Surface processing equipment

Abstract

To provide a technique for suppressing penetration of an electrolytic solution into the back surface of a flat workpiece such as a semiconductor wafer.SOLUTION: A chuck (2) that holds a workpiece while exposing a workpiece surface (W1) by sucking a workpiece surface (W2) of a workpiece (W) includes an adsorption portion (21) and an intrusion suppression portion (23). The adsorption portion adsorbs the surface to be adsorbed by coming into contact with the surface to be adsorbed. The intrusion suppression portion is provided outside the adsorption portion in the in-plane direction so as to adsorb an electrolytic solution (S) or eject gas at a position corresponding to the outer edge (W3) of the workpiece in the in-plane direction along the surface to be adsorbed. As a result, it is possible to prevent the electrolytic solution from entering the gap between the surface to be adsorbed and the chuck.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface processing device. [Background technology]

[0002] Various techniques for planarizing (i.e., grinding or polishing) the surface of a flat workpiece such as a semiconductor wafer have been known for some time. For example, Patent Document 1 discloses a polishing method in which an anodizing process and a polishing process are carried out simultaneously or alternately. In the anodizing process, a voltage is applied to the workpiece as an anode in the presence of an electrolyte, oxidizing the surface of the workpiece. In the polishing process, oxides formed on the surface of the workpiece are polished and removed using a fixed-abrasive polishing body in which abrasive grains of a predetermined hardness and grain size are fixed to a substrate.

[0003] Specifically, Patent Document 1 discloses a polishing apparatus suitable for polishing SiC wafers. In this polishing apparatus, a container is fixed on a rotatable disk via an insulator, and a metal plate serving as a cathode is placed on the bottom of the container. The SiC wafer is held in a rotatable wafer holder and pressed against a grinding wheel with a predetermined load in an electrolyte. The wafer holder is attached to a vacuum chuck provided on the underside of the rotating head via an insulating layer. The SiC wafer serves as the working electrode, and a positive potential is applied to modify the surface of the SiC wafer through anodic oxidation. The modified layer is then removed with a grinding wheel, gradually flattening the surface and resulting in a damage-free surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-27359 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in the polishing apparatus described in Patent Document 1, if an electrolyte solution penetrates into the backside of the processed surface of an SiC wafer, the portion in contact with the penetrated electrolyte solution may be oxidized, which may cause problems such as shape deterioration and poor electrical conductivity. The present invention has been made in consideration of the circumstances exemplified above. That is, the present invention provides a technology for suppressing the penetration of an electrolyte solution into the backside of the processed surface of a flat workpiece such as a semiconductor wafer. [Means for solving the problem]

[0006] The surface processing device (1) is configured to flatten a processing surface (W1), which is one of a pair of main surfaces of a flat workpiece (W). The surface processing device according to claim 1 is a chuck (2) configured to hold the workpiece while exposing the workpiece surface by attracting the other of the pair of main surfaces, that is, an attracting surface (W2), of the workpiece; an opposing member (3) disposed opposite the work surface of the workpiece held by the chuck; a current applying unit (5) configured to apply a current in the presence of an electrolytic solution (S) with the opposing member side as a cathode and the workpiece side as an anode; Equipped with The chuck is an adsorption portion (21) configured to adsorb the adsorbed surface by contacting the adsorbed surface; a first adsorption section (211) and a second adsorption section (212) as a penetration prevention section (23) provided outside the suction section in the in-plane direction so as to prevent the electrolyte from penetrating into a gap between the chuck and the attracted surface by sucking the electrolyte or ejecting gas at a position corresponding to an outer edge (W3) of the workpiece in the in-plane direction along the attracted surface; a first infiltration suppression section (234) and a second infiltration suppression section (235) as Equipped with picture, the first suction portion is provided corresponding to a first outer diameter of the workpiece, the first intrusion suppression portion is provided on the outside of the first suction portion in the in-plane direction in correspondence with the first outer diameter of the workpiece, the second suction portion is provided on the outside of the first suction portion and the first penetration suppression portion in the in-plane direction, corresponding to a second outer diameter of the workpiece that is larger than the first outer diameter, The second infiltration suppression portion is provided on the outside of the first infiltration suppression portion and the second suction portion in the in-plane direction, corresponding to the second outer diameter of the workpiece. There are.

[0007] In addition, in each section of the application documents, each element may be assigned a reference symbol in parentheses. In this case, the reference symbol merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present invention is not limited in any way by the description of the reference symbol. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side cross-sectional view showing a schematic configuration of a surface processing device according to a first embodiment of the present invention. [Figure 2] 2 is an enlarged side cross-sectional view of a portion of the chuck shown in FIG. 1. [Figure 3] FIG. 4 is a side cross-sectional view showing a schematic configuration of a surface processing device according to a second embodiment of the present invention. [Figure 4] 4 is an enlarged side cross-sectional view of a portion of the chuck shown in FIG. 3. [Figure 5] FIG. 10 is a side cross-sectional view showing a schematic configuration of a surface processing device according to a third embodiment of the present invention. [Figure 6] 6 is an enlarged side cross-sectional view of a portion of the chuck shown in FIG. 5. [Figure 7] FIG. 10 is a side cross-sectional view showing a schematic configuration of a surface processing device according to a fourth embodiment of the present invention. [Figure 8] 8 is an enlarged side cross-sectional view of a portion of the chuck shown in FIG. 7. [Figure 9] FIG. 10 is a side cross-sectional view showing a schematic configuration of a chuck used in a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that various modifications applicable to one embodiment may be hindered from being understood if they are introduced in the middle of a series of explanations relating to the embodiment. Therefore, the modifications will not be introduced in the middle of a series of explanations relating to the embodiment, but will be explained together after the series of explanations.

[0010] (First embodiment: configuration) Referring to FIG. 1, the surface processing apparatus 1 is configured to planarize a workpiece surface W1, which is the main surface of a flat workpiece W. The "main surface" is a surface perpendicular to the thickness direction of the plate-like workpiece W and is also referred to as the "plate surface." That is, the workpiece W has a workpiece surface W1, which is one of a pair of main surfaces, and an adsorption surface W2, which is the other, or back surface. The surface processing apparatus 1 according to this embodiment is configured to perform polishing or grinding using anodization on the workpiece surface W1, which is a semiconductor wafer such as a SiC wafer. That is, the surface processing apparatus 1 is configured as an ECMP apparatus or an ECMG apparatus. ECMP stands for Electro-Chemical Mechanical Polishing. ECMG stands for Electro-Chemical Mechanical Grinding.

[0011] The schematic configuration of a surface processing apparatus 1 according to this embodiment will be described below with reference to FIGS. 1 and 2. As will be described later, FIGS. 1 and 2 are simplified diagrams for explaining the schematic configuration and functions of the surface processing apparatus 1 according to this embodiment, and do not necessarily correspond to the specific configuration of the apparatus that is actually manufactured and sold. The same applies to the diagrams corresponding to other embodiments, such as FIG. 3 and subsequent figures. For ease of explanation, a right-handed XYZ coordinate system is set as shown. In this embodiment, the positive Z-axis direction indicates the vertically upward direction, i.e., the direction opposite to the direction of weight action. The X-axis and Y-axis directions both indicate the horizontal direction. Hereinafter, for convenience of explanation, the positive Z-axis direction corresponding to the vertically upward direction may be simply referred to as "upward," and the opposite direction may be simply referred to as "downward."

[0012] The surface processing device 1 includes a chuck 2, a facing member 3, a housing 4, and a current application unit 5. The chuck 2 is configured to hold the workpiece W with its surface W1 exposed downward by attracting the workpiece W to the facing member 3. The facing member 3 is disposed below the chuck 2 so as to face the surface W1 of the workpiece W held by the chuck 2. The housing 4 is shaped like a bathtub with an upward opening. The housing 4 is a container for accommodating the facing member 3 and an electrolytic solution S and is disposed below the facing member 3. In this embodiment, the electrolytic solution S is a solution that does not contain an etchant component, such as an aqueous solution of sodium chloride, potassium chloride, or sodium nitrate. The etchant component is a component (e.g., hydrofluoric acid) that constitutes a dissolving solution capable of dissolving an oxide film formed on the workpiece surface W1 by anodization. The chuck 2 and / or the housing 4 are movable up and down by a lifting mechanism (not shown). The chuck 2 and / or the housing 4 are provided so as to be movable in the X and Y directions in the drawing by a translation mechanism (not shown). The chuck 2 and / or the opposing member 3 are provided so as to be rotatable about a rotation center axis parallel to the Z axis in the drawing by a rotation mechanism (not shown). The current application unit 5 is provided so as to apply a current in the presence of the electrolyte S, with the opposing member 3 side serving as a cathode and the workpiece W side serving as an anode.

[0013] The chuck 2 has a horizontal chuck surface 20 exposed downward, and is configured to be able to hold the workpiece W by attracting it to the chuck surface 20 while passing electricity through the workpiece W. The chuck 2 is also configured to prevent the electrolyte S from penetrating between the chuck surface 20 and the attracted surface W2 during ECMP or ECMG processing of the workpiece W1. That is, the chuck 2 includes an attraction portion 21, a contact electrode 22, a penetration prevention portion 23, a partition portion 24, a negative pressure path 25, and a fluid path 26.

[0014] The adsorption unit 21 is configured to adsorb the adsorption target surface W2 by contacting the adsorption target surface W2. In this embodiment, the adsorption unit 21 is configured to adsorb the adsorption target surface W2 by negative air pressure. That is, the adsorption unit 21 has adsorption passages 210, which are internal passages through which air or negative pressure can pass in the thickness direction. Specifically, for example, the adsorption unit 21 can be formed by providing a large number of adsorption passages 210, which are through-holes along the thickness direction, in an insulating, dense ceramic plate (i.e., not porous enough to allow gas or liquid to pass through). Alternatively, for example, the adsorption unit 21 can be formed of an open-cell porous body such as porous ceramic having a network of adsorption passages 210 therein. The term "open-cell" refers to the property of a large number of pores or bubbles being interconnected, as opposed to "closed-cell" which refers to a large number of pores or bubbles being independent and not interconnected.

[0015] A contact electrode 22 is embedded in the chucking portion 21. The contact electrode 22 is provided inside the chucking portion 21 in the in-plane direction so that electrical continuity with the workpiece W is established by contacting the chucking target surface W2 when the chucking target surface W2 is attached to the chucking portion 21. The "in-plane direction" refers to the direction along the chucking target surface W2, which is parallel to the XY plane in the drawing. In this embodiment, the contact electrode 22 is formed in a disk shape from a good conductor metal such as copper. The bottom surface of the contact electrode 22 is provided flush with the chucking surface 20 so that the workpiece W does not lift up from the chucking surface 20 when in contact with the chucking target surface W2.

[0016] The infiltration suppression unit 23 is provided outside the suction unit 21 in the in-plane direction, i.e., at a position corresponding to the outer edge W3 of the workpiece W in the in-plane direction, so as to suppress infiltration of the electrolyte S into the gap between the attracted surface W2 and the chuck 2. The outer edge W3 includes the end surface W4 of the workpiece W and a portion nearby (specifically, for example, a beveled portion). In this embodiment, the infiltration suppression unit 23 is configured to suck the electrolyte S at a position corresponding to the outer edge W3 of the workpiece W.

[0017] Specifically, the infiltration suppression unit 23 includes an insulating, dense ceramic layer and electrolyte suction passages 231 formed of through-holes that penetrate the ceramic layer in the thickness direction. The bottom surface of the ceramic layer is flush with the bottom surface of the suction unit 21 to form the chuck surface 20. The electrolyte suction passages 231 are provided such that suction openings 232, which open on the chuck surface 20 side, face the outer edge W3 of the workpiece W. For example, the suction openings 232 may be provided such that their in-plane center positions substantially coincide with the end face W4. In this embodiment, the multiple suction openings 232 are disposed at equal intervals in the circumferential direction. The "circumferential direction" refers to the direction along the extension of the outer edge W3 or end face W4 of the approximately disk-shaped workpiece W, which extends circumferentially. More precisely, the "circumferential direction" refers to the circumferential direction of a circle drawn in the XY plane, the circle having its center at the intersection of an imaginary vertical line that passes through the center in the in-plane direction of the workpiece W held by the chuck surface 20 and is parallel to the Z axis and the XY plane. As shown in Figures 1 and 2, the suction opening 232 may be provided in a recess 233 recessed from the chuck surface 20. The recess 233 is formed in the shape of a square groove extending along the circumferential direction.

[0018] The adsorption unit 21 and the infiltration prevention unit 23 are blocked from exchanging fluid (i.e., electrolyte solution S) with each other by a partition wall 24. That is, the partition wall 24 is provided to block the exchange of fluid (i.e., gas and electrolyte solution S) between the adsorption passage 210 in the adsorption unit 21 and the electrolyte solution suction passage 231 in the infiltration prevention unit 23. The adsorption passage 210 in the adsorption unit 21 is connected to a negative pressure path 25. The negative pressure path 25 is connected to a vacuum source (not shown, for example, a vacuum pump). Meanwhile, the electrolyte solution suction passage 231 in the infiltration prevention unit 23 is connected to a fluid path 26. The fluid path 26 is provided at the most upstream end of an electrolyte solution return path (not shown) for returning the electrolyte solution S drawn by the electrolyte solution suction path 231 to the housing 4. The electrolyte solution return path is a fluid path separate from the negative pressure path 25 and is configured to prevent the electrolyte solution S from migrating toward the negative pressure path 25. Therefore, the negative pressure path 25 and the fluid path 26 can be connected to independent vacuum sources, or alternatively, the negative pressure path 25 and the fluid path 26 can be connected to a common vacuum source by using a filter means or the like that prevents the electrolyte S from entering the negative pressure path 25.

[0019] The facing member 3 is provided so that its upper surface, i.e., a processing surface 301, faces the processing surface W1 of the workpiece W held by the chuck 2 via the electrolytic solution S, and the current application unit 5 applies a current between the facing member 3 and the workpiece W to planarize the processing surface W1. In this embodiment, the facing member 3 is configured to anodize the processing surface W1 in the presence of the electrolytic solution S while selectively removing oxides formed on the processing surface W1. That is, the facing member 3 has a two-layer structure in which a grinding stone layer 302 having the processing surface 301 is joined to a counter electrode layer 303, which is a conductive layer made of a conductive metal or the like and supports the grinding stone layer 302. The facing member 3 may also be referred to as a "surface processing pad," "polishing pad," or "grinding pad."

[0020] (First embodiment: Actions and effects) An outline of the operation of the surface processing device 1 according to this embodiment will be described below, along with the effects achieved by the configuration of the surface processing device 1.

[0021] First, the internal space of the housing 4 containing the opposing member 3 is filled with the electrolyte S so that the liquid level of the electrolyte S is above the machining surface 301. As shown in FIG. 1 , with the chuck 2 and the housing 4 spaced apart from each other in the vertical direction, the workpiece W is attracted to the suction portion 21 of the chuck 2 by the negative pressure of the negative pressure path 25. Next, the chuck 2 attracting the workpiece W and the housing 4 containing the opposing member 3 and the electrolyte S are brought closer together in the presence of the electrolyte S until the workpiece W1 comes into contact with the machining surface 301. Then, while the chuck 2 and the opposing member 3 are rotated relative to each other, a current is applied by the current application unit 5, with the opposing member 3 serving as the cathode and the workpiece W serving as the anode. The anodized workpiece W1 is then ground or polished by the opposing member 3, selectively removing the oxide film (i.e., the oxide film) on the workpiece W1. This allows the workpiece W1 to be effectively planarized.

[0022] If the electrolyte S penetrates between the attracted surface W2, which is the backside of the workpiece surface W1 of the workpiece W, and the chuck surface 20, oxidation may occur on the attracted surface W2 and the contact electrode 22. This may cause a decrease in the flatness of the attracted surface W2 due to the generation of oxides, resulting in a loss of shape of the workpiece W, or an increase in electrical resistance, resulting in poor electrical conductivity. Therefore, it is necessary to prevent the electrolyte S from penetrating between the chuck surface 20 and the attracted surface W2.

[0023] In this regard, for example, a method of inserting a sealing member such as an O-ring between the chuck surface 20 and the attracted surface W2 can be considered. However, in such a method, the workpiece W may bend at the point of contact with the sealing member, which may deteriorate the flatness of the workpiece W. For this reason, when the workpiece W is a semiconductor wafer, which requires high flatness, such a method is difficult to adopt.

[0024] Another possible approach is to apply a sealant such as wax to the end surface W4 of the workpiece W. However, this approach is poor in productivity. Furthermore, if the sealant peels off during the planarization process and becomes trapped between the workpiece W and the opposing member 3, there is a risk of cracking or other problems occurring in the workpiece W.

[0025] Therefore, in this embodiment, by providing a penetration suppression portion 23 that sucks in the electrolyte S on the outer periphery of the chucking portion 21 of the chuck 2, it is possible to effectively suppress penetration of the electrolyte S into the attracted surface W2, which is the back surface of the processed surface W1 of the workpiece W. This makes it possible to achieve good planarization of the processed surface W1 without impairing productivity or the shape of the workpiece W.

[0026] Furthermore, in this embodiment, the contact electrode 22 is provided inside the suction portion 21 in the in-plane direction so that electrical continuity with the workpiece W is established by contacting the attracted surface W2 when the attracted surface W2 is attracted to the suction portion 21. That is, the contact electrode 22 is disposed inward in the in-plane direction and spaced apart from the location where the electrolyte S is sucked by the infiltration suppression portion 23. With this configuration, by spacing the contact electrode 22 away from the vicinity of the outer edge portion W3, deterioration of the contact electrode 22 due to contact with the electrolyte S can be effectively avoided.

[0027] Second Embodiment Other embodiments will be described below. Note that in the following description of the other embodiments, differences from the first embodiment will be mainly described. Furthermore, identical or equivalent parts between the first embodiment and the other embodiments are denoted by the same reference numerals. Therefore, in the following description of the other embodiments, the description of the first embodiment can be appropriately applied to components denoted by the same reference numerals as those in the first embodiment, unless there is a technical contradiction or a special additional explanation.

[0028] 3 and 4 show a configuration according to a second embodiment. In this embodiment, the suction portion 21 is formed of a conductor that is electrically connected to the workpiece W upon contact with the attracted surface W2. That is, the suction portion 21 is configured as an open-cell porous sintered metal plate or a porous carbon plate that allows air to flow through in the thickness direction. In other words, the suction portion 21 and the contact electrode 22 in FIG. 1 are integrated. In this way, by making the suction portion 21 a structure that also serves as an electrode, the configuration of the chuck 2 can be simplified. Furthermore, by making the electrical conduction state of the workpiece W uniform in the in-plane direction, it is possible to achieve good planarization of the workpiece surface W1.

[0029] The permeation suppression unit 23 is configured to suck the electrolyte S at a position corresponding to the outer edge W3 of the workpiece W. However, in this embodiment, the electrolyte suction passage 231 is formed of porous ceramic, through which the electrolyte S can flow. That is, the permeation suppression unit 23 has a configuration similar to that of a ring-shaped porous chuck. As in the first embodiment, this configuration can effectively suppress the permeation of the electrolyte S into the adsorption surface W2, which is the backside of the workpiece surface W1 of the workpiece W. This makes it possible to achieve good planarization of the workpiece surface W1 without compromising productivity or the shape of the workpiece W.

[0030] (Third embodiment) 5 and 6 show a configuration according to a third embodiment. In this embodiment, the suction unit 21 has the same configuration as that of the first embodiment. Meanwhile, the infiltration suppression unit 23 is configured to suppress infiltration of the electrolyte S into the gap between the chuck 2 and the attracted surface W2 by ejecting gas (e.g., air) at a position corresponding to the outer edge W3 of the workpiece W.

[0031] The infiltration suppression unit 23 has a configuration in which a gas ejection passage 234 consisting of a through-hole penetrating an insulating and dense ceramic layer in the thickness direction is provided. The gas ejection passage 234 is provided so that an ejection opening 235 opening on the chuck surface 20 side faces the outer edge portion W3 of the workpiece W. For example, the ejection opening 235 can be provided so that its center position in the in-plane direction substantially coincides with the end face W4. In this embodiment, a plurality of suction openings 232 are disposed at equal intervals in the circumferential direction. The ejection opening 235 can be provided in a recess 233 recessed from the chuck surface 20.

[0032] The partition wall 24 is provided to block the exchange of fluids (i.e., gas and electrolyte S) between the adsorption passage 210 in the adsorption unit 21 and the gas outlet passage 234 in the infiltration suppression unit 23. The gas outlet passage 234 in the infiltration suppression unit 23 is connected to a fluid path 26. The fluid path 26 is connected to a gas supply source (e.g., a compressor, a cylinder, etc.) not shown. The negative pressure path 25 and the fluid path 26 are provided to prevent the exchange of fluids (i.e., gas and electrolyte S) between them.

[0033] In this embodiment, by providing a permeation suppression portion 23 that ejects gas on the outer periphery of the chucking portion 21 of the chuck 2, it is possible to effectively suppress permeation of the electrolyte S into the attracted surface W2, which is the backside of the processed surface W1 of the workpiece W. This makes it possible to achieve good planarization of the processed surface W1 without impairing productivity or the shape of the workpiece W.

[0034] (Fourth embodiment) 7 and 8 show a configuration according to the fourth embodiment. In this embodiment, the suction unit 21 has a configuration similar to that of the second embodiment. That is, the suction unit 21 is formed of a conductor that is electrically connected to the workpiece W through contact with the attracted surface W2. Similarly to the third embodiment, the infiltration suppression unit 23 is configured to eject gas at a position corresponding to the outer edge W3 of the workpiece W. However, in this embodiment, the gas ejection path 234 is formed of porous ceramic that allows gas to flow. That is, the infiltration suppression unit 23 has a configuration similar to that of a ring-shaped porous chuck. This configuration effectively suppresses the infiltration of the electrolyte S into the attracted surface W2, which is the backside of the workpiece surface W1 of the workpiece W, as in the previous embodiments. This makes it possible to achieve excellent planarization of the workpiece surface W1 without sacrificing productivity or the shape of the workpiece W.

[0035] Fifth Embodiment Fig. 9 shows a configuration according to a fifth embodiment. In this embodiment, the chuck 2 is configured to be able to accommodate workpieces W of different sizes, i.e., different outer diameters. That is, the chuck 2 is provided with a plurality of suction portions 21 and intrusion suppression portions 23 to accommodate workpieces W of different outer diameters. Fig. 9 shows an example configuration of a chuck 2 capable of holding three different sizes of semiconductor wafers as workpieces W, e.g., semiconductor wafers with outer diameters of 4 inches, 6 inches, and 8 inches.

[0036] As shown in FIG. 9 , the chuck 2 has a first suction portion 211, a second suction portion 212, and a third suction portion 213 as the suction portion 21. The first suction portion 211 is provided corresponding to a first outer diameter (i.e., the smallest outer diameter) of the semiconductor wafer. That is, the first suction portion 211 is formed in an annular shape having an outer diameter equivalent to the outer diameter of a 4-inch wafer. The second suction portion 212 is provided outside the first suction portion 211 in the in-plane direction corresponding to a second outer diameter of the semiconductor wafer that is larger than the first outer diameter. That is, the second suction portion 212 is formed in an annular shape having an outer diameter equivalent to the outer diameter of a 6-inch wafer. The third suction portion 213 is provided outside the second suction portion 212 in the in-plane direction corresponding to a third outer diameter (i.e., the largest outer diameter) of the semiconductor wafer that is larger than the second outer diameter. That is, the third suction portion 213 is formed in an annular shape having an outer diameter equivalent to the outer diameter of an 8-inch wafer.

[0037] The contact electrode 22 has a bolt-like shape, including a small-diameter shaft portion 221 and a large-diameter head portion 222 provided on one axial end of the shaft portion 221. The contact electrode 22 is formed seamlessly and integrally from a good conductor metal such as copper.

[0038] The chuck 2 also has a first infiltration suppression portion 236, a second infiltration suppression portion 237, and a third infiltration suppression portion 238 as the infiltration suppression portion 23. The first infiltration suppression portion 236 is provided outside the first suction portion 211 and inside the second suction portion 212 in the in-plane direction to correspond to a first outer diameter of the semiconductor wafer. The second infiltration suppression portion 237 is provided outside the first suction portion 211 and the first infiltration suppression portion 236 and inside the third suction portion 213 in the in-plane direction to correspond to a second outer diameter of the semiconductor wafer. The third infiltration suppression portion 238 is provided outside the third suction portion 213 in the in-plane direction to correspond to a third outer diameter of the semiconductor wafer.

[0039] In this embodiment, the first infiltration suppression unit 236, the second infiltration suppression unit 237, and the third infiltration suppression unit 238 each have a gas ejection path 234. An ejection opening 235 provided at the end of the gas ejection path 234 is configured to eject gas in the negative Z-axis direction and radial direction in the figure when the chuck 2 is holding a semiconductor wafer. The "radial direction" refers to the radial direction of a substantially circular semiconductor wafer. More precisely, the "radial direction" refers to a direction extending radially from the center of a circle drawn in the XY plane, the circle having its center at the intersection of a virtual vertical line parallel to the Z-axis and the XY plane, which passes through the center of the in-plane direction of the workpiece W held by the chuck surface 20.

[0040] The chuck 2 has a first negative pressure path 251, a second negative pressure path 252, and a third negative pressure path 253 as the negative pressure path 25. The first negative pressure path 251 is connected to the first suction portion 211 so as to supply negative pressure to the first suction portion 211. The second negative pressure path 252 is connected to the second suction portion 212 so as to supply negative pressure to the second suction portion 212. The third negative pressure path 253 is connected to the third suction portion 213 so as to supply negative pressure to the third suction portion 213.

[0041] The chuck 2 has a first fluid path 261, a second fluid path 262, and a third fluid path 263 as the fluid paths 26. The first fluid path 261 is connected to the gas ejection path 234 in the first infiltration suppression part 236 to supply gas to the first infiltration suppression part 236. The second fluid path 262 is connected to the gas ejection path 234 in the second infiltration suppression part 237 to supply gas to the second infiltration suppression part 237. The third fluid path 263 is connected to the gas ejection path 234 in the third infiltration suppression part 238 to supply gas to the third infiltration suppression part 238.

[0042] In this embodiment, the chuck 2 is configured to be movable in the vertical direction while holding a semiconductor wafer. The chuck 2 is also configured to rotate the held semiconductor wafer around an axis parallel to the thickness direction. Specifically, the chuck 2 includes a main shaft portion 601, a rotation support portion 602, a wafer holding portion 603, a first flow path member 604, and a second flow path member 605.

[0043] The main shaft portion 601 is a rotational drive shaft parallel to the Z-axis direction in the figure and is formed in a substantially cylindrical shape. The main shaft portion 601 has vacuum passages 611 that constitute negative pressure path 25. In this embodiment, the main shaft portion 601 is formed with a plurality of vacuum passages 611 corresponding to a plurality of suction portions 21. That is, a first vacuum passage 611a that constitutes the vacuum passage 611 that constitutes the first negative pressure path 251, a second vacuum passage 611b that constitutes the vacuum passage 611 that constitutes the second negative pressure path 252, and a third vacuum passage 611c that constitutes the vacuum passage 611 that constitutes the third negative pressure path 253 are provided. The first vacuum passage 611a is formed as a single air passage that penetrates the main shaft portion 601 in the axial direction (i.e., the Z-axis direction in the figure). Similarly, the second vacuum passage 611b and the third vacuum passage 611c are each formed as a single air passage that penetrates the main shaft portion 601 in the axial direction. The first vacuum passage 611a, the second vacuum passage 611b, and the third vacuum passage 611c are configured so that a negative pressure supply switching device (not shown) connected to the chuck 2 can switch between supplying and not supplying negative pressure.

[0044] Main shaft portion 601 also has gas supply passages 612 that constitute fluid path 26. In the present embodiment, main shaft portion 601 is formed with a plurality of gas supply passages 612 corresponding to a plurality of infiltration suppression portions 23. That is, main shaft portion 601 is provided with first gas supply passage 612a, which is gas supply passage 612 that constitutes first fluid path 261, second gas supply passage 612b, which is gas supply passage 612 that constitutes second fluid path 262, and third gas supply passage 612c, which is gas supply passage 612 that constitutes third fluid path 263. First gas supply passage 612a, second gas supply passage 612b, and third gas supply passage 612c are each formed as a single gas passage that axially penetrates main shaft portion 601. The first gas supply path 612a, the second gas supply path 612b, and the third gas supply path 612c are configured so that a gas supply switching device (not shown) connected to the chuck 2 can switch between supplying and not supplying gas.

[0045] Furthermore, main shaft portion 601 is provided with wiring insertion hole 613 for inserting wiring (not shown) that supplies power to contact electrode 22. Wiring insertion hole 613 is a through-hole that passes through main shaft portion 601 in the axial direction, and is disposed in the center of main shaft portion 601 in the in-plane direction.

[0046] The main shaft portion 601 is rotatably supported by the rotation support portion 602. Specifically, the main shaft portion 601 has a stepped shape including a large diameter portion 614 and a small diameter portion 615. The small diameter portion 615 is provided at the axial tip of the main shaft portion 601. A flange abutment surface 616, which is an annular flat surface extending in an in-plane direction, is formed at the boundary between the large diameter portion 614 and the small diameter portion 615, i.e., at the axial tip of the large diameter portion 614. The rotation support portion 602 has a cylindrical portion 621 that houses the large diameter portion 614 and a flange portion 622 that protrudes inward from the axial tip of the cylindrical portion 621. The flange portion 622 is provided to abut against the flange abutment surface 616. The small diameter portion 615 of the main shaft portion 601 is inserted into a main shaft through-hole 623, which is a circular hole formed by the inner edge of the flange portion 622.

[0047] The wafer holding portion 603 is disposed at the lower end of the chuck 2. The wafer holding portion 603 is formed in a plate shape having a substantially flat (specifically, substantially disc-shaped) base plate portion 631. The base plate portion 631 has a pair of main surfaces, a base plate bottom surface 631a and a base plate top surface 631b. The base plate bottom surface 631a is joined to the first flow path member 604. A central protrusion 632 and an annular protrusion 633 protrude downward from the base plate top surface 631b. The central protrusion 632 is a substantially cylindrical protrusion and is disposed at the center position in the in-plane direction of the base plate portion 631. The annular protrusion 633 is disposed radially outward of the central protrusion 632. The base plate portion 631, the central protruding portion 632, and the annular protruding portion 633 are seamlessly and integrally formed from an insulating rigid material such as dense ceramic or synthetic resin.

[0048] In this embodiment, the central protrusion 632 and the three annular protrusions 633 are concentrically arranged in a bottom view seen in the positive direction of the Z axis in the figure. That is, the wafer holding part 603 is provided with three annular protrusions 633: a first annular protrusion 633a, a second annular protrusion 633b, and a third annular protrusion 633c. The first annular protrusion 633a is disposed at the innermost position in the radial direction among the three annular protrusions 633. The third annular protrusion 633c is disposed at the outermost position in the radial direction among the three annular protrusions 633.

[0049] An electrode through-hole 634 and an electrode accommodating hole 635 are provided at the axial center of the central protrusion 632, and are axially connected to each other. The electrode through-hole 634 and the electrode accommodating hole 635 are circular holes with different inner diameters and are formed coaxially. That is, the electrode through-hole 634 is the smaller inner diameter portion of the stepped through-hole that accommodates the contact electrode 22, and is provided so as to open at the chuck surface 20. The electrode through-hole 634 has an inner diameter that meets a predetermined fit intersection with the outer diameter of the shank 221 of the contact electrode 22 so as to accommodate the shank 221 of the contact electrode 22 so as to smoothly and slidably accommodate the shank 221 in the axial direction without any rattle. The electrode accommodating hole 635 is the larger inner diameter portion of the stepped through-hole that accommodates the contact electrode 22, and is provided so as to open at the base plate bottom surface 631a. The electrode accommodating hole 635 has an inner diameter slightly larger than the outer diameter of the head 222 of the contact electrode 22. One electrode through-hole 634 and one electrode accommodating hole 635 are also provided at predetermined circumferential positions of the first annular protruding portion 633a and the second annular protruding portion 633b.

[0050] Annular recesses 636 are provided between the central protrusion 632 and the first annular protrusion 633a, between the first annular protrusion 633a and the second annular protrusion 633b, and between the second annular protrusion 633b and the third annular protrusion 633c. That is, three annular recesses 636 are formed concentrically in the wafer holder 603. Negative pressure transmission holes 637 constituting the negative pressure path 25 are formed so as to penetrate from the bottom of the annular recesses 636 to the base plate bottom surface 631a. The negative pressure transmission holes 637 are through-holes that penetrate the base plate 631 in the thickness direction. Specifically, a plurality of negative pressure transmission holes 637 are disposed at equal intervals in the circumferential direction for each annular recess 636. A first suction portion 211 is fitted into the annular recess 636 between the central protrusion 632 and the first annular protrusion 633a. The second suction portion 212 is fitted into the annular recess 636 between the first annular protruding portion 633a and the second annular protruding portion 633b. The third suction portion 213 is fitted into the annular recess 636 between the second annular protruding portion 633b and the third annular protruding portion 633c.

[0051] The first flow path member 604 is disposed above the wafer holding part 603. That is, the first flow path member 604 is sandwiched between the wafer holding part 603 and the second flow path member 605. The first flow path member 604 is formed of an insulating rigid material such as dense ceramic or synthetic resin in the shape of a flat plate with its thickness direction in the Z-axis direction in the figure. The first flow path member 604 has a pair of main surfaces, namely, a base plate facing surface 640a and a flow path member connecting surface 640b. The base plate facing surface 640a is joined to the base plate bottom surface 631a.

[0052] The first flow path member 604 is provided with a negative pressure transmission groove 641 that opens toward the wafer holding unit 603 on the base plate opposing surface 640a. The negative pressure transmission groove 641 is formed in a ring shape when viewed from the bottom. The negative pressure transmission groove 641 is disposed at a position corresponding to the negative pressure transmission hole 637 in the radial direction. In other words, the negative pressure transmission groove 641 that constitutes the negative pressure path 25 is provided so as to communicate with the annular recess 636, i.e., the suction unit 21, via the negative pressure transmission hole 637 when the wafer holding unit 603 and the first flow path member 604 are joined together.

[0053] In this embodiment, three negative pressure transmission grooves 641 are arranged concentrically. The innermost of the three negative pressure transmission grooves 641 is provided to correspond to the innermost of the three annular recesses 636. Similarly, the intermediate of the three negative pressure transmission grooves 641 is provided to correspond to the intermediate of the three annular recesses 636. Furthermore, the outermost of the three negative pressure transmission grooves 641 is provided to correspond to the outermost of the three annular recesses 636. Negative pressure introduction holes 642 are formed so as to penetrate from predetermined positions in the circumferential direction of the negative pressure transmission grooves 641 to the flow path member connection surface 640b. One negative pressure introduction hole 642 constituting the negative pressure path 25 is provided for each of the three negative pressure transmission grooves 641.

[0054] The first flow path member 604 is also provided with a jetted gas transmission groove 643 that opens toward the wafer holding unit 603 on the base plate opposing surface 640a. The jetted gas transmission groove 643 is disposed at a position corresponding to the gas ejection path 234 in the radial direction. That is, the jetted gas transmission groove 643 that constitutes the fluid path 26 is provided so as to communicate with the gas ejection path 234 when the wafer holding unit 603 and the first flow path member 604 are joined together. The jetted gas transmission groove 643 is formed in a substantially C-shape in bottom view over the range in the circumferential direction where the gas ejection path 234 is provided. In other words, the jetted gas transmission groove 643 is provided in the circumferential direction, avoiding the electrode through-hole 634 and the area nearby.

[0055] In this embodiment, three ejected gas transmission grooves 643 are arranged concentrically. The innermost of the three ejected gas transmission grooves 643 is provided corresponding to the first annular protruding portion 633a. Similarly, the middle of the three ejected gas transmission grooves 643 is provided corresponding to the second annular protruding portion 633b. Furthermore, the outermost of the three ejected gas transmission grooves 643 is provided corresponding to the third annular protruding portion 633c. Ejected gas introduction holes 644 are formed so as to penetrate from predetermined positions in the circumferential direction of the ejected gas transmission groove 643 to the flow path member connecting surface 640b. The ejected gas introduction holes 644 constituting the fluid path 26 are provided one for each of the three ejected gas introduction holes 644.

[0056] A pin accommodating hole 645 and a pin through hole 646 that communicate with each other in the axial direction are provided at predetermined positions in the circumferential direction of the first flow path member 604, specifically at positions corresponding to the electrode accommodating hole 635 when the wafer holding unit 603 and the first flow path member 604 are joined. The pin accommodating hole 645 and the pin through hole 646 are circular holes with different inner diameters and are formed coaxially. That is, the pin accommodating hole 645 is a portion with a larger inner diameter of a stepped through hole that accommodates a conductive pin 647, and is positioned closer to the wafer holding unit 603 than the pin through hole 646 so as to open toward the wafer holding unit 603 at the base plate opposing surface 640a. The pin accommodating hole 645 is formed with the same diameter as the electrode accommodating hole 635. The pin through hole 646 is a portion with a smaller inner diameter that accommodates the conductive pin 647, and is provided so as to open toward the second flow path member 605 at the flow path member connecting surface 640b.

[0057] The conductive pin 647 is axially movably housed in a stepped through-hole formed by a pin housing hole 645 and a pin through-hole 646 that communicate with each other in the axial direction. The conductive pin 647 is made of a conductive metal such as copper and has a stepped cylindrical shape with a thick central portion in the axial direction. That is, the conductive pin 647 has a pin shank 647a, a pin central portion 647b, and a contact forming portion 647c. The pin shank 647a is a small-diameter portion on the base end side of the conductive pin 647 in the axial direction and is inserted into the pin through-hole 646 so as to be axially movably. The pin central portion 647b is a large-diameter portion in the axial center of the conductive pin 647 and is housed in the pin housing hole 645 so as to be axially movably. The contact forming portion 647c is a portion on the tip side of the conductive pin 647 in the axial direction and protrudes axially from the pin central portion 647b toward the head 222 of the contact electrode 22. A biasing spring 648 is disposed between the stepped portions of the pin accommodating hole 645 and the pin through-hole 646 and the pin central portion 647b. The biasing spring 648 is a coil spring wound around the pin shaft portion 647a, and is configured to bias the conductive pin 647 toward the contact electrode 22, thereby establishing contact conduction between the conductive pin 647 and the contact electrode 22.

[0058] Second flow path member 605 is disposed above first flow path member 604. That is, second flow path member 605 is sandwiched between first flow path member 604 and main shaft portion 601. Second flow path member 605 is formed from a dense metal material in the shape of a flat plate with its thickness direction in the Z-axis direction in the figure. Second flow path member 605 has a pair of main surfaces, namely flow path joining surface 650a and main shaft joining surface 650b. Flow path joining surface 650a is joined to flow path member connection surface 640b. Main shaft joining surface 650b is joined to the bottom surface of main shaft portion 601.

[0059] The second flow path member 605 is formed with a negative pressure connection passage 651 that constitutes the negative pressure path 25 and a gas connection passage 652 that constitutes the fluid path 26. The negative pressure connection passage 651 is provided so as to connect the negative pressure introduction hole 642 and the vacuum path 611 in a laminated and bonded state in which the first flow path member 604, the second flow path member 605, and the main shaft portion 601 are laminated and bonded in this order. The gas connection passage 652 is provided so as to connect the ejection gas introduction hole 644 and the gas supply path 612 in the above-mentioned laminated and bonded state.

[0060] The second flow path member 605 also has a wire penetration portion 653 and a wire accommodating portion 654, which are spaces that communicate with each other in the axial direction. The wire penetration portion 653 is disposed in the center of the second flow path member 605 in the radial direction so as to communicate with the wire insertion hole 613 in the above-mentioned laminated and joined state. Specifically, the wire penetration portion 653 is formed in the shape of a circular hole having the same diameter as the wire insertion hole 613. The wire accommodating portion 654 is a recess that opens toward the first flow path member 604 on the flow path joining surface 650a and is provided so as to communicate with all of the multiple pin through holes 646. The wire penetration portion 653 and the wire accommodating portion 654 are provided so as to be able to accommodate wires (not shown) that supply power to the contact electrodes 22.

[0061] In this embodiment, the supply of negative pressure to each of the multiple vacuum passages 611 is switched on and off depending on the size of the semiconductor wafer to be held. Specifically, for example, in the case of a 4-inch wafer, negative pressure is only supplied to the first vacuum passage 611a, and the supply of negative pressure to the second vacuum passage 611b and the third vacuum passage 611c is cut off. As a result, a suction force is generated only in the first suction portion 211 facing the 4-inch wafer. On the other hand, in the second suction portion 212 and the third suction portion 213, which do not face the 4-inch wafer in the wafer holding state and are exposed to the electrolyte S, no negative pressure is generated to generate a suction force. This effectively prevents the electrolyte S from penetrating the second suction portion 212 and the third suction portion 213 and entering the vacuum passage 611. In contrast, for example, in the case of a 6-inch wafer, negative pressure is only supplied to the first vacuum passage 611a and the second vacuum passage 611b, and the supply of negative pressure to the third vacuum passage 611c is cut off. As a result, an attraction force is generated only in the first attraction portion 211 and the second attraction portion 212 that face the 6-inch wafer. On the other hand, in the third attraction portion 213 that does not face the 6-inch wafer in the wafer holding state and is exposed to the electrolyte S, no negative pressure for generating an attraction force is generated. This effectively prevents the electrolyte S from penetrating the third attraction portion 213 and entering the vacuum passage 611.

[0062] In this embodiment, gas supply to each of the multiple gas supply paths 612 is switched on and off depending on the size of the semiconductor wafer to be held. Specifically, for example, in the case of a 6-inch wafer, gas is supplied only to the second gas supply path 612b, and gas supply to the first gas supply path 612a and the third gas supply path 612c is blocked. As a result, the second infiltration suppression part 237, which faces the edge of the 6-inch wafer, ejects gas to suppress infiltration of the electrolyte solution S between the back surface of the semiconductor wafer and the chuck surface 20. On the other hand, gas is not ejected from the first infiltration suppression part 236, which is radially inward from the wafer edge. This effectively prevents the semiconductor wafer from being subjected to a force in a direction that would peel the semiconductor wafer from the chuck surface 20 due to gas injection from the first infiltration suppression part 236, thereby maintaining a good holding state of the semiconductor wafer. Furthermore, gas is not ejected from the third infiltration suppression part 238, which is outer than the wafer edge. Therefore, it is possible to effectively prevent the electrolyte S from bubbling unintentionally and to prevent the electrolyte S from deteriorating due to oxidation when the ejected gas contains oxygen (for example, air).

[0063] In this embodiment, the energization state of the plurality of contact electrodes 22 is switched depending on the size of the semiconductor wafer to be held. Specifically, in the case of a 4-inch wafer, a machining voltage is applied to the contact electrode 22 provided on the central protruding portion 632, which abuts against the back surface of the wafer, to pass a current from the workpiece W toward the opposing member 3. On the other hand, no machining voltage is applied to the contact electrodes 22 provided on the first annular protruding portion 633a and the second annular protruding portion 633b, which may come into contact with the electrolytic solution S. Furthermore, in the case of a 6-inch wafer, a machining voltage is applied to the contact electrodes 22 provided on the central protruding portion 632 and the first annular protruding portion 633a, which abut against the back surface of the wafer. On the other hand, no machining voltage is applied to the contact electrode 22 provided on the second annular protruding portion 633b, which may come into contact with the electrolytic solution S. Furthermore, in the case of an 8-inch wafer, the machining voltage is applied to all of the contact electrodes 22 that contact the back surface of the wafer, i.e., the contact electrodes 22 provided on the central protrusion 632, the first annular protrusion 633a, and the second annular protrusion 633b. This makes it possible to apply electricity to the semiconductor wafer as uniformly as possible while avoiding oxidation of the contact electrodes 22 during machining.

[0064] In this embodiment, the wafer holder 603, which houses the contact electrode 22 slidably along the axial direction, and the first flow path member 604, which houses the conductive pin 647 movably along the axial direction, are made of an insulator. Therefore, the chuck 2 is configured as a so-called insulating chuck. Therefore, good insulation can be maintained between the outer surface of the chuck 2, which may come into contact with an operator's fingers, and the charged portion.

[0065] (Variation) The present invention is not limited to the above-described embodiment. Therefore, the above-described embodiment can be modified as appropriate. Representative modifications will be described below. In the following description of the modifications, differences from the above-described embodiment will be mainly described. Furthermore, the same reference numerals are used for parts that are identical or equivalent to each other in the above-described embodiment and the modifications. Therefore, in the following description of the modifications, the description of the above-described embodiment can be used as appropriate for components that have the same reference numerals as the above-described embodiment, unless there is a technical contradiction or special additional explanation.

[0066] The present invention is not limited to the exemplary device configurations shown in the above-described embodiments. Specifically, Figures 1 to 9 are simplified schematic diagrams for easily explaining the outline of the surface processing device 1 according to the present invention and the surface processing method that can be implemented by the surface processing device 1. Therefore, the configuration of the surface processing device 1 that is actually manufactured and sold does not necessarily match the exemplary configurations shown in Figures 1 to 9. Furthermore, the configuration of the surface processing device 1 that is actually manufactured and sold may be changed as appropriate from the exemplary configurations shown in Figures 1 to 9. The object to be processed is not limited to semiconductor wafers.

[0067] For example, in the exemplary configurations shown in FIGS. 1 to 9, the chuck 2 is located above the opposing member 3. However, the present invention is not limited to such a configuration. That is, for example, the chuck 2 may be located below the opposing member 3. In this case, the description of the up-down relationship in each of the above embodiments is reversed. Furthermore, the chuck surface 20 and the processing surface 301 do not have to be parallel to a horizontal or vertical plane, and may be inclined relative to these. Furthermore, the electrolyte S may be sprayed from a nozzle instead of being stored in a container.

[0068] The electrolytic solution S may contain an etchant component. That is, the surface processing apparatus 1 according to the present invention and the surface processing method that can be implemented thereby may polish or grind the workpiece surface W1 by selectively removing an oxide film formed by anodic oxidation using both the etchant and the opposing member 3.

[0069] The adsorption unit 21 may be configured to adsorb the workpiece W by a so-called electrostatic adsorption method. That is, the present invention is not limited to a configuration in which the workpiece W is adsorbed by negative pressure. There are no particular limitations on the type of gas ejected by the infiltration suppression unit 23, but it is preferable that the gas be one that is unlikely to cause deterioration of the electrolyte S due to oxidation or reduction (for example, an inert gas such as argon, nitrogen, etc.).

[0070] The opposing member 3 is not limited to the exemplary configuration shown in the above embodiment. Specifically, the type of abrasive grains contained in the grinding stone layer 302 is not particularly limited. The grinding stone layer 302 and the opposing electrode layer 303 do not have to be bonded in the thickness direction of the opposing member 3. More specifically, for example, the grinding stone portion and the opposing electrode portion may be adjacently disposed in an in-plane direction perpendicular to the thickness direction of the opposing member 3. That is, the surface processing device 1 may be configured so that the grinding stone portion and the opposing electrode portion alternately face specific portions of the workpiece surface W1 over time by rotating or moving the opposing member 3 relative to the chuck 2. Alternatively, the opposing electrode portion may be separate from the grinding stone portion. That is, the surface processing device 1 may be configured so that the opposing electrode portion and the grinding stone portion alternately face the entire workpiece surface W1 or specific portions thereof over time.

[0071] The present invention is also applicable to electrolytic polishing, which does not use the grinding stone layer 302. In this case, the facing member 3 functions as a counter electrode. The present invention is also applicable to CMP. CMP stands for Chemical Mechanical Polishing. However, in planarization (including electrolytic polishing, ECMP, etc.) in which an electric current is applied between the facing member 3 and the workpiece W, if the electrolyte S infiltrates the attracted surface W2, which is the backside of the workpiece surface W1, oxides are generated on the attracted surface W2 and the contact electrode 22. This can cause significant problems, such as a decrease in the flatness of the attracted surface W2, deformation of the workpiece W, or an increase in electrical resistance due to the oxides, resulting in poor electrical conductivity. In this respect, the degree of the problem is significantly different from that caused by the infiltration of the machining liquid onto the backside of the workpiece surface W1 in simple mechanical polishing or CMP. Therefore, the present invention is particularly effective in planarization (including electrolytic polishing, ECMP, etc.) in which an electric current is applied between the facing member 3 and the workpiece W.

[0072] The configuration shown in FIG. 9 that can effectively accommodate workpieces W of different sizes, i.e., outer diameters, is not limited to one that accommodates three sizes. That is, a configuration that accommodates two sizes or four or more sizes is also possible. Furthermore, the configuration shown in FIG. 9 that switches the supply mode of negative pressure or the like depending on the wafer size can also be applied to a configuration in which the infiltration suppression unit 23 sucks the electrolyte solution S. Specifically, the supply or non-supply of suction force for sucking the electrolyte solution S to each of the first infiltration suppression unit 236, the second infiltration suppression unit 237, and the third infiltration suppression unit 238 can be switched depending on the wafer size.

[0073] In the above description, multiple components that were formed seamlessly and integrally with each other may be formed by bonding separate members together. Similarly, multiple components that were formed by bonding separate members together may be formed seamlessly and integrally with each other. Furthermore, in the above description, multiple components that were formed from the same material may be formed from different materials. Similarly, multiple components that were formed from different materials may be formed from the same material.

[0074] It goes without saying that the elements constituting the above-described embodiments are not necessarily essential unless expressly stated as essential or clearly considered essential in principle. Furthermore, when numerical values ​​such as the number, amount, range, etc. of components are mentioned, the present invention is not limited to those specific numerical values ​​unless expressly stated as essential or clearly limited to specific numerical values ​​in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present invention is not limited to those shapes, directions, positional relationship, etc. unless expressly stated as essential or clearly limited to specific shapes, directions, positional relationship, etc. in principle.

[0075] The modified examples are not limited to the above examples. For example, other than those exemplified above, multiple embodiments may be combined with each other as long as there is no technical contradiction. Similarly, multiple modified examples may be combined with each other as long as there is no technical contradiction. [Explanation of symbols]

[0076] 1 Surface processing equipment 2 chucks 21 Adsorption part 23 Infiltration control part 3 opposing members 5. Voltage application section W Workpiece W1 Work surface W2 Adsorption surface W3 outer edge

Claims

1. A surface processing device (1) for flattening a work surface (W1), which is one of a pair of main surfaces of a flat workpiece (W), comprising: a chuck (2) configured to hold the workpiece while exposing the workpiece surface by attracting the other of the pair of main surfaces of the workpiece, that is, an attracting surface (W2); an opposing member (3) arranged opposite to the work surface of the workpiece held by the chuck; a current applying unit (5) configured to apply a current in the presence of an electrolytic solution (S) with the opposing member side as a cathode and the workpiece side as an anode; Equipped with The chuck is a first adsorption portion (211) and a second adsorption portion (212) as an adsorption portion (21) configured to adsorb the adsorbed surface by contacting the adsorbed surface; a first penetration suppression portion (234) and a second penetration suppression portion (235) as a penetration suppression portion (23) provided on the outside of the suction portion in the in-plane direction so as to suppress penetration of the electrolyte into a gap between the suction surface and the chuck by sucking the electrolyte or ejecting gas at a position corresponding to an outer edge portion (W3) of the workpiece in the in-plane direction along the suction surface; Equipped with the first suction portion is provided corresponding to a first outer diameter of the workpiece, the first intrusion suppression portion is provided on the outside of the first suction portion in the in-plane direction in correspondence with the first outer diameter of the workpiece, the second suction portion is provided on the outside of the first suction portion and the first penetration suppression portion in the in-plane direction, corresponding to a second outer diameter of the workpiece that is larger than the first outer diameter, The second intrusion suppression portion is provided on the outside of the first intrusion suppression portion and the second suction portion in the in-plane direction, corresponding to the second outer diameter of the workpiece. Surface processing equipment.

2. The adsorption unit is connected to a negative pressure path (25) so as to adsorb the adsorbed surface by negative pressure, The infiltration suppression unit, the adsorption unit, and the negative pressure path are provided so as to block fluid exchange between them. The surface processing device according to claim 1 .

3. the suction portion is formed of a conductor that is electrically connected to the workpiece by contact with the suction surface, The surface processing device according to claim 2 .

4. The chuck is a contact electrode (22) provided on the inside of the suction portion in the in-plane direction so as to establish electrical continuity with the workpiece by contacting the suction surface when the suction surface is suctioned to the suction portion; The surface processing device according to any one of claims 1 to 3.

5. the workpiece is a semiconductor wafer, the opposing member is provided to selectively remove oxides formed on the work surface while anodizing the work surface in the presence of the electrolytic solution; The surface processing device according to any one of claims 1 to 4.

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