Holding member

Abstract

To provide a holding member capable of suppressing the intensity of electrostatic attraction for each arbitrary region on a holding surface.SOLUTION: An electrostatic chuck 1 comprises a holding surface 11, a reverse surface 12 provided on the opposite side from the holding surface 11 in a thickness direction (X-axial direction), and a chuck electrode 50 arranged between the holding surface 11 and the reverse surface 12, and holds a semiconductor wafer W on the holding surface 11, wherein the chuck electrode 50 has a first chuck electrode 51 which is divided into two or more and arranged not overlapping with one another in thickness-directional view, and a second chuck electrode 52 which is at least arranged in a region more on the side of the reverse surface 12 than the first chuck electrode 51 and in a region where the first chuck electrode 51 is not arranged in thickness-directional view.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a holding member for holding an object. [Background technology]

[0002] In the semiconductor manufacturing process, an electrostatic chuck (holding member) is used to hold a semiconductor wafer. This electrostatic chuck generates an electrostatic attractive force to hold the semiconductor wafer on the holding surface. The electrostatic chuck is required to generate the electrostatic attractive force uniformly on the holding surface to prevent localized variation in the semiconductor wafer adsorption force within the surface.

[0003] For this reason, for example, the electrostatic chuck described in Patent Document 1 is provided with finely divided pixel electrodes. In this electrostatic chuck, the ON / OFF of each pixel electrode is controlled to generate a uniform electrostatic attractive force on the holding surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6126747 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above electrostatic chuck, there is a gap between the pixel electrodes, and no electrostatic attraction occurs in the gap, i.e., in the area where no electrodes are arranged. Here, when a process is performed on a semiconductor wafer held by the electrostatic chuck, the semiconductor wafer may be partially warped (for example, the outer periphery). When the semiconductor wafer is warped in this manner, there is a risk that the process cannot be performed accurately.

[0006] In the electrostatic chuck, if the semiconductor wafer is warped near the region directly above the gap between the pixel electrodes, the electrostatic attraction near that region is weaker than other regions, and therefore the warping of the semiconductor wafer cannot be suppressed. In addition, in recent years, the shape of semiconductor wafers has become more complex, and there is a demand for locally making the electrostatic attraction stronger than other portions.

[0007] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a holding member that can control the magnitude of electrostatic attraction for each arbitrary region on the holding surface. [Means for solving the problem]

[0008] In order to solve the above problems, one aspect of the present disclosure is to A holding member comprising a first surface, a second surface provided on an opposite side to the first surface in a thickness direction, and a chuck electrode disposed between the first surface and the second surface, the holding member holding an object on the first surface, The chuck electrode is A first chuck electrode that is divided into two or more parts and arranged so as not to overlap with each other when viewed in the thickness direction; and a second chuck electrode that is arranged on the second surface side of the first chuck electrode and at least in an area where the first chuck electrode is not arranged as viewed in the thickness direction.

[0009] In this holding device, the chuck electrode includes a first chuck electrode disposed on the first surface side and a second chuck electrode disposed on the second surface side, and therefore the electrostatic attractive force generated by the first chuck electrode is greater than the electrostatic attractive force generated by the second chuck electrode.

[0010] Here, the first chuck electrode is divided into two or more (plural) parts and arranged so as not to overlap when viewed in the thickness direction. A second chuck electrode is arranged in an area where the first chuck electrode is not arranged (i.e., between the first chuck electrodes) when viewed in the thickness direction. By arranging the second chuck electrode so as to overlap the first chuck electrode when viewed in the thickness direction, the electrostatic attractive force in the vicinity directly above the first chuck electrode can be made stronger.

[0011] This allows the electrostatic attractive force to be precisely controlled by the first chuck electrode, while the electrostatic attractive force can be generated by the second chuck electrode in the region where the first chuck electrode is not disposed (the gap between the first chuck electrodes). Therefore, the electrostatic attractive force can be precisely controlled in accordance with the shape of the object, while the chuck electrode generates an electrostatic attractive force necessary and sufficient for holding the object.

[0012] In the above-mentioned holding device, The first chuck electrode is preferably divided into a large number of parts, which means that the first chuck electrode is divided into 10 or more parts (two or more digits).

[0013] By dividing the first chuck electrode into smaller parts and arranging it in this manner, the electrostatic attractive force generated by the first chuck electrode can be controlled more finely and with higher precision on the first surface in accordance with the shape of the object to be held.

[0014] In any one of the above-mentioned holding devices, It is preferable that the first chuck electrodes are arranged at different positions in the thickness direction.

[0015] This allows the distance from the first chuck electrode to the first surface to be changed arbitrarily, and therefore the strength of the electrostatic attraction on the first surface can be adjusted with precision. That is, by arranging the first chuck electrode so that the distance to the first surface is small, the electrostatic attraction on the first surface can be made strong, and by arranging the first chuck electrode so that the distance to the first surface is large, the electrostatic attraction on the first surface can be made weak. In addition, since the gap between the first chuck electrodes can be made small, the occupancy rate of the first chuck electrode on the first surface can be made large (the area ratio can be increased) when viewed in the thickness direction. Therefore, the area on the first surface where the electrostatic attraction by the first chuck electrode is not generated can be made small. As a result, the electrostatic attraction for holding the object on the first surface can be more finely controlled in accordance with the shape of the object.

[0016] In any one of the above-mentioned holding devices, Of the first chuck electrodes, the one disposed on the outer periphery is preferably located closest to the first surface.

[0017] As a result, the electrostatic attraction is strongest on the outer periphery of the first surface, so that the outer edge of the object can be held firmly. Therefore, warping of the object held on the first surface can be effectively suppressed, and leakage of gas flowing into the minute space between the first surface and the object can also be suppressed. As a result, processing of the object held on the first surface can be performed with high accuracy (for example, the creation of a uniform resist film and the uniformity of the etching rate). Effect of the Invention

[0018] According to the present disclosure, it is possible to provide a holding member capable of controlling the magnitude of electrostatic attraction for each arbitrary region on the holding surface. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic perspective view of an electrostatic chuck according to a first embodiment. [Diagram 2] 1 is a schematic configuration diagram of an XZ cross section of an electrostatic chuck according to a first embodiment. FIG. [Diagram 3] 4 is a diagram showing the arrangement of a first chuck electrode and a second chuck electrode as viewed in the Z-axis direction. FIG. [Figure 4] FIG. 13 is a schematic configuration diagram of an electrostatic chuck of a modified example taken along an XZ cross section. [Diagram 5] 4 is a diagram showing the arrangement of a first chuck electrode and a second chuck electrode as viewed in the Z-axis direction. FIG. [Figure 6] FIG. 11 is a cross-sectional view showing a schematic configuration of an XZ cross section of an electrostatic chuck according to a second embodiment. [Figure 7] 4 is a diagram showing the arrangement of a first chuck electrode and a second chuck electrode as viewed in the Z-axis direction. FIG. [Figure 8] FIG. 13 is a diagram showing an example in which a first chuck electrode is divided into smaller parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A holding member according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In this embodiment, the present disclosure will be described as being applied to an electrostatic chuck used in a semiconductor manufacturing device such as a film forming device (such as a CVD film forming device or a sputtering film forming device) or an etching device (such as a plasma etching device).

[0021] 1 to 3, an electrostatic chuck 1 according to the present embodiment will be described. The electrostatic chuck 1 according to the present embodiment is a device that adsorbs and holds a semiconductor wafer W (object) by electrostatic attraction, and is used, for example, to fix the semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing device. As shown in FIG. 1, the electrostatic chuck 1 has a plate-shaped member 10 (holding member), a base member 20, and a bonding layer 30 that bonds the plate-shaped member 10 and the base member 20 together.

[0022] In the following description, for convenience of explanation, the X, Y and Z axes are defined as shown in Fig. 1. Here, the Z axis is an axis in the axial direction of the electrostatic chuck 1 (the vertical direction in Fig. 1) and is an example of the "thickness direction" in the present disclosure. The X and Y axes are axes in the radial direction of the electrostatic chuck 1.

[0023] As shown in Fig. 1, the plate-shaped member 10 is a disk-shaped member and is made of ceramics. Specifically, the plate-shaped member 10 has a stepped disk shape in which two disks of different diameters are overlapped with a common central axis (more specifically, a disk-shaped upper stage portion 10a having a smaller diameter is overlapped on a disk-shaped lower stage portion 10b having a larger diameter). In this way, the lower stage portion 10b is provided on the opposite side of the holding surface 11 side with respect to the upper stage portion 10a in the thickness direction of the plate-shaped member 10 (a direction that coincides with the Z-axis direction, a vertical direction), and has a larger outer periphery than the upper stage portion 10a when viewed from the thickness direction of the plate-shaped member 10.

[0024] As the ceramic, various ceramics are used. From the viewpoints of strength, abrasion resistance, plasma resistance, etc., for example, aluminum oxide (alumina, Al 2 O 3 It is preferable to use ceramics mainly composed of aluminum nitride (AlN) or aluminum nitride (AlN). Note that the main component here means the component with the highest content (for example, a component with a volume content of 90 vol% or more).

[0025] 1 to 3, the plate-shaped member 10 has a holding surface 11 (upper surface) for holding a semiconductor wafer W, and a lower surface 12 provided on the opposite side to the holding surface 11 in the thickness direction (i.e., the Z-axis direction) of the plate-shaped member 10. In this embodiment, the upper portion 10a has the holding surface 11. The holding surface 11 is an example of a "first surface" in the present disclosure, and the lower surface 12 is an example of a "second surface" in the present disclosure.

[0026] Here, the diameter of the plate-like member 10 is such that the lower part 10b is larger than the upper part 10a. For example, the upper part 10a is about 150 mm to 300 mm, and the lower part 10b is about 180 mm to 400 mm. The thickness of the plate-like member 10 is, for example, about 2 mm to 6 mm. Note that the thermal conductivity of the plate-like member 10 preferably falls within the range of 10 W / mK to 50 W / mK (more preferably, 18 W / mK to 30 W / mK).

[0027] Such a plate-like member 10 is provided with a chuck electrode 50 inside thereof. The chuck electrode 50 is formed of a conductive material (for example, tungsten, molybdenum, etc.). The chuck electrode 50 has a first chuck electrode 51 and a second chuck electrode 52. Note that the plate-like member 10 is an example of the "holding member" of the present disclosure.

[0028] The first chuck electrode 51 is divided into two or more parts (five parts in this embodiment: see FIG. 3), and is arranged on the holding surface 11 side of the second chuck electrode 52 so as not to overlap in the Z-axis direction view. In this embodiment, as the first chuck electrode 51, four first chuck electrodes 51a are arranged at equal intervals (about 90-degree intervals) on the outer peripheral side, and one first chuck electrode 51b is arranged at the center. The first chuck electrode 51a is electrically connected to the second chuck electrode 52 via a via 61a. The first chuck electrode 51b is electrically connected to the second chuck electrode 52 via a via 61b. Note that the shape (viewed in the Z-axis direction) of the first chuck electrode 51 is not particularly limited, and may be a shape other than a circular shape as shown in FIG. 3, such as a square or a triangle.

[0029] And, as shown in FIG. 2, the first chuck electrode 51a is located on the holding surface 11 side of the first chuck electrode 51b. That is, the insulation layer thickness A of the first chuck electrode 51a is thinner than the insulation layer thickness B of the first chuck electrode 51b (A < B). Therefore, the electrostatic attraction generated in the first chuck electrode 51a is stronger than the electrostatic attraction generated in the first chuck electrode 51b. As a result, a strong electrostatic attraction can be generated on the outer peripheral side on the holding surface 11.

[0030] On the other hand, the second chuck electrode 52 is disposed closer to the lower surface 12 than the first chuck electrode 51. That is, the second chuck electrode 52 is disposed at a different height position (different layer) in the Z-axis direction relative to the first chuck electrode 51. The second chuck electrode 52 has a circular shape occupying almost the entire area of ​​the holding surface 11 as viewed in the Z-axis direction, as shown in Fig. 3. As a result, the second chuck electrode 52 is disposed in an area where the first chuck electrode 51 is not disposed (the gap between the first chuck electrodes 51) as viewed in the Z-axis direction, and is disposed so as to overlap the first chuck electrode 51.

[0031] In this embodiment, the second chuck electrode 52 is formed in a circular shape occupying almost the entire area of ​​the holding surface 11, but the second chuck electrode 52 may have any shape that allows it to be positioned at least in the gap between the first chuck electrodes 51 when viewed in the Z-axis direction, and may be, for example, divided into multiple parts.

[0032] The second chuck electrode 52 is electrically connected to a power supply terminal 65 connected to an external power source through the via 62 on the side opposite to the surface to which the vias 61a and 61b are connected. As a result, when a voltage is applied from the external power source to the chuck electrode 50 (the first chuck electrode 51 and the second chuck electrode 52), an electrostatic attractive force is generated in the chuck electrode 50, and the semiconductor wafer W is attracted to and held on the holding surface 11 by this electrostatic attractive force.

[0033] The base member 20 is disposed on the side opposite to the holding surface 11 with respect to the plate-like member 10. The base member 20 is formed, for example, in a cylindrical shape. The base member 20 is formed, for example, from a metal (for example, aluminum or an aluminum alloy), but may be formed from a material other than metal.

[0034] 1 and 2, the base member 20 has an upper surface 21 and a lower surface 22 provided on the opposite side to the upper surface 21 in the thickness direction (i.e., the Z-axis direction) of the base member 20. The upper surface 21 of the base member 20 is thermally connected to the lower surface 12 of the plate-like member 10 via a bonding layer 30.

[0035] The diameter of the base member 20 is, for example, about 180 mm to 400 mm. The thickness (dimension in the Z-axis direction) of the base member 20 is, for example, about 20 mm to 50 mm. The thermal conductivity of the base member 20 (assumed to be aluminum) is desirably within the range of 160 mm to 250 W / mK (preferably, about 230 W / mK).

[0036] As shown in Figs. 1 and 2, the bonding layer 30 is disposed between the lower surface 12 of the plate-like member 10 and the upper surface 21 of the base member 20, and bonds the plate-like member 10 and the base member 20 in a heat-transferable manner. The bonding layer 30 is made of a resin adhesive such as silicone resin, acrylic resin, or epoxy resin. The thickness (dimension in the Z-axis direction) of the bonding layer 30 is, for example, about 0.1 mm to 1.5 mm. The thermal conductivity of the bonding layer 30 is, for example, 1.0 W / mK. The thermal conductivity of the bonding layer 30 (assuming a silicone resin) is desirably within a range of 0.1 W / mK to 2.0 W / mK (preferably, 0.5 W / mK to 1.5 W / mK).

[0037] As described above, the electrostatic chuck 1 of the present embodiment includes, as the chuck electrode 50, a first chuck electrode 51 divided into a plurality of electrodes and a second chuck electrode 52 arranged so as to overlap the first chuck electrode 51 and in the gaps between the first chuck electrodes 51 as viewed in the Z-axis direction. Therefore, while the electrostatic attractive force is finely controlled by the first chuck electrode 51 divided into a plurality of electrodes, the electrostatic attractive force can be generated by the second chuck electrode 52 in the gaps between the first chuck electrodes 51. In addition, since the second chuck electrode 52 is arranged so as to overlap the first chuck electrode 51 as viewed in the Z-axis direction, the electrostatic attractive force can be made stronger in the vicinity of directly above the first chuck electrode 51 on the holding surface 11.

[0038] As a result, while the electrostatic attractive force is precisely controlled by the first chuck electrode 51, the second chuck electrode 52 can generate an electrostatic attractive force in an area where the first chuck electrode 51 is not arranged (the gap between the first chuck electrodes 51). Therefore, the chuck electrode 50 can generate an electrostatic attractive force necessary and sufficient for holding the semiconductor wafer W over the entire holding surface 11, while precisely controlling the electrostatic attractive force in accordance with the shape of the semiconductor wafer W.

[0039] Moreover, the first chuck electrodes 51a, 51b are arranged at different positions in the Z-axis direction. Therefore, the strength of the electrostatic attractive force on the holding surface 11 can be adjusted with high precision. By arranging the first chuck electrodes 51a, 51b at different positions in the Z-axis direction, the gap between the first chuck electrodes can be made smaller than when the first chuck electrodes are arranged at the same position in the Z-axis direction, and therefore the occupancy rate of the first chuck electrode 51 on the holding surface 11 can be increased (the area rate can be increased). Therefore, the area on the holding surface 11 where the electrostatic attractive force by the first chuck electrode 51 is not generated can be made smaller. This allows the electrostatic attractive force to be controlled more precisely in accordance with the shape of the semiconductor wafer W.

[0040] Furthermore, in this embodiment, since the electrostatic attractive force by the first chuck electrode 51a is stronger than the electrostatic attractive force by the first chuck electrode 51b, the outer edge portion of the semiconductor wafer W can be firmly held. Therefore, warping of the semiconductor wafer W held on the holding surface 11 can be suppressed. This can suppress leakage of gas flowing into the minute space between the holding surface 11 and the semiconductor wafer W. As a result, processing of the semiconductor wafer W held on the holding surface 11 can be performed with high accuracy (for example, formation of a uniform resist film, uniform etching rate, etc.).

[0041] As described above, according to the electrostatic chuck 1 of the present embodiment, the first chuck electrode 51 is divided into two or more (a plurality of) parts and arranged so as not to overlap in the Z-axis direction view. In the region where the first chuck electrode 51 is not arranged in the Z-axis direction view (that is, the gap between the first chuck electrodes 51), the second chuck electrode 52 is arranged. Therefore, while finely controlling the electrostatic attraction force by the first chuck electrode 51, in the region where the first chuck electrode 51 is not arranged, the electrostatic attraction force can be generated by the second chuck electrode 52. Accordingly, the chuck electrode 50 including the first chuck electrode 51 and the second chuck electrode 52 can finely control the electrostatic attraction force according to the shape of the semiconductor wafer W while generating a sufficient electrostatic attraction force necessary for holding the semiconductor wafer W on the holding surface 11.

[0042] (Modification example) Here, a modification example of the first embodiment will be described with reference to FIGS. 4 and 5. In this modification example, as shown in FIG. 4, the first chuck electrode 51a arranged on the outer peripheral side of the first chuck electrode 51 is arranged closest to the holding surface 11 side, and the first chuck electrodes 51b and 51c arranged on the inner peripheral side thereof are arranged such that the distance from the holding surface 11 gradually increases. Therefore, the insulation layer thickness A of the first chuck electrode 51a, the insulation layer thickness B of the first chuck electrode 51b, and the insulation layer thickness C of the first chuck electrode 51c satisfy A < B < C. Thereby, the electrostatic attraction force generated on the holding surface 11 can be gradually increased toward the outer peripheral side.

[0043] Accordingly, since the outer edge portion of the semiconductor wafer W can be held more firmly on the holding surface 11, the warpage of the semiconductor wafer W held on the holding surface 11 can be effectively suppressed, and the leakage of the gas flowing through the minute space between the holding surface 11 and the semiconductor wafer W can be further suppressed. Thereby, the process treatment for the semiconductor wafer W held on the holding surface 11 can be performed with higher accuracy.

[0044] In this modified example, the first chuck electrodes 51a, 51b, and 51c are each formed and arranged as a single annular electrode, but each of the first chuck electrodes 51a, 51b, and 51c can also be divided into multiple electrodes and arranged.

[0045] [Second embodiment] Next, a second embodiment will be described. The second embodiment has the same basic configuration as the first embodiment, but is different in that the chuck electrode is a bipolar electrode instead of a monopolar electrode. Therefore, the same reference numerals are used to designate the same components as those in the first embodiment, and the description is omitted as appropriate, and the differences from the first embodiment will be mainly described.

[0046] As shown in FIGS. 6 and 7, the electrostatic chuck 1a of the second embodiment includes a pair of positive and negative chuck electrodes 150a (positive electrode) and 150b (negative electrode). The positive chuck electrode 150a includes a first chuck electrode 151a divided into a plurality of electrodes and a second chuck electrode 152a disposed on the lower surface 12 side of the first chuck electrode 151a. In this embodiment, the first chuck electrode 151a includes three first chuck electrodes 151aa disposed on the outer periphery side and one first chuck electrode 151ab disposed on the inner side. The first chuck electrode 151aa is disposed closer to the holding surface 11 than the first chuck electrode 151ab. Therefore, on the holding surface 11, the electrostatic attractive force generated by the first chuck electrode 151aa is stronger than the electrostatic attractive force generated by the first chuck electrode 151ab. These first chuck electrodes 151aa, 151ab are electrically connected to a second chuck electrode 152a through vias 61aa, 61ab. The second chuck electrode 152a has a semicircular shape that includes all of the first chuck electrodes 151aa and 151ab within its region when viewed in the Z-axis direction, and is electrically connected to a positive power supply terminal 65a through a via 62a.

[0047] Similarly, the negative chuck electrode 150b includes a first chuck electrode 151b divided into a plurality of parts and a second chuck electrode 152b disposed on the lower surface 12 side of the first chuck electrode 151b. In this embodiment, the first chuck electrode 151b includes three first chuck electrodes 151ba disposed on the outer periphery side and one first chuck electrode 151bb disposed on the inner side. The first chuck electrode 151ba is disposed closer to the holding surface 11 than the first chuck electrode 151bb. Therefore, on the holding surface 11, the electrostatic attraction generated by the first chuck electrode 151ba is stronger than the electrostatic attraction generated by the first chuck electrode 151bb. These first chuck electrodes 151ba and 151bb are electrically connected to the second chuck electrode 152b through vias 61ba and 61bb. This second chuck electrode 152b has a semicircular shape that includes all of the first chuck electrodes 151ba and 151bb within its area when viewed in the Z-axis direction, and is electrically connected to the positive power supply terminal 65b through a via 62b.

[0048] In the electrostatic chuck 1a of the second embodiment, a voltage is applied from an external power source to the chuck electrodes 150a and 150b, thereby generating an electrostatic attractive force between the chuck electrodes 150a and 150b, and the semiconductor wafer W is attracted to and held on the holding surface 11 by this electrostatic attractive force.

[0049] In the electrostatic chuck 1a of the second embodiment, similarly to the first embodiment, the electrostatic attractive force can be precisely controlled by the first chuck electrodes 151a, 151b, while the electrostatic attractive force can be generated by the second chuck electrodes 152a, 152b in the region where the first chuck electrodes 151a, 151b are not arranged. Therefore, even with a pair of chuck electrodes 150a, 150b (bipolar chuck electrodes) including the first chuck electrodes 151a, 151b and the second chuck electrodes 152a, 152b, it is possible to precisely control the electrostatic attractive force in accordance with the shape of the semiconductor wafer W while generating an electrostatic attractive force necessary and sufficient for holding the semiconductor wafer W on the holding surface 11.

[0050] The above-described embodiment is merely an example, does not limit the present disclosure in any way, and various improvements and modifications are possible without departing from the spirit of the present disclosure. For example, in the above-described embodiment, the first chuck electrode is divided into five or six parts, but the first chuck electrode may be divided into two or more parts. As shown in FIG. 8, the first chuck electrode 51 is preferably divided (subdivided into many parts) into ten or more parts (two or more digits). This allows the electrostatic attractive force generated on the holding surface 11 to be controlled more precisely and with higher accuracy in accordance with the shape of the semiconductor wafer W.

[0051] In addition, in the above embodiment, an example was given of a case in which some of the first chuck electrodes were arranged at different positions in the Z-axis direction (in different layers), but all of the first chuck electrodes may be arranged at the same positions in the Z-axis direction (in the same layer). [Explanation of symbols]

[0052] 1. Electrostatic chuck 10 Plate-shaped member 11 Holding surface 12 Bottom side 50 Chuck electrode 51 First chuck electrode 52 Second chuck electrode 150a Chuck electrode (positive electrode) 150b Chuck electrode (negative electrode) 151a First chuck electrode (positive electrode) 151b First chuck electrode (negative electrode) 152a Second chuck electrode (positive electrode) 152b Second chuck electrode (negative electrode) W Semiconductor wafer

Claims

1. A holding member comprising a first surface, a second surface provided on an opposite side to the first surface in a thickness direction, and a chuck electrode disposed between the first surface and the second surface, the holding member holding an object on the first surface, The chuck electrode is a first chuck electrode that is divided into two or more parts and arranged so as not to overlap with each other when viewed in the thickness direction; a second chuck electrode disposed at least in a region on the second surface side of the first chuck electrode and in which the first chuck electrode is not disposed as viewed in the thickness direction; A holding member characterized by:

2. 2. The holding member according to claim 1, The first chuck electrode is divided into a number of parts. A holding member characterized by:

3. 2. The holding member according to claim 1, The first chuck electrodes are disposed at different positions in the thickness direction. A holding member characterized by:

4. In any one of the holding members according to claims 1 to 3, The first chuck electrode disposed on the outer periphery is located closest to the first surface. A holding member characterized by:

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