Chuck Device

Abstract

To provide a chuck device capable of stably performing wafer flattening (that is, polishing or grinding) with the help of anodization.SOLUTION: A chuck device (2) is configured to hold a wafer during the wafer (W) flattening with the help of anodization. This chuck device includes a chuck cover (22), an adsorption portion (23), and a current-carrying portion (24). The adsorption portion (23) includes an adsorption surface (20) for adsorbing the wafer (W). The current-carrying portion (24) is provided in the adsorption portion (23) so as to conduct contact current with the wafer (W) attracted to the adsorption portion (23). The chuck cover (22) insulatively covers the adsorption portion (23) and the current-carrying portion (24) while exposing the adsorption surface (20).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chuck device for holding a wafer. [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. This polishing method is called ECMP. ECMP stands for Electro-Chemical Mechanical Polishing.

[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] In order to stably perform the above-described ECMP, i.e., anodization-assisted polishing, various functions are required of the chuck device that holds the wafer. For example, in addition to the function of holding the wafer, the chuck device must also have a function of passing electricity through the wafer and an insulating function from other parts of the polishing device. In this regard, Patent Document 1 does not disclose any of the required functions of such a chuck device or a specific structure for realizing these functions.

[0006] The present invention has been made in view of the circumstances exemplified above. That is, the present invention provides a chuck device that enables stable wafer planarization (i.e., polishing or grinding) using anodization, for example. [Means for solving the problem]

[0007] The chuck device (2) according to claim 1 is configured to hold a wafer (W) during planarization of the wafer using anodization. This chucking device is a suction portion (23) having a suction surface (20) for suctioning the wafer; a current-carrying portion (24) provided on the suction portion so as to come into contact with and conduct electricity to the wafer sucked on the suction portion; a chuck cover (22) that insulates and covers the suction portion and the conductive portion while exposing the suction surface; Equipped with picture, The conductive portion is embedded in the suction portion so as to be exposed on the suction surface. There are.

[0008] 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]

[0009] [Figure 1]1 is a side cross-sectional view showing a schematic configuration of a surface processing device equipped with a chuck device according to an embodiment of the present invention. [Figure 2A] 2 is a graph showing the results of evaluating the relationship between the size and shape of the current-carrying part and the variation in oxidation rate in the chuck device shown in FIG. 1. [Figure 2B] 2 is a graph showing the results of evaluating the relationship between the size and shape of the current-carrying part and the variation in oxidation rate in the chuck device shown in FIG. 1. [Figure 2C] 2 is a graph showing the results of evaluating the relationship between the size and shape of the current-carrying part and the variation in oxidation rate in the chuck device shown in FIG. 1. [Figure 3] 2 is a bottom view showing an example of an arrangement of contact electrodes in an in-plane direction when the contact electrodes shown in FIG. 1 are formed in a pin shape. FIG. [Figure 4] 1. FIG. 4 is a bottom view showing another example of arrangement of contact electrodes in the in-plane direction when the contact electrodes shown in FIG. 1 are formed in a pin shape. [Figure 5] FIG. 10 is a side cross-sectional view showing a schematic configuration of a surface processing device including a chuck device according to a modified example. [Figure 6] FIG. 10 is a side cross-sectional view showing a schematic configuration of a surface processing device including a chuck device according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] (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.

[0011] (Embodiment: Overall 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 wafer W, a flat workpiece. The "main surface" is the surface perpendicular to the thickness direction of the plate-like object and is also referred to as the "plate surface." That is, the wafer W has a pair of main surfaces, the workpiece surface W1, which is one of the pair of main surfaces, and an attached 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 of a semiconductor wafer such as a SiC wafer. In other words, the surface processing apparatus 1 is configured as an ECMP apparatus or an ECMG apparatus. ECMG stands for Electro-Chemical Mechanical Grinding.

[0012] The schematic configuration of a surface processing apparatus 1 according to this embodiment will be described below with reference to FIG. 1. For ease of explanation, a right-handed XYZ coordinate system is used as shown. In this embodiment, the positive Z-axis direction indicates the vertically upward direction, i.e., the direction opposite to the direction of gravity. The X-axis and Y-axis directions are both horizontal. Hereinafter, for convenience of explanation, the positive Z-axis direction corresponding to the vertically upward direction may be referred to simply as "upward," and the opposite direction may be referred to simply as "downward." Note that FIG. 1 is a simplified schematic diagram for the purpose of briefly explaining the present invention and is not intended to limit the present invention in any way. Therefore, it goes without saying that FIG. 1 does not necessarily correspond to a diagram showing the specific configuration of an actual manufactured and sold apparatus. This also applies to the vertical direction and the vertical positional relationships between components. The same applies to other configuration diagrams.

[0013] The surface processing apparatus 1 includes a chuck device 2, a processing pad 3, and a container 4. The chuck device 2 is configured to hold the wafer W during planarization of the wafer W using anodic oxidation. Specifically, in the example shown in FIG. 1, the chuck device 2 is configured to hold the wafer W by suctioning the attracted surface W2 of the wafer W, thereby holding the wafer W while exposing the processing surface W1 downward. The chuck device 2 is also configured to be able to rotate the held wafer W about a central axis L parallel to the up-down direction. The processing pad 3 is provided below the chuck device 2 so as to face the processing surface W1 of the wafer W held by the chuck device 2.

[0014] The container 4 is shaped like a bathtub with an upward opening. The container 4 is disposed below the chuck device 2 and the processing pad 3 to accommodate the processing pad 3 and the electrolytic solution S. 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 processing surface W1 by anodization. The chuck device 2 and / or the container 4 are provided so as to be movable up and down by a lifting mechanism (not shown). The chuck device 2 and / or the container 4 are also provided so as to be movable in the X and Y directions in the figure by a translation mechanism (not shown). The surface processing device 1 is configured to generate an oxide film on the processing surface W1 by applying a current in the presence of the electrolytic solution S, with the processing pad 3 serving as a cathode and the wafer W serving as an anode, and to selectively remove the generated oxide film using the processing pad 3.

[0015] (Chuck device) The chuck device 2 is configured to apply electricity to the wafer W while holding the wafer W by using negative pressure to attract the attracted surface W2 of the wafer W to the chucking surface 20, which is a horizontal plane exposed downward. That is, the chuck device 2 is configured as a vacuum chuck device that attracts the wafer W to the chucking surface 20 using negative pressure. The chuck device 2 is also provided with an electrode mounting hole 21. The electrode mounting hole 21 is formed in a stepped shape having a large diameter portion 21a that opens at the chucking surface 20 and a small diameter portion 21b that is provided above the large diameter portion 21a and communicates with the large diameter portion 21a. The electrode mounting hole 21 may be formed, for example, in a ring shape surrounding the central axis L. Alternatively, multiple electrode mounting holes 21 formed as stepped circular holes may be arranged two-dimensionally in an in-plane direction. The "in-plane direction" refers to a direction along the chucking surface 20, which is parallel to the XY plane in the figure. Specifically, for example, a plurality of electrode mounting holes 21 may be arranged on a circumference surrounding the central axis L.

[0016] The chuck device 2 includes a chuck cover 22, a suction portion 23, and a contact electrode 24. The chuck cover 22 is configured to insulate the suction portion 23 and the contact electrode 24 while leaving the suction surface 20 provided on the suction portion 23 exposed. That is, the chuck cover 22 has an upper cover portion 221 that covers the upper side of the suction portion 23, and a side cover portion 222 that covers the side of the suction portion 23. The chuck cover 22 is integrally formed from an insulating material (e.g., insulating ceramics).

[0017] The suction portion 23 has a suction surface 20 that suctions the wafer W by negative pressure. In the example shown in Fig. 1, the suction portion 23 is formed in a plate shape using an insulating porous material such as porous ceramic, with the suction surface 20 as the bottom surface and an internal passage through which air or negative pressure can pass in the plate thickness direction. In other words, the suction portion 23 has a configuration as a so-called porous chuck. The suction portion 23 is provided with at least a large diameter portion 21a in the electrode mounting hole 21.

[0018] The contact electrode 24 as a current-carrying part is provided in the chucking part 23 so as to come into contact with and conduct electricity to the chucking part 23, i.e., the wafer W chucking-mounted on the chucking surface 20. In the example shown in FIG. 1 , the contact electrode 24 is embedded in the chucking part 23 so as to be exposed on the chucking surface 20. Specifically, the contact electrode 24 has an outer shape corresponding to the electrode mounting hole 21 and is detachably mounted on the chucking part 23 by being fitted into the electrode mounting hole 21. That is, the contact electrode 24 has a base portion 241 fitted into the small diameter portion 21 b and an exposed portion 242 fitted into the large diameter portion 21 a. The exposed portion 242 has a contact surface 243 exposed on the chucking surface 20 and coming into contact with the attracted surface W2 of the wafer W. The contact surface 243 is provided flush with the chucking surface 20 so that the wafer W does not lift up from the chucking surface 20 when in contact with the attracted surface W2. The contact electrode 24 is integrally formed from a low-resistance conductor such as copper. When the electrode mounting hole 21 is formed in a ring shape surrounding the central axis L, the contact electrode 24 is formed in a ring shape. On the other hand, when the electrode mounting hole 21 is formed in a circular hole shape, the contact electrode 24 is formed in a pin shape.

[0019] The processing pad 3 is provided so that its upper surface, i.e., a processing surface 301, faces the processing surface W1 of the wafer W held by the chuck device 2 via the electrolytic solution S, and a current is passed through the wafer W as an anode to planarize the processing surface W1. In this embodiment, the processing pad 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 processing pad 3 has a two-layer structure in which a grinding stone layer 302 having the processing surface 301 is bonded 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 processing pad 3 may also be referred to as a "polishing pad" or a "grinding pad."

[0020] (Embodiment: Action and effect) Below, an outline of the operation of the surface processing device 1 equipped with the chuck device 2 according to this embodiment will be described together with the effects achieved by the configuration of the chuck device 2.

[0021] First, the electrolytic solution S is stored in the internal space of the container 4 containing the processing pad 3 so that the liquid level of the electrolytic solution S is above the processing surface 301. As shown in FIG. 1 , the chuck device 2, the processing pad 3, and the container 4 are vertically spaced apart, and the wafer W is attracted to the suction portion 23 of the chuck device 2 by negative pressure. Next, the chuck device 2 attracting the wafer W and the container 4 containing the processing pad 3 and the electrolytic solution S are brought closer together in the presence of the electrolytic solution S until the processing surface W1 and the processing surface 301 come into contact. Then, a current is applied with the processing pad 3 as the cathode and the wafer W as the anode. The chuck device 2 and the processing pad 3 are rotated relative to each other. The anodized processing surface W1 is thereby ground or polished by the processing pad 3, selectively removing the oxide film (i.e., oxide film-like oxide) on the processing surface W1, thereby achieving excellent planarization of the processing surface W1.

[0022] Here, in order to stably perform the above-described ECMP or ECMG, i.e., anodic oxidation-assisted planarization of the wafer W, the chuck device 2 that holds the wafer W is required to have various functions. For example, in addition to the holding function of holding the wafer W, the chuck device 2 is required to have an electrical conduction function for passing electrical current through the wafer W and an insulating function from other parts of the surface processing device 1. By realizing these functions, it becomes possible to achieve highly efficient and high-quality wafer processing.

[0023] In this regard, during processing in ECMP or ECMG, the workpiece, the wafer W, is in contact with the processing pad 3. For this reason, if a conventional vacuum chuck mechanism used in physical polishing or CMP, which are different from ECMP or ECMG, is simply used, it is difficult to apply electricity to the wafer W from outside the conventional vacuum chuck mechanism. CMP is an abbreviation for Chemical Mechanical Polishing.

[0024] Therefore, in this embodiment, the chuck device 2 includes a chuck cover 22, a suction portion 23, and a contact electrode 24. The suction portion 23 has a suction surface 20 that suctions the wafer W by negative pressure. The contact electrode 24 is provided on the suction portion 23 so as to come into contact with and be electrically connected to the wafer W suctioned to the suction portion 23. The chuck cover 22 insulatively covers the suction portion 23 and the contact electrode 24 while exposing the suction surface 20 so as to be able to hold, i.e., suction, the wafer W. In this way, by embedding the contact electrode 24 as a current-carrying portion in the suction portion 23 and insulatingly covering them with the chuck cover 22, the holding function, current-carrying function, and insulating function are satisfactorily achieved, thereby enabling stable ECMP and ECMG.

[0025] Furthermore, by ensuring the uniformity of the oxide film on the workpiece surface W1, a good surface condition can be obtained after grinding or polishing. The uniformity of the oxide film is considered to be affected by the uniformity of the current flowing through the wafer W in the in-plane direction. The uniformity of the current flowing through the wafer W in the in-plane direction is affected by the arrangement (e.g., area ratio) of the exposed portion 242 of the contact electrode 24 that is exposed on the chucking surface 20, i.e., the contact surface 243.

[0026] 2A to 2C show the results of evaluating the relationship between the size and shape of the contact surface 243 and the variation in oxidation rate. In FIGS. 2A to 2C, the vertical axis represents the variation in oxidation rate. FIG. 2A shows the relationship between the area of ​​the contact surface 243 and the variation in oxidation rate. The horizontal axis in FIG. 2A represents the electrode area, i.e., the area of ​​the contact surface 243. The in-plane shape of the contact surface 243 is also shown beside each plot in FIG. 2A. FIG. 2B shows the relationship between the area ratio of the electrode area to the chucking surface 20 and the variation in oxidation rate. The horizontal dashed line in FIG. 2B indicates the boundary of the ECMP conditions. That is, ECMP processing is possible under conditions below the horizontal dashed line in FIG. 2B. The vertical dashed line in FIG. 2B indicates the wafer retention limit. That is, the wafer W can be stably held on the chucking surface 20 under the condition on the left side of the vertical dashed line in Fig. 2B, i.e., when the area ratio is 0.83 or less. The area ratio value in the leftmost plot in Fig. 2B is 0.00017. Fig. 2C shows the relationship between the electrode shape, i.e., the shape of the contact surface 243, and the variation in the oxidation rate.

[0027] In principle, assuming a constant outer shape of the chucking surface 20, it is believed that the larger the electrode area, the better the in-plane uniformity of the current flow. However, if the electrode area is too large, the chucking state, i.e., the contact state between the contact surface 243 and the workpiece surface W1, becomes unstable, which is expected to degrade the in-plane uniformity of the current flow. Therefore, a graph with electrode area on the horizontal axis and oxidation rate variation on the vertical axis is expected to form an approximately V- or U-shape with a lower middle. In other words, the optimal electrode area is determined based on the trade-off between increasing the current flow area and decreasing chucking force as the electrode area increases. The electrode area is then optimized to the maximum area possible without impairing chucking force. The graph shown in Figure 2A is consistent with this assumption. When the area ratio was varied and the variation in oxidation rate was evaluated, as shown in FIG. 2B, the area ratio of the electrode area to the adsorption surface 20 was preferably 0.00017 to 0.83 (i.e., 0.017 to 83%), and more preferably 0.2 to 0.75 (i.e., 20 to 75%). That is, if the electrode area is S1 and the sum of the electrode area and the area of ​​the adsorption surface 20 is S2, then the area ratio DS = S1 / S2 = 0.00017 to 0.83, and more preferably 0.2 to 0.75. S2 is calculated by the following equation: S2 = πR, where R is the radius of the approximately circular adsorption surface 20. 2 is.

[0028] In FIG. 2C , Shape Example 1 has a circular electrode shape whose center is the intersection of the plane including the chucking surface 20 and the central axis L, and whose outer diameter is half the outer diameter of the chucking surface 20. Shape Example 2 has a circular shape with the same outer diameter as Shape Example 1. Comparing Shape Example 1 and Shape Example 2, Shape Example 2 has a smaller electrode area than Shape Example 1, but providing the chucking surface 20 in the center stabilizes the chucking state, i.e., the contact state between the contact surface 243 and the workpiece surface W1. Therefore, Shape Example 2 has a variation in the oxidation rate that is approximately the same as Shape Example 1 or slightly better than Shape Example 1. Shape Example 3 has the same electrode area as Shape Example 2, but the electrode shape is changed from a single ring to a double ring. Shape Example 3 has a significantly better variation in the oxidation rate than Shape Example 2. As such, even if the electrode area is the same, it is possible to improve the variation in the oxidation rate by more uniformly distributing the contact surface 243 in the in-plane direction. Specifically, for example, when the contact electrodes 24 are formed in the shape of pins having a generally cylindrical shape, it is possible to arrange one contact electrode 24 at the center of the chucking surface 20, and to arrange a plurality of contact electrodes 24 at equal intervals on a circumference surrounding the center, as shown in Fig. 3. Such a plurality of circumferential contact electrodes 24 may be arranged in multiple concentric rows. Alternatively, as shown in Fig. 4, it is possible to disperse the plurality of contact electrodes 24 as evenly as possible in the in-plane direction.

[0029] The contact electrode 24 may deteriorate due to oxidation or wear. Furthermore, there may be cases where it is desired to change the resistivity of the contact electrode 24 in order to change the oxidation conditions, i.e., the anodization current density. In this regard, by making the contact electrode 24 detachable from the chucking portion 23, i.e., easily replaceable, it becomes possible to appropriately respond to such demands.

[0030] (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.

[0031] The present invention is not limited to the exemplary device configuration shown in the above embodiment. That is, Fig. 1 is a simplified schematic diagram for easily explaining the outline of the chuck device 2 according to the present invention. Therefore, the configuration of the surface processing device 1 that is actually manufactured and sold does not necessarily match the exemplary configuration shown in Fig. 1. Furthermore, the configuration of the surface processing device 1 that is actually manufactured and sold can be changed as appropriate from the exemplary configuration shown in Fig. 1.

[0032] 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 processing pad 3.

[0033] In the above embodiment, the surface processing device 1 has a configuration in which the electrolytic solution S is stored in the internal space of the container 4 so that the liquid level of the electrolytic solution S is above the processing surface 301 of the processing pad 3, and the surface W1 to be processed is planarized. However, the present invention is not limited to such a configuration. That is, for example, the electrolytic solution S may be sprayed from a nozzle (not shown).

[0034] For example, in the exemplary configuration shown in Fig. 1, the chucking device 2 is located above the processing pad 3. However, the present invention is not limited to such a configuration. That is, for example, the chucking device 2 may be located below the processing pad 3. In this case, the description of the up-down relationship in the above embodiment is reversed. The suction 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.

[0035] In the above embodiment, the chuck device 2 is configured so that the chuck cover 22 and the suction portion 23 can rotate around the central axis L. However, the present invention is not limited to this configuration. That is, for example, the processing pad 3 may be provided so as to be rotatable around a rotation central axis parallel to the Z axis in the drawing by a rotation mechanism (not shown).

[0036] 5, the large diameter portion 21a of the electrode mounting hole 21 may be formed as a tapered hole whose in-plane width increases toward the chucking surface 20 along an axial direction parallel to the central axis L. Correspondingly, the contact electrode 24 may also be formed in a frustum shape whose in-plane width increases toward the contact surface 243 along the axial direction.

[0037] The electrode mounting hole 21 is not limited to a shape having a large diameter portion 21 a and a small diameter portion 21 b. That is, for example, the electrode mounting hole 21 may be formed so that its width in the in-plane direction is constant. Correspondingly, the contact electrode 24 may also be formed so that its width in the in-plane direction is constant.

[0038] The suction portion 23 may be formed integrally with the current-carrying portion. FIG. 6 shows a configuration corresponding to such an embodiment. That is, the suction portion 23 is formed of a conductor that is electrically connected to the wafer W upon contact with the attracted surface W2. Specifically, the suction portion 23 is configured as a porous sintered metal plate or a porous carbon plate (i.e., a conductive porous body) through which air can flow in the thickness direction. Alternatively, the suction portion 23 may be configured by forming a conductive adhesive or pressure-sensitive adhesive layer on the bottom surface of a block-shaped or plate-shaped electrode body. In this way, by making the suction portion 23 a structure that also serves as an electrode or current-carrying portion (i.e., a structure that also functions as a current-carrying portion), the configuration of the chuck device 2 can be simplified. Furthermore, by uniforming the current flow to the wafer W in the in-plane direction, it is possible to achieve good planarization of the processing surface W1.

[0039] "Anodization is used" can also be expressed as "anodic oxidation is utilized."

[0040] 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.

[0041] 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.

[0042] 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]

[0043] 1 Surface processing equipment 2. Chuck device 20 Adsorption surface 21 Mounting hole 22 Zipper cover 23 Adsorption part 24 Current-carrying electrode (current-carrying part) 241 Shaft 242 Exposed part W wafer

Claims

1. A chuck device (2) for holding a wafer (W) during anodization-assisted planarization of the wafer, comprising: a suction portion (23) having a suction surface (20) for suctioning the wafer; a current-carrying portion (24) provided on the suction portion so as to come into contact with and conduct electricity to the wafer sucked on the suction portion; a chuck cover (22) that insulates and covers the suction portion and the conductive portion while exposing the suction surface; Equipped with The conductive portion is embedded in the suction portion so as to be exposed on the suction surface. Chuck device.

2. the suction unit is configured to suction the wafer to the suction surface by negative pressure; The chuck device according to claim 1 .

3. The current-carrying unit is detachably attached to the adsorption unit. The chuck device according to claim 1 or 2.

4. The conductive portion is formed into a pin shape by a conductor. The chuck device according to claim 3 .

5. The area ratio of the exposed portion (242) of the conductive portion exposed on the adsorption surface to the adsorption surface is 0.00017 to 0.

83. The chuck device according to any one of claims 1 to 4.

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