Retainer

Abstract

To provide a technique capable of improving at least any one of a cooling speed of a side surface where an object is mounted and a uniformity of an in-surface temperature distribution of the side surface where the object is mounted in a retainer holding the object.SOLUTION: A retainer comprises: a plate-like part that is formed in a plate-like shape having a first surface on the side where an object is mounted and a second surface as a back surface of the first surface; a base part that is arranged onto the second surface side of the plate-like part, supports the plate-like part, includes a cooling function, and is formed in the plate-like shape; and a joint part that is arranged between the plate-like part and the base part, and joints the plate-like part and the base part. A heat resistance of the joint part is 1.1×10-3 (m2K / W) or less at the time of -60°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a retention device. [Background technology]

[0002] Conventionally, as a holding device for holding an object, for example, a wafer or the like in manufacturing semiconductors has been used. Electrostatic chucks for holding objects are known. Generally, electrostatic chucks have a structure in which an object is placed on the electrostatic chuck. a plate-like portion in which the cooling medium is inserted, a base portion in which a coolant flow path is formed, and a joining portion for joining the plate-like portion and the base portion. For example, Patent Documents 1 and 2 disclose a method for manufacturing a bonding material layer (bonding portion) using silicone. Thermally conductive films such as silicone resin and aluminum oxide or aluminum nitride are used. It is described that an adhesive made of a composite resin containing a filler is used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-287344 [Patent Document 2] JP 2014-207374 A Summary of the Invention [Problem to be solved by the invention]

[0004] In environments where the electrostatic chuck is exposed to strong plasma energy or where high power is applied to the electrostatic chuck When the device is used in an environment where a large amount of heat is input, the wafer mounting surface is likely to become hot. If the electrostatic chucks described in 1 and 2 are used in such an environment, the thermal conductivity of the adhesive layer will decrease. Since the conductivity is relatively low, there is a risk that the cooling rate of the wafer mounting surface may not be sufficient. , in order to increase the cooling rate of the wafer mounting surface, it is desirable to improve the heat extraction at the joint. Yes.

[0005] Further, when the wafer mounting surface is likely to become high temperature as described above, in order to cool this, since the base side is used at an extremely low temperature, the temperature difference in the vertical and in-plane directions of the joint increases. The silicone resins described in Patent Documents 1 and 2 above have a temperature range in which the thermal conductivity changes greatly in the low temperature region. Therefore, when a temperature distribution occurs at the joint and the thermal conduction characteristics of the joint change, there is a risk that the non-uniformity of the in-plane temperature distribution of the wafer mounting surface of the electrostatic chuck will increase. Therefore, a joint portion with a small degree of change in thermal conductivity depending on temperature is required. These problems are not limited to electrostatic chucks, but are common problems in various holding devices such as semiconductor manufacturing devices such as plasma etching devices. Yes. The silicone resins described in Patent Documents 1 and 2 have a temperature range in which the thermal conductivity changes greatly in the low temperature region. Therefore, when a temperature distribution occurs at the joint and the thermal conduction characteristics of the joint change, there is a risk that the non-uniformity of the in-plane temperature distribution of the wafer mounting surface of the electrostatic chuck will increase. Therefore, there is a risk that the non-uniformity of the in-plane temperature distribution of the wafer mounting surface of the electrostatic chuck will increase. Therefore, a joint portion with a small degree of change in thermal conductivity depending on temperature is required. Incidentally, These problems are not limited to electrostatic chucks, but are common problems in various holding devices such as semiconductor manufacturing devices such as plasma etching devices. Manufacturing equipment, etc.

[0006] The present disclosure has been made to solve at least a part of the above-described problems, and in a holding device that holds an object, it improves at least one of the cooling rate of the surface on which the object is placed and the uniformity of the in-plane temperature distribution of the surface on which the object is placed. The purpose is to provide technology. The present disclosure has been made to solve at least a part of the above-described problems, and in a holding device that holds an object, it improves at least one of the cooling rate of the surface on which the object is placed and the uniformity of the in-plane temperature distribution of the surface on which the object is placed. The purpose is to provide technology.

Means for Solving the Problems

[0007] The present disclosure can be realized in the following forms. (1) According to one aspect of the present disclosure, a holding device for holding an object is provided. This holding device has a plate-like portion formed in a plate shape having a first surface on the side on which the object is placed and a second surface that is the back surface of the first surface, and is disposed on the second surface side of the plate-like portion to support the plate-like portion. Yes. It has a cooling function, a base portion formed in a plate shape, and is disposed between the plate-shaped portion and the base portion a joining portion that joins the plate-shaped portion and the base portion, and the thermal resistance of the joining portion is , at -60 °C, 1.1×10 -3 (m 2 K / W) or less.

[0008] According to the holding device of this form, the thermal resistance of the joining portion is 1.1×10 -3 (m 2 K / W) or less at -60 °C. Since the thermal resistance is small, for example, when the plate-shaped portion of the holding device becomes high temperature and the base portion is used at an extremely low temperature of about -60 °C, the plate-shaped portion can be rapidly cooled. Therefore, the cooling rate of the surface on which the object is placed can be improved.

[0009] (2) In the holding device of the above form, when the thermal conductivity at -60 °C of the joining portion is λ1 and the thermal conductivity at 25 °C is λ2, λ1 / λ2 is 1.18 or less, and when the thermal resistance at -60 °C is θ1 and the thermal resistance at 25 °C is θ2, θ 1 / θ2 is 0.85 or more, and at least one of them may be satisfied. With such a configuration, since the change in thermal conductivity accompanying the temperature change of the joining portion is small, the uniformity of the temperature distribution of the plate-shaped portion can be improved.

[0010] (3) In the holding device of the above form, the joining portion may have a thermal resistance at 25 °C of 1.2×1 0 -3 (m 2 K / W) or less. With such a configuration, even when the operating temperature of the holding device is room temperature (25 °C), since the joining portion has good thermal conductivity, the plate-shaped portion can be rapidly cooled.

[0011] (4) In the above-mentioned holding device, the joint has a thermal conductivity of 25°C and -60°C. The electrical conductivity may be 0.7 (W / mK) or more. With this configuration, For example, sufficient thermal conductivity can be obtained even at low temperatures (for example, -60°C) or at room temperature.

[0012] (5) In the holding device of the above embodiment, the joint portion contains aluminum nitride (AlN). In this way, the flexibility and stress relaxation performance are good, and the thermal conductivity is good. It is possible to provide a suitable joint.

[0013] (6) In the above-mentioned holding device, the strain amount at the maximum shear stress of the joint is 0.5 In this way, the flexibility of the joint and the stress relaxation Therefore, when a shear force is applied to the joint, This can reduce damage to the joints.

[0014] (7) In the holding device of the above embodiment, a hole penetrating the base portion and an inner wall of the hole an insulating portion covering the plate-shaped portion; an end surface of the insulating portion facing the second surface of the plate-shaped portion; and a hole joint portion that joins the hole joint portion to the material constituting the joint portion. The second portion may be made of the same material and may be thinner than the joint portion. In the holding device, the base portion has a hole portion penetrating therethrough, and therefore the plate portion has a corresponding hole portion. Therefore, with this configuration, the hole joint has good thermal conductivity. Since the plate-shaped portion and the corresponding hole can dissipate heat through the hole, the temperature of the plate-shaped portion can be Non-uniformity can be suppressed.

[0015] The present disclosure can be realized in various forms other than those described above. For example, it can be realized in the form of a semiconductor manufacturing apparatus including a holding device, a method for manufacturing the holding device, a method for forming a joint portion, and the like. It can be realized in the form of a semiconductor manufacturing apparatus including a holding device, a method for manufacturing the holding device, a method for forming a joint portion, and the like.

Brief Description of the Drawings

[0016]

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Mode for Carrying Out the Invention

[0017] A. First Embodiment: (A-1) Overall Configuration of the Electrostatic Chuck: FIG. 1 is an explanatory diagram schematically showing the configuration of the electrostatic chuck 10 in the first embodiment. FIG. 2 is an explanatory diagram schematically showing the cross-sectional configuration of the electrostatic chuck 10. In FIG. 1, a part of the electrostatic chuck 10 is shown broken. Also, in the figure, for the purpose of specifying directions, XYZ axes perpendicular to each other are shown. In this specification, for convenience, the positive direction of the Z-axis is referred to as the upward direction, and the negative direction of the Z-axis is referred to as the downward direction. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part. The electrostatic chuck 10 is a device that adsorbs and holds an object by electrostatic attraction. For example, it is used to fix a wafer W (FIG. 2), which is an object, in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a plate-like portion 20, a base portion 30, and a joint portion 40. Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction for convenience in this specification. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part. Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction for convenience in this specification. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part. Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction for convenience in this specification. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part. Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction for convenience in this specification. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part. Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction for convenience in this specification. However, the electrostatic chuck 10 may actually be installed in a different orientation. The X-axis, Y-axis, and Z-axis shown in each figure represent the same orientation. Note that the above figures schematically show the arrangement of each part and do not accurately represent the ratio of the dimensions of each part.

[0018] The electrostatic chuck 10 is a device that adsorbs and holds an object by electrostatic attraction. For example, it is used to fix a wafer W (FIG. 2), which is an object, in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a plate-like portion 20, a base portion 30, and a joint portion 40. The electrostatic chuck 10 is a device that adsorbs and holds an object by electrostatic attraction. For example, it is used to fix a wafer W (FIG. 2), which is an object, in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a plate-like portion 20, a base portion 30, and a joint portion 40. The electrostatic chuck 10 is a device that adsorbs and holds an object by electrostatic attraction. For example, it is used to fix a wafer W (FIG. 2), which is an object, in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a plate-like portion 20, a base portion 30, and a joint portion 40. . These are stacked in the order of the plate-like portion 20, the joint portion 40, and the base portion 3 toward the -Z axis direction (vertically downward). The electrostatic chuck 10 in the present embodiment is also referred to as a "holding device". .

[0019] The plate-like portion 20 is a substantially circular plate-like member having a first surface 24 on the side where the object is placed and a second surface 26 that is the back surface of the first surface 24, and is formed mainly of ceramic (for example, aluminum oxide, aluminum nitride, etc.). In the present specification, that a specific component is "the main component" or "the material mainly forming" means that the content rate of the specific component is 50% by volume or more. The diameter of the plate-like portion 20 may be, for example, about 50 mm to 500 mm, and is usually about 200 mm to 350 mm. The thickness of the plate-like portion 20 may be, for example, about 1 mm to 10 mm. In other embodiments, the plate-like portion 20 may be formed mainly of a material other than ceramic, such as resin such as polyimide. As shown in FIG. 2, an adsorption electrode 22 is disposed inside the plate-like portion 20. The adsorption electrode 22 is formed of a conductive material such as tungsten or molybdenum, for example. When a voltage is applied to the adsorption electrode 22 from a power source (not shown), an electrostatic attraction force is generated, and the wafer W is adsorbed and fixed to the first surface 24 of the plate-like portion 20 by this electrostatic attraction force. The adsorption electrode 22 may be bipolar or unipolar. Further, inside the plate-like portion 20, a heater electrode (not shown) for heating the wafer W adsorbed and fixed to the first surface 24 may be provided, which is constituted by a resistance heating element formed of a conductive material (for example, tungsten, molybdenum, etc.).

[0020]

[0021] ​​​​​​​​​​​​​​ The base portion 30 is disposed on the second surface 26 side of the plate-like portion 20, supports the plate-like portion 20, and has a cooling function, and is a plate-like member formed in a substantially circular shape. The base portion 30 is made of, for example, aluminum , magnesium, molybdenum, titanium, tungsten, nickel, or at least one of these metals. Molybdenum, titanium, and tungsten have a relatively small coefficient of thermal expansion among the above-mentioned metals. Therefore, when the base portion 30 is configured using at least one of these metals, it is desirable to suppress the difference in the coefficient of thermal expansion between the base portion 30 and the plate-like portion 20. In the present specification, the "coefficient of thermal expansion" refers to the "linear expansion coefficient". Also, since magnesium has a relatively small Young's modulus, when the base portion 30 is configured using magnesium, it is desirable to reduce the thermal stress generated in the base portion 30. Further, aluminum has a relatively high thermal conductivity, is easy to process, and has a low cost. Therefore, when the base portion 30 is configured using aluminum, the cooling efficiency of the plate-like portion 20 and the wafer W by the base portion 30 can be increased, and the manufacturing cost of the electrostatic chuck 10 can be suppressed, which is desirable. From the viewpoint of increasing the cooling efficiency by the base portion 30 while suppressing the manufacturing cost, it is desirable that the metal content ratio in the base portion 30 is high, and the base portion 30 desirably has a metal as the main component. For example, it is desirable to contain 90 mass% or more of aluminum with high versatility (for example, being composed of an aluminum alloy such as A6061 or A5052). However, the base portion 30 may contain components other than metals such as ceramics. The diameter of the base portion 30 is, for example, about 220 mm to 550 mm. Moreover, aluminum has a relatively high thermal conductivity, is easy to process, and has a low cost. Therefore, when the base portion 30 is configured using aluminum, the cooling efficiency of the plate-like portion 20 and the wafer W by the base portion 30 can be increased, and the manufacturing cost of the electrostatic chuck 10 can be suppressed, which is desirable. From the viewpoint of increasing the cooling efficiency by the base portion 30 while suppressing the manufacturing cost, it is desirable that the metal content ratio in the base portion 30 is high, and the base portion 30 desirably has a metal as the main component. For example, it is desirable to contain 90 mass% or more of aluminum with high versatility (for example, being composed of an aluminum alloy such as A6061 or A5052). However, the base portion 30 may contain components other than metals such as ceramics. The diameter of the base portion 30 is, for example, about 220 mm to 550 mm. 30 is desirably made mainly of a metal. For example, it is desirable to contain 90 mass% or more of aluminum with high versatility (for example, being composed of an aluminum alloy such as A6061, A5052, etc.). However, the base portion 30 may contain components other than metals such as ceramics. The diameter of the base portion 30 is, for example, about 220 mm to 550 mm. from the viewpoint of suppressing the manufacturing cost while increasing the cooling efficiency by the base portion 30, it is desirable that the metal content ratio in the base portion 30 is high, and the base portion 30 desirably has a metal as the main component. For example, it is desirable to contain 90 That's fine. Usually, it is 220 mm to 350 mm. The thickness of the base portion 30 may be, for example, 2 about 0 mm to 40 mm.

[0022] Inside the base portion 30, a plurality of refrigerant flow paths 32 are formed along the XY plane. By flowing a refrigerant such as a fluorine-based inert liquid, water, or liquid nitrogen through the refrigerant flow path 32, the base portion 30 is cooled. Then, due to the heat transfer between the base portion 30 and the plate-like portion 20 through the joint portion 40, the plate-like portion 20 is cooled, and the wafer W held on the first surface 24 of the plate-like portion 20 is cooled. Thereby, temperature control of the wafer W is realized. In addition to the form having the refrigerant flow path 32 inside the base portion 30, the base portion 30 may be cooled from the outside of the base portion 30, or the base portion 30 may be provided with a cooling function.

[0023] The joint portion 40 is disposed between the plate-like portion 20 and the base portion 30 and joins the plate-like portion 20 and the base portion 30. The joint portion 40 includes an adhesive formed of a resin material. The joint portion 4 0 may further include various fillers (inorganic fillers) for adjusting the properties of the joint portion 40 and the paste for forming the joint portion 40. That is, the joint portion 40 can be composed of a composite including an adhesive and an inorganic filler. However, if the joint portion 40 satisfies the properties described later, the joint portion 40 may not include an inorganic filler. The thickness of the joint portion 40 is, from the viewpoint of reducing the thermal resistance of the joint portion 40, for example, 1.00 mm or less, preferably 0.60 mm or less, more preferably 0.50 mm or less, and even more preferably 0.35 mm or less. The thickness of the joint portion 40 is, for example, related to the flexibility of the joint portion 40 and ​​From the viewpoint of ensuring strength, it may be set to 0.05 mm or more. The joint portion 40 will be described in detail later. described later.

[0024] The electrostatic chuck 10 further has a plurality of gas supply paths 50 formed therein. The gas supply paths 50 are provided so as to penetrate the plate-like portion 20, the joint portion 40, and the base portion 30 in the Z direction, and open at the gas discharge port 52 formed on the first surface 24 (see FIG. 1). The gas supply paths 50 are supplied with an inert gas such as helium gas from a gas supply device (not shown), and the inert gas is supplied from the gas discharge port 52 to the space between the first surface 24 and the wafer W. Thereby, the heat transfer property between the plate-like portion 20 and the wafer W is enhanced, and the controllability of the temperature distribution of the wafer W is further enhanced. Note that the gas supply paths 50 are not essential, and the gas supply paths 50 may not be provided in the electrostatic chuck 1 0. 0.

[0025] (A-2) Configuration of joint portion: The thermal resistance of the joint portion 40 included in the electrostatic chuck 10 of the present embodiment is 1.1 ×10 -3 (m 2 K / W) or less at -60°C. When the thermal resistance of the joint portion 40 is R (m 2 K / W), the thickness of the joint portion 40 is t (m), and the thermal conductivity of the joint portion 40 is λ (W / mK), the thermal resistance R of the joint portion 40 is obtained by the following equation (1). resistance R of the joint portion 40 is obtained by the following equation (1).

[0026] R (m 2 K / W) = t (m) ÷ λ (W / mK) …(1)

[0027] When the electrostatic chuck 10 is used in an environment where it is exposed to strong plasma energy or in an environment where high power is input to the electrostatic chuck 10, the first surface 24 of the plate-like portion 20 tends to become high temperature. When used in an environment where high power is input to the electrostatic chuck 10, the first surface 24 of the plate-like portion 20 tends to become high temperature. For example, when the first surface 24 of the plate-like portion 20 is under operating conditions such that it reaches 120°C, the temperature of the refrigerant supplied to the base portion 30 may be set to, for example, about -60°C in order to cool the plate-like portion 20. When the base portion 30 becomes low in temperature, the joint portion 40 also becomes low in temperature. Therefore, by setting the thermal resistance of the joint portion 40 at -60°C to the above value, when the temperature of the base portion 30 is extremely low (for example, -60°C), heat transfer between the base portion 30 and the plate-like portion 20 through the joint portion 40, that is, heat extraction from the plate-like portion 20 to the base portion 30, becomes likely to occur, and the cooling efficiency in the electrostatic chuck 10 can be enhanced. As described above, the joint portion 40 includes an adhesive composed of a resin, and generally, the higher the temperature, the lower the thermal conductivity of the adhesive . That is, when the thickness of the joint portion 40 is constant, the higher the temperature, the greater the tendency for the thermal resistance to increase. If the thermal resistance of the joint portion 40 at -60°C is set to the above value, sufficient cooling performance can be obtained even if the temperature of the joint portion 400 becomes higher than -60°C. Therefore, the cooling rate of the surface (the first surface 24) on which the object to be processed is placed can be improved. The thermal conductivity of the joint portion 40 is not particularly limited, but when the thermal conductivity at -60°C is λ1 and the thermal conductivity at 25°C is λ2, it is preferable that λ1 / λ2 is 1.18 or less. Here, 25°C is the room temperature (normal temperature) when the electrostatic chuck 10 is used. As described above, generally, the higher the temperature, the lower the thermal conductivity of the adhesive. If the thermal conductivity of the joint portion 40 is set as described above, the change in thermal conductivity accompanying the temperature change of the joint portion 40 is small. When the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, the lower-temperature portion is more cooled, and the higher- temperature portion is less cooled, which may cause problems such as uneven cooling. By setting the thermal conductivity of the joint portion 40 as described above, the cooling efficiency of the electrostatic chuck 10 can be improved. heat transfer between the base portion 30 and the plate-like portion 20 through the joint portion 40, that is, heat extraction from the plate-like portion 20 to the base portion 30, becomes likely to occur, and the cooling efficiency in the electrostatic chuck 10 can be enhanced. As described above, the joint portion 40 includes an adhesive composed of a resin, and generally, the higher the temperature, the lower the thermal conductivity of the adhesive . That is, when the thickness of the joint portion 40 is constant, the higher the temperature, the greater the tendency for the thermal resistance to increase. If the thermal resistance of the joint portion 40 at -60°C is set to the above value, sufficient cooling performance can be obtained even if the temperature of the joint portion 40 becomes higher than -60°C. Therefore, the cooling rate of the surface (the first surface 24) on which the object to be processed is placed can be improved. The thermal conductivity of the joint portion 40 is not particularly limited, but when the thermal conductivity at -60°C is λ1 and the thermal conductivity at 25°C is λ2, it is preferable that λ1 / λ2 is 1.18 or less. Here, 25°C is the room temperature (normal temperature) when the electrostatic chuck 10 is used. As described above, generally, the higher the temperature, the lower the thermal conductivity of the adhesive. If the thermal conductivity of the joint portion 40 is set as described above, the change in thermal conductivity accompanying the temperature change of the joint portion 40 is small. When the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, the lower-temperature portion is more cooled, and the higher- temperature portion is less cooled, which may cause problems such as uneven cooling. By setting the thermal conductivity of the joint portion 40 as described above, the cooling efficiency of the electrostatic chuck 10 can be improved. If the thermal resistance of the joint portion 40 at -60°C is set to the above value, sufficient cooling performance can be obtained even if the temperature of the joint portion 4 0 becomes higher than -60°C. Therefore, the cooling rate of the surface (the first surface 24) on which the object to be processed is placed can be improved. The thermal conductivity of the joint portion 40 is not particularly limited, but when the thermal conductivity at -60°C is λ1 and the thermal conductivity at 25°C is λ2, it is preferable that λ1 / λ2 is 1.18 or less. Here, 25°C is the room temperature (normal temperature) when the electrostatic chuck 10 is used. As described above, generally, the higher the temperature, the lower the thermal conductivity of the adhesive. If the thermal conductivity of the joint portion 40 is set as described above, the change in thermal conductivity accompanying the temperature change of the joint portion 40 is small. When the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, the lower-temperature portion is more cooled, and the higher-

[0028] The thermal conductivity of the joint portion 40 is not particularly limited, but when the thermal conductivity at -60°C is λ1 and the thermal conductivity at 25°C is λ2, it is preferable that λ1 / λ2 is 1.18 or less. Here, 25°C is the room temperature (normal temperature) when the electrostatic chuck 10 is used. As described above, generally, the higher the temperature, the lower the thermal conductivity of the adhesive. If the thermal conductivity of the joint portion 40 is set as described above, the change in thermal conductivity accompanying the temperature change of the joint portion 40 is small. When the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, the lower-temperature portion is more cooled, and the higher- temperature portion is less cooled, which may cause problems such as uneven cooling. By setting the thermal conductivity of the joint portion 40 as described above, the cooling efficiency of the electrostatic chuck 10 can be improved. temperature portion is less cooled, which may cause problems such as uneven cooling. By setting the thermal conductivity of the joint portion 40 as described above, the cooling efficiency of the electrostatic chuck 10 can be improved. As described above, generally, the higher the temperature, the lower the thermal conductivity of the adhesive. If the thermal conductivity of the joint portion 40 is set as described above, the change in thermal conductivity accompanying the temperature change of the joint portion 40 is small. When the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, the lower-temperature portion is more cooled, and the higher- temperature portion is less cooled, which may cause problems such as uneven cooling. By setting the thermal conductivity of the joint portion 40 as described above, the cooling efficiency of the electrostatic chuck 10 can be improved. If the change in thermal conductivity accompanying the temperature change of the joint portion 40 is large, or if the lower-temperature portion is more cooled and the higher- Since the cooling of the warm part is slow, there is a risk that the temperature difference in the vertical and in-plane directions of the joint 40 will increase. . On the other hand, when the thermal conductivity of the joint 40 is made as described above, since the change in thermal conductivity accompanying the temperature change of the joint 40 is small, it is possible to suppress the temperature difference in the vertical and in-plane directions of the joint 40. In other words, it is possible to improve the uniformity of the temperature distribution of the plate-like part 20. Note that , λ1 / λ2 is usually 1.00 or more.

[0029] Regarding the thermal resistance of the joint 40, when the thermal resistance at -60°C is θ1 and the thermal resistance at 25°C is θ2, it is preferable that θ1 / θ2 is 0.85 or more. By doing so, since the change in thermal resistance accompanying the temperature change of the joint 40 is small, it is possible to suppress the temperature difference in the vertical and in-plane directions of the joint 40. In other words, it is possible to improve the uniformity of the temperature distribution of the plate-like part 20. Note that θ1 / θ2 is usually 1.00 or less.

[0030] The thermal resistance of the joint 40 at 25°C is not particularly limited, but it is preferably 1.2×10 -3 (m 2 K / W) or less. By doing so, even when the operating temperature of the electrostatic chuck 10 is room temperature (25°C), since the joint 40 has good thermal conductivity, the plate-like part 20 can be rapidly cooled.

[0031] The amount of strain at the maximum shear stress of the joint 40 is not particularly limited, but it is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 1.1 mm or more. Note that the amount of strain at the maximum shear stress of the joint 40 is usually 5.0 mm or less. The amount of strain at the maximum shear stress represents an index of the flexibility and stress relaxation performance of the joint 40. is a value, and when a shear force is applied to the joint portion 40, the shear stress generated at the joint portion 40 is the most When it becomes large, that is, when the maximum shear stress is generated at the joint portion 40, at the joint portion 40 It refers to the magnitude of the strain generated (the displacement amount in the shear force direction). The larger the strain amount at the maximum shear stress, the higher the flexibility of the joint portion 40. A specific measurement method using a tensile testing machine for measuring the strain amount at the maximum shear stress will be described in detail later. If the strain amount at the maximum shear stress of the joint portion 4 0 is set to the above value, it becomes possible to sufficiently ensure the flexibility and stress relaxation performance of the joint portion 40. Therefore, it is possible to suppress damage to the joint portion 40 when a shear force is applied to the joint portion 40. When

[0032] In addition, the lower limit value of the thermal resistance of the joint portion 40 is, for example, 0.6×10 -4 (m 2 K / W) It can be set as such. In order to suppress the thermal resistance of the joint portion 40, as described above, a method of appropriately selecting a material constituting the inorganic filler and increasing the content ratio of the inorganic filler can be considered. However, if the content ratio of the inorganic filler is excessively increased, the flexibility of the joint portion 40 will be impaired, and it may become difficult to sufficiently ensure the magnitude of the strain amount at the maximum shear stress of the joint portion 40 described later. Also, in order to suppress the thermal resistance of the joint portion 40, a method of thinning the joint portion 40 can be considered. However, if the joint portion 40 is excessively thinned, the strength of the joint portion 40 will decrease, and it will become difficult to ensure the flexibility of the joint portion 40, and it may become difficult to set the strain amount at the maximum shear stress to a desired numerical range. Therefore, it is desirable that the thermal resistance of the joint portion 40 is 0.6×10 described above or more (m K / W). -4 (m 2 K / W) ​

[0033] The amount of strain at the maximum shear stress of the joint 40 is determined by the adhesive (resin) contained in the joint 40. For example, the maximum shear stress can be changed depending on the type of resin that constitutes the joint 40. In addition to being able to change the amount of strain when force is applied, even if the same type of resin is used, the resin is a polymer material. By controlling the distance between the crosslinking points in the resin, the strain amount at the maximum shear stress of the joint 40 can be Specifically, the content of the functional group that serves as the crosslinking point in the resin (functional group equivalent) By reducing the crosslinking point distance, the flexibility of the resin is improved, and the maximum shear strength is reduced. The amount of strain under stress can be increased. In addition, the content of reactive functional groups in the resin is Even in the same case, the distance between crosslinks may vary depending on the curing conditions such as the resin curing temperature and curing time. That is, when the curing temperature is increased or the curing time is extended, In this case, the resin hardens further, the crosslink density increases, and the distance between crosslinks becomes shorter. become.

[0034] In addition, the amount of strain at the maximum shear stress of the joint 40 increases as the thickness of the joint 40 increases. So it can be made larger.

[0035] In addition, the greater the content of the inorganic filler in the joint 40, the greater the maximum shear strength of the joint 40. The strain under tensile stress tends to be smaller. This is because the content of inorganic filler is higher. The degree to which the inorganic filler binds the surrounding resin (resin composition) increases, and the flexibility of the joint 40 increases. This is believed to be because the flexibility decreases, making the joint 40 less susceptible to distortion.

[0036] The adhesive that constitutes the joint 40 may be, for example, a silicone resin, an acrylic resin, or the like. Alternatively, an epoxy resin or the like can be used. In particular, a silicone resin is desirable because it has relatively high heat resistance and flexibility. Among these resins, the silicone resin has a relatively low elastic modulus, so it has a high function of relaxing the thermal stress generated at the joint 40, and also has a relatively high heat resistance temperature, so it is desirable.

[0037] As the inorganic filler, substances in the form of granules or powders composed of various inorganic materials including ceramics, metal oxides, metals, or other inorganic compounds can be used. Specifically speaking, as the inorganic filler, for example, aluminum nitride (AlN), aluminum oxide (al umina: Al2O3), zirconium oxide (zirconia: ZrO2), yttrium oxide ([[]] yttria: Y2O3), yttrium fluoride (YF3), silicon carbide (SiC), silicon nitride (Si3N4), silicon dioxide (silica: SiO2), iron oxide, barium sulfate, calcium carbonate etc. can be used. The inorganic materials as described above that constitute the inorganic filler generally have a higher thermal conductivity than the resin that is the adhesive. Therefore, by adding an inorganic filler to the joint 40 , the thermal conductivity at the joint 40 can be increased. In particular, from the viewpoint of having a relatively high thermal conductivity and being able to easily suppress the thermal resistance of the joint 40, as the material that constitutes the inorganic filler , aluminum nitride, aluminum oxide, and silicon carbide are preferable, and aluminum nitride and aluminum oxide are particularly preferable. Note that the joint 40 may further contain a catalyst that promotes the curing reaction, a silane coupling agent for promoting curing and adhesion to impart adhesiveness

[0038] , a crosslinking agent, a reaction inhibitor for adjusting the curing rate of the adhesive, or a viscosity modifier, etc. As the catalyst contained in the joint 40, ​ Various conventionally known catalysts can be used. For example, a platinum catalyst, a rhodium catalyst, a titanium catalyst, a bismuth catalyst, etc. can be used. Among them, it is desirable to use a platinum catalyst with high reactivity. There are no particular restrictions on the silane coupling agent contained in the joint portion 40. For example, it can be appropriately selected from among conventionally known silane coupling agents such as those having any one of a vinyl group, an epoxy group, a methacrylic group, an amino group, a mercapto group, and an isocyanate group as an organic reactive group. Further, instead of the above silane coupling agent, a titanate coupling agent or an aluminate coupling agent may be used. As the crosslinking agent contained in the joint portion 40, an organohydrogenpolysiloxane having at least three hydrosilyl groups in one molecule can be used. More specifically, for example, polymethylhydrogensiloxane and / or at least one of poly(dimethylsiloxane-methylhydrogensiloxane) can be used.

[0039] As the reaction inhibitor contained in the joint portion 40, various conventionally known reaction inhibitors can be used. For example, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, triallyl isocyanurate, etc. can be used. As the viscosity modifier contained in the joint portion 40, various conventionally known viscosity modifiers can be used. For example, fumed silica, pyrogenic silica, colloidal silica, fumed alumina, pyrogenic alumina, colloidal alumina, etc. can be used. The above-mentioned catalyst, silane coupling agent, crosslinking agent, reaction inhibitor, Alternatively, the type and addition amount of the viscosity modifier or the like may be appropriately selected according to, for example, the type of the resin constituting the joint portion 40 and the like. For example, it may be appropriately selected according to the type of the resin constituting the joint portion 40 and the like.

[0040] The thermal resistance of the joint portion 40 can be reduced by making the thickness of the joint portion 40 thinner according to the formula (1). For example, by setting the thickness of the joint portion 40 to 0.5 mm or less, the thermal resistance of the joint portion 40 at -60 °C can be made 1.1×10 -3 (m 2 K / W) or less, which makes it easier. Also, by increasing the thermal conductivity of the joint portion 40, for example, to 0.7 W / mK or more, even if the thickness of the joint portion 40 is made larger than 0.5 mm, the thermal resistance of the joint portion 40 at -60 °C can be made 1.1×10 1.1×10 -3 (m 2 K / W) or less, which is relatively easy. To increase the thermal conductivity of the joint portion 40, for example, as described later, an inorganic filler made of a material with a higher thermal conductivity may be used, or the content ratio of the inorganic filler may be increased. To increase the thermal conductivity of the joint portion 40, for example, as described later, an inorganic filler made of a material with a higher thermal conductivity may be used, or the content ratio of the inorganic filler may be increased. For example, it may be used or the content ratio of the inorganic filler may be increased.

[0041] Also, the thermal resistance of the joint portion 40 can be changed, for example, by the material of the inorganic filler contained in the joint portion 40, the content of the inorganic filler in the joint portion 40, or the type of the resin contained in the joint portion 40. The thermal resistance of the joint portion 40 can be changed, for example, by the material of the inorganic filler contained in the joint portion 40, the content of the inorganic filler in the joint portion 40, or the type of the resin contained in the joint portion 40. By using an inorganic filler composed of a material with a higher thermal conductivity, furthermore, by increasing the content of the inorganic filler, and by using a resin with a higher thermal conductivity, the thermal conductivity of the joint portion 40 can be increased and the thermal resistance of the joint portion 40 can be reduced. For example, it can be achieved.

[0042] Furthermore, the thermal resistance of the joint portion 40 can be changed by the shape of the particles of the inorganic filler contained in the joint portion 40. For example, it can be changed.

[0043] The inorganic filler may be formed of a homogeneous material, or may have a coating layer made of a material different from the material constituting the particle body of the inorganic filler provided on its surface. By appropriately selecting the material constituting the coating layer, it is possible to improve the water resistance of the inorganic filler, improve the compatibility between the inorganic filler and the resin, and enhance the flexibility of the joint portion 40. For example, when using aluminum nitride powder as the inorganic filler, a coating layer containing silicon dioxide (SiO2), aluminum oxide (Al2O3), or aluminum phosphate (AlPO4) may be provided on the surface of the aluminum nitride particles constituting the inorganic filler. In the electrostatic chuck 10, generally, the base portion 30 has a higher coefficient of thermal expansion than the plate-like portion 20 and expands and contracts significantly due to temperature changes. Therefore, depending on the temperature conditions, the base portion 30 may expand more than the plate-like portion 20. Since the degrees of expansion and contraction between the plate-like portion 20 and the base portion 30 are different in this way, a shearing force in the X-axis direction is applied to the joint portion 40, generating a shear stress. Therefore, as described above, by making the amount of strain at the maximum shear stress of the joint portion 40 larger, even when a large shearing force is applied to the joint portion 40, the shear stress generated at the joint portion 40 can be reduced and damage to the joint portion 40 can be suppressed. As described above, according to the electrostatic chuck 10 of the present embodiment, the thermal resistance of the joint portion 40 provided in the electrostatic chuck 10 is 1.1×10 (m K / W) or less at -60°C. Therefore, even when the heat input to the plate-like portion 20 becomes larger and the base portion 30 is at a very low temperature,

[0044] temperature, the heat input to the plate-like portion 20 can be effectively dissipated through the joint portion 40, preventing the temperature of the plate-like portion 20 from rising excessively. As described above, by making the amount of strain at the maximum shear stress of the joint portion 40 larger, even when a large shearing force is applied to the joint portion 40, the shear stress generated at the joint portion 40 can be reduced and damage to the joint portion 40 can be suppressed.

[0045] As described above, according to the electrostatic chuck 10 of the present embodiment, the thermal resistance of the joint portion 40 provided in the electrostatic chuck 10 is 1.1×10 -3 (m 2 K / W) or less at -60°C. Therefore, even when the heat input to the plate-like portion 20 becomes larger and the base portion 30 is at a very low Even when the temperature is low (e.g., -60 °C), the cooling performance of the electrostatic chuck 10 can be enhanced. As a result, excessive temperature rise of the plate-like portion 20 can be suppressed, and a decrease in the processing accuracy of the wafer due to the temperature rise can be suppressed. At the same time, shear stress generated at the joint portion 40 due to the temperature difference between the plate-like portion 20 and the base portion 30 can be suppressed.

[0046] Also, regarding the joint portion 40, when the thermal conductivity at -60 °C is λ1 and the thermal conductivity at 25 °C is λ2, λ1 / λ2 is set to 1.18 or less, or when the thermal resistance at -60 °C is θ1 and the thermal resistance at 25 °C is θ2, θ1 / θ2 is set to 0.85 or more, the change in thermal conductivity accompanying the temperature change of the joint portion 40 can be reduced. Therefore, the temperature difference in the vertical and in-plane directions of the joint portion 40 can be suppressed.

[0047] Also, when the thermal resistance of the joint portion 40 at 25 °C is 1.2×10 -3 (m 2 K / W) or less, even when the operating temperature of the electrostatic chuck 10 is room temperature (25 °C), the joint portion 40 has good thermal conductivity, so the plate-like portion 20 can be rapidly cooled.

[0048] Also, the larger the strain amount at the maximum shear stress of the joint portion 40, the higher the stress relaxation performance of the joint portion 40. Therefore, the strain amount at the maximum shear stress of the joint portion 40 is set to 0.5 mm or more, so that even when shear stress is generated in the joint portion 40, damage to the joint portion 40 caused by the shear stress can be suppressed.

[0049] Such an effect is particularly remarkable when the electrostatic chuck 10 is exposed to higher output plasma. It can be significantly obtained when the heat input to the plate-like part is large. For example, even when no heater electrode for heating the plate-like part 20 is provided, when the electrostatic chuck 10 is used together with high plasma power, the temperature difference between the mounting surface of the plate-like part 20 and the base part 30 is likely to become large, so the effect according to this embodiment can be significantly obtained. Even when there is no heater electrode for heating, when the electrostatic chuck 10 is used together with high plasma power, the temperature difference between the mounting surface of the plate-like part 20 and the base part 30 is likely to become large, so the effect according to this embodiment can be significantly obtained.

Example

[0050] Hereinafter, the holding device of the present disclosure will be described based on examples. Here, various joint parts having at least one of different thermal conductivity, thermal resistance, and strain amount at maximum shear stress were prepared as samples corresponding to samples 1 to 11 in the form of sheets. Also, electrostatic chuck-shaped samples having joint parts with the same composition as each of the sheet-like samples 1 to 11 were prepared. Hereinafter, the electrostatic chuck-shaped samples will also be referred to by the same sample numbers as the sheet-like samples having the same composition as the joint parts. For various joint parts having at least one of different thermal conductivity, thermal resistance, and strain amount at maximum shear stress, sheet-like samples from Sample 1 to Sample 11 were prepared as corresponding samples. Also, electrostatic chuck-shaped samples having joint parts with the same composition as each of the sheet-like samples 1 to 11 were prepared. Hereinafter, the electrostatic chuck-shaped samples will also be referred to by the same sample numbers as the sheet-like samples having the same composition as the joint parts.

[0051] FIG. 3 is an explanatory diagram collectively showing the evaluation results of the thickness, thermal conductivity (-60 °C, 25 °C), ratio of thermal conductivity (-60 °C / 25 °C), thermal resistance, ratio of thermal resistance (-60 °C / 25 °C), strain amount at maximum shear stress of the joint parts of each sample, the temperature distribution of the plate-like part in the electrostatic chuck, and the temperature drop rate. FIG. 4 is an explanatory diagram showing the composition of each sample. FIG. 5 is a diagram showing the particle size distribution of 10 μm alumina used in the sample. FIG. 6 is a diagram showing the SEM image and particle size distribution of 15 μm aluminum nitride used in the sample. FIG. 7 is a diagram showing the SEM image and particle size distribution of 5 μm aluminum nitride used in the sample. FIG. 8 is a diagram showing the SEM image and particle size distribution of 2 μm aluminum nitride used in the sample. together with the values of the strain amount at maximum shear stress, the temperature distribution of the plate-like part in the electrostatic chuck, and the temperature drop rate. FIG. 3 is an explanatory diagram collectively showing the evaluation results. FIG. 4 is an explanatory diagram showing the composition of each sample. FIG. 5 is a diagram showing the particle size distribution of the alumina 10 μm used in the sample. FIG. 6 is a diagram showing the SEM image and particle size distribution of the aluminum nitride 15 μm used in the sample. FIG. 7 is a diagram showing the SEM image and particle size distribution of the aluminum nitride 5 μm used in the sample. FIG. 5 is a diagram showing the particle size distribution of the 10 μm alumina used in the sample. FIG. 6 is a diagram showing the SEM image and particle size distribution of the 15 μm aluminum nitride used in the sample. FIG. 7 is a diagram showing the SEM image and particle size distribution of the 5 μm aluminum nitride used in the sample. FIG. 6 is a diagram showing the SEM image and particle size distribution of the 15 μm aluminum nitride used in the sample and the particle size distribution. FIG. 7 is a diagram showing the SEM image and particle size distribution of the 5 μm aluminum nitride used in the sample. . FIG. 8 is a diagram showing the SEM image and particle size distribution of the 2 μm aluminum nitride used in the sample.​ is a diagram. FIG. 9 is an explanatory diagram showing the temperature dependence of the thermal conductivity of each sample. FIGS. 10 and 11 are explanatory diagrams showing the temperature dependence of the thermal resistance of each sample. FIGS. 10 and 1 1 show samples with a thickness of 0.5 mm (Samples 1, 3, 4, 6, 8, 10). FIG. 11 shows Samples 1, 3, 4, and 6 in an enlarged manner (with the maximum value on the vertical axis made smaller than in FIG. 10). ).

[0052] <Fabrication of Each Sample> [Fabrication of Sheet-like Samples] In each sample, a silicone resin was used as the adhesive. Specifically, as the uncured adhesive material (resin material), either polydimethylsiloxane or polydimethylsiloxane containing 5 mol% phenyl groups was used. Specifically, for Samples 1 to 3, polydimethylsiloxane containing 5 mol% phenyl groups was used, and for Samples 4 to 11, polydimethylsiloxane was used. As shown in FIG. 4, Samples 1 and 2, Samples 4 and 5, Samples 6 and 7, Samples 8 and 9, and Samples 10 and 11 have the same composition, respectively. As shown in FIG. 3, one has a thickness of 0.5 mm and the other has a thickness of 1 mm. The composition of each sample is as shown in FIG. 4. siloxane was used. As shown in FIG. 4, Samples 1 and 2, Samples 4 and 5, Samples 6 and 7, Samples 8 and 9, and Samples 10 and 11 have the same composition, respectively. As shown in FIG. 3, one has a thickness of 0.5 mm and the other has a thickness of 1 mm. The composition of each sample is as shown in FIG. 4. The filler described in FIG. 4, "alumina 10 μm", is alumina particles with an average particle diameter of 10 μm, and the BET specific surface area is 1.3 m / g. The particle size distribution is as shown in FIG. 5. The average particle diameter was determined by the following method using the particle size distribution. Note that the shape of alumina 10 μm is approximately spherical (FIG. 4). Here, when the filler is viewed in cross-section, the inner

[0053] The filler described in FIG. 4, "alumina 10 μm", is alumina particles with an average particle diameter of 10 μm, and the BET specific surface area is 1.3 m / g. The particle size distribution is as shown in FIG. 5. The average particle diameter was determined by the following method using the particle size distribution. Note that the shape of alumina 10 μm is approximately spherical (FIG. 4). Here, when the filler is viewed in cross-section, the inner 2 / g. The particle size distribution is as shown in FIG. 5. The average particle diameter was determined by the following method using the particle size distribution. Note that the shape of alumina 10 μm is approximately spherical (FIG. 4). Here, when the filler is viewed in cross-section, the inner is as follows. is as follows. ​When the radius of the inscribed circle is R1 and the radius of the circumscribed circle is R2, the average value of the "R2 / R1" value that is close to 1.0 (for example, less than 1.05) is defined as a "true sphere". The average particle size can be measured using a known particle size distribution measuring device. After dispersing the filler in water and then, for example, using Microtrac MT3000II for measurement, the diameter at which the cumulative frequency becomes 50% is taken as the average particle size. The method for obtaining the average particle size is the same for aluminum nitride as well.

[0054] "Aluminum nitride 15 μm" refers to aluminum nitride particles with an average particle size of 15 μm and the BET specific surface area is 0.9 m 2 / g. The particle size distribution is as shown in Fig. 6. " Aluminum nitride 5 μm" refers to aluminum nitride particles with an average particle size of 5 μm, and the BET specific surface area is 1.3 m 2 / g. The particle size distribution is as shown in Fig. 7. "Aluminum nitride 2 μm" refers to aluminum nitride particles with an average particle size of 2 μm, and the BET specific surface area is 2.8 m 2 / g. The particle size distribution is as shown in Fig. 8. The shape of the aluminum nitride is angular granular. Here, "angular granular" means, as shown in the SEM (scanning electron microscope) images of Figs. 6 to 8 irregularly shaped angular particles, not in the shape of a rectangular parallelepiped, true sphere, rod, or plate If the particle shape of the filler has corners different from a true sphere, the number of contacts between particles increases and it becomes easier to form a heat conduction path within the joint 40, and the thermal resistance of the joint 40 becomes smaller.

[0055] The method for producing the sheet-like sample is as follows. The filler and the silicone resin were mixed to prepare a paste-like adhesive. The mixing method is not particularly limited There is no limit, and known mixing with stirring blades, three-roll mills, kneaders, rotating and revolving mixers, planetary mixers, etc. can be used. The prepared paste-like adhesive can be spread on a release film using a known coating device and cured to obtain a sheet-like sample. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing. For example, roll coaters, bar coaters, die coaters, knife coaters, etc. can be used as the coating device. As the release film, for example, polyethylene terephthalate (PET) film can be used, and a PET film coated with a release agent may be used to enhance the release property. In the above various coating devices, in order to obtain a thick cured product or a block-shaped cured product that is difficult to form, the adhesive may be put into a container of a predetermined size and then cured. Using a container made of polytetrafluoroethylene (PTFE) is suitable as it is easy to take out. Heating may be performed as necessary for curing.

[0056] [Fabrication of Samples in the Form of Electrostatic Chucks] The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm. The electrostatic chucks of Samples 1 to 12 all have the same configuration as the electrostatic chuck 10 of the first embodiment shown in FIG. 2. The sample in the form of the electrostatic chuck 10 is fabricated by placing the above-mentioned semi-cured adhesive paste between the plate-like part 20 and the base part 30, and then curing the adhesive paste. As the plate-like part 20, a plate-like part made of aluminum oxide (thermal expansion coefficient is 7 ppm / K) is used, and as the base part 30, a base part made of aluminum (thermal expansion coefficient is 23 ppm / K) is used. The diameters of the plate-like part 20 and the joint part are 350 mm.

[0057] [Evaluation Method] · Thermal Conductivity The thermal conductivity was measured by the heat ray method (probe method) using a known thermal conductivity meter (thermal conductivity measuring device ARC-TC-1000 manufactured by Agne) for block-shaped samples. When measuring the thermal conductivity for the joint incorporated in the electrostatic chuck instead of the block-shaped sample, the plate portion of the electrostatic chuck should be shaved off with a surface grinding machine or the like, and after exposing the joint, the joint can be peeled off using a knife or the like and then the thermal conductivity can be measured.

[0058] · Thermal resistance The thermal resistance R was obtained by the following formula (1) using the measured values of the thermal conductivity of each sample measured as described above. In formula (1), t is the thickness of the joint, and λ is the thermal conductivity of the joint, that is, the thermal conductivity of each sample measured as described above.

[0059] R (m 2 K / W) = t (m) ÷ λ (W / mK) …(1)

[0060] · Strain amount at maximum shear stress The strain amount at maximum shear stress was measured by a tensile test using a known tensile testing machine (Autograph AGS-5kNX manufactured by Shimadzu Corporation).

[0061] Figure 12 is an explanatory diagram schematically showing the calculation method of the maximum shear stress and the strain amount. Figure 12(A) shows the state of the tensile test seen from the front, and Figures 12(B) and 12(C) show the state seen from the side. Also, Figures 12(A) and 12(B) show the state at the start of the test, and Figure 12(C) shows the state after the start of the test. The test pieces 70 of Samples 1 to 12 were prepared by using two semi-cured adhesive sheets of each sample with a width of 25 mm × a length of 100 mm × a thickness of 1 mm. From the edge of the aluminum plate 80 to the position 12.5 mm, a 25 mm×12.5 mm portion is respectively pasted, and after bonding the two aluminum plates 80 in a direction where they can be pulled in opposite directions to each other, it is produced by curing the above-mentioned semi-cured adhesive sheet 。The thickness t of the test piece 70 at the start of the test was set as the thickness of the joint shown in FIGS. 8 to 11. Next, The two aluminum plates 80 were gripped by the jig of the tensile test so that a shearing force acted on the above test piece and relatively moved 。Here, using a tensile testing machine, while moving one aluminum plate at a tensile speed of 2 mm / min in one direction parallel to the bonding surface, the load and the strain amount δ as the moving distance were measured (see FIG. 12(C)). The tensile testing machine and the jig were made of materials with sufficiently high rigidity, and the moving distance of the jig of the tensile testing machine was taken as the strain amount δ. In FIG. 12(B), The relative moving direction of the two aluminum plates is indicated by a white arrow. By dividing the load by the bonding area (25 mm×12.5 mm) of the test piece before the movement, the shear stress was calculated 。Such relative movement of the two aluminum plates was continued until the test piece 70 broke, and the shear stress at the time when the shear stress became maximum was taken as the maximum shear stress (unit: MPa) 。The strain amount (unit: mm) at the maximum shear stress was taken as the strain amount δ at the time when the shear stress became maximum in the tensile test shown in FIG. 12. In addition, when measuring the strain amount at the maximum shear stress of the joint already incorporated in the electrostatic chuck, for example, it is carried out as follows 。First, the joint is cut out together with the adherend (plate-like part and base part) by a processing method such as laser cutting. The shape of the cut-out test piece can be held by the jig of the tensile testing machine, and the two adherends to be joined are pulled in opposite directions as shown in FIG. 12 。 。 。 。 。Note that when measuring the strain amount at the maximum shear stress of the joint already incorporated in the electrostatic chuck, for example, it is carried out as follows 。First, the joint is cut out together with the adherend (plate-like part and base part) by a processing method such as laser cutting. The shape of the cut-out test piece can be held by the jig of the tensile testing machine, and the two adherends to be joined are pulled in opposite directions as shown in FIG. 12 。 。 Any shape is acceptable. Before conducting the tensile test, measure the area of the joint and the thickness of the joint in the cut test piece. After that, perform the tensile test in the same manner as the method described above, and measure the strain amount at the maximum shear stress.

[0062] · Temperature distribution of the plate-like part For each of the samples 1 to 11 of the electrostatic chuck, the temperature distribution of the plate-like part was evaluated. Specifically, while heating the plate-like part so that the average value of the surface temperature of the plate-like part of each sample becomes approximately 100 °C and is constant over time, simultaneously supply a refrigerant at -60 °C to the refrigerant flow path of the base part for cooling. At that time, a temperature difference of less than 2 °C between the maximum value and the minimum value of the surface temperature of the plate-like part was evaluated as "◎", a temperature difference of 2 °C or more and less than 5 °C was evaluated as "〇", and a temperature difference of 5 °C or more was evaluated as "×". The surface temperature of the plate-like part and its change over time were measured using an infrared radiation thermometer. The plate-like part can be heated by irradiating the plate-like part with plasma. In addition, when a heater electrode is provided on the plate-like part, it can also be heated by energizing the heater electrode, and it may be used in combination with heating by plasma irradiation.

[0063] · Cooling rate of the plate-like part For each of the samples 1 to 11 of the electrostatic chuck, in the same manner as the evaluation method of the temperature distribution of the plate-like part described above, heat the plate-like part so that the average value of the surface temperature of the plate-like part becomes approximately 100 °C and is constant over time, and simultaneously supply a refrigerant at -60 °C to the refrigerant flow path of the base part for cooling. After that, stop heating the plate-like part and continue cooling the base part. Starting from the time when heating of the plate-like part was stopped, the change over time of the average value of the surface temperature of the plate-like part was measured. Measure the time required for the average temperature of the plate-like part to be cooled to 0 °C or lower, and evaluate it as "〇" when it is 15 seconds or less, and as "×" when it exceeds 15 seconds.

[0064] Samples 1 to 7 meet the requirements of [1] below. [1] The thermal resistance of the joint is 1.1×10 -3 (m 2 K / W) or less at -60°C.

[0065] In addition to the requirements of [1] above, Samples 1 to 3 also meet the requirements of [2] and [3] below. That is, they satisfy the conditions. [2] When the thermal conductivity of the joint at -60°C is λ1 and the thermal conductivity at 25°C is λ2, λ1 / λ2 is 1.18 or less. [3] When the thermal resistance of the joint at -60°C is θ1 and the thermal resistance at 25°C is θ2, θ1 / θ2 is 0.85 or more.

[0066] In addition to the requirements of [1] above, Samples 1 to 6 also meet the requirement of [4] below. That is, they satisfy the condition. [4] The thermal resistance of the joint at 25°C is 1.2×10 -3 (m 2 K / W) or less.

[0067] Samples 1 to 7 also meet the requirement of [5] below. [5] The thermal conductivity of the joint at 25°C and -60°C is 0.7 (W / mK) or more. That is, it satisfies the condition.

[0068] Samples 1, 2, 4, and 5 also meet the requirement of [6] below. [6] The joint contains aluminum nitride (AlN).

[0069] Samples 1 to 7 also meet the requirement of [7] below. [7] The strain amount at the maximum shear stress of the joint is 0.5 (mm) or more.

[0070] In this way, Samples 8 to 11 all meet at least the requirement of [1] above. Absent, and the evaluation of the temperature distribution and the temperature drop rate of the plate-like part is "×" (Fig. 3).

[0071] As shown in Fig. 3, for Samples 1 to 8, the evaluation of the temperature distribution and the temperature drop rate is "〇" or "◎", indicating good performance. That is, by satisfying the above requirement [1], it can be said that the heat transfer from the plate-like part to the base part has been improved well.

[0072] Furthermore, Samples 1 to 3 satisfy the requirements of the above [2] and [3], and there is no temperature range where the thermal conductivity and the thermal resistance change rapidly as shown in Figs. 9 and 11. Samples 4 to 7 have a smaller thermal resistance compared with Samples 8 to 11 and can rapidly cool the plate-like part. The thermal conductivity and the thermal resistance of Samples 4 to 7 change rapidly in the range of -20°C to -40°C (Figs. 9 and 1 1). Then, since the lower temperature part of the plate-like part is cooled more, there is a risk of a decrease in temperature uniformity. In contrast, for Samples 1 to 3, as described above, since there is no temperature range where the thermal conductivity and the thermal resistance change rapidly, the temperature uniformity of the plate-like part is better than that of Samples 4 to 7 . Samples 1 to 7 satisfy the requirement of the above [5], and the evaluation of the temperature distribution and the temperature drop rate is good. When the thermal conductivity of the joint part is 0.7 (W / mK) or more at 25°C and -60°C , sufficient thermal conductivity can be obtained over the range from cryogenic temperature to normal temperature.

[0073] Samples 1 to 7 satisfy the requirement of the above [5], and the evaluation of the temperature distribution and the temperature drop rate is good. When the thermal conductivity of the joint part is 0.7 (W / mK) or more at 25°C and -60°C , sufficient thermal conductivity can be obtained over the range from cryogenic temperature to normal temperature.

[0074] Samples 1, 2, 4, and 5 contain aluminum nitride (AlN) as a filler , and Samples 3, 6, and 7 contain alumina as a filler (Fig. 4). Therefore , Samples 1, 2, 4, and 5 have a higher thermal conductivity and a lower thermal resistance than Samples 3, 6, and 7​ The resistance is small (Figs. 3, 9 to 11), and the cooling rate of the plate-like portion is faster than 3, 6, and 7.

[0075] For Samples 1, 3, 4, and 6, the strain amount at the maximum shear stress is 0.5 mm or more. The maximum strain amount at the maximum shear stress is a value that represents flexibility and stress relaxation performance, and if it is 0.5 m m or more, it is possible to sufficiently ensure the flexibility and stress relaxation performance of the bonding portion of the electrostatic chuck.

[0076] <Examination of the method for adjusting the thermal conductivity> In order to create a material capable of forming the bonding portion 40 of the above-described embodiment, the method for adjusting the thermal conductivity of the forming material was examined. Specifically, a plurality of samples were created by changing the type of silicone resin (silicone adhesive), the type of filler, and the ratio, and the thermal conductivity was measured. Specifically, as the first silicone resin, a silicone resin containing 5 mol% of phenyl groups and having polydimethylsiloxane as the main component was used, and as the second silicone resin, a silicone resin having polydimethylsiloxane as the main component was used. As the filler, three types (15 μm, 5 μm, 2 μm) having different particle diameters of aluminum nitride were used. Both the first silicone resin and the second silicone resin are silicone resins (silicone adhesives) that can be cured and adhered by heating, and in addition to the main components, they contain a known silane coupling agent, a crosslinking agent having a polydimethylsiloxane structure and a functional group necessary for curing, and a curing catalyst for silicone.

[0077] Figs. 13 and 14 are diagrams showing the composition and thermal conductivity of the samples using the first silicone resin. Fig. 15 shows a triangular diagram of the thermal conductivity of the samples using the first silicone resin. Fig. 1 ​​​​6. Figure 17 is a diagram showing the composition and thermal conductivity of samples using the second silicone resin. Figure 18 shows a triangular diagram of the thermal conductivity of samples using the second silicone resin. In Figures 15 and 18, the axes represent weight ratios, and the conductivity is illustrated horizontally at the points. In Figures 13, 1 4, Figure 16, and Figure 17, the thermal conductivity was measured using a thermal conductivity measuring device TCi manufactured by C-THERM. Note that the thermal conductivity shown in Figure 3 above was measured using a thermal conductivity measuring device (Agne ARC-TC-1000) by the hot wire method (probe method). Although the measurement mechanism is different, the magnitude relationship of the measurement results does not change, but the values themselves do not necessarily match.

[0078] The composition of sample S1 shown in Figure 13 is consistent with the compositions of samples 1 and 2 shown in Figure 4. In Figures 13 and 14, the thermal conductivity of sample S1 is used as a reference ("1"), and the thermal conductivities of the remaining samples are shown as "ratio of thermal conductivities". Also, the composition of sample S18 shown in Figure 16 is consistent with the compositions of samples 4 and 5 shown in Figure 4. In Figures 16 and 17, the thermal conductivity of sample S18 is used as a reference ("1"), and the thermal conductivities of the remaining samples are shown as "ratio of thermal conductivities".

[0079] In Figure 15, the area surrounding a thermal conductivity of 1.35 W / mK or higher is illustrated. Also, in Figure 18 , the area surrounding a thermal conductivity of 1.30 W / mK or higher is illustrated. Also, as shown in Figures 15 and 18, when using the first silicone resin or the second silicone resin, a higher proportion of 15-μm particles resulted in a higher thermal conductivity. However, adding 5-μm and 2-μm particles resulted in a higher thermal conductivity than when using only 15-μm particles. was obtained. It is considered that small particles entered between large particles and the particles were close to each other .

[0080] An adhesive with a large change in thermal conductivity is an adhesive in which phase transition temperatures such as glass transition temperature and crystallization temperature do not exist in the use temperature range. Such an adhesive is a silicone adhesive containing 5 mol% of phenyl groups among silicone adhesives. Since the phenyl group has a large steric hindrance, it is presumed that it does not crystallize even at low temperatures, is flexible, and has a small change in thermal conductivity . . . .

[0081] The high thermal conductivity of silicone adhesives can be achieved by compounding inorganic fillers. For high thermal conductivity, it is necessary to compound a large amount of fillers, but the shape of the fillers that can be compounded in a large amount is spherical or granular. Rod-shaped, plate-shaped, and needle-shaped fillers reduce fluidity, making it difficult to compound a large amount, and even a small amount increases the hardness of the adhesive, so it cannot be used for applications where materials with different coefficients of thermal expansion such as electrostatic chucks are joined . . . .

[0082] In order to further increase the thermal conductivity of the adhesive containing fillers, the shape of the fillers is more preferably granular than spherical. It is preferable that there are many places where the filler particles are in contact or as close as possible to each other. In the case of granular particles, it is considered that there are partially protrusions or depressions, which increases the contact points with adjacent particles . . .

[0083] From the viewpoint of high thermal conductivity of the adhesive, it is preferable to have an aromatic functional group. The density is higher when the aromatic functional group is included. When compounded at the same weight ratio, the content in terms of volume ratio of the one containing the aromatic functional group is considered to reduce the resin and increase the filler. Another reason is that polydime . . Pi bonds such as aromatic groups are thought to have higher thermal conductivity than sigma bonds such as siloxanes. In addition, aromatic groups can coordinate with metal atoms such as aluminum in alumina or aluminum nitride, and phosphorus atoms contained in the surface treatment agent, thus contributing to reducing the thermal resistance at the interface between the filler and the adhesive and increasing the overall thermal conductivity. This is also conceivable.

[0084] B. Second Embodiment: FIG. 19 is a cross-sectional view schematically showing the configuration of the electrostatic chuck 10A according to the second embodiment. FIG. 20 is an enlarged view of part X in FIG. 19. The electrostatic chuck 10A according to the second embodiment includes a terminal through-hole 60 (FIG. 19) in addition to the electrostatic chuck 10 of the first embodiment. In the electrostatic chuck 10A of the second embodiment, the same reference numerals are given to the parts common to the electrostatic chuck 10 of the first embodiment. The terminal through-hole 60 is also simply referred to as a "hole portion". As shown in FIG. 19, the terminal through-hole 60 penetrates through the base portion 30A and the joint portion 40A,

[0085] and reaches below the adsorption electrode 22 in the plate-like portion 20A. An electrode terminal 62 is disposed in the terminal through-hole 60 and is electrically connected to the adsorption electrode 22 via a via 72. Specifically, as shown in FIG. 20, an electrode pad 74 that conducts to the adsorption electrode 22 via a via 72 is disposed on the plate-like portion 20A. In this embodiment, the shape of the electrode pad 74 in the Z-axis direction view is substantially circular. The electrode pad 74 and the via 72 are formed of a conductive material (for example,

[0086] tungsten, molybdenum, etc.). In this embodiment, the shape of the electrode pad 74 in the Z-axis direction view is substantially circular. The electrode pad 74 and the via 72 are formed of a conductive material (for example, tungsten, molybdenum, etc.). tungsten, molybdenum, etc.).

[0087] In the terminal through-hole 60 formed in the base portion 30A, a columnar electrode terminal 62 extending in the Z-axis direction is disposed. In this embodiment, the cross section (a cross section parallel to the surface direction) of the electrode terminal 62 is circular. The upper end of the electrode terminal 62 reaches the electrode pad 74, and the electrode terminal 62 is joined to the electrode pad 74 by, for example, a joint portion made of a metal brazing material.

[0088] In order to insulate between the electrode terminal 62 disposed in the terminal through-hole 60 of the base portion 30A and the base portion 30A, an insulating portion 64 is disposed in the terminal through-hole 60 of the base portion 30A. The insulating portion 64 continuously surrounds the electrode terminal 62 so as to be interposed between the electrode terminal 62 and the surface of the terminal through-hole 60. The insulating portion 64 is made of, for example, an insulating material such as resin or ceramics. In this embodiment, the thermal conductivity of the insulating portion 64 is lower than the thermal conductivity of the plate-like portion 20A (that is, the thermal conductivity of the plate-like portion 20A is higher than the thermal conductivity of the insulating portion 64). Around the insulating portion 64, specifically, between the insulating portion 64 and the electrode terminal 62, between the insulating portion 64 and the plate-like portion 20A, and between the insulating portion 64 and the base portion 30A, a hole joint portion 66 is disposed. The hole joint portion 66 is formed of the same material as the material constituting the joint portion 40A, and joins the insulating portion 64 to the electrode terminal 62, the plate-like portion 20A, and the base portion 30A. Specifically, the hole joint portion 66 joins an end face 64S facing the second face 26 of the plate-like portion 20A in the insulating portion 64 and the plate-like portion 20A. The hole joint portion 66 is thinner than the joint portion 40A. Since the portion of the terminal through-hole 60 has low thermal conductivity in the base portion 30A, it is likely to cause a temperature difference in the temperature distribution of the plate-like portion 20A. The material to be used and the material forming the base portion 30A have a lower thermal conductivity than the material forming the joint portion 40A. Therefore, by making the hole joint portion 66 thinner than the joint portion 40A, a decrease in thermal conductivity is suppressed, and the possibility of a temperature difference occurring is reduced. The configuration for supplying power to the adsorption electrode 22 is as described above. When the electrostatic chuck 10 is in use, a voltage is applied to the adsorption electrode 22 through a conduction path leading from a power source (not shown) through the electrode terminal 62, the electrode pad 74, and the via 72 to the adsorption electrode 22. As a result, an electrostatic attraction force for adsorbing and fixing the wafer W to the adsorption surface S1 is generated.

[0089] The configuration for supplying power to the adsorption electrode 22 is as described above. When the electrostatic chuck 10 is in use, a voltage is applied to the adsorption electrode 22 through a conduction path leading from a power source (not shown) through the electrode terminal 62, the electrode pad 74, and the via 72 to the adsorption electrode 22. As a result, an electrostatic attraction force for adsorbing and fixing the wafer W to the adsorption surface S1 is generated. When the insulating portion 64 and the electrostatic chuck 10A are joined using a resin adhesive such as a general silicone adhesive in the terminal through-hole 60, since the thermal conductivity of the adhesive is not good, in the plate-like portion 20A, the heat dissipation performance of the portion corresponding to the terminal through-hole 60 deteriorates, and there is a risk that the temperature non-uniformity on the first surface 24 of the plate-like portion 20A increases. On the other hand, according to the electrostatic chuck 10A of the present embodiment,

[0090] it is formed of the same material as the joint portion 40A, and heat dissipation can be performed for the portion corresponding to the terminal through-hole 60 of the plate-like portion 20A through the hole joint portion 66 having good thermal conductivity. As a result, the temperature non-uniformity of the plate-like portion 20A can be further suppressed. When the insulating portion 64 and the electrostatic chuck 10A are joined using a resin adhesive such as a general silicone adhesive in the terminal through-hole 60, since the thermal conductivity of the adhesive is not good, in the plate-like portion 20A, the heat dissipation performance of the portion corresponding to the terminal through-hole 60 deteriorates, and there is a risk that the temperature non-uniformity on the first surface 24 of the plate-like portion 20A increases. On the other hand, according to the electrostatic chuck 10A of the present embodiment, it is formed of the same material as the joint portion 40A, and heat dissipation can be performed for the portion corresponding to the terminal through-hole 60 of the plate-like portion 20A through the hole joint portion 66 having good thermal conductivity. As a result, the temperature non-uniformity of the plate-like portion 20A can be further suppressed. The present disclosure is not limited to the above-described embodiments and the like, and can be realized in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention are,

[0091] for solving some or all of the above-described problems, or for achieving some or all of the above-described effects, can be appropriately replaced or combined as needed. The technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention are, for solving some or all of the above-described problems, or for achieving some or all of the above-described effects, It is possible to perform alignment. Also, if the technical features are not described as essential in this specification, they can be appropriately deleted.

[0092] This disclosure can also be realized as the following application examples. [Application Example 1] A holding device for holding an object, a plate-like part formed on a plate having a first surface on which the object is placed and a second surface which is the back surface of the first surface, a base part arranged on the second surface side of the plate-like part, supporting the plate-like part, having a cooling function, and formed in a plate shape, a joining part arranged between the plate-like part and the base part and joining the plate-like part and the base part, and having, wherein the thermal resistance of the joining part is 1.1×10 (m K / W) or less at -60°C, characterized by -3 (m 2 K / W) or less at -60°C, a holding device. [Application Example 2] The holding device according to Application Example 1, wherein the joining part when the thermal conductivity at -60°C is λ1 and the thermal conductivity at 25°C is λ2, λ 1 / λ2 is 1.18 or less, and when the thermal resistance at -60°C is θ1 and the thermal resistance at 25°C is θ2, θ1 / θ2 is 0.85 or more, characterized by satisfying at least one of the above, a holding device. [Application Example 3] The holding device according to Application Example 1 or Application Example 2, wherein the joining part has a thermal resistance of 1.2×10 -3 (m 2 K / W) or less at 25°C, characterized by​​ Retention device [Application Example 4] The retention device according to any one of Application Examples 1 to 3, wherein the joint has a thermal conductivity of 0.7 (W / mK) or more at 25°C and -60°C. Characterized by: Retention device [Application Example 5] The retention device according to any one of Application Examples 1 to 4, wherein the joint contains aluminum nitride (AlN). Characterized by: [Application Example 6] The retention device according to any one of Application Examples 1 to 5, wherein the strain amount at the maximum shear stress of the joint is 0.5 (mm) or more. Characterized by: Retention device [Application Example 7] The retention device according to any one of Application Examples 1 to 6, comprising a hole passing through the base portion, an insulating portion covering the inner wall of the hole, a hole joint for joining an end face of the insulating portion facing the second surface of the plate-like portion and the plate-like portion, and having wherein the hole joint is formed of the same material as the material constituting the joint, and furthermore, the hole joint is thinner than the joint. Characterized by:

Explanation of Reference Numerals

[0093] 10, 10A... Electrostatic chuck 20, 20A... Plate-like portion 22... Adsorption electrode 24... First surface 26... Second surface 30, 30A... Base portion 32... Refrigerant flow path 40, 40A... Joint 50…Gas supply path 52…Gas discharge port 60…Through-hole for terminal 62…Electrode terminal 64…Insulating part 64S…End face 66…Joint part for hole 70…Test piece 72…Via 74…Electrode pad 80…Aluminum plate W…Wafer

Claims

1. A holding device for holding an object, A plate-like plate having a first surface on which the object is placed and a second surface opposite to the first surface. and a plate-shaped portion formed on the The plate-shaped portion is disposed on the second surface side of the plate-shaped portion, and the plate-shaped portion is supported by the plate-shaped portion. The plate-shaped portion has a cooling function. A base portion formed; The plate-shaped portion and the base portion are disposed between the plate-shaped portion and the base portion, and the plate-shaped portion and the base portion are joined together. A joint, Equipped with The thermal resistance of the junction is 1.1×10 at −60° C. -3 (m 2 K / W) or less Characterized by: holding device.

2. 2. The holding device according to claim 1, The joint is When the thermal conductivity at −60° C. is λ1 and the thermal conductivity at 25° C. is λ2, λ 1 / λ2 is 1.18 or less; and When the thermal resistance at -60°C is θ1 and the thermal resistance at 25°C is θ2, then θ1 / θ2 is 0.85 or more; The present invention is characterized in that at least one of the following is satisfied: holding device.

3. 2. The holding device according to claim 1, The thermal resistance of the joint at 25° C. is 1.2×10 -3 (m 2 K / W) or less Characterized by: holding device.

4. A holding device according to any one of claims 1 to 3, The joint has a thermal conductivity of 0.7 (W / mK) or more at 25°C and -60°C. Characterized in that holding device.

5. A holding device according to any one of claims 1 to 3, The bonding portion contains aluminum nitride (AlN). holding device.

6. A holding device according to any one of claims 1 to 3, The strain amount at the maximum shear stress of the joint is 0.5 (mm) or more. R, holding device.

7. A holding device according to any one of claims 1 to 3, a hole penetrating the base portion; an insulating portion covering an inner wall of the hole; The plate-shaped portion is joined to an end surface of the insulating portion that faces the second surface of the plate-shaped portion. a hole joint; having The hole joint is made of the same material as the material constituting the joint, and and is thinner than the joint portion. holding device.

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