Holding device

Abstract

To provide a holding device which allows improvement in insulation quality.SOLUTION: An electrostatic chuck 1 for holding a semiconductor wafer W on a holding surface of a plate-like member 10 comprises: the plate-like member 10 having the holding surface and a lower surface 12; a metal base member 20 having an upper surface 21, a lower surface 22 provided on the opposite side to the upper surface 21, and a through-hole 25; a bonding layer 40 which bonds the plate-like member 10 to the base member 20; and an annular insulation sleeve 30 disposed around the through-hole 25. The insulation sleeve 30 has an annular protruding part 31 which protrudes outward. The protruding part 31 has: an upper surface 31a on the plate-like member 10 side; a lower surface 31b on the base member 20 side; and a side peripheral surface 31c connecting the upper surface 31a to the lower surface 31b. An adhesive part 70 is formed to bond the insulation sleeve 30 to the plate-like member 10. The adhesive part 70 has a first adhesive part 71 and a second adhesive part 72.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A known holding device is, for example, an electrostatic chuck described in Patent Document 1. This electrostatic chuck includes a mounting table (plate-shaped member) that holds an object, and a metal base plate (base member) joined to the mounting table. An electrostatic electrode is disposed inside the mounting table, and is connected to a connection electrode provided on the bottom surface of the mounting table.

[0003] On the other hand, a through hole is formed in the base plate, and a power supply terminal is disposed in the through hole. This power supply terminal is joined to a connection terminal provided on the mounting table. Then, to ensure insulation between the connection electrode and the power supply terminal and the base plate, a cylindrical insulating part (insulating member) is disposed in the through hole of the base plate. This cylindrical insulating part is fixed to the mounting table using an adhesive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6308871 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the electrostatic chuck described above, a paste-like adhesive is filled into the bonding portion to fix the insulating member to the plate-like member and then hardened, and air may become trapped during filling, forming bubbles inside the hardened adhesive. Furthermore, when used in recent high-voltage environments, if bubbles are formed inside the adhesive, a discharge path is formed through the bubbles, which may reduce the insulating properties and cause dielectric breakdown.

[0006] Therefore, the present disclosure has been made to solve the above-mentioned problems, and has an object to provide a holding device that can improve insulation properties. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present disclosure is to a plate-like member including a first surface, a second surface provided on the opposite side of the first surface, and a hole opening in the second surface; a metal base member including a third surface, a fourth surface provided on the opposite side of the third surface, and a through hole penetrating the third surface and the fourth surface and communicating with the hole; a bonding layer disposed between the second surface and the third surface and bonding the plate-like member and the base member; an annular insulating member disposed in the through hole, A holding device for holding an object on the first surface of the plate-like member, the insulating member has an annular protrusion that protrudes outward, the protrusion has a surface on the plate-like member side, a surface on the base member side, and a side circumferential surface connecting the surface on the plate-like member side and the surface on the base member side, an adhesive portion is formed to join the insulating member to the plate-like member; The adhesive portion is a first adhesive portion that is filled between the surface of the protrusion that faces the plate-like member and the side peripheral surface and the plate-like member; The protruding portion has a surface on the base member side, the second surface, and a second adhesive portion in contact with the first adhesive portion.

[0008] In this holding device, when the insulating member is fixed to the plate-like member, the first adhesive portion is filled between the plate-like member-side surface and the peripheral side surface of the protrusion, so that there is no gap between the insulating member and the plate-like member, but air may get trapped and form bubbles inside. In that case, if only the first adhesive portion is used, a discharge path may be formed via the bubbles formed inside, which could cause insulation breakdown.

[0009] On the other hand, the second adhesive portion is arranged so as to contact the surface of the protruding portion facing the base member, the second surface, and the first adhesive portion, so that the second adhesive portion is continuously attached to both the protruding portion of the insulating member and the second surface of the plate-like member so as to cover the first adhesive portion.

[0010] Therefore, because the adhesive portion has a first adhesive portion and a second adhesive portion, the discharge path via the adhesive portion is formed so as to detour along the surface of the second adhesive portion to the insulating member side even if air bubbles are present inside the first adhesive portion. This allows the second adhesive portion to extend the insulation distance, thereby improving insulation properties.

[0011] In the above-mentioned holding device, The second adhesive portion is preferably a part of the joining layer.

[0012] By arranging the bonding layer so that it penetrates into the through hole, a part of the bonding layer can form a second adhesive portion. By forming such a second adhesive portion, even if air bubbles are present inside the first adhesive portion, the path of dielectric breakdown can be reliably formed so that it detours along the surface of the second adhesive portion toward the insulating member side. Therefore, the insulation distance can be reliably increased, thereby further improving insulation properties.

[0013] In any of the above-mentioned holding devices, It is preferable that no air bubbles exist inside the second adhesive portion.

[0014] By using a sheet-like adhesive for the second adhesive portion, it is possible to achieve an adhesive portion that is free of air bubbles. Furthermore, because there are no air bubbles inside the second adhesive portion, a path for dielectric breakdown is formed that bypasses the surface of the second adhesive portion toward the insulating member. Therefore, even if air bubbles are present inside the first adhesive portion, the second adhesive portion can extend the insulation distance, thereby improving insulation properties.

[0015] In any of the above-mentioned holding devices, It is preferable that the end face of the insulating member on the second surface side extends to the bottom surface of the hole that opens into the second surface.

[0016] This allows the insulating member to completely cover the area around the connection between the power supply terminal placed inside the insulating member and the terminal pad placed on the bottom of the hole and connected to the power supply terminal. In other words, the terminal pad and the power supply terminal are completely covered with the insulating member. This improves insulation compared to when the area around the connection between the terminal pad and the power supply terminal is covered only with adhesive.

[0017] The insulating member may extend to the fourth surface and be disposed over the entire area of ​​the through hole, thereby covering the entire inner circumferential surface of the through hole in the base member, thereby further improving insulation.

[0018] In any of the above-mentioned holding devices, a step portion is formed in the hole of the plate-like member, It is preferable that the surface of the protrusion on the plate-like member side is in contact with the step portion.

[0019] The surface of the protrusion facing the plate-like member and the step of the hole are polished. Therefore, by bringing the surface of the protrusion facing the plate-like member into contact with the step, the insulating member can be positioned with the polished surfaces abutting each other. This improves the accuracy of the amount of protrusion from the fourth surface (bottom surface) of the base member. Therefore, the end of the insulating member can be positioned flush with the fourth surface (bottom surface) of the base member, improving insulation. [Effects of the Invention]

[0020] According to the present disclosure, it is possible to provide a holding device that can improve insulation properties. [Brief explanation of the drawings]

[0021] [Figure 1]FIG. 1 is a schematic perspective view of an electrostatic chuck according to a first embodiment. [Figure 2] 1 is a schematic configuration diagram of an XZ cross section of an electrostatic chuck according to a first embodiment. [Figure 3] FIG. 3 is an enlarged view of part A shown in FIG. 2. [Figure 4] FIG. 10 is a diagram showing a discharge path when bubbles are generated in an adhesive portion (first adhesive portion) of a conventional electrostatic chuck. [Figure 5] FIG. 4 is a diagram showing a discharge path when bubbles are generated in a first adhesive portion of the electrostatic chuck of the first embodiment. [Figure 6] FIG. 10 is a schematic diagram of the XZ cross section near the adhesive portion in the electrostatic chuck of the second embodiment. [Figure 7] FIG. 11 is a schematic configuration diagram of an XZ cross section near an adhesive portion in an electrostatic chuck according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] A holding device according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In this embodiment, the holding device will be described by taking as an example an electrostatic chuck used in semiconductor manufacturing equipment such as a film forming apparatus (such as a CVD film forming apparatus or a sputtering film forming apparatus) or an etching apparatus (such as a plasma etching apparatus).

[0023] 1 to 4, 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 attracts 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 includes a plate-like member 10, a base member 20, and a bonding layer 40 that bonds the plate-like member 10 and the base member 20 together.

[0024] 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 the X and Y axes are axes in the radial direction of the electrostatic chuck 1.

[0025] As shown in Fig. 1, the plate-shaped member 10 is a circular member made of ceramics. Various ceramics can be used, but from the viewpoints of strength, wear resistance, plasma resistance, etc., it is preferable to use ceramics whose main component is, for example, aluminum oxide (alumina, Al2O3) or aluminum nitride (AlN). Note that the term "main component" here refers to the component with the highest content (for example, a component with a volume content of 90 vol% or more). The diameter of the plate-shaped member 10 is, for example, about 150 mm to 350 mm, and the thickness of the plate-shaped member 10 is, for example, about 2 mm to 6 mm.

[0026] 1 and 2, the plate-shaped member 10 has a holding surface 11 that holds a semiconductor wafer W, and a bottom surface 12 that is provided on the opposite side of the holding surface 11 in the thickness direction of the plate-shaped member 10 (a direction that coincides with the Z-axis direction, the up-down direction). The semiconductor wafer W is held on this holding surface 11. Note that the holding surface 11 is an example of a "first surface" in the present disclosure, and the bottom surface 12 is an example of a "second surface" in the present disclosure.

[0027] 2, the plate-shaped member 10 has a chuck electrode 50 therein. The chuck electrode 50 has, for example, a substantially circular shape when viewed in the Z-axis direction, and is made of a conductive material (for example, tungsten or molybdenum). The chuck electrode 50 is an example of an "internal electrode" in the present disclosure. A via 61 is connected to the chuck electrode 50. The via 61 is arranged to extend from the chuck electrode 50 toward the lower surface 12 in the Z-axis direction.

[0028] A bottomed hole 15 is formed in the lower surface 12 of the plate-like member 10. This bottomed hole 15 is a circular recess that opens to the lower surface 12 side, and when viewed in the Z-axis direction, an area that overlaps with a through-hole 25 of the base member 20, which will be described later, is recessed toward the holding surface 11 side. The diameter of the bottomed hole 15 is, for example, 7 mm to 8 mm. A terminal pad 60 is disposed on the bottom surface 15b of this bottomed hole 15. When viewed in the Z-axis direction, the shape of the terminal pad 60 is, for example, approximately circular. The bottomed hole 15 is an example of a "hole" in the present disclosure.

[0029] The other end of the via 61 connected to the chuck electrode 50 is connected to the upper surface of the terminal pad 60. As a result, the terminal pad 60 is electrically connected to the chuck electrode 50 through the via 61. The terminal pad 60 and the via 61 are formed of a conductive material (e.g., tungsten, molybdenum, etc.). In this embodiment, as shown in FIG. 2 , the entire terminal pad 60 is exposed from the plate-shaped member 10 in the thickness direction (Z-axis direction). However, as long as the lower surface of the terminal pad 60 is exposed from the plate-shaped member 10, a part or the entire terminal pad 60 in the thickness direction may be embedded in the plate-shaped member 10. A power supply terminal 62 for connection to an external power source is joined (brazed) to the lower surface (exposed surface) of the terminal pad 60. Power is supplied from the external power source to the chuck electrode 50 via the power supply terminal 62, the terminal pad 60, and the via 61.

[0030] 1, the base member 20 is cylindrical, more specifically, a stepped cylindrical shape formed by stacking two cylinders of different diameters with a common central axis, with the lower surface of the cylinder with the smaller diameter placed on the upper surface of the cylinder with the larger diameter. The base member 20 is made of metal (for example, aluminum or an aluminum alloy).

[0031] 1 and 2, the base member 20 has an upper surface 21 and a lower surface 22 provided on the opposite side of the upper surface 21 in the Z-axis direction. The upper surface 21 is an example of a "third surface" in the present disclosure, and the lower surface 22 is an example of a "fourth surface" in the present disclosure.

[0032] The diameter of the upper portion of the base member 20 is, for example, about 150 mm to 300 mm, and the diameter of the lower portion is, for example, about 180 mm to 350 mm. The thickness of the base member 20 (dimension in the Z-axis direction) is, for example, about 20 mm to 50 mm.

[0033] In addition, a refrigerant flow path is formed in the base member 20 for flowing a refrigerant (e.g., a fluorine-based inert liquid, water, etc.), and by flowing the refrigerant in the refrigerant flow path, the base member 20 is cooled, and thereby the plate-like member 10 is cooled via the bonding layer 40.

[0034] The base member 20 has a cylindrical through-hole 25 formed therein, penetrating between the upper surface 21 and the lower surface 22 in the thickness direction (the Z-axis direction, the up-down direction in FIG. 2). A power supply terminal 62 and an insulating sleeve 30 are disposed within this through-hole 25. The insulating sleeve 30 is an annular member disposed so as to cover the power supply terminal 62, and its end on the bottomed hole 15 side is joined to the plate-like member 10 by an adhesive portion 70. The insulating sleeve 30 and the adhesive portion 70 will be described in detail below.

[0035] The bonding layer 40 is disposed between the lower surface 12 of the plate-shaped member 10 and the upper surface 21 of the base member 20, and bonds the plate-shaped member 10 to the base member 20. The lower surface 12 of the plate-shaped member 10 and the upper surface 21 of the base member 20 are thermally connected via the bonding layer 40. The thickness of the bonding layer 40 (dimension in the Z-axis direction) is, for example, about 0.1 mm to 1.0 mm.

[0036] The bonding layer 40 is made of a resin adhesive such as a silicone resin, an acrylic resin, or an epoxy resin. As shown in FIG. 2 , a through hole 45 is formed in the bonding layer 40, in which the insulating sleeve 30 is disposed. That is, a cylindrical through hole 45 is formed between the bottomed hole 15 and the through hole 25. The through hole 45 is coaxial with the bottomed hole 15 and the through hole 25, and the bottomed hole 15, the through hole 45, and the through hole 25 are arranged in series in the Z-axis direction (the axial direction of the electrostatic chuck 1), forming a terminal hole 65 in which a terminal pad 60 and a power supply terminal 62 are disposed. In this embodiment, the diameter of the through hole 45 is smaller than the diameters of the bottomed hole 15 and the through hole 25. As will be described later, the periphery of the through hole 45 forms a part of the adhesive portion 70.

[0037] The configuration inside the terminal hole 65 will now be described with reference to Figures 2 and 3. As shown in Figure 2, a terminal pad 60 and a power supply terminal 62 are arranged inside the terminal hole 65, and an insulating sleeve 30 is arranged around these. The insulating sleeve 30 is fixed to the plate-like member 10 on the bottomed hole 15 side by an adhesive part 70 (see Figure 3), and its tip is located on the lower surface 22 of the base member 20. In other words, the insulating sleeve 30 extends to the lower surface 22 of the base member 20 and is arranged over the entire area of ​​the through hole 25. A certain gap is formed between the insulating sleeve 30 and the through hole 25.

[0038] The insulating sleeve 30 is made of ceramics, just like the plate-shaped member 10, and has an annular protruding portion 31 that protrudes radially outward, as shown in Fig. 3. That is, the protruding portion 31 is an annular convex portion that protrudes radially outward from the outer circumferential surface of the insulating sleeve 30, and has an upper surface 31a that faces the plate-shaped member 10, a lower surface 31b that faces the base member 20, and a side circumferential surface 31c that connects the upper surface 31a and the lower surface 31b. Such protruding portion 31 is formed at the end of the insulating sleeve 30 and is located within the bottomed hole 15.

[0039] The adhesive portion 70 that fixes the insulating sleeve 30 to the plate-like member 10 has a first adhesive portion 71 and a second adhesive portion 72. The first adhesive portion 71 and the second adhesive portion 72 are made of a resin adhesive such as a silicone resin, an acrylic resin, or an epoxy resin.

[0040] The first adhesive portion 71 is a portion where a paste-like adhesive is filled and hardened between the upper surface 31a and the side peripheral surface 31c of the protrusion 31 and the plate-like member 10 (the inner peripheral surface 15a and the bottom surface 15b of the bottomed hole 15). The second adhesive portion 72 is a portion where a sheet-like adhesive is hardened in contact with the lower surface 31b of the protrusion 31, the lower surface 12 of the plate-like member 10, and the first adhesive portion 71. In this embodiment, the second adhesive portion 72 is a portion of the bonding layer 40 (the peripheral portion of the through hole 45). That is, because the diameter of the through hole 45 of the bonding layer 40 is smaller than the diameter of the through hole 25 (the bottomed hole 15), the bonding layer 40 (the second adhesive portion 72) is arranged to enter the inside of the terminal hole 65, and as a result, the second adhesive portion 72 is formed in a portion of the bonding layer 40 (the peripheral portion of the through hole 45). In Figures 2 and 3, the first adhesive portion 71 and the second adhesive portion 72 are clearly distinguished for easy understanding, but in the actual product (after the adhesive has hardened), the first adhesive portion 71 and the second adhesive portion 72 are integrated to form the adhesive portion 70.

[0041] The electrostatic chuck 1 having such a configuration is manufactured by the following procedure. First, the plate-shaped member 10, the base member 20, the first adhesive portion 71, the second adhesive portion 72, and the insulating sleeve 30 are prepared. At this time, it is confirmed whether or not air bubbles are contained in the second adhesive portion 72. Next, the insulating sleeve 30 is bonded to the plate-shaped member 10 with the first adhesive portion 71, and the first adhesive portion 71 is filled between the upper surface 31a and the side peripheral surface 31c of the protrusion 31 and the plate-shaped member 10. Then, the plate-shaped member 10 and the base member 20 are bonded using the second adhesive portion 72, which does not contain air bubbles. Thereafter, the first adhesive portion 71 and the second adhesive portion 72 are cured, and the electrostatic chuck 1 is completed.

[0042] Here, because the first adhesive portion 71 is a paste-like adhesive before hardening, it can be disposed without gaps in the space defined between the insulating sleeve 30 and the plate-shaped member 10, specifically, the space defined by the outer peripheral surface of the insulating sleeve 30, the upper surface 31 a and the side peripheral surface 31 c of the protrusion 31, and the wall surfaces (bottom and inner peripheral surfaces) of the bottomed hole 15 of the plate-shaped member 10. However, there is a possibility that air may be trapped during filling, resulting in the formation of bubbles inside the first adhesive portion 71 when the adhesive hardens. In such a case, in a conventional electrostatic chuck configuration without the second adhesive portion 72, a discharge path (a path of dielectric breakdown) may be formed in the first adhesive portion 71 via the bubbles B formed inside, i.e., the shortest distance to the base member 20 as shown by the arrow in FIG. 4, which may result in dielectric breakdown.

[0043] Therefore, in the electrostatic chuck 1 of this embodiment, the adhesive portion 70 is composed of a first adhesive portion 71 and a second adhesive portion, and the second adhesive portion 72 is arranged so as to contact the lower surface 31b of the protruding portion 31, the lower surface 12 of the plate-shaped member 10, and the first adhesive portion 71. Therefore, the second adhesive portion 72 is continuously attached to both the protruding portion 31 of the insulating sleeve 30 and the lower surface 12 of the plate-shaped member 10 so as to cover the first adhesive portion 71.

[0044] The contact portion of the second adhesive portion 72 is a flat surface where the lower surface 31b of the protrusion 31, the lower surface 12 of the plate-like member 10, and the first adhesive portion 71 are substantially flush with each other. The second adhesive portion 72 is made of a sheet-like adhesive. Since it is easy to visually determine whether a sheet-like adhesive contains air bubbles after production, not using such a sheet in a product and applying only good sheets to the product can prevent air bubbles from forming in the product. In other words, during the manufacturing process of the electrostatic chuck 1, the second adhesive portion 72 is visually inspected to see if it contains any air bubbles, and any second adhesive portion 72 containing air bubbles is not used in the product. Therefore, no air bubbles are present inside the second adhesive portion 72 of the electrostatic chuck 1.

[0045] Therefore, in the second adhesive portion 72, discharge does not occur via the bubbles, but rather occurs along the surface. As a result, even if bubbles B are present inside the first adhesive portion 71, the discharge path via the adhesive portion 70 is formed so as to detour along the surface of the second adhesive portion 72 toward the insulating sleeve 30. That is, as shown by the arrow in FIG. 5 , the second adhesive portion 72 forms a discharge path from the surface of the bonding layer 40 facing the plate-like member 10 to the base member 20 along the surface of the bonding layer 40 facing the base member 20 via the through hole 45. In this way, the second adhesive portion 72 can increase the insulation distance, thereby improving the insulation properties of the electrostatic chuck 1.

[0046] Furthermore, since the second adhesive portion 72 is formed of a part of the bonding layer 40 (the peripheral portion of the through hole 45), it is possible to reliably form a discharge path that runs from the surface of the bonding layer 40 facing the plate-like member 10 toward the base member 20, via the through hole 45, along the surface of the bonding layer 40 facing the base member 20. That is, it is possible to reliably form a discharge path that bypasses the surface of the second adhesive portion 72 toward the insulating sleeve 30. Therefore, it is possible to reliably lengthen the insulation distance in the adhesive portion 70, thereby further improving the insulation properties of the electrostatic chuck 1.

[0047] Furthermore, in the electrostatic chuck 1 of this embodiment, the end surface 30a of the insulating sleeve 30 on the lower surface 12 side of the plate-shaped member 10 extends to the bottom surface 15b of the blind hole 15. That is, the end surface 30a of the insulating sleeve 30 is in contact with the bottom surface 15b of the blind hole 15. This allows the insulating sleeve 30 to completely cover the vicinity of the connection portion between the terminal pad 60 and the power supply terminal 62 arranged inside the insulating sleeve 30. That is, the terminal pad 60 and the power supply terminal 62 are covered not only by the adhesive portion 70 but also by the insulating sleeve 30. Therefore, the insulation properties of the electrostatic chuck 1 can be further improved.

[0048] The insulating sleeve 30 extends to the lower surface 22 of the base member 20 and is disposed over the entire area of ​​the through hole 25. As a result, the entire inner circumferential surface of the through hole 25 of the base member 20 is covered with the insulating sleeve 30, which further improves the insulation properties of the electrostatic chuck 1.

[0049] As described above, according to the electrostatic chuck 1 of this embodiment, the adhesive portion 70 for fixing the insulating sleeve 30 to the plate-like member 10 is composed of the first adhesive portion 71 formed by hardening a paste-like adhesive and the second adhesive portion 72 formed by hardening a sheet-like adhesive. The second adhesive portion 72 is formed by a part of the bonding layer 40 (the part around the through hole 45). Therefore, even if bubbles B are present inside the first adhesive portion 71, the discharge path passing through the adhesive portion 70 is formed so as to detour along the surface of the second adhesive portion 72 toward the insulating sleeve 30 (via the through hole 45). Therefore, the second adhesive portion 72 can increase the insulation distance, thereby improving insulation properties.

[0050] [Second embodiment] Next, a second embodiment will be described. The second embodiment has the same basic configuration as the first embodiment, but differs from the first embodiment in the shape of the bottomed hole 15 and the position of the protrusion 31. Therefore, the same components as those in the first embodiment will be denoted by the same reference numerals and their description will be omitted as appropriate, and the differences from the first embodiment will be mainly described.

[0051] As shown in Fig. 6, in the electrostatic chuck 1a of the second embodiment, a stepped portion 16 is formed in the bottomed hole 15 of the plate-shaped member 10. That is, the bottomed hole 15 is formed by a small diameter portion 17 and a large diameter portion 18 having a diameter larger than that of the small diameter portion 17. The bottom surface 18b of the large diameter portion 18 is polished. The bottom surface 18b of the large diameter portion 18 is an example of the "stepped portion" of the present disclosure. Fig. 6 shows the vicinity of the adhesive portion in the electrostatic chuck 1a of the second embodiment (a portion corresponding to portion A in Fig. 2).

[0052] Furthermore, the protruding portion 31 of the insulating sleeve 30 is formed in a position where the upper surface 31a of the protruding portion 31 is flush with the end surface 30a of the insulating sleeve 30. In other words, the upper surface 31a of the protruding portion 31 also serves as the end surface 30a of the insulating sleeve 30. The upper surface 31a of the protruding portion 31 and the end surface 30a of the insulating sleeve 30 are polished. The upper surface 31a of the protruding portion 31 (end surface 30a of the insulating sleeve 30) is in contact with the bottom surface 18b (step portion) of the large diameter portion 18, and the insulating sleeve 30 is fixed to the plate-like member 10 by the adhesive portion 70.

[0053] Here, similar to the first embodiment, the adhesive portion 70 is composed of a first adhesive portion 71 and a second adhesive portion 72, and the second adhesive portion 72 is formed from a part of the bonding layer 40 (the peripheral portion of the through hole 45). Therefore, even if bubbles B are present inside the first adhesive portion 71, the discharge path passing through the adhesive portion 70 is formed so as to detour along the surface of the second adhesive portion 72 to the insulating sleeve 30 side (via the through hole 45). Therefore, the second adhesive portion 72 can extend the insulation distance, thereby improving the insulation properties.

[0054] The upper surface 31a of the protruding portion 31 is in contact with the bottom surface 18b of the large-diameter portion 18. This allows for accurate positioning of the insulating sleeve 30 relative to the plate-like member 10 with the polished surfaces abutting against each other. This improves the accuracy of the amount by which the tip of the insulating sleeve 30 protrudes from the lower surface 22 of the base member 20. That is, the tip of the insulating sleeve 30 can be positioned flush with the lower surface 22 of the base member 20 without protruding from the lower surface 22. This allows the insulating sleeve 30 to completely cover the entire inner circumferential surface of the through hole 25 of the base member 20. Furthermore, because the tip of the insulating sleeve 30 does not protrude from the lower surface 22 of the base member 20, it is less likely to come into contact with other components, preventing damage to the insulating sleeve 30 or the adhesive portion 70. These factors contribute to improved insulation in the electrostatic chuck 1a.

[0055] As described above, according to the electrostatic chuck 1a of this embodiment, similarly to the first embodiment, the discharge path passing through the adhesive portion 70 is formed so as to detour (via the through-hole 45) along the surface of the second adhesive portion 72 to the insulating sleeve 30 side even if bubbles B are present inside the first adhesive portion 71. Therefore, the second adhesive portion 72 can increase the insulation distance, thereby improving the insulation properties.

[0056] Furthermore, according to the electrostatic chuck 1a of this embodiment, the insulating sleeve 30 can be positioned by abutting the polished upper surface 31a of the protruding portion 31 against the bottom surface 18b of the large diameter portion 18. This allows the tip of the insulating sleeve 30 to be positioned flush with the lower surface 22 of the base member 20 without protruding from the lower surface 22, thereby improving insulation properties.

[0057] [Third embodiment] Finally, a third embodiment will be described. The third embodiment has the same basic configuration as the second embodiment, but differs from the second embodiment in that the second adhesive portion 72 is not formed by a part of the bonding layer 40. Therefore, the same components as those in the second embodiment will be denoted by the same reference numerals and their description will be omitted as appropriate, and the description will focus on the differences from the second embodiment.

[0058] As shown in FIG. 7 , in the electrostatic chuck 1b of the third embodiment, the second adhesive portion 72 of the adhesive portion 70 is configured as a separate body from the bonding layer 40. However, after the adhesive portion 70 is cured, the second adhesive portion 72 is integrated with the bonding layer 40 and the first adhesive portion 71. The second adhesive portion 72 is a cured portion of the sheet-like adhesive that is in contact with the lower surface 31b of the protruding portion 31, the lower surface 12 of the plate-shaped member 10, and the first adhesive portion 71. Therefore, the second adhesive portion 72 is continuously attached to both the protruding portion 31 of the insulating sleeve 30 and the lower surface 12 of the plate-shaped member 10 so as to cover the first adhesive portion 71. Note that FIG. 7 shows the periphery of the adhesive portion in the electrostatic chuck 1b of the second embodiment (a portion corresponding to portion A in FIG. 2 ).

[0059] The electrostatic chuck 1b is manufactured by the following procedure. First, the plate-shaped member 10, the base member 20, the first adhesive portion 71, the second adhesive portion 72, and the insulating sleeve 30 are prepared. At this time, it is confirmed whether or not the second adhesive portion 72 contains any air bubbles. Next, the plate-shaped member 10 and the base member 20 are bonded together via a bonding layer. Next, the insulating sleeve 30 is bonded to the plate-shaped member 10 by the first adhesive portion 71 while filling the space between the protruding portion 31 and the plate-shaped member 10 with the first adhesive portion 71. Then, the second adhesive portion 72, which does not contain any air bubbles, is used and the second adhesive portion 72 is continuously attached to both the protruding portion 31 of the insulating sleeve 30 and the lower surface 12 of the plate-shaped member 10. Thereafter, the first adhesive portion 71, the second adhesive portion 72, and the bonding layer are cured to complete the electrostatic chuck 1b.

[0060] Therefore, according to the electrostatic chuck 1b of the third embodiment, similarly to the first embodiment, the discharge path passing through the adhesive portion 70 is formed so as to detour (via the through-hole 45) along the surface of the second adhesive portion 72 to the insulating sleeve 30 side even if bubbles B are present inside the first adhesive portion 71. Therefore, the second adhesive portion 72 can increase the insulation distance, thereby improving the insulation properties.

[0061] Furthermore, according to the electrostatic chuck 1b of the present embodiment, before the adhesive portion 70 is hardened, the second adhesive portion 72 is separate from the bonding layer 40. Therefore, after the plate-shaped member 10 with the insulating sleeve 30 attached and the base member 20 are bonded together by the bonding layer 40, the second adhesive portion 72 can be provided to form the adhesive portion 70. This simplifies the assembly work of the insulating sleeve 30 compared to the case in which the adhesive portion 70 is formed simultaneously when the plate-shaped member 10 and the base member 20 are bonded together by the bonding layer 40, as in the first and second embodiments, thereby improving work efficiency.

[0062] The above-described embodiment is merely an example and does not limit the present disclosure in any way, and various improvements and modifications are possible without departing from the spirit and scope of the present disclosure. For example, in the above-described embodiment, the terminal hole 65 is exemplified as the terminal hole of the chuck electrode 50, but the present disclosure is not limited to the chuck electrode 50, and can also be applied to terminal holes of a high-frequency electrode, a heater electrode, or the like.

[0063] Furthermore, in the above embodiment, an example has been given in which the present disclosure is applied when the insulating sleeve 30 is placed in the terminal hole 65, but the present disclosure can also be applied when an insulating sleeve is placed in a through-hole formed in the electrostatic chuck, such as a gas hole for supplying an inert gas to the holding surface 11 or a lift pin hole in which a lift pin is placed, without being limited to the terminal hole. [Explanation of symbols]

[0064] 1. Electrostatic chuck 10 Plate-shaped member 11 Holding surface 12 Bottom side 15 Bottomed hole 16 Step 20 Base member 21 Top side 22 Bottom side 30 Insulating sleeve 30a end face 31 Protrusion 31a Top surface 31b Bottom surface 31c Side surface 40 Bonding layer 70 Adhesive part 71 1st adhesive part 72 2nd adhesive part W Semiconductor wafer

Claims

1. a plate-like member including a first surface, a second surface provided on the opposite side of the first surface, and a hole opening in the second surface; a metal base member including a third surface, a fourth surface provided on the opposite side of the third surface, and a through hole penetrating the third surface and the fourth surface and communicating with the hole; a bonding layer disposed between the second surface and the third surface and bonding the plate-like member and the base member; an annular insulating member disposed in the through hole, A holding device for holding an object on the first surface of the plate-like member, the insulating member has an annular protrusion that protrudes outward, the protrusion has a surface on the plate-like member side, a surface on the base member side, and a side circumferential surface connecting the surface on the plate-like member side and the surface on the base member side, an adhesive portion is formed to join the insulating member to the plate-like member; The adhesive portion is a first adhesive portion that is filled between the plate-like member and the surface of the protruding portion that faces the plate-like member and the side peripheral surface of the protruding portion; a second adhesive portion in contact with the surface of the protruding portion on the base member side, the second surface, and the first adhesive portion; A holding device characterized by:

2. 2. The holding device according to claim 1, The second adhesive portion is a part of the bonding layer. A holding device characterized by:

3. The holding device according to claim 1 or 2, No air bubbles exist inside the second adhesive portion. A holding device characterized by:

4. 2. The holding device according to claim 1, The end face of the insulating member on the second surface side extends to the bottom surface of the hole that opens into the second surface. A holding device characterized by:

5. 5. The holding device according to claim 4, a step portion is formed in the hole of the plate-like member, The surface of the protrusion on the plate-like member side is in contact with the step portion. A holding device characterized by:

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