Holding device

Abstract

To provide a retainer device capable of improving insulation properties.SOLUTION: An electrostatic chuck 1 has: a plate-like member 10 which comprises a retention surface 11, a lower surface 12 provided on the opposite side from the retention surface 11, and a bottomed hole 15 opened in the lower surface 12 and provided with a metallic pad 60 on a bottom surface 15b; a metallic base member 20 which comprises an upper surface 21, a lower surface 22 provided on the opposite side from the upper surface 21, and a through hole 25 penetrating the upper surface 21 and the lower surface 22 to communicate with the bottomed hole 15; a joint layer 40 which is arranged between the lower surface 12 and the upper surface 21, and joins the plate-like member 10 and the base member 20 together; and an annular insulation sleeve 30 which is arranged in the through hole 25 and is joined to the plate-like member 10, wherein a semiconductor wafer W is retained on the retention surface 11 of the plate-like member 10. Here, the insulation sleeve 30 is joined to the pad 60 through a metallic joint part 31 and also is in contact with the joint layer 40.SELECTED DRAWING: Figure 5

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] Meanwhile, a through hole is formed in the base plate, and a power supply terminal is disposed within the through hole. This power supply terminal is joined to a connection electrode 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 within the through hole of the base plate. This cylindrical insulating part is fixed to the mounting table using a resin 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, a resin adhesive is used to fix the insulating member to the plate-like member, and this resin adhesive inhibits heat transfer between the plate-like member and the base member, which reduces thermal conductivity between the plate-like member and the base member in the area where the insulating member is disposed, potentially reducing the uniform temperature distribution on the holding surface of the plate-like member.

[0006] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a holding device that can improve thermal conductivity between a plate-shaped member and a base member in the area where the insulating member is arranged. [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 metal pad provided on 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, the through hole being disposed at a position corresponding to the metal pad; 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 and joined to the plate-like member; A holding device for holding an object on the first surface of the plate-like member, The insulating member is bonded to the pad via a metal bonding portion and is in contact with the bonding layer.

[0008] By joining the insulating member to the plate-shaped member via a metal joint in this manner, heat transfer between the plate-shaped member and the insulating member is promoted because it occurs via the metal. Furthermore, because the insulating member is in contact with the bonding layer, heat transfer between the insulating member and the bonding layer can be promoted. Therefore, in the area where the insulating member is disposed, heat transfer between the plate-shaped member and the base member via the insulating member and the bonding layer is promoted, thereby improving thermal conductivity between the plate-shaped member and the base member.

[0009] In the above-mentioned holding device, the plate-like member has a bottomed hole that opens on the second surface and has a metal pad provided on the bottom surface; It is preferable that a resin portion filled with resin is provided between the outer peripheral surface of the insulating member and the inner peripheral surface of the bottomed hole.

[0010] By providing such a resin portion, metal parts such as pads disposed between the insulating member and the plate-shaped member can be sealed with the resin portion, thereby improving the insulation between the metal parts such as pads and the metal base member. As a result, the thickness of the insulating member can be reduced, allowing the diameter of the through-holes in the base member to be reduced, thereby improving the thermal uniformity on the first surface of the plate-shaped member. Note that, because heat transfer between the plate-shaped member and the base member occurs via the insulating member and the bonding layer, providing the resin portion does not impair thermal conductivity.

[0011] Furthermore, fillers such as inorganic materials, metal powder, metal fibers, and metal foil may be mixed into the resin portion, thereby improving the thermal conductivity of the resin portion and further improving the thermal conductivity between the plate-like member and the insulating member.

[0012] In any of the above-mentioned holding devices, The insulating member has an annular flange that protrudes radially outward, The bonding layer is a first bonding portion disposed between the second surface and the third surface; a second joint portion disposed between the surface of the flange portion facing the base member and the third surface, It is preferable that the surface of the flange portion facing the base member protrudes beyond the second surface of the plate-like member and contacts the second joint portion.

[0013] By providing the flange portion on the insulating member, the area of ​​metal bonding between the insulating member and the plate-shaped member can be increased, further facilitating heat transfer between the plate-shaped member and the insulating member. Furthermore, the surface of the flange portion facing the base member (bonding layer) protrudes beyond the second surface of the plate-shaped member and is in contact with the bonding layer (specifically, the second bonding portion), thereby increasing the area over which the insulating member contacts the bonding layer. Therefore, heat transfer between the insulating member and the bonding layer can be further promoted.

[0014] These features further promote heat transfer between the plate-shaped member and the base member via the insulating member and the bonding layer, thereby further improving the thermal conductivity between the plate-shaped member and the base member.

[0015] In any of the above-mentioned holding devices, The insulating member has an annular flange that protrudes radially outward, The flange preferably has an annular projection formed so as to project toward the plate member and surround the pad.

[0016] By providing such an annular convex portion, metal parts such as pads that are arranged between the insulating member and the plate-shaped member can be surrounded by the insulating member, thereby increasing the insulation distance between the metal parts such as pads and the metal base member, and further improving the insulation properties.

[0017] In any of the above-mentioned holding devices, a thermal expansion coefficient of a material constituting the plate-like member is different from a thermal expansion coefficient of a material constituting the base member; It is preferable that a gap is formed between the outer peripheral surface of the insulating member and the through hole.

[0018] Because there is a difference in thermal expansion between the plate-shaped member and the base member, when the temperature of the holding device rises / falls, the difference in thermal expansion may cause the insulating member to come into contact with the inner surface of the through hole (base member), which may damage the insulating member or the joint between the insulating member and the plate-shaped member.

[0019] Therefore, by providing a gap between the insulating member and the through hole, it is possible to prevent the insulating member from coming into contact with the inner circumferential surface of the through hole due to the difference in thermal expansion, and therefore damage to the insulating member and the joint between the insulating member and the plate-like member can be prevented. This allows insulation to be ensured by the insulating member, improving the insulating properties.

[0020] Furthermore, since the insulating member ensures insulation, the gap between the outer peripheral surface of the insulating member and the through hole can be narrowed to the limit where the insulating member does not come into contact with the inner peripheral surface of the through hole (base member) due to the difference in thermal expansion. In other words, the diameter of the through hole in the base member can be reduced. As a result, the thermal uniformity on the first surface of the plate-like member can be improved. [Effects of the Invention]

[0021] According to the present disclosure, it is possible to provide a holding device that can improve thermal conductivity between a plate-like member and a base member in the area where an insulating member is arranged. [Brief explanation of the drawings]

[0022] [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. 2 is a plan view showing the shape of a pad. [Figure 4] FIG. 10 is a plan view showing another shape of the pad. [Figure 5] FIG. 3 is an enlarged view of part A shown in FIG. 2. [Figure 6] 10A to 10C are diagrams showing a procedure for fixing the insulating sleeve to the plate-shaped member. [Figure 7] FIG. 10 is a schematic configuration diagram of an XZ cross section near a joint portion of an insulating sleeve in an electrostatic chuck according to a second embodiment. [Figure 8] FIG. 11 is a schematic configuration diagram of an XZ cross section near a joint portion of an insulating sleeve in an electrostatic chuck according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] 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).

[0024] 1 to 5, 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 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 pad 60 is, for example, approximately circular.

[0030] The other end of the via 61 connected to the chuck electrode 50 is connected to the upper surface of the pad 60. As a result, the pad 60 is electrically connected to the chuck electrode 50 through the via 61. The 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 pad 60 in the thickness direction (Z-axis direction) is exposed from the plate-shaped member 10. However, as long as the lower surface of the pad 60 is exposed from the plate-shaped member 10, a part or the entire 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 pad 60, and power is supplied from the external power source to the chuck electrode 50 via the power supply terminal 62, the pad 60, and the via 61.

[0031] Here, the pad 60 is bonded to the power supply terminal 62 and also to a bonding portion 31 provided on the insulating sleeve 30, which will be described later. More specifically, the pad 60 is bonded to the power supply terminal 62 at its center and to the bonding portion 31 at its outer periphery. That is, as shown in FIG. 3, the pad 60 in this embodiment is disk-shaped and serves as both a pad for bonding the power supply terminal 62 and a pad for bonding the insulating sleeve 30. Note that the shape of the pad 60 is not limited to that shown in FIG. 3, and it may also be configured with a circular terminal pad 60a that bonds to the power supply terminal 62 and a ring-shaped insulating sleeve pad 60b that bonds to the insulating sleeve 30, as shown in FIG. 4.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 vertical 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 a joint 31. Details of the insulating sleeve 30 and the joint 31 will be described later.

[0037] 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 (the dimension in the Z-axis direction) is, for example, about 0.1 to 1.0 mm.

[0038] 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 , the bonding layer 40 has a through hole 45 formed therein, in which the insulating sleeve 30 is disposed. That is, the 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 the pad 60 and the power supply terminal 62 are disposed. In this embodiment, the diameter of the through hole 45 is approximately the same as the diameter of the through hole 25 and is smaller than the diameter of the bottomed hole 15.

[0039] The bonding layer 40 has a first bonding portion 41 and a second bonding portion 42. The first bonding portion 41 is a portion that is disposed between the lower surface 12 of the plate-like member 10 and the upper surface 21 of the base member 20. The second bonding portion 42 is a portion that is disposed between the lower surface 32b (the surface facing the base member 20) of a flange portion 32 of the insulating sleeve 30 (described later) and the upper surface 21 of the base member 20 (see FIG. 5).

[0040] The configuration inside the terminal hole 65 will now be described with reference to Figures 2 and 5. As shown in Figure 2, a pad 60, a power supply terminal 62, and an insulating sleeve 30 are arranged inside the terminal hole 65. The insulating sleeve 30 is arranged so as to cover the power supply terminal 62, and is joined by brazing to the plate-shaped member 10 on the bottomed hole 15 side, with its tip 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 S is formed between the insulating sleeve 30 and the through hole 25 and between the insulating sleeve 30 and the through hole 45.

[0041] The insulating sleeve 30 is made of ceramics, similar to the plate-shaped member 10, and has a flange 32 that projects radially outward, as shown in FIG. 5 . The flange 32 is located within the bottomed hole 15. A joint 31 is provided on the surface (upper surface) 32a of the flange 32 that faces the plate-shaped member 10. The joint 31 is made of a metal material and has substantially the same shape (annular shape) as the upper surface 32a of the flange 32. The joint 31 is joined to the pad 60 with brazing material, thereby fixing the insulating sleeve 30 to the plate-shaped member 10. That is, in this embodiment, the insulating sleeve 30 is fixed to the plate-shaped member 10 using a metal joining material (brazing material) rather than a resin adhesive as in the conventional case.

[0042] The procedure for fixing the insulating sleeve 30 to the plate-shaped member 10 will now be briefly described with reference to Fig. 6. The power supply terminal 62 and the insulating sleeve 30 are prepared, and the power supply terminal 62 and the insulating sleeve 30 are placed in a fixed position relative to the plate-shaped member 10. As a result, with the power supply terminal 62 inserted into the insulating sleeve 30, the flange portion 32 of the insulating sleeve 30 is placed in the bottomed hole 15 of the plate-shaped member 10. At this time, a brazing material 70 is placed between the joining portion 31 and the end face 62a of the power supply terminal 62 of the insulating sleeve 30 and the pad 60 of the plate-shaped member 10. As a result, the joining portion 31 of the insulating sleeve 30 and the end face 62a of the power supply terminal 62 come into contact with the pad 60 via the brazing material 70. By heating in this state, the solder material 70 solders the joint 31 and the end face 62a to the pad 60, and the insulating sleeve 30 and the power supply terminal 62 are joined to the pad 60, thereby fixing the insulating sleeve 30 to the plate-like member 10.

[0043] Then, the resin that becomes the resin portion 80 is filled between the outer peripheral surface 32c of the flange portion 32 and the inner peripheral surface 15a of the bottomed hole 15 and cured, thereby providing the resin portion 80 between the outer peripheral surface of the insulating sleeve 30 fixed to the plate-shaped member 10 and the inner peripheral surface of the bottomed hole 15. The resin portion 80 seals the joint portion 31, the brazing material 70, and the metal parts of the pad 60, ensuring insulation in the plate-shaped member 10 in a state in which the power supply terminal 62 and the insulating sleeve 30 are fixed.

[0044] Furthermore, when the insulating sleeve 30 is fixed to the plate-shaped member 10, the lower surface 32b of the flange 32 of the insulating sleeve 30 protrudes from the lower surface 12 of the plate-shaped member 10. In this embodiment, the lower surface 32b of the flange 32 of the insulating sleeve 30 protrudes from the lower surface 12 of the plate-shaped member 10 by, for example, about 5 to 10 μm. Therefore, in the electrostatic chuck 1, the insulating sleeve 30 (the lower surface 32b of the flange 32) comes into contact with the bonding layer 40 (the second bonding portion 42) in a compressed state, and the lower surface 32b and the outer peripheral side surface of the flange 32 bite into the bonding layer 40 (the second bonding portion 42). That is, in the bonding layer 40, the thickness of the second bonding portion 42 is smaller than the thickness of the first bonding portion 41.

[0045] In the electrostatic chuck 1 having such a configuration, the thermal conductivity between the plate-shaped member 10 and the base member 20 is poor in the portion where the insulating sleeve 30 is arranged (the portion of the terminal hole 65). Therefore, the portion directly above the terminal hole 65 is likely to become a temperature singular point, which may reduce the thermal uniformity on the holding surface 11 of the plate-shaped member 10. Note that, in the portion of the terminal hole 65, heat transfer between the plate-shaped member 10 and the base member 20 occurs via the insulating sleeve 30 and the bonding layer 40.

[0046] Therefore, in the electrostatic chuck 1 of this embodiment, a joining portion 31 made of a metal material is provided on the upper surface 32a of the flange portion 32 of the insulating sleeve 30, and the joining portion 31 is joined to the pad 60 of the plate-shaped member 10 with a brazing material 70, thereby fixing the insulating sleeve 30 to the plate-shaped member 10. Therefore, heat transfer between the plate-shaped member 10 and the insulating sleeve 30 is promoted because it occurs via the metal.

[0047] In addition, in the electrostatic chuck 1 of this embodiment, the flange 32 is provided on the insulating sleeve 30, which increases the area of ​​the joint (metal portion) between the insulating sleeve 30 and the plate-like member 10. Furthermore, in the electrostatic chuck 1, the pad 60 is integrally formed so as to serve both as a pad for joining the power supply terminal 62 and as a pad for joining the insulating sleeve 30, which increases the area of ​​the metal joint. These factors further promote heat transfer between the plate-like member 10 and the insulating sleeve 30.

[0048] In the electrostatic chuck 1 of this embodiment, the lower surface 32b of the flange 32 of the insulating sleeve 30 comes into contact with the bonding layer 40 (second bonding portion 42) in a compressed state, and the lower surface 32b and the outer peripheral side surface of the flange 32 bite into the bonding layer 40 (second bonding portion 42), increasing the area over which the insulating sleeve 30 comes into contact with the bonding layer 40. This promotes heat transfer between the insulating sleeve 30 and the bonding layer 40.

[0049] In this way, the electrostatic chuck 1 can promote heat transfer between the plate-shaped member 10 and the insulating sleeve 30 and between the insulating sleeve 30 and the bonding layer 40. Therefore, in the portion of the terminal hole 65 where the insulating sleeve 30 is disposed, heat transfer between the plate-shaped member 10 and the base member 20 via the insulating sleeve 30 and the bonding layer 40 can be promoted, and the thermal conductivity between the plate-shaped member 10 and the base member 20 can be improved.

[0050] Furthermore, in the electrostatic chuck 1 of this embodiment, a resin portion 80 is provided between the outer peripheral surface 32c of the flange portion 32 of the insulating sleeve 30 and the inner peripheral surface 15a of the bottomed hole 15. Therefore, the resin portion 80 seals the joint portion 31, the brazing material 70, and the metal portions of the pad 60, thereby improving the insulation of the electrostatic chuck 1. This allows the thickness of the insulating sleeve 30 to be reduced, which in turn allows the diameter of the through hole 25 in the base member 20 to be reduced, thereby improving the thermal uniformity on the holding surface 11 of the plate-shaped member 10. Note that heat transfer between the plate-shaped member 10 and the base member 20 occurs via the insulating sleeve 30 and the joint layer 40, so providing the resin portion 80 does not deteriorate thermal conductivity.

[0051] 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.

[0052] The thermal conductivity of the resin portion 80 can be improved by mixing fillers such as inorganic materials, metal powder, metal fibers, and metal foil into the resin portion 80. This further improves the thermal conductivity between the plate-shaped member 10 and the insulating sleeve 30. Although mixing such fillers hardens the resin portion 80, the difference in thermal expansion between the plate-shaped member 10 and the insulating sleeve 30 is small, and the diameter of the bottomed holes 15 is small. Therefore, when the temperature of the electrostatic chuck 1 rises or falls, there is almost no difference in the amount of deformation between the plate-shaped member 10 and the insulating sleeve 30 due to thermal expansion or contraction. Therefore, the resin portion 80 is not damaged.

[0053] Furthermore, since insulation can be ensured by the insulating sleeve 30, the gap S provided between the outer peripheral surface of the insulating sleeve 30 and the through hole 25 can be reduced to the limit at which the insulating sleeve 30 does not come into contact with the inner peripheral surface of the through hole 25 due to the difference in thermal expansion. This allows the diameter of the through hole 25 in the base member 20 to be reduced, thereby improving the thermal uniformity on the holding surface 11 of the plate-like member 10.

[0054] As described above, according to the electrostatic chuck 1 of this embodiment, the insulating sleeve 30 is joined to the plate-shaped member 10 via the metal joint 31, and therefore heat transfer between the plate-shaped member 10 and the insulating sleeve 30 is promoted because it occurs via the metal. Furthermore, because the insulating sleeve 30 is in contact with the joint layer 40, heat transfer between the insulating sleeve 30 and the joint layer 40 can be promoted. Therefore, in the area where the insulating sleeve 30 is disposed (near the terminal hole 65), heat transfer between the plate-shaped member 10 and the base member 20 via the insulating sleeve 30 and the joint layer 40 is promoted, and therefore thermal conductivity between the plate-shaped member 10 and the base member 20 can be improved.

[0055] [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 shapes of the insulating sleeve 30 and the bottomed hole 15. Therefore, the same components as those in the first embodiment will be assigned the same reference numerals and their description will be omitted as appropriate, and the description will focus on the differences from the first embodiment.

[0056] As shown in FIG. 7 , in the electrostatic chuck 1a of the second embodiment, an insulating sleeve 30 is provided with an annular protrusion 33, and an annular groove 16 is formed in the bottomed hole 15. The annular protrusion 33 is formed on the outer periphery of the upper surface 32a of the flange portion 32 of the insulating sleeve 30, protruding toward the plate-like member 10 and surrounding the pad 60, the brazing material 70, and the joint portion 31. The annular groove 16 is formed on the outer periphery of the bottom surface 15b of the bottomed hole 15 and has a shape recessed toward the holding surface 11 corresponding to the annular protrusion 33. As a result, the annular protrusion 33 of the insulating sleeve 30 is positioned within the annular groove 16 of the bottomed hole 15. Note that FIG. 7 shows the periphery of the joint portion of the insulating sleeve 30 in the electrostatic chuck 1a of the second embodiment (a portion corresponding to portion A in FIG. 2 ).

[0057] By providing such an annular protrusion 33, the pad 60, the brazing material 70, and the metal portion of the joint 31 arranged between the insulating sleeve 30 and the plate-like member 10 can be enclosed by the insulating sleeve 30, thereby increasing the insulation distance. Therefore, it is possible to improve insulation without providing the resin portion 80. Of course, in this embodiment, the resin portion 80 may be provided as in the first embodiment.

[0058] In the electrostatic chuck 1a of this embodiment, the insulating sleeve 30 is also joined to the plate-shaped member 10 via the metal joint 31, which promotes heat transfer between the plate-shaped member 10 and the insulating sleeve 30. Furthermore, the insulating sleeve 30 is in contact with the joint layer 40, which promotes heat transfer between the insulating sleeve 30 and the joint layer 40. Therefore, in the area where the insulating sleeve 30 is disposed (near the terminal hole 65), heat transfer between the plate-shaped member 10 and the base member 20 via the insulating sleeve 30 and the joint layer 40 is promoted, which improves thermal conductivity between the plate-shaped member 10 and the base member 20.

[0059] [Third embodiment] Finally, a third embodiment will be described. The third embodiment has the same basic configuration as the first embodiment, but differs from the first embodiment in that the insulating sleeve 30 does not have a flange portion 32. Therefore, the same components as those in the first embodiment will be assigned the same reference numerals and their description will be omitted as appropriate, and the description will focus on the differences from the first embodiment.

[0060] As shown in FIG. 8 , in the electrostatic chuck 1b of the third embodiment, the insulating sleeve 30 does not have a flange, and a joint portion 31 is provided on an end surface 30a of the insulating sleeve 30. The joint portion 31 is brazed and fixed to a pad 60 of the plate-shaped member 10 with a brazing material 70. Even if the insulating sleeve 30 does not have a flange portion 32, the insulating sleeve 30 can be joined to the plate-shaped member 10 via a metal portion. Furthermore, in this embodiment, since the insulating sleeve 30 does not have a flange portion, the inner circumferential surface of the through hole 45 of the bonding layer 40 is brought into contact with the outer circumferential surface of the insulating sleeve 30, thereby bringing the insulating sleeve 30 into contact with the bonding layer 40. Note that FIG. 8 shows the periphery of the joint portion of the insulating sleeve 30 in the electrostatic chuck 1b of the third embodiment (a portion corresponding to portion A in FIG. 2 ).

[0061] As described above, in the electrostatic chuck 1b of this embodiment, the insulating sleeve 30 is also joined to the plate-shaped member 10 via the joint 31, which promotes heat transfer between the plate-shaped member 10 and the insulating sleeve 30. Furthermore, the insulating sleeve 30 is in contact with the joint layer 40, which promotes heat transfer between the insulating sleeve 30 and the joint layer 40. Therefore, in the portion where the insulating sleeve 30 is disposed (near the terminal hole 65), heat transfer between the plate-shaped member 10 and the base member 20 via the insulating sleeve 30 and the joint layer 40 is promoted, which improves thermal conductivity between the plate-shaped member 10 and the base member 20.

[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] Although the above embodiment illustrates the bonding layer 40 being made of a resin adhesive, the bonding layer 40 may also be made of a metal bonding material. Examples of metal bonding materials include metal adhesives that use metal powder or metal foil for bonding, materials made of metal fibers, porous materials, or metal meshes (e.g., mesh structures) and brazing material, and materials made of multiple columnar metal pieces and brazing material. Metals that can be used to form the metal adhesive, metal mesh, or metal pieces include titanium, nickel, aluminum, copper, brass, alloys thereof, and stainless steel. When using a bonding layer 40 made of a metal bonding material, it is preferable to provide a resin portion 80 to ensure insulation.

[0064] Furthermore, in the above-described first and second embodiments, a certain gap S is formed between the insulating sleeve 30 and the through hole 45. However, as in the third embodiment, the gap S may not be provided and the inner circumferential surface of the through hole 45 of the bonding layer 40 may be brought into contact with the outer circumferential surface of the insulating sleeve 30. This can further promote heat transfer between the insulating sleeve 30 and the bonding layer 40. [Explanation of symbols]

[0065] 1. Electrostatic chuck 10 Plate-shaped member 11 Holding surface 12 Bottom side 15 Bottomed hole 20 Base member 21 Top side 22 Bottom side 25 through holes 30 Insulating sleeve 31 Joint 32 Tsuba 33 Annular convex part 40 Bonding layer 41 1st joint 42 Second joint 60 pads 80 Resin part S Gap 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 metal pad provided on 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, the through hole being disposed at a position corresponding to the metal pad; 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 and joined to the plate-like member; A holding device for holding an object on the first surface of the plate-like member, The pad has a first major surface and a second major surface opposite the first major surface, the first main surface of the pad and the second surface of the plate-like member are in contact with each other, The insulating member is joined to the second main surface of the pad via a metal joint and is in contact with the joint layer. A holding device characterized by:

2. 2. The holding device according to claim 1, the plate-like member has a bottomed hole that opens to the second surface and has the metal pad provided on the bottom surface; A resin portion filled with resin is provided between the outer peripheral surface of the insulating member and the inner peripheral surface of the bottomed hole. A holding device characterized by:

3. The holding device according to claim 1 or 2, The insulating member has an annular flange that protrudes radially outward, The bonding layer is a first joint portion disposed between the second surface and the third surface; a second joint portion disposed between the surface of the flange portion facing the base member and the third surface, The surface of the flange portion facing the base member protrudes from the second surface of the plate-like member and is in contact with the second joint portion. A holding device characterized by:

4. The holding device according to claim 1 or 2, The insulating member has an annular flange that protrudes radially outward, The flange has an annular projection that projects toward the plate-like member and surrounds the pad. A holding device characterized by:

5. The holding device according to claim 1 or 2, a thermal expansion coefficient of a material constituting the plate-like member is different from a thermal expansion coefficient of a material constituting the base member; A gap is formed between the outer peripheral surface of the insulating member and the through hole. A holding device characterized by:

6. A plate-like member having a first surface, a second surface provided on the opposite side of the first surface, and a metal pad provided on 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, the through hole being disposed at a position corresponding to the metal pad; 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 and joined to the plate-like member; A holding device for holding an object on the first surface of the plate-like member, the insulating member is joined to the pad via a metal joint and is in contact with the joint layer; The insulating member has an annular flange that protrudes radially outward, The bonding layer is a first joint portion disposed between the second surface and the third surface; a second joint portion disposed between the surface of the flange portion facing the base member and the third surface, The surface of the flange portion facing the base member protrudes from the second surface of the plate-like member and is in contact with the second joint portion. A holding device characterized by:

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