Substrate processing apparatus and method

Abstract

To provide an apparatus and a method that avoid leakage in a processing chamber having a movable part.SOLUTION: An apparatus 200 for electrochemically processing a semiconductor substrate 208 comprises: a processing chamber 202 of a kind capable of defining a covered processing volume 218 by sealing a peripheral portion of the semiconductor substrate 208; a substrate support 206 for supporting the semiconductor substrate 208; a magnet array 232 disposed outside the processing chamber 202 and generating a magnetic field; a controller for changing the magnetic field by controlling the magnet array 232; and an agitator 220 disposed in the processing chamber 202 and provided with a magnetic reaction element 230. The magnetic reaction element 230 reacts to a change in the magnetic field of the magnet array 232 to cause repetitive motion of the agitator 220.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for electrochemically processing a semiconductor substrate, in particular an apparatus for electrochemically processing the front side of a semiconductor substrate. The present invention also relates to a method for processing a semiconductor substrate, including electrochemical processing of the semiconductor substrate and electrochemical deposition on the semiconductor substrate. [Background technology]

[0002] Electrochemical deposition (also known as electrodeposition or electrolytic plating) is used to deposit (grow) metal coatings onto conductive substrates in the manufacture of printed circuit boards (PCBs), semiconductor devices, and flat panel displays (FPDs). To achieve acceptable deposition, deposition characteristics, such as deposition uniformity and deposition rate, must be carefully controlled.

[0003] A key factor in determining the deposition characteristics (e.g., uniformity and rate) of an electrochemical deposition process is the mass transport of material to the surface of the substrate being coated. The rate of mass transport of material to the electrode surface is a function of the current density and therefore the deposition rate in an electrochemical deposition process. The maximum current density, which limits the deposition rate, is determined by the diffusion boundary layer thickness (also called the "diffusion layer" thickness) at the surface of the substrate. Reducing the diffusion boundary layer thickness increases the rate of mass transport of material to the substrate surface, which in turn increases the current density and deposition rate. The diffusion boundary layer thickness (and therefore the deposition rate) can be controlled by controlling the flow of electrolyte across the substrate surface, for example, by electrode motion (e.g., rotation), fluid agitation with bubbles, ultrasonic vibration, or mechanical motion. Generally, faster mass transport results in higher deposition rates.

[0004] Semiconductor and related industries, such as LED and FPD manufacturing, require electrochemical deposition (ECD) systems to be cost-effective. To provide excellent cost of ownership (CoO), ECD systems in these fields require excellent throughput, high deposition rates with good uniformity control, and reliable and repeatable operation at low operating costs. This is especially true in applications requiring relatively thick coatings or films, e.g., greater than several microns. Thus, there is a need to improve the deposition rate of ECD processes while maintaining good uniformity control in a reliable and repeatable manner.

[0005] The running cost of an ECD system is further evaluated based on its tool footprint. Because wafer fabrication space is expensive, the tool footprint of an ECD system should be minimized while still increasing the productivity of the system.

[0006] The semiconductor substrate front-side processing apparatus disclosed in the above publication includes a vertical stack of wafer processing modules, the aim of which is to increase productivity while reducing the tool footprint by reducing the height and spacing between adjacent wafer processing modules. This allows a larger number of processing modules to be stacked in a fixed (vertical) space. If the type of processing chamber defines a covered processing volume (also called a "closed" processing chamber), adjacent processing modules can be stacked with smaller vertical separation between them, since no bulky hardware (e.g., for substrate loading / unloading) needs to be placed on the chamber. However, with this type of covered or "closed" processing module, it becomes more challenging to form reliable seals for all moving parts. If the fluid seals are not properly formed, leakage can occur, which can lead to contamination problems. In addition, as the height of the wafer processing module is reduced, it becomes more challenging to maintain efficient mixing of the electrolyte near the substrate surface. Poor mixing can result in non-uniform deposition and slow deposition rates. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 3352206 [Patent Document 2] European Patent Application Publication No. 2652178 [Patent Document 3] European Patent Application Publication No. 2781630 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, it is desirable to avoid leakage in processing chambers having moving parts. It is also desirable to improve electrolyte mixing in electrochemical processing chambers, especially in low profile, small volume chambers, to increase deposition rate and uniformity. [Means for solving the problem]

[0009] The present invention, in at least some of its embodiments, addresses at least some of the problems, desires and needs described above. In particular, the present invention, in at least some of its embodiments, provides at least one of high deposition rates, good deposition uniformity and efficient electrolyte mixing, which are particularly beneficial in small volume, low profile electrochemical processing chambers. Additionally, the present invention, in at least some of its embodiments, provides an apparatus that provides a more reliable fluid seal for moving parts.

[0010] According to a first aspect of the present invention there is provided an apparatus for electrochemically processing a semiconductor substrate, comprising: a processing chamber of a type capable of sealing a peripheral portion of a semiconductor substrate to define an enclosed processing volume; a substrate support for supporting the semiconductor substrate; a magnet array disposed outside the processing chamber and configured to generate a magnetic field; A controller that changes the magnetic field by controlling the magnet arrangement; an agitator disposed within the processing chamber and including a magnetic responsive element, the magnetic responsive element responsive to changes in the magnetic field of a magnet array to impart reciprocal motion to the agitator; Equipped with.

[0011] A type of processing chamber capable of sealing a peripheral portion of a semiconductor substrate to define an enclosed processing volume can be referred to as a "closed" processing chamber. The term "closed processing chamber" corresponds to a chamber having a substantially sealed processing volume. As will be appreciated, such a closed processing chamber typically requires some opening or orifice to perform a processing step. For example, a closed processing chamber typically includes one or more fluid inlets for introducing fluids into the processing volume and / or one or more fluid outlets for removing fluids from the processing volume.

[0012] Providing an agitator in such a process chamber helps to increase the rate of mass transport to the semiconductor substrate surface during processing. Coupling a magnet array to a magnetically responsive element allows for a repetitive motion to be applied to the agitator without bulky hardware above or below the process chamber. Thus, efficient stirring and mixing of the electrolyte can be achieved even in low profile, small volume process chambers. This has the added benefit of allowing multiple devices to be stacked compactly. Furthermore, magnetic coupling of the agitator with a magnet array eliminates mechanical moving parts that extend through the chamber wall, which would otherwise have to be sealed. This inherently reduces the likelihood of leakage and therefore contamination.

[0013] The magnetically responsive element may comprise at least one permanent magnet. The at least one permanent magnet may comprise a plurality of permanent magnets. The magnetically responsive element may comprise a magnet array, e.g. a magnet array of permanent magnets. The magnetically responsive element may comprise an electromagnet. The magnetic coupling between the magnet array and the magnetically responsive element is stronger if the magnetically responsive element can generate a magnetic field by itself. The magnetically responsive element may generate a magnetic field. The magnetic field of the magnet array may be devised to magnetically couple with the magnetic field of the magnetically responsive element. The polarity of the magnet array may be reversed with respect to the polarity of the magnetically responsive element to which it is magnetically coupled.

[0014] The magnetically responsive element may be responsive to changes in position of the magnetic field of the magnet array.The magnetically responsive element may be responsive to changes in magnitude of the magnetic field of the magnet array.

[0015] The magnetically responsive element may respond to changes in the magnetic field through a sidewall of the process chamber. Using a magnetic coupling through the sidewall helps prevent the magnetic field from affecting a process step, such as an electrochemical deposition step. The magnetically responsive element may be disposed adjacent to an inner surface of the sidewall of the process chamber. The magnet array may be disposed adjacent to an outer surface of the sidewall of the process chamber. In such a configuration, the magnetically responsive element may respond to changes in the magnetic field through the sidewall. The thickness of the sidewall through which the magnetically responsive element responds to changes in the magnetic field may be less than the thickness of the other sidewalls of the process chamber. This creates a stronger magnetic coupling through the sidewall. The thickness of the sidewall through which the magnetically responsive element responds to changes in the magnetic field may be 3-10 mm, preferably about 5 mm. Additionally, the magnetically responsive element may respond to changes in the magnetic field through a top or bottom wall of the process chamber. For example, the top or bottom wall of the process chamber may be a lid, a substrate support, or a semiconductor substrate. The magnet array may be positioned above or below the processing chamber (eg, adjacent to a top or bottom wall) such that the magnet array can be magnetically coupled to a magnetically responsive element through the top or bottom of the processing chamber.

[0016] The separation of the magnetic response element and the magnet array may be less than 30 mm, less than 25 mm, less than 20 mm, or less than 10 mm.

[0017] The agitator may include two magnetic reaction elements arranged adjacent to opposite side walls of the processing chamber, each of which reacts to a change in the magnetic field of the magnet array to induce repetitive motion in the agitator. Typically, the two magnetic reaction elements are arranged in radially opposed positions on the agitator. By arranging the two magnetic reaction elements and the magnet array in this manner, a stronger magnetic coupling can be achieved. In addition, the agitator is driven with a more uniform power.

[0018] The magnet arrangement may comprise a permanent magnet, an electromagnet, or a magnet array. The magnet arrangement may comprise an arrangement of two or more permanent magnets, electromagnets, and / or magnet arrays. The two or more permanent magnets, electromagnets, and / or magnet arrays may be disposed adjacent opposing sidewalls of the process chamber. The magnet arrangement may correspond to an arrangement of the two magnetic response elements such that magnetic coupling can occur across each of the opposing sidewalls. Each magnetic response element may respond to a change in the magnetic field of at least one of the two permanent magnets, electromagnets, or magnet arrays to provide repetitive motion to the agitator.

[0019] The agitator may be a paddle assembly. The agitator may further comprise at least one paddle. The at least one paddle may be a plurality of paddles. Typically, the direction of reciprocating motion is substantially perpendicular to a surface of the at least one paddle. Preferably, adjacent paddles of the plurality of paddles are spaced apart at substantially regular intervals. The plurality of paddles may be supported on a frame. The frame may be substantially annular.

[0020] The agitator may have tabs (ears) that are received by a complementary portion of the processing chamber and support the agitator. The complementary portion of the processing chamber may be a portion of a sidewall of the processing chamber. The complementary portion of the sidewall may be recessed. The complementary portion of the processing chamber may have a step that receives and supports the tab. The tab may be supported on a frame. In embodiments that include paddles, each paddle may have at least one tab that is received by a complementary portion of the processing chamber. Each paddle may have a tab on each end of the paddle. The or those tabs may support the agitator above the semiconductor substrate during processing, thereby separating the agitator from the semiconductor substrate being processed. The tabs allow for a controlled spacing between the agitator and the semiconductor substrate being processed. This prevents the agitator from contacting the semiconductor substrate, which would damage the substrate being processed. Additionally, the tabs provide a consistent spacing between the agitator and the semiconductor substrate being processed. For example, the agitator can be positioned and maintained within a few mm of the substrate being processed. Maintaining a constant position of the agitator relative to the substrate helps improve deposition uniformity and deposition rate in electrochemical deposition processes.

[0021] The tab may include a magnetically responsive element.

[0022] The stirrer may be made from a metallic material, such as titanium, platinum coated titanium, a dielectric material, or a plastic material, such as polyvinyl chloride (PVC).

[0023] The substrate support may be of a type that supports the semiconductor substrate thereon in a substantially horizontal position (lateral support).Optionally, the substrate support may be of a type that supports the semiconductor substrate with the front surface of the semiconductor substrate facing upward.

[0024] The cross-sectional dimension of the processing chamber may be less than 500 mm, preferably less than 300 mm or less than 200 mm. For example, the cross-sectional dimension may be the distance from the top wall to the bottom wall of the processing chamber. The cross-sectional dimension may be the height.

[0025] The controller may be a user interface system, such as a computer, a pneumatic actuator, or an electric motor.

[0026] Typically, the apparatus further comprises one or more electrodes. The one or more electrodes may be arranged opposite the substrate support. The apparatus may further comprise one or more electrical contacts arranged to be in electrical contact with the one or more electrodes and / or the semiconductor substrate. The apparatus may further comprise one or more fluid inlets. The apparatus may further comprise one or more fluid outlets. The apparatus may further comprise a seal configured to seal a peripheral portion of the semiconductor substrate to define an enclosed processing volume. The seal may form a fluid seal with the semiconductor substrate at a distance of 3 mm or less from the semiconductor substrate. The seal may be located on one of the side walls of the processing chamber. The seal may prevent leakage of fluid, e.g. electrolyte, from contaminating other components of the apparatus.

[0027] The apparatus may be an electrochemical processing chamber.The apparatus may be an electrochemical deposition chamber.

[0028] A processing system according to a second aspect of the invention comprises a vertical stack comprising a plurality of devices according to the first aspect of the invention.

[0029] Adjacent devices in the vertical stack may be separated by a distance of not more than 200mm, optionally not more than 150mm.

[0030] A third aspect of the present invention provides a method of processing a semiconductor substrate using an apparatus according to the first aspect of the present invention, comprising the steps of: forming a seal between a processing chamber and a peripheral portion of a semiconductor substrate to define a covered processing volume; controlling a magnet array to vary a magnetic field of the magnet array and a magnetically responsive element to the variation in the magnetic field of the magnet array to provide repetitive motion to the agitator; performing a processing step on the semiconductor substrate while subjecting the agitator to its repetitive motion; has.

[0031] The processing steps may include wet chemical processing steps, such as electrochemical deposition steps, electroless deposition steps, chemical etching steps, electropolishing steps, etc. The processing steps may be cleaning, rinsing and / or drying steps.

[0032] The stirrer may be spaced from the semiconductor substrate.

[0033] The stirrer may be spaced from the semiconductor substrate by a distance of 1.5 to 30 mm, 2 to 20 mm, or 3 to 10 mm. Reducing the stirrer-to-semiconductor substrate spacing improves mixing of the electrolyte and improves the rate of mass transport to the substrate.

[0034] The agitator may be moved in a reciprocating motion along a direction substantially parallel to the semiconductor substrate. The reciprocating motion typically has a velocity component reciprocating along a first axis. The reciprocating motion may be a linear reciprocating motion. Additionally, the reciprocating motion may be a non-linear reciprocating motion or may follow a serpentine path. The reciprocating motion may have at least one other velocity component orthogonal to the first axis. For example, the reciprocating motion may have a second velocity component reciprocating along a second axis orthogonal to the first axis.

[0035] Repetitive movement speed is 5-30cm·s -1 may be also possible.

[0036] The repetitive motion may have a forward stroke and a backward stroke. The stroke speed and / or stroke length of the forward stroke may be different from the stroke speed and / or stroke length of the backward stroke, i.e. the repetitive motion may be asymmetric. By using an asymmetric stroke pattern, resonance effects can be avoided, which helps to improve the process uniformity, e.g. the deposition uniformity.

[0037] The agitator may include a plurality of paddles, adjacent paddles of the plurality of paddles may be separated by a paddle spacing, and the stroke length of the repetitive motion may be equal to or greater than the paddle spacing.

[0038] The invention has been described above and is intended to extend to any and all combinations of the features set forth above or below in the description, drawings and claims, for example any feature disclosed in connection with one aspect of the invention may be combined with any feature provided in any of the other aspects of the invention.

[0039] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0040] [Figure 1] 1 is a schematic cross-sectional view of a substrate processing system. [Diagram 2] 1 is a schematic cross-sectional view of a substrate processing apparatus according to a first embodiment of the present invention. [Diagram 3] 1 is a partially cutaway view of a substrate processing apparatus according to a first embodiment, in which substrates and substrate supporters are not shown. [Figure 4] FIG. 2 is a schematic plan view of the stirrer according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] The inventors of the present invention have considered various problems associated with practical commercialization of the electrochemical processing chambers in the prior applications U.S. Pat. No. 6,393,633, U.S. Pat. No. 6,499,423 and U.S. Pat. No. 6,523,635, which are incorporated herein by reference in their entireties. Figure 1 illustrates a substrate processing system 100 of the present invention. The substrate processing system may be of the type described in U.S. Pat. No. 6,499,635 (SPTS Technologies Limited).

[0042] The substrate processing system 100 comprises a frame 102 defining a handling environment 104, a loading / unloading port 106, and at least one vertical stack 108 having substrate processing modules 110a-d. FIG. 1 shows one vertical stack 108. However, the substrate processing system 100 may have multiple vertical stacks. The vertical stack 108 shown in FIG. 1 comprises four processing modules 110a-d. Each vertical stack 108 may have any number of processing modules, typically more than three. Each of the substrate processing modules 110a-d may be individually suitable for one or more wet chemical processing steps, such as electrochemical deposition, electroless deposition, chemical etching, electropolishing, etc., and / or cleaning, rinsing and / or drying processing steps.

[0043] A transfer robot 112 having an end effector 114 is disposed within the handling environment 104. The transfer robot 112 may transfer a substrate 116 in contact with the end effector 114 between the loading / unloading port 106 and any of the substrate processing modules 110a-d and / or between the individual substrate processing modules 110a-d. The handling environment 104 may be kept substantially particle free, for example, using a filtered air supply from a fan / filtration system 118, to avoid contamination of the substrate 116.

[0044] Fluid suppliers, eg electrolyte suppliers, and controls, eg pumps, filters, etc. 120 are provided below or adjacent to the substrate processing modules 110a-b.

[0045] A substrate processing apparatus 200 suitable for electrochemically processing semiconductor substrates will now be described with reference to Figures 2 and 3. The substrate processing apparatus 200 is adapted to be incorporated into the substrate processing system 100 as one of the substrate processing modules 110a-d.

[0046] The apparatus 200 includes a process chamber 202 having one or more side walls 204. In a first embodiment, the process chamber 202 is an electrochemical process chamber. The process chamber 202 is typically substantially cylindrical, for example when processing circular substrates. However, the process chamber 202 may be of any other geometric shape. For example, for rectangular substrates such as panels, the chamber may be substantially cubic or box-shaped. The process chamber 202 is of a type that can seal a peripheral portion of a substrate 208 to define an enclosed process volume 218. In a first embodiment, the process chamber 202 has a height of less than 300 mm. The apparatus 200 is fabricated using materials that are compatible with the electrolytes and reagents used in the process. Suitable materials include, but are not limited to, dielectric materials such as polypropylene, polyvinyl chloride (PVC), polyetheretherketone (PEEK), and fluorinated polymers such as polytetrafluoroethylene (PTFE) or perfluoroalkoxyalkane (PFA).

[0047] The apparatus 200 further includes a substrate support 206 on which a substrate 208 to be processed is placed. The substrate support 206 supports the substrate in a substantially horizontal position. The substrate 208 is a semiconductor substrate and acts as an electrode during electrochemical processing steps. For example, in an electrochemical deposition process, the substrate 208 acts as a cathode. The substrate 208 is typically a wafer, for example a silicon wafer. In a first embodiment, the substrate 208 faces front-side up into the processing chamber. In an alternative embodiment, the substrate 208 faces front-side down into the processing chamber 202.

[0048] A second electrode 210 is disposed on the opposite side of the substrate 208. The second electrode 210 is the anode in the electrochemical deposition process. The anode may be a disposable or inert electrode. A DC power source 212 is connected between the substrate 208 and the second electrode 210 via an ohmic connection. The DC power source allows a potential difference to be applied between the substrate 208 and the second electrode 210. The ohmic connection to the substrate 208 is typically made by making a series or ring of ohmic contacts 214 around the periphery of the substrate, for example about 1-1.5 mm from the edge of the substrate. The ohmic contacts 214 are typically made of titanium or platinum coated titanium.

[0049] When the substrate 208 is to be processed, it is brought into contact with a seal 216 at the base of the processing chamber 202. The seal 216 contacts the periphery of the substrate 208, forming a fluidic seal between the substrate 208 and the processing chamber 202. The seal 216 contacts the substrate 208 within about 3 mm of the edge of the substrate 208. The fluidic seal defines a covered processing volume 218 by the walls 204 and the substrate 208. During electrochemical processing, the covered processing volume 218 is filled with electrolyte. The fluidic seal prevents electrolyte from leaking out of the covered processing volume 218 during processing. This helps to avoid contamination of the backside of the substrate 208 as well as other components of the apparatus 200. The seal 216 is made of an inert material, for example an inert elastomeric material such as Viton®.

[0050] The apparatus 200 further includes a fluid agitation means, such as an agitator 220. An agitator is a device for stirring a fluid, such as a liquid, solution, or electrolyte. In the first embodiment, the agitator is a paddle assembly. The agitator 220 is disposed within the process chamber 202. The agitator 220 includes one or more paddles, fins, or blades 222. Typically, a number of blades 222 are arranged parallel to one another with a predetermined spacing between adjacent blades. The spacing between adjacent blades 222 is determined by the fluid dynamic requirements of the process. The blades 222 can be made of metallic or insulating materials. The blades 222 are held adjacent to (but spaced from) the substrate 208 to be processed. Each blade 222 is supported on a frame 224 by tabs 226 at each end of the blade 222. Securing the blade 222 to the frame 224 in this manner allows the vertical spacing between the blade 222 and the substrate 208 being processed to be precisely controlled and maintained at a fixed, predetermined spacing. The spacing between the substrate 208 and the blade 222 can be 1.5 mm to 30 mm, 2 mm to 20 mm, or 3 mm to 10 mm. The substrate 208 and the blade 222 can be separated by a predetermined distance within any combination of these ranges. The height of the blades (represented in FIG. 2 by a double-headed line with an h mark) can be about 10 to 50% of the distance between the substrate 208 and the second electrode 210.

[0051] The agitator 220 is configured to move in a reciprocating manner (i.e., oscillate forward and backward). The reciprocating motion includes a forward stroke and a backward stroke, each having a stroke speed and stroke length. The agitator 220 reciprocates along a direction parallel to the substrate 208 and the substrate support 206. The inventors of the present invention have discovered that the precise positioning of the agitator 220, coupled with its reciprocating motion, allows for efficient mixing of a small volume of electrolyte. In addition, the reciprocating motion of the agitator 220 helps to increase the rate of mass transport of the electrolyte to the surface (i.e., electrode surface) of the substrate 208. This helps to reduce the diffusion boundary layer thickness and thus increase the rate of the electrochemical reaction (which is mass transport limited). For example, the reciprocating motion of the agitator 220 can be used to increase the deposition rate in an electrochemical deposition process. In addition, the reciprocating motion of the agitator 220 helps to ensure that the mass transport is uniform across the surface of the substrate (electrode). This results in a uniform coating being deposited during electrochemical deposition.

[0052] The agitator includes a magnetically responsive element 230. The magnetically responsive element 230 is disposed within the process chamber 202. The magnetically responsive element 230 can be a magnetic material, such as a magnetizable metal, or a magnet, such as a permanent magnet, an electromagnet, or a magnet array. Preferably, the magnetically responsive element 230 is a permanent magnet. Preferably, the apparatus 200 includes a pair of magnetically responsive elements arranged such that each magnetically responsive element 230 is mounted on opposite sides of the agitator 220. Typically, the magnetically responsive elements of the pair are disposed on opposite diametric sides across the process volume 218. Typically, the (or each) magnetically responsive element 230 is associated with a magnetic field. The apparatus 200 according to the first embodiment includes a pair of permanent magnets arranged and mounted on opposite ends of the blades 222 or tabs 226 to function as a pair of magnetically responsive elements 230. Movement of the magnetically responsive element 230 causes movement of the agitator 220.

[0053] The magnet array 232 provides a magnetic field and is located outside the process chamber 202. The magnet array 232 can be a permanent magnet, an electromagnet, or a magnet array. Preferably, the apparatus 200 includes a pair of magnets 232 located outside the process chamber 202 and in opposite directions. Typically, the position of the magnet array 232 outside the process chamber 202 corresponds to the arrangement of magnetic reaction elements located in the process chamber 202. The magnetic field of the magnet array 232 couples to the magnetic reaction elements 230. The strength of the magnetic coupling between the magnet array 232 and the magnetic reaction elements 230 can be increased by reducing the distance between them. The polarity of the magnetic field is adjusted to maintain the magnetic coupling between the magnet array 232 and the magnetic reaction elements 230. In some embodiments, the polarity of the magnetic reaction elements 230 and the polarity of the magnet array 232 are adjusted to maintain a close magnetic coupling. For example, the polarity of the magnet array can be opposite to that of the magnetic reaction elements. In doing so, a change in the magnetic field of magnet array 232 can move magnetically responsive element 230. For example, a change in the position of magnet array 232 can change the position of magnetically responsive element 230, thereby moving agitator 220. According to other embodiments, the change in the magnetic field can be a change in the magnitude of the magnetic field.

[0054] In the first embodiment, a pair of permanent magnets 232 are disposed adjacent to the outer surfaces of the chamber sidewalls 204 on the opposite sides. The magnets 232 are magnetically coupled to a pair of magnetically responsive elements 230 through the chamber sidewalls 204. However, the magnet array 232 can be disposed above or below the processing chamber 202 so that the magnet array 232 is magnetically coupled to the magnetically responsive elements 230 through the top or bottom of the processing chamber 202. Using a pair of magnets 232 and a pair of magnetically responsive elements 230 in this manner can increase the magnetic coupling and thus the force biasing the agitator 220 to move. The strength of the magnetic coupling between the magnet array 232 and the magnetically responsive elements 230 can be increased by making the thickness of the chamber wall through which the magnetic coupling occurs smaller (thinner) than the remaining chamber walls. For example, the thin chamber wall (through which the magnetic coupling occurs) is typically about 3-10 mm, optionally about 5 mm. The magnet array 232 and the magnetic response element 230 are disposed near the thin chamber wall, and preferably the distance between the magnet array 232 and the magnetic response element 230 is minimized.

[0055] In the first embodiment, a motion generating controller 234 is used to energize the reciprocating motion of the magnet array 232. The controller 234 may be a pneumatic actuator or an electric motor.

[0056] In operation, the controller 234 moves the magnet array 232 forward and backward in a reciprocating motion. The reciprocating motion of the magnet array 232 causes the magnetic reaction element 230 to move synchronously, which in turn causes the agitator 220 to move in a reciprocating motion, thereby mixing the electrolyte in the processing chamber 202.

[0057] By energizing the movement of the agitator 220 in this manner, excellent stirring of the electrolyte in the processing chamber 202 is achieved. Using magnetic coupling, it is possible to seal and close the processing space 218, without the need for moving parts extending through the chamber wall. This has a twofold advantage. Firstly, it allows to isolate the processing chamber 202 from the surroundings, which helps to avoid contamination. Secondly, it further reduces the risk of leakage (which can also lead to contamination), where it is very difficult to maintain a reliable fluid seal with moving parts extending through the chamber wall.

[0058] The length of the agitator's forward and rearward strokes is typically determined by the separation between adjacent blades 222. Preferably, the stroke length is the same as or greater than the separation between adjacent blades 222. The repetitive motion is preferably asymmetric to avoid the occurrence of resonance effects. For example, the forward stroke speed can be faster (or slower) than the rearward stroke speed. The agitator speed during operation is approximately 5-30 cm s -1 Let us assume that.

[0059] A Hall sensor (not shown) can be used to monitor the position of the magnet embedded in the agitator 220. The Hall sensor allows real-time monitoring of the position of the agitator 220. The Hall sensor is a transducer whose output changes in response to a magnetic field and can be used to measure the strength of the magnetic field. Real-time monitoring of the position of the agitator 220 allows precise control of the motion of the agitator 220, such as the agitator frequency and speed. This helps to improve the uniformity and speed of mass transport of fluid, such as electrolyte, to the surface of the substrate being processed.

Claims

1. 1. An apparatus for electrochemically processing a semiconductor substrate, comprising: a processing chamber capable of sealing a peripheral portion of a semiconductor substrate to define an enclosed processing volume; a substrate support for supporting the semiconductor substrate; a magnet arrangement disposed outside the processing chamber and configured to generate a magnetic field; a controller for controlling the magnet arrangement to vary the magnetic field; an agitator disposed within the processing chamber and including a magnetic response element, the magnetic response element responding to changes in the magnetic field of the magnet array through a sidewall of the processing chamber to impart repetitive motion to the agitator; Equipped with The apparatus wherein the agitator comprises two magnetic reaction elements arranged adjacent to opposing side walls of the processing chamber, each magnetic reaction element responding to changes in the magnetic field of the magnet array to impart repetitive motion to the agitator.

2. 10. The apparatus of claim 1, wherein the magnetic reaction element comprises at least one permanent magnet.

3. 3. The apparatus of claim 1 or 2, wherein the magnetically responsive element responds to changes in position of the magnetic field of the magnet array.

4. 2. The apparatus of claim 1, wherein a sidewall through which the magnetically responsive element responds to changes in the magnetic field has a thickness that is less than a thickness of other sidewalls of the processing chamber.

5. 2. The device of claim 1, wherein the sidewall through which the magnetically responsive element responds to changes in the magnetic field has a thickness of between 3 and 10 mm.

6. 10. The device of claim 1, wherein the separation of the magnetic response element and the magnet array is less than 30 mm, less than 25 mm, less than 20 mm, or less than 10 mm.

7. 10. The apparatus of claim 1, wherein the magnetic arrangement comprises a permanent magnet, an electromagnet, or a magnetic array.

8. 10. The apparatus of claim 1, wherein the agitator further comprises at least one paddle.

9. 9. The apparatus of claim 8, wherein the paddle is a plurality of paddles, adjacent paddles of the plurality being spaced apart at regular intervals.

10. 10. The apparatus of claim 1, wherein the agitator comprises tabs received by a complementary portion of the processing chamber to support the agitator.

11. 11. The device of claim 10, wherein the tab comprises the magnetically responsive element.

12. 10. The apparatus of claim 1, wherein the agitator is constructed from one of a metallic material, a platinum-coated titanium material, a dielectric material, and a plastic material.

13. 2. The apparatus of claim 1, wherein said substrate support is of a type that supports a semiconductor substrate thereon in a horizontal position, and incidentally, the front side of the semiconductor substrate to be processed faces upward.

14. 2. The apparatus of claim 1, wherein the processing chamber has a cross-sectional dimension of less than 300 mm or less than 200 mm.

15. 13. A processing system comprising a vertical stack having a plurality of devices according to claim 1.

16. 16. A processing system according to claim 15, wherein adjacent devices in the vertical stack are separated by a distance of 200 mm or less.

17. 1. An apparatus for electrochemically processing a semiconductor substrate, comprising: a processing chamber capable of defining a covered processing volume by sealing a peripheral portion of a semiconductor substrate to define a covered processing volume; a substrate support for supporting the semiconductor substrate; a magnetic device disposed outside the processing chamber and configured to generate a magnetic field; a controller for controlling the magnetic device to vary the magnetic field; an agitator disposed within the processing chamber and including a magnetic responsive element, the magnetic responsive element responsive to changes in the magnetic field of the magnetic device through a sidewall of the processing chamber to impart repetitive motion to the agitator; Equipped with The agitator comprises two magnetic reaction elements arranged adjacent to opposing side walls of the processing chamber, each of the magnetic reaction elements responding to changes in the magnetic field of the magnetic device to impart repetitive motion to the agitator.

18. 20. The apparatus of claim 17, wherein the magnetic reaction element comprises at least one permanent magnet.

19. 20. The apparatus of claim 17, wherein the magnetically responsive element is responsive to changes in position of a magnetic field of the magnetic device.

20. 20. The apparatus of claim 17, wherein the sidewall along which the magnetically responsive element responds to changes in a magnetic field has a thickness that is less than a thickness of another sidewall of the processing chamber.

21. 18. The apparatus of claim 17, wherein the sidewall along which the magnetically responsive element responds to changes in a magnetic field has a thickness of between 3 and 10 mm.

22. 20. The apparatus of claim 17, wherein the magnetically responsive element and the magnetic device have a separation of less than 30 mm, less than 25 mm, less than 20 mm, or less than 10 mm.

23. 20. The apparatus of claim 17, wherein the magnetic device comprises a permanent magnet, an electromagnet, or a magnetic array.

24. 20. The apparatus of claim 17, wherein the agitator further comprises at least one paddle.

25. 25. The apparatus of claim 24, wherein the paddle is a plurality of paddles, adjacent paddles within the plurality of paddles being spaced apart by regular intervals.

26. 20. The apparatus of claim 17, wherein the agitator comprises tabs received by a complementary portion of the processing chamber to support the agitator.

27. 27. The device of claim 26, wherein the tab includes a magnetically responsive element.

28. 20. The apparatus of claim 17, wherein the agitator is made of a metallic, dielectric or plastic material.

29. 18. The apparatus of claim 17, wherein the substrate support is of a type that supports a semiconductor substrate thereon in a horizontal position, and incidentally, the front side of the semiconductor substrate to be processed is facing upward.

30. 20. The apparatus of claim 17, wherein the processing chamber has a cross-sectional dimension of less than 300 mm, or less than 200 mm.

31. 20. A processing system comprising a vertical stack having a plurality of the apparatus of claim 17.

32. 32. The processing system of claim 31 , wherein adjacent devices in the vertical stack are spaced apart by no more than 200 mm.

33. 20. A method for processing a semiconductor substrate using the apparatus of claim 17, comprising the steps of: forming a seal between the processing chamber and a peripheral edge of a semiconductor substrate to define the covered processing volume; controlling a magnetic array to vary a magnetic field, the magnetic reaction element responding to the variation in the magnetic field of the magnetic device to provide a repetitive motion to the agitator; performing a processing step on the semiconductor substrate while applying a reciprocating motion to the agitator; The method according to claim 1,

34. 34. The method of claim 33, wherein the agitator is spaced from the semiconductor substrate.

35. 34. The method of claim 33, wherein the agitator is spaced from the semiconductor substrate by a distance of 1.530 mm, 2-20 mm, or 3-10 mm.

36. 34. The method of claim 33, wherein the agitator moves reciprocally in a direction parallel to the semiconductor substrate.

37. 34. The method of claim 33, wherein the repetitive motion is performed at a rate of 5 to 30 cm·s －１ A method having a speed of.

38. 34. The method of claim 33, wherein the repetitive motion comprises a forward stroke and a backward stroke, the forward stroke having a stroke speed and / or stroke length different from the stroke speed and / or stroke length of the backward stroke.

39. 34. The method of claim 33, wherein the agitator comprises a plurality of paddles, adjacent paddles in the plurality of paddles being separated by a paddle spacing, and the repetitive motion has a stroke length equal to or greater than the paddle spacing.

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