JP2021111662A - Holding device - Google Patents

Abstract

To improve heat resistance of a holding device while suppressing bonding failure at a bonding part, deformation of the holding device and so forth caused by difference in thermal expansion between a tabular part and a base part.SOLUTION: The holding device comprises: the tabular part which has a first surface substantially perpendicular to a first direction; and the base part which is made of a material having a thermal expansion coefficient different from that of a formation material of the tabular part. The holding device is configured so as to hold an object on the first surface of the tabular part. The holding device comprises a plurality of metal parts which are made of a metal material, and are disposed between the tabular part and the base part. One of the tabular part and the base part is provided with a plurality of recesses each of which at least partially houses each of the metal parts. The holding device further comprises the bonding part, made of an inorganic material and disposed inside each of the recesses, which bonds a surface of each of the recesses to each of the metal parts housed therein.SELECTED DRAWING: Figure 2

Description

The techniques disclosed herein relate to holding devices that hold objects.

For example, an electrostatic chuck is used as a holding device for holding a wafer in a vacuum chamber of a semiconductor manufacturing device. The electrostatic chuck is provided inside, for example, a plate-shaped member made of a material containing ceramics, a base member made of metal, for example, a joint portion for joining the plate-shaped member and the base member, and the inside of the plate-shaped member. It is equipped with a chuck electrode. The electrostatic chuck uses the electrostatic attraction generated by applying a voltage to the chuck electrode to attract and hold the wafer on the surface of the plate-shaped member. The joint portion for joining the plate-shaped member and the base member is formed of, for example, a material containing, for example, a resin (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-143796

In the conventional electrostatic chuck configuration, since the joint portion for joining the plate-shaped member and the base member is formed of a material containing a resin, there is room for improvement in terms of heat resistance. In order to improve the heat resistance of the electrostatic chuck, it is also conceivable to form the joint portion with an inorganic material (inorganic adhesive such as metal or ceramics) having higher heat resistance than resin. However, when the joint is formed of an inorganic material, the stress relaxation function is low because the inorganic material is harder than the resin, so that the stress caused by the difference in thermal expansion between the plate-shaped member and the base member is effectively applied. It cannot be relaxed, and it is not possible to suppress the occurrence of poor joining of the joint and deformation of the electrostatic chuck due to the difference in thermal expansion. As described above, in the conventional electrostatic chuck, the heat resistance is improved while suppressing the occurrence of joint failure and deformation of the electrostatic chuck due to the difference in thermal expansion between the plate-shaped member and the base member. There is a problem that it cannot be done.

It should be noted that such a problem is not limited to the electrostatic chuck that holds the wafer by utilizing electrostatic attraction, and includes a plate-shaped portion, a base portion, and a joint portion for joining the two, and the surface of the plate-shaped portion. A holding device that holds an object on top is a common issue in general.

This specification discloses a technique capable of solving the above-mentioned problems.

The techniques disclosed herein can be realized, for example, in the following forms.

(1) The holding device disclosed in the present specification includes a plate-shaped portion having a first surface substantially orthogonal to the first direction and a second surface opposite to the first surface. , The third surface is arranged so as to be located on the second surface side of the plate-shaped portion, and the thermal expansion is different from the thermal expansion coefficient of the material for forming the plate-shaped portion. In a holding device comprising a base portion formed of a material having a coefficient and holding an object on the first surface of the plate-shaped portion, the plate formed of a metallic material and formed in the first direction. A plurality of metal portions arranged between the shaped portion and the base portion are provided, and a plurality of recesses for accommodating at least a part of the metal portion are formed on one of the plate-shaped portion and the base portion. The holding device is further formed of an inorganic material, arranged in each of the recesses, and has a joint portion for joining the surface of each of the recesses and each of the metal portions housed in the recesses. Be prepared. According to this holding device, the plate-shaped portion and the base portion can be joined by a joint portion formed of an inorganic material having higher heat resistance than an organic material such as resin, so that the heat resistance of the holding device is high. Can be improved. Further, according to this holding device, even if a joint portion formed of an inorganic material having a lower stress relaxation function than an organic material such as resin is used, a plurality of metal portions formed of the metal material are deformed. As a result, the stress caused by the difference in thermal expansion between the plate-shaped portion and the base portion can be relaxed, and the occurrence of poor joining of the joint portion and deformation of the holding device due to the difference in thermal expansion can be suppressed. Can be done. Therefore, according to this holding device, the heat resistance of the holding device is improved while suppressing the occurrence of poor joining of the joint portion and deformation of the holding device due to the difference in thermal expansion between the plate-shaped portion and the base portion. be able to.

(2) In the holding device, each metal portion has a first end portion which is an end portion on the plate-shaped portion side and a second end portion which is an end portion on the base portion side. The diameter of the first end portion of each of the metal portions may be larger than the diameter of the second end portion. According to such a configuration, by making the diameter of the second end portion of each metal portion relatively small, the deformation performance of each metal portion can be ensured, and the plate-shaped portion and the base portion of each metal portion can be ensured. It is possible to secure the function of relaxing the stress caused by the difference in thermal expansion between the metal and the metal. Further, according to this holding device, the contact area between each metal portion and the plate-shaped portion is increased by making the diameter of the first end portion of the metal portion having a higher thermal conductivity than that of ceramics relatively large. By increasing the number, the heat transferability between the plate-shaped portion and the base portion via each metal portion can be improved, and as a result, the controllability of the temperature distribution on the first surface of the plate-shaped portion can be improved. ..

(3) In the holding device, the plate-shaped portion may be formed of ceramics, the plurality of recesses may be formed in the plate-shaped portion, and the inorganic material may be made of metal. According to such a configuration, since the joint portion is formed of metal, the heat between the plate-shaped portion and the base portion is caused not only by the deformation of the plurality of metal portions but also by the deformation of the metal joint portion. The stress caused by the difference in expansion can be relaxed, and the occurrence of poor joining of the joint portion and deformation of the holding device due to the difference in thermal expansion can be effectively suppressed. Further, in this holding device, since the metal joint is divided and arranged in each recess formed in the ceramic plate-shaped portion, the joint is continuously arranged over the entire surface of the plate-shaped portion. Compared with the formed configuration, the stress caused by the difference in thermal expansion between the plate-shaped portion and the joint portion can be reduced, and the joint defect and the deformation of the holding device due to the difference in thermal expansion can be reduced. Etc. can be effectively suppressed.

(4) In the holding device, the base portion is formed of metal, and the plurality of metal portions and the base portion may be configured as an integral member. According to such a configuration, it is possible to realize a simplification of the configuration of the holding device and simplification of manufacturing as compared with a configuration in which a plurality of metal portions are separate members from the base portion.

(5) In the holding device, each metal portion has a first end portion which is an end portion on the plate-shaped portion side and a second end portion which is an end portion on the base portion side. The first end portion of each of the metal portions is brazed to the surface of the plate-shaped portion by a metal brazing portion, and the area of each brazed portion is viewed in the first direction. May be configured to be larger than the area of the first end of each metal portion. According to such a configuration, the heat transfer property between the plate-shaped portion and the base portion via the metal portion and the metal brazed portion can be improved, and as a result, the first surface of the plate-shaped portion can be improved. The controllability of the temperature distribution of the above can be effectively improved.

The technique disclosed in the present specification can be realized in various forms, for example, a holding device, an electrostatic chuck, a method for manufacturing the same, and the like.

A perspective view schematically showing an external configuration of the electrostatic chuck 100 according to the first embodiment. Explanatory drawing schematically showing the XZ cross-sectional structure of the electrostatic chuck 100 in 1st Embodiment Explanatory drawing which shows the detailed structure of the connection between the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of 1st Embodiment. Explanatory drawing which shows the outline of the manufacturing method of the electrostatic chuck 100 in 1st Embodiment Explanatory drawing which shows the detailed structure of the connection between the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of 2nd Embodiment. Explanatory drawing which shows the detailed structure of the connection between the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of 3rd Embodiment. Explanatory drawing which shows the outline of the manufacturing method of the electrostatic chuck 100 in 3rd Embodiment

A. First Embodiment:
A-1. Configuration of electrostatic chuck 100:
FIG. 1 is a perspective view schematically showing an external configuration of the electrostatic chuck 100 according to the first embodiment, and FIG. 2 is an explanatory view schematically showing an XZ cross-sectional configuration of the electrostatic chuck 100 according to the first embodiment. Is. Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as an upward direction, and the Z-axis negative direction is referred to as a downward direction, but the electrostatic chuck 100 is actually installed in a direction different from such a direction. May be done.

The electrostatic chuck 100 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is for a semiconductor manufacturing apparatus used for fixing a wafer W in a vacuum chamber of the semiconductor manufacturing apparatus, for example. It is a part. The electrostatic chuck 100 includes a plate-shaped member 10 and a base member 20 arranged side by side in a predetermined arrangement direction (in the present embodiment, the vertical direction (Z-axis direction)). The base member 20 is arranged so that the upper surface S3 of the base member 20 is located on the lower surface S2 side of the plate-shaped member 10. The lower surface S2 of the plate-shaped member 10 corresponds to the second surface in the claims, and the upper surface S3 of the base member 20 corresponds to the third surface in the claims.

The plate-shaped member 10 is a plate-shaped member that is substantially circular in the Z-axis direction, and is made of ceramics (for example, alumina, aluminum nitride, etc.). The plate-shaped member 10 is composed of an outer peripheral portion OP, which is a portion in which a notch is formed on the upper side along the outer circumference, and an inner portion IP located inside the outer peripheral portion OP. The thickness of the inner IP of the plate-shaped member 10 (thickness in the Z-axis direction, the same applies hereinafter) is thicker than the thickness of the outer peripheral OP by the amount of the notch formed in the outer peripheral OP. .. That is, the thickness of the plate-shaped member 10 changes at the position of the boundary between the outer peripheral portion OP and the inner portion IP of the plate-shaped member 10.

The diameter of the inner IP of the plate-shaped member 10 is, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and the diameter of the outer peripheral OP of the plate-shaped member 10 is, for example, about 60 mm to 510 mm (usually about 210 mm to 360 mm). (However, the diameter of the outer peripheral OP is larger than the diameter of the inner IP). The thickness of the inner IP of the plate-shaped member 10 is, for example, about 1 mm to 10 mm, and the thickness of the outer peripheral OP of the plate-shaped member 10 is, for example, about 0.5 mm to 9.5 mm (however, the outer peripheral portion). The thickness of OP is thinner than the thickness of inner IP).

Of the upper surface S1 of the plate-shaped member 10, the upper surface (hereinafter, also referred to as “adsorption surface”) S11 in the inner portion IP is a substantially circular surface substantially orthogonal to the Z-axis direction. The suction surface S11 corresponds to the first surface in the claims, and the Z-axis direction corresponds to the first direction in the claims. In this specification, the direction orthogonal to the Z-axis direction is referred to as "plane direction".

Of the upper surface S1 of the plate-shaped member 10, the upper surface (hereinafter, also referred to as “outer peripheral upper surface”) S12 in the outer peripheral portion OP is a substantially annular surface substantially orthogonal to the Z-axis direction. For example, a jig (not shown) for fixing the electrostatic chuck 100 is engaged with the outer peripheral upper surface S12 of the plate-shaped member 10.

As shown in FIG. 2, a chuck electrode 40 formed of a conductive material (for example, tungsten, molybdenum, platinum, etc.) is arranged inside the plate-shaped member 10. The shape of the chuck electrode 40 in the Z-axis direction is, for example, substantially circular. When a voltage is applied to the chuck electrode 40 from a chuck power supply (not shown), an electrostatic attraction is generated, and the wafer W is attracted and fixed to the suction surface S11 of the plate-shaped member 10 by this electrostatic attraction.

Inside the plate-shaped member 10, a heater electrode 50 composed of a resistance heating element containing a conductive material (for example, tungsten, molybdenum, platinum, etc.) is arranged. When a voltage is applied to the heater electrode 50 from a heater power supply (not shown), the heater electrode 50 generates heat to heat the plate-shaped member 10, and the wafer W held on the suction surface S11 of the plate-shaped member 10 is formed. It is warmed up. As a result, the temperature distribution of the wafer W can be controlled.

The base member 20 is, for example, a circular flat plate-shaped member having the same diameter as the outer peripheral OP of the plate-shaped member 10 or having a diameter larger than the outer peripheral OP of the plate-shaped member 10, and is a metal (aluminum, aluminum alloy, etc.). Is formed by. The coefficient of thermal expansion of the material (metal) for forming the base member 20 is different from the coefficient of thermal expansion of the material (ceramics) for forming the plate-shaped member 10. More specifically, the coefficient of thermal expansion of the material (metal) for forming the base member 20 is larger than the coefficient of thermal expansion of the material (ceramics) for forming the plate-shaped member 10. The diameter of the base member 20 is, for example, about 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base member 20 is, for example, about 20 mm to 40 mm.

The base member 20 is joined to the plate-shaped member 10. The structure of joining the plate-shaped member 10 and the base member 20 will be described in detail later.

A refrigerant flow path 21 is formed inside the base member 20. When a refrigerant (for example, a fluorine-based inert liquid, water, etc.) is flowed through the refrigerant flow path 21, the base member 20 is cooled, and the plate is transferred (heat-pulled) between the base member 20 and the plate-shaped member 10. The shaped member 10 is cooled, and the wafer W held on the suction surface S11 of the plate-shaped member 10 is cooled. As a result, the temperature distribution of the wafer W can be controlled.

A-2. Detailed configuration of joining the plate-shaped member 10 and the base member 20:
Next, a detailed configuration of joining the plate-shaped member 10 and the base member 20 will be described. FIG. 3 is an explanatory diagram showing a detailed configuration of joining the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of the first embodiment. FIG. 3 shows an enlarged XZ cross-sectional configuration of a part of the electrostatic chuck 100 (X1 portion in FIG. 2).

As shown in FIGS. 2 and 3, a plurality of columnar convex portions 70 extending in the Z-axis direction are formed on the upper surface S3 of the base member 20. The plurality of convex portions 70 are arranged substantially evenly over substantially the entire upper surface S3 of the base member 20. The shape of each convex portion 70 in the Z-axis direction is, for example, a circle or a polygon. The outer diameter of each convex portion 70 is, for example, about 1 mm to 5 mm, and the height of each convex portion 70 is, for example, about 2 mm to 10 mm.

Further, a plurality of recesses 80 are formed on the lower surface S2 of the plate-shaped member 10. Each of the plurality of recesses 80 accommodates at least a portion of one convex portion 70. The shape of each recess 80 in the Z-axis direction is, for example, a circle or a polygon. The inner diameter of each recess 80 is, for example, about 2 mm to 10 mm (however, it is larger than the outer diameter of the convex portion 70), and the depth of each recess 80 is, for example, about 1 mm to 5 mm.

In each recess 80, a joint portion 90 formed of an inorganic material (for example, a metal such as solder, ceramics such as alumina or zirconia) is arranged. In this embodiment, the joint 90 is made of metal. The joint portion 90 joins the surface of each concave portion 80 and each convex portion 70 housed in each concave portion 80. As described above, in the electrostatic chuck 100 of the present embodiment, the plate-shaped member 10 and the base member 20 are joined by joining the surface of each concave portion 80 and each convex portion 70 by the metal joining portion 90. Has been done.

As shown in FIG. 3, when the base member 20 is virtually divided into a plurality of convex portions 70 and other portions (hereinafter, referred to as "main body portion 22"), the plurality of convex portions 70 are formed. , Which is formed of a metal material and is arranged between the plate-shaped member 10 and the main body portion 22 of the base member 20 in the Z-axis direction, and can be expressed as an integral member with the main body portion 22 of the base member 20. In the present embodiment, the plurality of convex portions 70 of the base member 20 correspond to a plurality of metal portions in the claims, and the main body portion 22 of the base member 20 corresponds to the base portion in the claims, and is a plate. The shaped member 10 corresponds to a plate-shaped portion within the scope of claims.

A-3. Manufacturing method of electrostatic chuck 100:
Next, an example of the method for manufacturing the electrostatic chuck 100 according to the first embodiment will be described. FIG. 4 is an explanatory diagram showing an outline of a method for manufacturing the electrostatic chuck 100 according to the first embodiment.

First, the plate-shaped member 10 and the base member 20 are prepared. The plate-shaped member 10 and the base member 20 can be manufactured by a known manufacturing method. For example, the plate-shaped member 10 is manufactured by the following method. That is, a plurality of ceramic green sheets (for example, alumina green sheet) are prepared, and metallized ink for forming the chuck electrode 40, the heater electrode 50, etc. is printed on each ceramic green sheet, and then the plurality of ceramic green sheets are printed. The plate-shaped member 10 is manufactured by laminating the sheets, thermocompression-bonding them, cutting them into a predetermined disk shape, firing them, and finally performing a polishing process or the like. The plurality of recesses 80 on the lower surface S2 of the plate-shaped member 10 can be formed by, for example, blasting or machining. Further, the plurality of convex portions 70 on the upper surface S3 of the base member 20 can be formed by, for example, blasting or machining.

Next, the inorganic adhesive 92 for forming the joint portion 90 is arranged in each recess 80 formed in the lower surface S2 of the plate-shaped member 10 (see column A in FIG. 4). Then, the base member 20 is arranged so that the convex portions 70 formed on the upper surface S3 of the base member 20 are accommodated in the concave portions 80 formed in the plate-shaped member 10, and the base member 20 is placed in the plate-shaped member 20. By curing the inorganic adhesive 92 while applying a load so as to press it against 10, a joint portion 90 that joins the surface of each concave portion 80 and each convex portion 70 is formed (see column B in FIG. 4). As a result, the plate-shaped member 10 and the base member 20 are joined. Mainly by the above steps, the production of the electrostatic chuck 100 having the above-described configuration is completed.

A-4. Effect of the first embodiment:
As described above, the electrostatic chuck 100 of the first embodiment has a plate-shaped member 10 having a suction surface S11 substantially orthogonal to the Z-axis direction and a lower surface S2 on the opposite side of the suction surface S11, and an upper surface. A base member having S3, the upper surface S3 is arranged so as to be located on the lower surface S2 side of the plate-shaped member 10, and the base member is formed of a material having a coefficient of thermal expansion different from the coefficient of thermal expansion of the material for forming the plate-shaped member 10. It is a holding device that includes the main body portion 22 of 20 and holds the wafer W on the suction surface S11 of the plate-shaped member 10. The electrostatic chuck 100 of the first embodiment further includes a plurality of convex portions 70 formed on the base member 20. The plurality of convex portions 70 are formed of a metal material and are arranged between the plate-shaped member 10 and the main body portion 22 of the base member 20 in the Z-axis direction. Further, the plate-shaped member 10 is formed with a plurality of recesses 80 each accommodating at least a part of the convex portion 70. Further, the electrostatic chuck 100 of the first embodiment is further formed of an inorganic material and arranged in each recess 80, and joins the surface of each recess 80 and each convex portion 70 housed in each recess 80. The joint portion 90 is provided.

As described above, according to the electrostatic chuck 100 of the first embodiment, the plate-shaped member is formed by the joint portion 90 formed of the inorganic material (inorganic adhesive 92) having higher heat resistance than the organic material such as resin. Since the 10 and the base member 20 can be joined, the heat resistance of the electrostatic chuck 100 can be improved. Further, according to the electrostatic chuck 100 of the first embodiment, even if a joint portion 90 formed of an inorganic material (inorganic adhesive 92) having a low stress relaxation function as compared with an organic material such as resin is used, a metal is used. By deforming the plurality of convex portions 70 formed of the material, the stress caused by the difference in thermal expansion between the plate-shaped member 10 and the base member 20 can be relaxed, and the joint caused by the difference in thermal expansion can be relaxed. It is possible to suppress the occurrence of poor bonding of the portion 90 and deformation of the electrostatic chuck 100. Therefore, according to the electrostatic chuck 100 of the first embodiment, the joint failure of the joint portion 90 and the deformation of the electrostatic chuck 100 due to the difference in thermal expansion between the plate-shaped member 10 and the base member 20 occur. The heat resistance of the electrostatic chuck 100 can be improved while suppressing the pressure.

Further, in the electrostatic chuck 100 of the first embodiment, the plate-shaped member 10 is formed of ceramics, the plurality of recesses 80 are formed in the plate-shaped member 10, and the forming material of the joint portion 90 is metal. .. As described above, in the electrostatic chuck 100 of the first embodiment, since the joint portion 90 is formed of metal, in addition to the deformation of the plurality of metal convex portions 70, the deformation of the metal joint portion 90 causes the joint portion 90 to be deformed. Also, the stress caused by the thermal expansion difference between the plate-shaped member 10 and the base member 20 can be relaxed, and the joint portion 90 due to the thermal expansion difference, the deformation of the electrostatic chuck 100, and the like can be alleviated. Occurrence can be effectively suppressed. Further, in the electrostatic chuck 100 of the first embodiment, since the metal joint 90 is separately arranged in each recess 80 formed in the ceramic plate-shaped member 10, the joint 90 is a plate. The stress caused by the thermal expansion difference between the plate-shaped member 10 and the joint portion 90 can be reduced as compared with the configuration formed continuously over the entire surface of the shaped member 10, and the thermal expansion difference can be reduced. It is possible to effectively suppress the occurrence of joint failure of the joint portion 90 and deformation of the electrostatic chuck 100 due to the above.

Further, in the electrostatic chuck 100 of the first embodiment, the main body portion 22 of the base member 20 is formed of metal, and the plurality of metal convex portions 70 and the main body portion 22 of the base member 20 are integral members. .. Therefore, according to the electrostatic chuck 100 of the first embodiment, the configuration of the electrostatic chuck 100 is simpler than the configuration in which the plurality of convex portions 70 are separate members from the main body portion 22 of the base member 20. It is possible to realize the simplification of manufacturing and manufacturing.

B. Second embodiment:
FIG. 5 is an explanatory diagram showing a detailed configuration of joining the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of the second embodiment. In the following, among the configurations of the electrostatic chuck 100 of the second embodiment, the same configurations as the configurations of the electrostatic chuck 100 of the first embodiment described above will be appropriately omitted by adding the same reference numerals. ..

As shown in FIG. 5, the electrostatic chuck 100 of the second embodiment is different from the electrostatic chuck 100 of the first embodiment in that a plurality of convex portions 70 formed on the base member 20 are configured. More specifically, in the electrostatic chuck 100 of the second embodiment, each convex portion 70 has a lower portion 72 which is a part of the lower side (the main body portion 22 side of the base member 20) and an upper side (plate-shaped member 10). It is composed of an upper portion 71 which is a part of the side). The lower portion 72 and the upper portion 71 constituting each convex portion 70 are both columnar portions extending in the Z-axis direction, but the outer diameter of the upper portion 71 is larger than the outer diameter of the lower portion 72. That is, the diameter of the upper end (hereinafter referred to as "upper end P1") of each convex portion 70 is the lower end (the main body 22 side of the base member 20). Hereinafter, it is larger than the diameter of "lower end P2"). The outer diameter of the upper end P1 of each convex portion 70 is, for example, about 7 mm to 12 mm, and the outer diameter of the lower end P2 is, for example, about 1 mm to 5 mm. The upper end P1 corresponds to the first end in the claims and the lower end P2 corresponds to the second end in the claims.

The plurality of convex portions 70 of the base member 20 in the second embodiment form the lower portion 72 of each convex portion 70 by, for example, blasting or machining, and then on the tip of the lower portion 72. It can be formed by joining the upper portion 71 by, for example, brazing. A plate-shaped metal member may be joined to the tip of the lower portion 72 of each convex portion 70, and then the metal member may be processed to produce the upper portion 71 of each convex portion 70.

As described above, the electrostatic chuck 100 of the second embodiment includes a plurality of convex portions 70 formed on the base member 20, and the plurality of convex portions are provided, similarly to the electrostatic chuck 100 of the first embodiment. The 70 is formed of a metal material and is arranged between the plate-shaped member 10 and the main body 22 of the base member 20 in the Z-axis direction. Further, the plate-shaped member 10 is formed with a plurality of recesses 80 each accommodating at least a part of the convex portion 70. Further, the electrostatic chuck 100 is further formed of an inorganic material, is arranged in each recess 80, and has a joint portion 90 for joining the surface of each recess 80 and each convex portion 70 housed in each recess 80. Be prepared. Therefore, according to the electrostatic chuck 100 of the second embodiment, similarly to the electrostatic chuck 100 of the first embodiment, the joint portion 90 caused by the difference in thermal expansion between the plate-shaped member 10 and the base member 20 It is possible to improve the heat resistance of the electrostatic chuck 100 while suppressing the occurrence of poor bonding and deformation of the electrostatic chuck 100.

Further, in the electrostatic chuck 100 of the second embodiment, each convex portion 70 has an upper end portion P1 which is an end portion on the plate-shaped member 10 side and a lower end portion which is an end portion on the main body portion 22 side of the base member 20. It has an end portion P2, and the diameter of the upper end portion P1 is larger than the diameter of the lower end portion P2. Therefore, according to the electrostatic chuck 100 of the second embodiment, the deformation performance of each convex portion 70 can be ensured by making the diameter of the lower end portion P2 of each convex portion 70 relatively small. It is possible to secure the function of relaxing the stress caused by the difference in thermal expansion between the plate-shaped member 10 and the base member 20 due to the convex portion 70. Further, according to the electrostatic chuck 100 of the second embodiment, each convex portion 70 is made by relatively increasing the diameter of the upper end portion P1 of each convex portion 70 made of metal having a higher thermal conductivity than ceramics. The contact area between the plate-shaped member 10 and the plate-shaped member 10 can be increased to improve the heat transfer property between the plate-shaped member 10 and the base member 20 via each of the convex portions 70, and as a result, the plate-shaped member 10 can be improved. The controllability of the temperature distribution of the suction surface S11 can be improved.

C. Third Embodiment:
FIG. 6 is an explanatory diagram showing a detailed configuration of joining the plate-shaped member 10 and the base member 20 in the electrostatic chuck 100 of the third embodiment. In the following, among the configurations of the electrostatic chuck 100 of the third embodiment, the same configurations as the configurations of the electrostatic chuck 100 of the first and second embodiments described above will be appropriately described by adding the same reference numerals. Omit.

The shape and size of each convex portion 70 in the electrostatic chuck 100 of the third embodiment is the same as the shape and size of each convex portion 70 in the electrostatic chuck 100 of the second embodiment. That is, as shown in FIG. 6, in the electrostatic chuck 100 of the third embodiment, a plurality of convex portions 70 are composed of a lower portion 72 and an upper portion 71, and the upper end portion of each convex portion 70. The diameter of P1 is larger than the diameter of the lower end P2. However, in the electrostatic chuck 100 of the third embodiment, each convex portion 70 is provided as a separate member from the base member 20.

That is, each convex portion 70 is a metal member independent of the base member 20. The upper end portion P1 of each convex portion 70 is brazed to the lower surface S2 of the plate-shaped member 10 by a metal brazing portion 60. In the present embodiment, a plurality of recesses 14 are formed on the lower surface S2 of the plate-shaped member 10, and each convex portion 70 is joined to the surface of the recess 14 in a state of being housed in the recess 14. .. In the Z-axis direction, the area of each brazed portion 60 is larger than the area of the upper end portion P1 of each convex portion 70. That is, the entire upper end portion P1 of each convex portion 70 is joined to the surface of the plate-shaped member 10 by the brazing portion 60.

Further, a plurality of recesses 82 are formed on the upper surface S3 of the base member 20. Each of the plurality of recesses 82 accommodates at least a portion of one convex portion 70. The shape and size of each recess 82 is the same as that of the recess 80 formed on the lower surface S2 of the plate-shaped member 10 in the first embodiment.

In each recess 82, a joint portion 90 formed of an inorganic material (for example, a metal such as solder, ceramics such as alumina or zirconia) is arranged. In this embodiment, the joint 90 is made of metal. The joint portion 90 joins the surface of each concave portion 82 and each convex portion 70 housed in each concave portion 82. As described above, in the electrostatic chuck 100 of the present embodiment, the plate-shaped member 10 and the base member 20 are joined by joining the surface of each concave portion 82 and each convex portion 70 by the metal joining portion 90. Has been done.

In the present embodiment, the plurality of convex portions 70 correspond to a plurality of metal portions in the claims, the base member 20 corresponds to the base portion in the claims, and the plate-shaped member 10 is a patent. Corresponds to the plate-shaped part in the claims.

FIG. 7 is an explanatory diagram showing an outline of a method for manufacturing the electrostatic chuck 100 according to the third embodiment. When manufacturing the electrostatic chuck 100 in the third embodiment, a plurality of recesses 14 are formed on the lower surface S2 of the plate-shaped member 10 by, for example, blasting or machining, and the protrusions 70 are accommodated in the recesses 14. A brazed portion 60 is formed to join the convex portion 70 to each concave portion 14 (see column A in FIG. 7). Further, a plurality of recesses 82 are formed on the upper surface S3 of the base member 20 by, for example, blasting or machining (see column B in FIG. 7).

Next, the inorganic adhesive 92 for forming the joint portion 90 is arranged in each recess 82 formed in the base member 20 (see column B in FIG. 7). Then, the plate-shaped member 10 is arranged so that each convex portion 70 joined to the plate-shaped member 10 is accommodated in each recess 82 formed in the base member 20, and the plate-shaped member 10 is used as the base member 20. By curing the inorganic adhesive 92 while applying a load so as to press it, a joint portion 90 for joining the surface of each concave portion 82 and each convex portion 70 is formed (see column C in FIG. 7). As a result, the plate-shaped member 10 and the base member 20 are joined.

As described above, the electrostatic chuck 100 of the third embodiment includes a plurality of convex portions 70 like the electrostatic chuck 100 of the first and second embodiments, and the plurality of convex portions 70 are made of a metal material. Is formed between the plate-shaped member 10 and the base member 20 in the Z-axis direction. Further, the base member 20 is formed with a plurality of recesses 82 for accommodating at least a part of the convex portion 70. Further, the electrostatic chuck 100 is further formed of an inorganic material, is arranged in each recess 82, and has a joint portion 90 for joining the surface of each recess 82 and each convex portion 70 housed in each recess 82. Be prepared. Therefore, according to the electrostatic chuck 100 of the third embodiment, as in the electrostatic chuck 100 of the first and second embodiments, the joint portion caused by the thermal expansion difference between the plate-shaped member 10 and the base member 20. The heat resistance of the electrostatic chuck 100 can be improved while suppressing the occurrence of poor bonding of the 90 and deformation of the electrostatic chuck 100.

Further, in the electrostatic chuck 100 of the third embodiment, similarly to the electrostatic chuck 100 of the second embodiment, each convex portion 70 has an upper end portion P1 which is an end portion on the plate-shaped member 10 side and a base member. Since it has a lower end portion P2 which is an end portion on the 20 side and the diameter of the upper end portion P1 is larger than the diameter of the lower end portion P2, the deformation performance of each convex portion 70 is ensured and each convex portion 70 is secured. The stress relaxation function can be ensured, and the contact area between each convex portion 70 and the plate-shaped member 10 is increased to transmit the stress between the plate-shaped member 10 and the base member 20 via each convex portion 70. It is possible to improve the thermal property and improve the controllability of the temperature distribution of the suction surface S11 of the plate-shaped member 10.

Further, in the electrostatic chuck 100 of the third embodiment, each convex portion 70 has an upper end portion P1 which is an end portion on the plate-shaped member 10 side and a lower end portion P2 which is an end portion on the base member 20 side. The upper end portion P1 of each convex portion 70 is brazed to the lower surface S2 of the plate-shaped member 10 by a metal brazing portion 60, and the area of each brazed portion 60 is viewed in the Z-axis direction. Is larger than the area of the upper end P1 of each convex portion 70. Therefore, according to the electrostatic chuck 100 of the third embodiment, the heat transfer property between the plate-shaped member 10 and the base member 20 via the metal convex portion 70 and the brazing portion 60 can be improved. As a result, the controllability of the temperature distribution of the suction surface S11 of the plate-shaped member 10 can be effectively improved.

D. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof, and for example, the following modifications are also possible.

The configuration of the electrostatic chuck 100 in the above embodiment is merely an example and can be variously deformed. For example, the configuration (shape, size, etc.) of the convex portion 70 in the above embodiment is merely an example and can be variously deformed.

The material for forming each member (plate-shaped member 10, base member 20, joint 90, convex 70, etc.) of the electrostatic chuck 100 of the above embodiment is merely an example and can be changed in various ways. For example, in the above embodiment, the base member 20 is made of metal, but at least a part of the base member 20 may be made of ceramics. Further, in the above embodiment, the joint portion 90 is formed of metal, but the joint portion 90 may be formed of an inorganic material other than metal.

Further, in the above embodiment, a notch is formed on the upper side along the outer circumference of the plate-shaped member 10 on the upper surface side, but the notch may not be formed. Further, in the above embodiment, a unipolar method in which one chuck electrode 40 is provided inside the plate-shaped member 10 is adopted, but a bipolar system in which a pair of chuck electrodes 40 are provided inside the plate-shaped member 10 is adopted. The method may be adopted. Further, the electrostatic chuck 100 of the above embodiment includes a heater electrode 50 that heats the suction surface S11 of the plate-shaped member 10, but the electrostatic chuck 100 may not include the heater electrode 50.

Further, the method for manufacturing the electrostatic chuck 100 in the above embodiment is merely an example and can be changed in various ways. For example, in the above embodiment, the plate-shaped member 10 is produced by firing the ceramic green laminate, but the plate-shaped member 10 may be produced by another method (for example, hot press firing).

Further, the present invention is not limited to the electrostatic chuck 100, and can be used for other holding devices that include a plate-shaped member, a base member, and a joint portion for joining the two, and hold an object on the surface of the plate-shaped member. Is also applicable.

10: Plate-shaped member 14: Recessed part 20: Base member 21: Refrigerant flow path 22: Main body part 40: Chuck electrode 50: Heater electrode 60: Brazing part 70: Convex part 71: Upper part 72: Lower part 80: Recessed part 82: Concave part 90: Joint part 92: Inorganic adhesive 100: Electrostatic chuck IP: Inner part OP: Outer part P1: Upper end P2: Lower end S11: Adsorption surface S12: Outer upper surface S1: Upper surface S2: Lower surface S3: Top surface W: Wafer

Claims (5)

A plate-like portion having a first surface substantially orthogonal to the first direction and a second surface opposite to the first surface.
It has a third surface, and the third surface is arranged so as to be located on the second surface side of the plate-shaped portion, and has a coefficient of thermal expansion different from the thermal expansion coefficient of the material for forming the plate-shaped portion. With a base made of a material with
In a holding device for holding an object on the first surface of the plate-shaped portion.
A plurality of metal portions formed of a metal material and arranged between the plate-shaped portion and the base portion in the first direction are provided.
A plurality of recesses for accommodating at least a part of the metal portion are formed on one of the plate-shaped portion and the base portion.
The holding device further includes a joint formed of an inorganic material, arranged in each of the recesses, and joined to the surface of each recess and each of the metal portions housed in the recess.
A holding device characterized by that. In the holding device according to claim 1,
Each of the metal portions has a first end portion which is an end portion on the plate-shaped portion side and a second end portion which is an end portion on the base portion side.
The diameter of the first end of each metal portion is larger than the diameter of the second end.
A holding device characterized by that. In the holding device according to claim 1 or 2.
The plate-shaped portion is formed of ceramics.
The plurality of recesses are formed in the plate-shaped portion.
The inorganic material is a metal.
A holding device characterized by that. In the holding device according to any one of claims 1 to 3.
The base portion is made of metal and
The plurality of metal portions and the base portion are integral members.
A holding device characterized by that. In the holding device according to claim 1 or 2.
Each of the metal portions has a first end portion which is an end portion on the plate-shaped portion side and a second end portion which is an end portion on the base portion side.
The first end portion of each of the metal portions is brazed to the surface of the plate-shaped portion by a metal brazing portion.
In the first directional view, the area of each brazed portion is larger than the area of the first end of each metal portion.
A holding device characterized by that.

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