite side. In this way, the workpiece 101 is disposed at the center by the contact 140. By aligning the workpiece in the center in the contact assembly 100, the tip segment 144 of the contact 140 is always positioned to contact the workpiece within a small distance from the outer periphery. Thereby, the area occupied by the tip segment 144 of each contact 140 can be limited to a small area on the outer periphery of the workpiece 101. A workpiece such as a semiconductor wafer has an “exclusion zone” on the outer periphery of the “device side (surface on which the processing is typically performed)” of the workpiece. Contacts 140 increase the usable surface radially inward of the peripheral exclusion zone in the work piece by providing reliable electrical contact with the work surface of the work piece in the narrow exclusion zone.

  The transient segments (curves 143) of the individual contacts 140 are also flexible, with the result that the tip segment 144 pivots as the workpiece 101 is loaded into the contact assembly 100 (FIG. 2A). As a result, the transition segment 143 and the tip segment 144 are deformed. In the electroplating process, the electroplated metal tends to accumulate on the surface of the workpiece 101 around the leading edge 145 and tends to stick the leading edge 145 to the workpiece 101. . The tip segment 144 is much shorter than the cantilevered segment 142 and is therefore much stiffer, so that deformations that have occurred in the transient segment 143 and tip segment 144 are subject to the tip edge 145 when the backing 60 is retracted. The tip segment 144 is returned to an undeformed state by releasing from adhesion to the workpiece 101. Deformation caused by the flexing of the individual contacts 140 creates a discharge force to break the mechanical bond between the workpiece 101 and the contacts 140 when the workpiece 101 is removed after processing. The discharging force is generated when the contact 140 bounces back to its original state before bending. This feature facilitates the separation of the workpiece 101 from the tip segment 144 of the individual contacts 140 without damaging the contacts 140.

  Referring to FIGS. 1 and 2A, the contact assembly 100 is a “wet contact” assembly in the sense that a portion of the contact 140 protrudes into the processing fluid during electrical processing. Specifically, at the processing position where the workpiece 101 is brought into contact with the electrolytic solution, the workpiece 101 is partly submerged in the processing fluid in a downward direction, and the tip segment 144 of the contact 140 is connected to the workpiece 101. It is immersed in the processing fluid below. In order to minimize the negative impact on the plating process in the immediate vicinity of the tip segment 144, the transient segment 143, and a portion of the cantilever segment 142 submerged, the cantilever segment 142 has a small planar shape. Formed as follows. This is because the cantilevered segment 142 is wider at the root (shown in line BB) and at the tip (shown in line AA), as shown in FIGS. 5A and 5B. This can be achieved by forming with a narrower trapezoidal shape.

  The contacts 140 may not be covered with an insulating material so that the submerged portions of the individual contacts 140 take away metal from the processing fluid near the periphery of the workpiece 101. The advantage of this feature is that the stripping reduces the thickness of the plating layer on the outer periphery of the workpiece 101, and the material is plated more uniformly throughout the workpiece 101. This feature is particularly useful in applications where it is desirable to reduce the thickness of the plating layer at the outer periphery of the workpiece to compensate for the edge effect.

  Referring to FIGS. 2A and 2B, the contact assembly 100 further includes an insulating splash guard 160 attached to the support member 110. The insulating splash guard 160 protrudes from the support member 110 in a direction generally parallel to the contact 140, and forms a skirt around the contact 140 to protect the contact 140. This protective feature allows the contact assembly to be stored, transported, or placed on a flat surface with the tip segment 144 lifted away from such a flat surface. Insulating splash guard 160 also helps to collect rinse water in place after the rinse cycle.

  Contact assembly 100 is particularly advantageous for electroprocessing large workpieces having small features. In addition to the point that the work piece is always centered and the work piece can be removed, the contact also has a small profile to reduce turbulence and a high current density uniformity. It has a density. Some specific features of the contacts according to the present invention will be described in more detail with reference to FIGS. 6, 7A and 7B.

  FIG. 7A is an isometric view of the lower surface of the contact assembly 100, and FIG. 7B is an enlarged isometric sectional view of the contact assembly 100. Referring to both FIGS. 7A and 7B, the support member 110 has an opening 111 for receiving the workpiece 101 along the loading path P. More specifically, the support member 110 includes an inner wall 112, an outer wall 114 opposite to the inner wall 112, a first wall 116, and a second wall 118 opposite to the first wall 116. Yes. The illustrated outer wall 114 extends from the second wall 118 toward the first wall 116 and tapers inwardly. Further, the support member 110 includes a rim 120 that protrudes radially inward from the inner wall 112 and defines a part of the first wall 116. The rim 120 is dimensioned so that the opening 111 (FIG. 7A) is large enough to receive the workpiece along the loading path P (FIG. 7A). The support member 110 is conductive and is made of titanium formed by plating a platinum layer on the outer surface. The illustrated support member 110 is a continuous ring designed for a circular workpiece, but may be a series of separate curved segments arranged to accommodate any type of workpiece.

  Referring only to FIG. 7B, the contact 140 is a portion of the contact member 130, and the contact member 130 is proximate to the first edge 133 proximate the rim 120 and the junction of the inner wall 112 and the second wall 118. And a second edge 134. The illustrated mounting portion 132 includes a plurality of generally flat segments 136 separated by corresponding bends 137 so that the mounting portion 132 is generally annular or otherwise configured to accommodate a workpiece. Yes. The attachment portion 132 is a single continuous band extending around the inner wall 112 of the support member 110, or several individual sites that are connected together to form a ring-shaped conductor. In either case, the individual portions 136 of the attachment 132 are in electrical communication with each other regardless of the position of the contact assembly 100 or workpiece. As already mentioned, the individual sites are abutted end-to-end and secured to the inner wall 112 of the support member by screws or rivets (not shown) that are inserted through the mounting holes 239 and 241. Yes. The support member 110 provides a conductive attachment to the contact assembly, such as is made of a conductive material, or includes an inner wall 112 made of a conductive material, or is otherwise a contact attachment. 132 provides the appropriate power connection.

  The contact 140 is a cantilever finger that protrudes inward in the radial direction from the mounting portion 132 and generally downward. The contact 140 and the attachment portion 132 shown in FIGS. 7A and 7B are an integral component of the contact member 130. Specifically, the contact 140 and the attachment portion 132 are an integral part made of a common piece of metal thin plate. The illustrated contact member 130 includes a bend 138 at the second edge 134 of the mounting portion 132 so that the contact 140 protrudes into the opening 111 (FIG. 7A).

  The cantilevered segments 142 of the individual contacts 140 project inward from the attachment portion 132 in a first direction that is at an oblique angle with respect to the loading path P (FIG. 7A), and are determined by the workpiece at the processing position. Extending to the processing surface of the workpiece to be processed. The tip segment 144 of each contact 140 protrudes inward in a second direction at an oblique angle with respect to the loading path P and extends again toward the processing surface of the workpiece. Because of the orientation of the cantilevered segment 142, the workpiece is aligned and centered in the opening 111 (FIG. 7A), and because of the oblique orientation of the tip segment 144, the leading edge 145 contacts the workpiece, Ensures electrical contact of the contact assembly 100 to the workpiece. These aspects have been described in more detail with respect to FIGS.

  In the illustrated contact 140, the length of the cantilevered segment 142 is greater than the length of the tip segment 144, so that the leading edge 145 of each contact 140 is below the second wall 118 of the support member 110. positioned. The advantage of this feature is that the contact member 110 is at least partially submerged in the processing fluid to contact the workpiece while the support member 110 is located above the processing fluid. This eliminates the need for an insulating layer on the outer surface of the support member 110 to prevent the material from being plated on the support member, and further, the support member 110 has a processing fluid along the processing surface. Will not hinder the flow.

The illustrated individual contacts 140 are tapered and have a first width W ₁ at the junction between the attachment portion 132 and the cantilevered segment 142 and between the cantilevered segment 142 and the tip segment 144. The joint has a _second width W2. Accordingly, the distance between the tip segments 144 of adjacent contacts 140 is greater than the distance between the cantilevered segments 142 of adjacent contacts 140. Further, as described above, the contact 140 is a thin and flexible member. For example, the illustrated contact 140 and contact member 130 have a thickness of about 0.05 mm to about 1.25 mm. Although thin and flexible, the contact 140 is used to break the mechanical bond between the workpiece and the contact 140 when the backing member 60 is retracted due to deformation caused by loading the workpiece. It is stiff enough to produce a draining force. This feature facilitates separation of the workpiece from the contact 140 without damaging the contact 140.

  Contact 140 may be composed of a conductive material that is inert in a particular electrical processing fluid. Suitable conductive materials include platinum / iridium alloys, platinum, stainless steel, tungsten, and / or molybdenum. For example, the contact 140 can be comprised of a platinum / iridium alloy having about 5-30% iridium, especially about 20% iridium. The illustrated contact 140 does not have an insulating coating on the conductive material. Accordingly, the contact 140 takes away material from the processing fluid near the periphery of the workpiece. This feature is particularly useful in applications where it is desired to reduce the thickness of the plating layer around the work piece to compensate for the edge effect.

  One feature of the contact assembly 100 shown in FIGS. 1-7 is that because of the flexible nature of the contact 140, the tip segment 144 protrudes very slightly beyond the topographical surface of the workpiece 101, The electrical connection with the workpiece 101 can be improved. In addition, a number of individual contacts 140 improve the uniformity of the potential around the workpiece 101. Therefore, according to this contact assembly 100, it is expected that the uniformity of the plating layer will be further improved by providing a number of contacts 140 that can be configured for various topographical features on the workpiece 101. The

  Referring again to FIGS. 2A, 2B, and 7B, the illustrated contact assembly 100 further includes a plurality of drains 122 that extend through the support member 110. The drainage groove 122 includes a first end 124 located on the first wall 116 and a second end 126 located on the second wall 118. The drains 122 allow the liquid from the plating or rinsing process to have an outlet when the contact assembly 100 is rotating and later drop onto the workpiece when the contact assembly 100 is inverted. It is arranged so that there is no.

An insulating splash guard 160 is attached to the outer wall 114 and the second wall 118 of the support member 110. The insulating splash guard 160 includes a first portion 162 and a second portion 164 protruding inward and downward from the first portion 162 in a direction generally parallel to the contact 140. The second portion 164 from the second wall 118 protrudes downward by a first distance D _1, the contact 140, when the workpiece contact assembly 100 is not loaded, the second wall projects downward from 118 by a second distance _{D 2.} The distance _{D 1} is such that the skirt around the contact 140 by the splash guard 160 to protect the contacts 140 are formed, larger than the second distance _{D 2,} or equal to the second distance _{D 2.} Splash guard 160 is also useful for collecting rinsing water in-situ after the rinsing cycle and includes a plurality of grooves 166 for flushing the rinsing water during the rinsing cycle.

  With reference to FIGS. 6 and 8, the head assembly 20 further includes a slot 22 through which the workpiece can be inserted and withdrawn, and a backing member 60 is provided with a plurality of slots for pressing the workpiece against the contact assembly 100. A tab 62 is provided. The workpiece is loaded into the contact assembly 100 in an upward state so that the workpiece is moved upwardly by the tab 62 with the contacts 140 projecting generally upwards of the contact 140. Is done. After loading, work piece 101 and contact assembly 100 are inverted, work piece 101 is directed downward as shown in FIGS. 1-2B, and contacts 140 protrude downward from support member 110.

  FIG. 8 shows a reactor head 350 of an electrical processing reactor that can use the contact assembly 100. The reactor head 350 includes a rotor assembly 330 and a stationary assembly 360. The rotor assembly 330 accommodates and holds the corresponding wafer or workpiece 101, places the workpiece 101 in the reactor bowl with the processing surface facing down, and sets the conductive surface of the workpiece 101 to the reactor. The workpiece 101 is configured to rotate or spin while connected to the plating circuit of the assembly. The reactor head 350 typically has a reactor head 350 facing upward (which receives the workpiece 101 to be plated) from a downward orientation (the surface to be plated of the workpiece 101 is subjected to electrical processing). It is attached to a lift / rotator 370 that is configured to rotate (positioned downward in the reactor bowl). A robot arm 390 (sometimes referred to as an end effector) places the workpiece 101 at a predetermined position on the rotor assembly 330 and takes out the workpiece 101 after plating from the rotor assembly 330. Typically, it is used.

B. Electrochemical Processing Station with Contact Assembly FIG. 9 illustrates another environment in which the contact assembly 100 can be used. FIG. 9 is a schematic side cross-sectional view of an electrochemical processing station 420 having a head assembly 450 and a treatment chamber 470. The head assembly 450 includes a spin motor 452, a rotor 454 connected to the spin motor 452, and a contact assembly 100 held by the rotor 454. The rotor 454 has a bellows 456 and a backing plate 460. The backing plate 460 moves with respect to the workpiece 101 between a first position contacting the back surface of the workpiece 101 and a second position spaced from the back surface of the workpiece 101 (arrow T). Contact assembly 100 is connected to head assembly 450 by a plurality of shafts 459.

  A processing chamber 470 defines a reactor comprising an outer housing 480 and a reaction vessel 490 in the housing 480. The reaction vessel 490 includes a plurality of electrodes 492 and an insulating partition 494 for guiding the flow of processing fluid between the electrodes 492 and the workpiece 101. The processing fluid flows, for example, over the weir (arrow F) to the housing 480 where it is reused. As an alternative, the reaction vessel 490 may comprise only one electrode. Suitable processing chambers are disclosed in US patent application Ser. Nos. 10 / 729,349 and 10 / 860,384, which are hereby incorporated by reference.

  Head assembly 450 and contact assembly 100 hold workpiece 101 in a workpiece processing position within reaction vessel 490 such that at least the processing surface of workpiece 101 is in contact with the processing fluid. An electric field is established in the fluid by generating a potential between the surface of the workpiece 101 and the electrode 492 by the contact assembly 100. For example, the contact assembly 100 can be biased to a negative potential with respect to the electrode 492 to plate the workpiece 101 with a metal or other type of material. Alternatively, (a) for removing the plating of the contact 140 or electropolishing the plating material of the workpiece 101, or (b) for depositing another material (for example, an electrophoretic resist) on the workpiece 101. Contact assembly 100 can be biased to a positive potential with respect to electrode 492. Thus, depending on the type of specific material used in the electrochemical process, it is common for the workpiece to function as a cathode or an anode to deposit or remove material from the workpiece. Is possible.

C. Integrated Tool and Electroprocessing Reactor FIG. 10 is an isometric view of a processing apparatus 500 having an electrochemical processing station 420. A portion of the processing device 500 is shown in cutaway view to show some internal components. The processing apparatus 500 includes a cabinet 502 that has an internal region 504 that defines an enclosure that is at least partially insulated from the external region 505. Further, the illustrated cabinet 502 includes a plurality of openings 506 through which the workpiece 101 can be taken in and out between the internal region 504 and the loading / unloading station 510.

  The loading / unloading station 510 has two container supports 512 housed inside the protective covering 513, respectively. The container support 512 is configured to position the workpiece container 514 with respect to the opening 506 of the cabinet 502. Each of the workpiece containers 514 accommodates a plurality of microfabricated workpieces 101 in a “small” clean environment for transporting the workpieces 101 through other environments not at the level of a clean room. Each of the workpiece containers 514 can be accessed from the interior region 504 of the cabinet 502 through an opening 506.

The processing apparatus 500 further includes one or more workpiece cleaning stations, a workpiece etching station 522, an electrochemical processing station, and a transfer device 530 in the interior region 504 of the cabinet 502. A transfer device 530 moves the microfabricated workpiece 101 between the workpiece container 514 and the processing stations 420 and 522. For example, the transfer device 530 includes a straight rail 532 that extends between the processing stations 420 in the length direction of the internal region 504. The illustrated apparatus 500 includes a first set of processing stations 420 disposed along a _first row R ₁ -R ₁ and a second set of processing disposed along a _second row R ₂ -R _2. Station 420. A straight rail 532 extends between the first and second rows R ₁ -R ₁ and R ₂ -R ₂ of the processing station 420. Further, the transport device 530 includes a robot unit 534 that is held by rails 532 and can access any processing station 420 along the rails 532. Suitable transport devices are all described in US Pat. Nos. 6,752,584, 6,749,391, 6,749,390, 6, which are incorporated herein by reference. 318,951 and 6,322,119.

  From the foregoing, although specific embodiments of the present invention have been described herein for purposes of illustration, it will be understood that various modifications can be made without departing from the technical spirit and scope of the present invention. It will be possible. For example, the contact member can be manufactured using a method different from that described above with respect to FIGS. 5A and 5B, or the contact 140 can be a separate independent finger that is directly attached to the mounting portion of the support member 110 or contact member 130. Good. Also, the contact assembly described above can be used in various types of reactors. Accordingly, the invention is not limited by anything other than the scope of the appended claims.

1 is a schematic cross-sectional side view of an electrical processing system according to the present invention for applying a potential to a workpiece. FIG. FIG. 2 is an enlarged detail view of FIG. 1 showing a portion of the contact system in contact with the workpiece. FIG. 2B is a side cross-sectional view similar to FIG. 2A, although there is no workpiece. FIG. 3 shows individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 3 shows individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 3 shows individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 3 shows the tip segments of individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 3 shows the tip segments of individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 3 shows the tip segments of individual contacts of a contact assembly for various stages when a workpiece is loaded into the contact assembly. FIG. 5 illustrates a method for forming a contact member of a contact assembly. FIG. 5 illustrates a method for forming a contact member of a contact assembly. FIG. 3 is an isometric view of a contact assembly attached to a plating rotor. FIG. 6 is an isometric view of the bottom of the contact assembly. FIG. 6 is an enlarged isometric sectional view of a portion of the contact assembly. FIG. 6 is an isometric view of a reactor head of an electroplating reactor that can use a contact assembly. 1 is a schematic side cross-sectional view of an electrochemical processing station that can use a contact assembly. FIG. 1 is an isometric view of a processing apparatus that can use a contact assembly. FIG.

Claims (30)

A workpiece holder for holding a workpiece and providing electrical contact to the workpiece in an electrical processing system to apply a potential to the workpiece when the workpiece is placed in a processing position. The workpiece holder is
(A) a workpiece backing member that is extendable in the axial direction relative to the support member to move the workpiece along a loading path from a loading position to a processing position;
(B) a contact assembly;
The contact assembly comprises:
The support member defining an opening for receiving a workpiece;
A plurality of contacts arranged around the opening of the support member and connected to the support member;
A cantilever segment projecting into the opening of the support member at an acute angle with respect to the loading path such that each individual contact contacts the outer periphery of the workpiece when the workpiece is moved to a processing position; The cantilever segment projecting from the cantilever segment to contact the workpiece and support the workpiece when the workpiece is moved to the processing position;
The cantilever segment is constructed and arranged to guide and position the work piece when the work piece is moved to a processing position by the work piece backing member;
The tip segment is configured and arranged to provide a tip edge that is in electrical contact with a workpiece in a processing position;
A workpiece holder characterized by that.   The workpiece holder according to claim 1, wherein the cantilever segment is integral with a contact mounting portion, and the contact mounting portion is fixed to the support member.   The contact assembly further includes a plurality of attachments aligned end-to-end and secured to the support member, each of the attachments having a plurality of contacts integrated therein; The workpiece holder according to claim 1.   The workpiece holder of claim 1, wherein the cantilever segment protrudes at an acute angle between about 30 degrees and 60 degrees relative to the loading path.   The workpiece according to claim 1, wherein the cantilever segment has a trapezoidal planar shape that tapers from a wide root to a thin outer end, and the tip segment extends from the outer end of the cantilever segment. Object holder.   2. A workpiece holder according to claim 1, wherein each tip segment extends substantially perpendicular to the integral cantilever segment.   The workpiece holder according to claim 1, wherein the cantilever segment is not in contact with the workpiece when the workpiece is in the processing position.   The support member has a conductive inner wall that defines the opening, the cantilever segment is integral with a contact mounting portion, and the contact mounting portion is fixed to the inner wall of the support member. The workpiece holder according to claim 1.   Each contact has a first width at the junction between the attachment portion and the cantilever segment and a second width at the junction between the cantilever segment and the tip segment. 9. A workpiece holder according to claim 8, wherein the first width is greater than the second width such that adjacent tip segments are spaced apart from each other.   A workpiece holder for use in an electroplating operation, the plated workpiece surface having a tip edge of the tip segment generated in the electroplating operation by retracting the workpiece backing member The workpiece holder of claim 1, wherein the cantilevered segment is deflected when loaded into the tip segment so as to be released from the workpiece.   The skirt ring of claim 1, further comprising a skirt ring attached to the support member and extending from the support member to extend beyond the contact when a workpiece is removed from the contact. Workpiece holder.   The workpiece holder according to claim 11, wherein the support member and the skirt ring are provided with fluid discharge holes for discharging a fluid for electrical processing from the workpiece during processing. A contact assembly for use in an electrochemical processing system to apply a potential to a microfabricated workpiece,
A support member having an inner wall defining an opening, the opening being configured to receive a workpiece along a loading path;
A plurality of contacts connected to the support member;
Each contact includes a cantilever segment and a tip segment integral with and projecting from the cantilever segment, the cantilever segment in a first direction along the loading path Projecting inward, the tip segment projecting inward in a second direction along the loading path, the first direction is opposite to the second direction, and the individual contacts are processed They are in electrical communication with each other regardless of the position of the object,
A contact assembly characterized by that.   A contact assembly for use in electroplating operations, by retracting a workpiece backing member so that the leading edge of the tip segment is released from the plated workpiece surface generated in the electroplating operation 14. The contact assembly of claim 13, wherein the cantilever segment is deflected when loading a workpiece onto the tip segment.   The contact assembly of claim 13, further comprising an outer insulating member projecting from the support member in the first direction.   It further has a contact member having an attachment portion attached to the inner wall of the support member, the plurality of contacts projecting from the attachment portion, and the attachment portion and the contact are an integral part of the contact member The contact assembly according to claim 13, wherein   A contact member having an attachment portion attached to the inner wall of the support member, wherein the plurality of contacts protrude from the attachment portion, and each contact is formed between the attachment portion and the cantilever segment. A distance between the cantilevered segments of adjacent contacts having a first width at the junction between them and a second width at the junction between the cantilevered segment and the tip segment The contact assembly of claim 13, wherein the first width is greater than the second width such that is less than a distance between the tip segments of adjacent contacts. A reactor for electrical processing of a workpiece,
A container for holding a fluid for electrical processing;
A plurality of electrodes disposed relative to the container and dielectrically separated from each other to provide a potential within the container;
It is movable relative to the container between a loading / unloading position and a processing position, and can be extended axially with respect to the support member to move the workpiece along the loading path from the loading position to the processing position. A head assembly comprising a workpiece backing member;
A contact assembly held by the head assembly,
The contact assembly comprises:
A support member defining an opening for receiving the workpiece;
A plurality of contacts arranged around the opening of the support member and connected to the support member;
A cantilever segment projecting into the opening of the support member at an acute angle with respect to the loading path such that each individual contact contacts the outer periphery of the workpiece when the workpiece is moved to a processing position; The cantilever segment projecting from the cantilever segment to contact the workpiece and support the workpiece when the workpiece is moved to the processing position;
The cantilever segment is constructed and arranged to guide and position the work piece when the work piece is moved to a processing position by the work piece backing member;
The tip segment is configured and arranged to provide a tip edge that is in electrical contact with a workpiece in a processing position;
A reactor characterized by that.   The reactor according to claim 18, wherein the cantilever segment is integral with a contact attachment, and the contact attachment is fixed to the support member.   The contact assembly further includes a plurality of attachments that are end-to-end aligned and secured to the support member, each of the attachments having a plurality of cantilevered segments integrated therein. The reactor according to claim 18.   The reactor of claim 18, wherein the cantilever segment protrudes at an acute angle between about 30 degrees and 60 degrees relative to the loading path.   The reactor of claim 18, wherein the cantilever segment has a trapezoidal planar shape that tapers from a wide root to a thin outer end, and the tip segment extends from the outer end of the cantilever segment.   The reactor of claim 18, wherein each tip segment extends substantially perpendicular to the integral cantilever segment.   The reactor of claim 18, wherein the cantilever segment is not in contact with the workpiece when the workpiece is in the processing position.   The support member has a conductive inner wall that defines the opening, the cantilever segment is integral with a contact mounting portion, and the contact mounting portion is fixed to the inner wall of the support member. The reactor according to claim 18.   Reactor for use in electroplating operations, by retracting the workpiece backing member, the leading edge of the tip segment is released from the plated workpiece surface generated in the electroplating operation The reactor of claim 18, wherein the cantilever segment is deflected when loading a workpiece into the tip segment.   There is further provided a lift / rotation assembly configured to rotate the head assembly from an upward arrangement for receiving the workpiece to a downward arrangement for placement in the workpiece container for electrical processing. The reactor according to claim 18. (A) a cabinet having an internal region capable of processing the workpiece;
(B) a plurality of workpiece processing stations located in the internal region, wherein at least one of the stations has a reactor for electrical processing of the workpiece;
The reactor is
A container for holding a fluid for electrical processing;
A plurality of electrodes disposed relative to the container and electrically isolated from each other to provide an electrical potential within the container;
It is movable with respect to the container between a loading / unloading position and a processing position, and can be extended axially with respect to the support member to move the workpiece from the loading position to the processing position along the loading path. A head assembly comprising a workpiece backing member;
A contact assembly held by the head assembly;
The contact assembly comprises:
The support member defining an opening for receiving a workpiece;
A plurality of contacts arranged around the opening of the support member and connected to the support member;
A cantilever segment projecting into the opening of the support member at an acute angle with respect to the loading path so that each individual contact contacts the outer periphery of the workpiece when the workpiece is moved to a processing position; The cantilever segment projecting from the cantilever segment to contact the workpiece and support the workpiece when the workpiece is moved to the processing position;
The cantilever segment is constructed and arranged to guide and position the work piece when the work piece is moved to a processing position by the work piece backing member, and the tip segment is treated Constructed and arranged to provide a leading edge that is in electrical contact with the workpiece in position;
A plurality of workpiece processing stations;
(C) a loading / unloading station for delivering work pieces to and receiving from the internal area;
(D) a workpiece conveying tool for delivering a workpiece to a processing station in the inner region and delivering from the processing station in the inner region;
An electric processing device comprising:   30. The electroprocessing apparatus of claim 28, wherein the processing station includes at least one workpiece cleaning station.   30. The electroprocessing apparatus of claim 28, wherein the processing station includes at least one workpiece etching station.

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