JP6634315B2 - Holding device and method of manufacturing holding device - Google Patents

Description

  The technology disclosed in this specification relates to a holding device that holds an object.

  For example, an electrostatic chuck is used as a holding device for holding a wafer when manufacturing a semiconductor. The electrostatic chuck has a configuration in which a ceramic plate and a base plate are joined by an adhesive layer (hereinafter, referred to as a “first adhesive layer”). The electrostatic chuck has an internal electrode, and uses an electrostatic attraction generated when a voltage is applied to the internal electrode to suction a wafer onto a surface of a ceramic plate (hereinafter, referred to as a “suction surface”). And hold.

  If the temperature distribution of the wafer held by the electrostatic chuck becomes non-uniform, the accuracy of each processing (film formation, etching, exposure, etc.) on the wafer may be reduced. Performance to make it uniform is required. Therefore, when the electrostatic chuck is used, the ceramic plate is heated by a heater disposed inside the ceramic plate or on the base plate side of the ceramic plate, or cooled by supplying a coolant to a coolant passage formed in the base plate. Of the adsorption surface is controlled.

  In addition, in order to increase the heat transfer between the ceramic plate and the wafer to further improve the uniformity of the temperature distribution of the wafer, a technique of supplying a gas such as helium to the space between the adsorption surface of the ceramic plate and the surface of the wafer. Is known (for example, see Patent Document 1). According to this technique, a gas supply passage communicating with a gas supply hole that is opened on the surface of the base plate on the ceramic plate side is formed inside the base plate. Further, a through-hole is formed in the first adhesive layer and communicates with the gas supply hole of the base plate and penetrates the first adhesive layer in the thickness direction. A recess communicating with the through hole is formed on the surface of the ceramic plate on the base plate side, and the bottom surface of the recess (the surface on the side close to the suction surface) and the gas opening on the suction surface are formed inside the ceramic plate. A gas ejection channel connecting the ejection hole is formed. When the gas is supplied to the gas supply passage of the base plate, the supplied gas passes through the gas supply hole of the base plate, the through hole of the first adhesive layer, the concave portion of the ceramic plate, and the gas ejection hole. And is supplied to the space between the suction surface of the ceramic plate and the surface of the wafer.

 Further, in this technique, in order to suppress the generation of electric discharge or gas discharge between the ceramic plate and the base plate through the inside of the concave portion formed in the ceramic plate, an insulating material is formed in the concave portion, The filling member (air permeable plug) having the property is filled.

JP 2013-232640 A

  In the above-mentioned conventional technique, the filling member filled in the concave portion is bonded to the ceramic plate by an adhesive layer (hereinafter, referred to as a “second adhesive layer”) disposed between the filling member and the bottom surface of the concave portion. The second adhesive layer is not disposed between the filling member and the side surface of the concave portion. Therefore, in order to ensure the withstand voltage of the second adhesive layer, it is necessary to increase the area of the second adhesive layer by making the size of the concave portion in the radial direction (the direction parallel to the suction surface) relatively large. .

  Here, since the ceramic plate does not come into contact with the first adhesive layer in the region where the concave portion is formed in the ceramic plate, the region between the base plate and the ceramic plate is smaller in this region than in the region where the concave portion is not formed. As a result, the cooling effect of the ceramic plate by the refrigerant supplied to the refrigerant passage formed in the base plate is reduced. In the above conventional technique, since the radial dimension of the concave portion needs to be relatively large, the region where the heat conductivity between the base plate and the ceramic plate is reduced, that is, the cooling effect of the ceramic plate by the refrigerant is reduced. There is a problem that the area becomes large and the uniformity of the temperature distribution on the adsorption surface of the ceramic plate may be reduced.

  Such a problem is not limited to an electrostatic chuck that holds a wafer using electrostatic attraction, but is common to a holding device that includes a ceramic plate and a base plate and holds an object on the surface of the ceramic plate. It is an issue of.

   This specification discloses a technique capable of solving the above-described problem.

  The technology disclosed in this specification can be realized, for example, as the following modes.

(1) A holding device disclosed in the present specification includes a plate-shaped ceramic plate having a first surface, a second surface opposite to the first surface, and a third surface. A base plate having a coolant flow path formed therein, wherein the third surface is arranged so that the third surface faces the second surface of the ceramic plate, and A heater disposed on the base plate side of a plate, and a first adhesive layer disposed between the ceramics plate and the base plate and bonding at least one of the ceramics plate and the heater to the base plate. A holding device for holding an object on the first surface of the ceramic plate, wherein the inside of the base plate communicates with a gas supply hole opened on the third surface of the base plate. Gas supply path A through hole communicating with the gas supply hole and penetrating through the first adhesive layer in a thickness direction is formed in the first adhesive layer. A concave portion communicating with the through hole and having a bottom surface and a side surface is formed on a front surface side of the ceramic plate. Inside the ceramic plate, the bottom surface of the concave portion and the first surface of the ceramic plate are formed. A gas ejection passage connecting the gas ejection hole and the gas ejection hole that opens into the concave portion, wherein the holding device is further formed of an insulating material, and has a gas-permeable filling member filled in the concave portion; A second adhesive layer that is disposed between the filling member and the side surface of the concave portion and adheres the filling member and the ceramic plate. According to the present holding device, the second adhesive layer for adhering the filling member and the ceramic plate is disposed between the filling member and the side surface of the concave portion, and the withstand voltage is ensured by the second adhesive layer. Since the occurrence of discharge between the ceramic plate and the base plate passing through the inside of the concave portion and gas discharge inside the concave portion is suppressed, it is not necessary to increase the radial size of the concave portion in order to ensure withstand voltage. . Therefore, according to the present holding device, the radial dimension of the concave portion can be made relatively small, and the area where the cooling effect of the ceramic plate by the cooling medium is reduced can be made relatively small. A decrease in the uniformity of the temperature distribution on the first surface can be suppressed.

(2) In the holding device, the second adhesive layer that bonds the filling member and the ceramic plate may be arranged only between the filling member and the side surface of the concave portion. According to the present holding device, since the second adhesive layer is not disposed between the filling member and the bottom surface of the concave portion, the connection hole with the gas ejection channel on the bottom surface of the concave portion is closed by the second adhesive layer. Can be suppressed, and a decrease in the uniformity of the temperature distribution of the holding object can be suppressed.

(3) In the holding device, the filling member may be in contact with the bottom surface of the recess. According to this holding device, since the filling member is in contact with the bottom surface of the concave portion and the space around the filling member can be reduced, the transmission between the base plate and the ceramic plate at the position where the filling member is disposed is provided. A decrease in thermal property can be suppressed, and a decrease in uniformity of the temperature distribution on the first surface of the ceramic plate can be more effectively suppressed. Further, according to the present holding device, since the filling member and the bottom surface of the concave portion are in contact with each other, compared with the configuration in which a space exists between the filling member and the bottom surface of the concave portion, the ceramic plate passing through the inside of the concave portion can be used. Discharge between the base plate and the base plate can be effectively suppressed.

(4) In the holding device, the depth of the concave portion may be larger than the radial size of the concave portion. According to the present holding device, the area of the second adhesive layer disposed between the filling member and the side surface of the recess can be relatively increased by making the depth dimension of the recess relatively large. In addition, the discharge between the ceramic plate and the base plate via the inside of the concave portion can be more reliably suppressed. Further, according to the present holding device, by making the radial size of the recess relatively small, it is possible to reduce the area of the ceramic plate that is not in contact with the first adhesive layer, and to reduce the area of the first surface of the ceramic plate. A decrease in the uniformity of the temperature distribution can be more effectively suppressed.

(5) The method for manufacturing a holding device disclosed in this specification includes a plate-shaped ceramic plate having a first surface and a second surface opposite to the first surface; A base plate having a coolant flow path formed therein, wherein the third surface is arranged so that the third surface faces the second surface of the ceramic plate, or the inside of the ceramic plate, or A heater disposed on the base plate side of the ceramic plate, a first heater disposed between the ceramic plate and the base plate, and bonding at least one of the ceramic plate and the heater to the base plate; And a holding device for holding an object on the first surface of the ceramic plate, wherein an opening is provided inside the base plate on the third surface of the base plate. Gas communicating with the gas supply hole A supply path is formed, and a through hole communicating with the gas supply hole and penetrating through the first adhesive layer in a thickness direction is formed in the first adhesive layer. On the second surface side, a concave portion communicating with the through hole and having a bottom surface and a side surface is formed, and inside the ceramic plate, the bottom surface of the concave portion and the second surface of the ceramic plate are formed. A gas ejection passage connecting the gas ejection hole opening to the surface of the first member, and a gas-permeable filling member formed of an insulating material and filled in the concave portion; And a second adhesive layer that is disposed between the filling member and the ceramic plate, and is disposed between the filling member and the ceramic plate, wherein an adhesive is applied to the side surface of the filling member. And the adhesive Inserting a coated the filling member in the recess of the ceramic plate, characterized in that it comprises a step of forming the second adhesive layer by curing the adhesive. According to the method for manufacturing the holding device, the second adhesive layer is disposed between the filling member and the side surface of the concave portion, and is not disposed between the filling member and the bottom surface of the concave portion. Can be formed.

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

FIG. 1 is a perspective view schematically illustrating an external configuration of an electrostatic chuck 10 according to an embodiment. FIG. 2 is an explanatory diagram schematically illustrating an XZ cross-sectional configuration of the electrostatic chuck 10 according to the embodiment. FIG. 3 is an explanatory diagram schematically showing an XY cross-sectional configuration of the electrostatic chuck according to the embodiment. FIG. 3 is an explanatory diagram showing an X1 part of FIG. 2 in an enlarged manner. 4 is a flowchart illustrating a method for manufacturing the electrostatic chuck 10 according to the embodiment. It is explanatory drawing which shows schematically the manufacturing method of the electrostatic chuck 10 in embodiment. FIG. 4 is an explanatory diagram schematically showing a configuration of an electrostatic chuck 10a of a comparative example.

A. Embodiment:
A-1. Configuration of electrostatic chuck 10:
FIG. 1 is a perspective view schematically illustrating an external configuration of the electrostatic chuck 10 according to the present embodiment, and FIG. 2 is an explanatory diagram schematically illustrating an XZ cross-sectional configuration of the electrostatic chuck 10 according to the present embodiment. FIG. 3 is an explanatory diagram schematically showing an XY cross-sectional configuration of the electrostatic chuck 10 according to the present embodiment. 2 shows an XZ cross-sectional configuration of the electrostatic chuck 10 at a position II-II in FIG. 3. FIG. 3 shows an XY cross-sectional configuration of the electrostatic chuck 10 at a position III-III in FIG. It is shown. Each drawing shows XYZ axes orthogonal to each other for specifying the direction. In this specification, for the sake of convenience, the positive direction of the Z-axis is referred to as an upward direction, and the negative direction of the Z-axis is referred to as a downward direction. May be done.

  The electrostatic chuck 10 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used, for example, for fixing the wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a ceramic plate 100 and a base plate 200 arranged side by side in a predetermined arrangement direction (in the present embodiment, a vertical direction (Z-axis direction)). In the ceramic plate 100 and the base plate 200, the lower surface of the ceramic plate 100 (hereinafter, referred to as “ceramic-side bonding surface S2”) and the upper surface of the base plate 200 (hereinafter, referred to as “base-side bonding surface S3”) are arranged in the above arrangement direction. It is arranged so that it may face. The electrostatic chuck 10 further includes a first adhesive layer 300 disposed between the ceramic-side bonding surface S2 of the ceramic plate 100 and the base-side bonding surface S3 of the base plate 200. The ceramic-side bonding surface S2 of the ceramic plate 100 corresponds to the second surface in the claims, and the base-side bonding surface S3 of the base plate 200 corresponds to the third surface in the claims.

  The ceramics plate 100 is, for example, a plate member having a circular flat surface, and is formed of ceramics (for example, alumina or aluminum nitride). The diameter of the ceramic plate 100 is, for example, about 50 mm to 500 mm (normally, about 200 mm to 350 mm), and the thickness of the ceramic plate 100 is, for example, about 1 mm to 10 mm.

  Inside the ceramic plate 100, a pair of internal electrodes 400 formed of a conductive material (for example, tungsten or molybdenum) is provided. When a voltage is applied to the pair of internal electrodes 400 from a power supply (not shown), an electrostatic attraction is generated, and the wafer W is placed on the upper surface of the ceramic plate 100 (hereinafter, referred to as “suction surface S1”) by the electrostatic attraction. Is fixed by suction. A plurality of minute projections are formed on the suction surface S1 of the ceramic plate 100. When the wafer W is fixed to the suction surface S1 by suction, there is a slight gap between the suction surface S1 and the surface of the wafer W. Space exists. The suction surface S1 of the ceramic plate 100 corresponds to a first surface in the claims. Further, in this specification, a direction parallel to the suction surface S1 is referred to as a “plane direction”.

  Inside the ceramic plate 100, a heater 500 formed of a resistance heating element formed of a conductive material (for example, tungsten or molybdenum) is provided. When a voltage is applied to the heater 500 from a power supply (not shown), the heater 500 generates heat, thereby heating the ceramic plate 100 and the wafer W held on the suction surface S1 of the ceramic plate 100. Thereby, the temperature control of the wafer W is realized.

  The base plate 200 is, for example, a plate member of a circular flat surface having the same diameter as the ceramic plate 100 or having a diameter larger than that of the ceramic plate 100, and is formed of a metal (for example, aluminum or an aluminum alloy). The diameter of the base plate 200 is, for example, about 220 mm to 550 mm (usually, 220 mm to 350 mm), and the thickness of the base plate 200 is, for example, about 20 mm to 40 mm.

  A coolant channel 210 is formed inside the base plate 200. When a coolant (for example, a fluorine-based inert liquid or water) flows through the coolant channel 210, the base plate 200 is cooled, and the space between the base plate 200 and the ceramic plate 100 via the first adhesive layer 300 is formed. The ceramic plate 100 is cooled by the heat transfer, and the wafer W held on the suction surface S1 of the ceramic plate 100 is cooled. Thereby, the temperature control of the wafer W is realized.

  The first adhesive layer 300 includes, for example, an adhesive such as a silicone resin, an acrylic resin, or an epoxy resin, and bonds the ceramic plate 100 and the base plate 200 together. The thickness of the first adhesive layer 300 is, for example, about 0.1 mm to 1 mm.

  In addition, the electrostatic chuck 10 increases the heat conductivity between the ceramics plate 100 and the wafer W to further increase the uniformity of the temperature distribution of the wafer W, so that the suction surface S1 of the ceramics plate 100 and the surface of the wafer W A structure is provided for supplying gas to a space existing therebetween. In the present embodiment, helium gas (He gas) is used as such a gas. Hereinafter, a configuration for supplying a helium gas will be described with reference to FIGS. 1 to 3 and FIG. 4 showing an enlarged view of a portion X1 in FIG.

  As shown in FIGS. 2 and 4, a gas source connection hole 221 that is connected to a helium gas source (not shown) is formed on the lower surface of the base plate 200. The gas supply hole 222 is open. Inside the base plate 200, a gas supply path 220 that connects the gas source connection hole 221 and the gas supply hole 222 is formed.

  As shown in FIGS. 2 and 4, the first adhesive layer 300 communicates with the gas supply holes 222 formed in the base plate 200, and the first adhesive layer 300 is placed in the thickness direction (vertical direction). ) Are formed.

  As shown in FIGS. 2 and 4, a recess 140 having a bottom surface 144 and a side surface 142 is formed on the ceramic-side bonding surface S2 of the ceramic plate 100. The recess 140 communicates with a through hole 310 formed in the first adhesive layer 300. In addition, that the concave portion 140 communicates with the through hole 310 means that the concave portion 140 is in communication with the through hole 310 in a state where other members (for example, a filling member 160 and a second adhesive layer 170 described later) do not exist in the concave portion 140. Means that you are communicating with Specifically, the recess 140 is formed so as to overlap with the through hole 310 in the thickness direction of the first adhesive layer 300.

  In the present embodiment, the recess 140 has a shape having a substantially circular cross section (a cross section parallel to the surface direction) having a diameter R1 over a depth D1. The bottom surface 144 of the concave portion 140 is a surface on the side closer to the suction surface S1 in the concave portion 140, and has a substantially circular shape in the present embodiment. The side surface 142 of the concave portion 140 is a surface parallel to the thickness direction (up-down direction) of the first adhesive layer 300, and has a shape like an inner peripheral surface of a cylinder in the present embodiment. In this embodiment, the depth D1 of the recess 140 is larger than the radial dimension R1 of the recess 140.

  As shown in FIGS. 1 and 2, eight gas ejection holes 102 are opened on the adsorption surface S1 of the ceramic plate 100. Further, inside the ceramic plate 100, a gas ejection flow path connecting the bottom surface 144 (FIG. 4) of the concave portion 140 formed in the ceramic plate 100 and the gas ejection hole 102 opening on the adsorption surface S1 of the ceramic plate 100. Are formed. More specifically, the gas ejection flow passage communicates with the first vertical flow passage 132 (FIGS. 2 to 4) extending upward from the bottom surface 144 of the concave portion 140 and has a planar direction. 2 and 3 and a second vertical flow path 122 (FIG. 2) extending upward from the horizontal flow path 112 and communicating with the gas ejection holes 102.

  In the electrostatic chuck 10 of the present embodiment, there are two helium gas supply paths. That is, as shown in FIG. 3, two lateral flow channels 112 are formed inside the ceramic plate 100. As shown in FIGS. 2 and 3, one of the two horizontal flow paths 112, which is closer to the center of the ceramic plate 100, communicates with the illustrated recess 140 via a first vertical flow path 132. In addition, through the second vertical flow path 122, it communicates with four gas ejection holes 102 close to the center of the ceramic plate 100 among the eight gas ejection holes 102 opened on the adsorption surface S <b> 1. Further, one of the two horizontal channels 112, which is farther from the center of the ceramic plate 100, communicates with a recess 140 (not shown) through a first vertical channel 132, and a second vertical channel. The four gas ejection holes 102 far from the center of the ceramic plate 100 among the eight gas ejection holes 102 opening to the adsorption surface S1 are communicated via the flow path 122. The not-shown recess 140 also communicates with a through-hole 310 (not shown) formed in the first adhesive layer 300, similarly to the illustrated recess 140, and the through-hole 310 has a gas supply passage 220. Are in communication.

  As shown in FIGS. 2 and 4, each of the recesses 140 formed in the ceramic plate 100 is filled with a gas-permeable filling member (gas-permeable plug) 160. The filling member 160 is formed of an insulating material. As a material for forming the filling member 160, for example, a porous ceramic body, glass fiber, heat-resistant polytetrafluoroethylene resin sponge, or the like can be used.

  In the present embodiment, the filling member 160 has a substantially cylindrical shape, and the diameter of the filling member 160 is smaller than the diameter R1 of the concave portion 140. Thereby, the filling member 160 can be smoothly inserted into the recess 140. Further, a second adhesive layer 170 is disposed between the side surface of the filling member 160 and the side surface 142 of the concave portion 140. The second adhesive layer 170 contains an adhesive such as a silicone resin, an acrylic resin, or an epoxy resin. The filling member 160 is joined to the ceramic plate 100 by the second adhesive layer 170.

  In the present embodiment, the top surface of the filling member 160 is in contact with the bottom surface 144 of the concave portion 140. That is, the second adhesive layer 170 that bonds the filling member 160 and the ceramic plate 100 is not disposed between the top surface of the filling member 160 and the bottom surface 144 of the concave portion 140. The height of the filling member 160 is substantially the same as the depth D1 of the recess 140. Therefore, the position of the lower surface of the filling member 160 in the up-down direction is substantially the same as the position of the lower surface of the ceramic plate 100.

  As described above, the recess 140 is filled with the filling member 160 formed of an insulating material, and the second adhesive layer 170 is disposed between the filling member 160 and the side surface 142 of the recess 140. The generation of electric discharge between the ceramic plate 100 and the base plate 200 and the electric discharge of the helium gas in the concave portion 140 via the semiconductor substrate 100 are suppressed.

  As shown in FIGS. 2 and 4, when helium gas supplied from a helium gas source (not shown) flows into the gas supply path 220 inside the base plate 200 from the gas source connection hole 221, It flows into the through hole 310 of the first adhesive layer 300 from the supply hole 222, and further passes through the inside of the air-permeable filling member 160 filled in the recess 140, and the first vertical portion inside the ceramic plate 100. The gas flows into the flow channel 132, and further flows through the horizontal flow channel 112 and the second vertical flow channel 122, and is jetted from each of the gas jet holes 102 formed on the adsorption surface S <b> 1. Thus, the helium gas is supplied to the space existing between the suction surface S1 and the surface of the wafer W.

A-2. Manufacturing method of the electrostatic chuck 10:
FIG. 5 is a flowchart illustrating a method for manufacturing the electrostatic chuck 10 according to the present embodiment. FIG. 6 is an explanatory view schematically showing a method of manufacturing the electrostatic chuck 10 according to the present embodiment. First, the ceramic plate 100 and the base plate 200 are prepared (S110). The ceramic plate 100 and the base plate 200 can be manufactured by a known manufacturing method.

  For example, the ceramic plate 100 is manufactured by the following method. That is, a plurality of ceramic green sheets (for example, alumina green sheets) are prepared, and a punching process for forming the internal electrode 400, the heater 500, each gas flow path, etc., printing of metallized ink, and the like are performed on each of the ceramic green sheets. After that, a plurality of ceramic green sheets are laminated, thermocompression bonded, cut into a predetermined disc shape, fired, and finally subjected to polishing or the like, whereby the ceramic plate 100 is manufactured. In the present embodiment, the gas ejection flow paths (the first vertical flow path 132, the horizontal flow path 112, the second vertical flow path 112, and the second flow path 112) that connect the bottom surface 144 of the above-described concave portion 140 and each of the gas ejection holes 102 opened to the adsorption surface S1 are connected. The vertical flow path 122) is formed by performing the above-described perforation processing on the ceramic green sheet.

  Further, the above-described gas source connection hole 221, gas supply passage 220, and gas supply hole 222 are formed in the base plate 200.

  Next, a recess 140 is formed on the ceramic-side bonding surface S2 of the ceramic plate 100 (S120, see FIG. 6). The recess 140 is formed by, for example, polishing. The concave portion 140 is formed so as to communicate with the first vertical channel 132 that constitutes the gas ejection channel.

  Next, an adhesive Ad2 is applied to the side surface of the filling member 160 formed of an insulating material (S130, see FIG. 6), and the filling member 160 is inserted into the recess 140 formed in the ceramic plate 100 (S140). At this time, the filling member 160 is pushed in until the top surface of the filling member 160 contacts the bottom surface 144 of the recess 140. Here, since the adhesive is not applied to the side surface 142 of the concave portion 140, the adhesive is not pushed inward when the filling member 160 is inserted, and does not adhere to the bottom surface 144 of the concave portion 140. Therefore, when the insertion of the filling member 160 is completed, the adhesive Ad2 is disposed between the filling member 160 and the side surface 142 of the concave portion 140, and the adhesive is placed between the filling member 160 and the bottom surface 144 of the concave portion 140. It does not exist.

  The adhesive Ad2 is a paste prepared by mixing an adhesive component (eg, a silicone resin, an acrylic resin, an epoxy resin, etc.) and a powder component (eg, alumina, silica, silicon carbide, silicon nitride, etc.). For example, an adhesive or a paste adhesive is applied in the form of a film on a release sheet and then semi-cured by a curing treatment to form a gel-like sheet adhesive. The adhesive Ad2 may include an additive such as a coupling agent.

  Next, the second adhesive layer 170 is formed by curing the adhesive Ad2 (S150). The content of the curing process differs depending on the type of the adhesive used, and a process of applying heat is performed as a curing process in the case of a thermosetting adhesive, and a curing process in the case of a moisture-curable adhesive. A process of providing moisture by a method such as humidification is performed. Thus, the filling member 160 is bonded to the ceramic plate 100.

  Next, in a state where the ceramic-side adhesive surface S2 of the ceramic plate 100 and the base-side adhesive surface S3 of the base plate 200 are bonded together via the adhesive Ad1, a curing process for curing the adhesive Ad1 is performed. The first adhesive layer 300 is formed (S160). Note that the adhesive Ad1 is a paste-like adhesive or a sheet-like adhesive like the above-mentioned adhesive Ad2. In addition, as the hardening process, as described above, a process (a process of applying heat or a process of applying moisture) according to the type of the adhesive to be used is performed. When the adhesive Ad1 is disposed between the ceramic plate 100 and the base plate 200, holes corresponding to the above-described through holes 310 are provided, and the first adhesive layer 300 formed by curing the adhesive Ad1 is formed. The through holes 310 are formed. At least the operation of bonding the ceramic plate 100 and the base plate 200 in the step of S160 is performed in a state where the ceramic plate 100 and the base plate 200 are housed in a vacuum-sealed container. This is preferable in that air bubbles are not easily generated in the adhesive layer 300. Through the above steps, the manufacture of the electrostatic chuck 10 having the above-described configuration is completed.

A-3. Effects of the embodiment:
As described above, in the electrostatic chuck 10 of the present embodiment, the gas supply passage 220 communicating with the gas supply hole 222 opened in the third surface S3 of the base plate 200 is formed inside the base plate 200. I have. Further, the first adhesive layer 300 has a through hole 310 which communicates with the gas supply hole 222 of the base plate 200 and penetrates the first adhesive layer 300 in the thickness direction. On the second surface S2 side of the ceramic plate 100, a concave portion 140 having a bottom surface 144 and a side surface 142 is formed so as to communicate with the through hole 310 of the first adhesive layer 300. Further, inside the ceramic plate 100, a gas ejection flow path (first vertical flow path 132, a first vertical flow path 132, The horizontal flow path 112 and the second vertical flow path 122) are formed. Further, the electrostatic chuck 10 of the present embodiment is further arranged between a filling member 160 formed of an insulating material and filled in the recess 140 and having air permeability, and between the filling member 160 and the side surface 142 of the recess 140. And a second bonding layer 170 for bonding the filling member 160 and the ceramic plate 100.

  As described above, in the electrostatic chuck 10 of the present embodiment, the second bonding layer 170 that bonds the filling member 160 and the ceramic plate 100 is disposed between the filling member 160 and the side surface 142 of the concave portion 140. As described below, it is possible to suppress a decrease in the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 100.

  FIG. 7 is an explanatory diagram schematically showing the configuration of the electrostatic chuck 10a of the comparative example. FIG. 7 shows, on an enlarged scale, a configuration of a portion equivalent to the portion (X1 portion) shown in FIG. 4 among the configurations of the electrostatic chuck 10a of the comparative example. In the electrostatic chuck 10a of the comparative example, the second adhesive layer 170a for bonding the filling member 160a and the ceramic plate 100a is not provided between the filling member 160a and the side surface 142a of the recess 140a, but is formed between the filling member 160a and the recess 140a. It is arranged between the bottom surface 144a. Also, in the electrostatic chuck 10a of the comparative example, the diameter of the filling member 160a is set smaller than the diameter R1 of the concave portion 140a in order to smoothly insert the filling member 160a into the concave portion 140a. Therefore, a space Sp exists between the side surface of the filling member 160a and the side surface 142a of the concave portion 140a. In the electrostatic chuck 10a of the comparative example, the depth D1 of the recess 140a is smaller than the radial dimension R1 of the recess 140a.

  In the electrostatic chuck 10a of the comparative example shown in FIG. 7, the withstand voltage is ensured by the second adhesive layer 170a disposed between the filling member 160a and the bottom surface 144a of the concave portion 140a. It is necessary to make R1 relatively large to increase the area of the second adhesive layer 170a. Here, since the region where the concave portion 140a is formed in the ceramic plate 100a does not contact the first adhesive layer 300, the heat transfer between the base plate 200 and the ceramic plate 100a is reduced in this region, and as a result, The cooling effect of the coolant supplied to the coolant passage 210 formed in the base plate 200 on the ceramic plate 100a is reduced. In the electrostatic chuck 10a of the comparative example, since the radial dimension R1 of the concave portion 140a formed in the ceramic plate 100a needs to be relatively large, the heat transfer between the base plate 200 and the ceramic plate 100a decreases. The area, that is, the area where the cooling effect of the cooling of the ceramic plate 100a by the refrigerant is reduced becomes relatively large, and the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 100a may be reduced.

  On the other hand, in the electrostatic chuck 10 of the present embodiment, the second adhesive layer 170 that bonds the filling member 160 and the ceramic plate 100 is disposed between the filling member 160 and the side surface 142 of the concave portion 140. By ensuring the withstand voltage by the second adhesive layer 170, the generation of the discharge between the ceramic plate 100 and the base plate 200 via the inside of the recess 140 and the discharge of the helium gas in the recess 140 are suppressed. . Therefore, in the electrostatic chuck 10 of the present embodiment, it is not necessary to increase the radial dimension of the concave portion 140 in order to secure the withstand voltage. Therefore, in the electrostatic chuck 10 of the present embodiment, since the radial dimension of the concave portion 140 can be made relatively small, the region where the cooling effect of the ceramic plate 100 by the refrigerant is reduced can be made relatively small. As a result, it is possible to suppress a decrease in the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 100.

  In the electrostatic chuck 10a of the comparative example, since the second adhesive layer 170a for bonding the filling member 160a and the ceramic plate 100a is disposed between the filling member 160a and the bottom surface 144a of the concave portion 140a, for example, When the ceramic plate 100a is sintered at the time of firing and deviates from the design value, or when the processing of the recess 140a occurs, the gap between the ceramic plate 100a and the gas ejection channel (first vertical channel 132) at the bottom surface 144a of the recess 140a is reduced. The connection hole may be closed by the second adhesive layer 170a. When such a blockage occurs, the ejection of the helium gas to the adsorption surface S1 side of the ceramic plate 100a is hindered or the uniformity of the helium gas ejection amount is reduced, and the gap between the ceramic plate 100a and the wafer W is reduced. The uniformity of the heat transfer may be reduced, and the uniformity of the temperature distribution of the wafer W may be reduced. Note that it is possible to prevent such blockage from occurring by reducing the amount of the adhesive Ad2 applied when forming the second adhesive layer 170a. There is a place where the area of the adhesive layer 170a becomes locally small, and the withstand voltage may decrease.

  On the other hand, in the electrostatic chuck 10 of the present embodiment, the second adhesive layer 170 that bonds the filling member 160 and the ceramic plate 100 is disposed only between the filling member 160 and the side surface 142 of the concave portion 140. It is not disposed between the filling member 160 and the bottom surface 144 of the recess 140. For this reason, in the electrostatic chuck 10 of the present embodiment, it is possible to prevent the connection hole with the gas ejection channel (the first vertical channel 132) on the bottom surface 144 of the concave portion 140 from being closed by the second adhesive layer 170. Therefore, it is possible to suppress a decrease in the uniformity of the temperature distribution of the wafer W.

  In the electrostatic chuck 10a of the comparative example, since the space Sp exists between the side surface of the filling member 160a and the side surface 142a of the concave portion 140a, the base plate 200 and the ceramic plate 100a are located at the position where the filling member 160a is arranged. And the heat transfer between the two may significantly decrease, and the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 100a may greatly decrease.

  On the other hand, in the electrostatic chuck 10 of the present embodiment, since the filling member 160 is in contact with the bottom surface 144 of the concave portion 140, there is no space Sp around the filling member 160. Therefore, in the electrostatic chuck 10 of the present embodiment, a decrease in the heat transfer between the base plate 200 and the ceramic plate 100 at the position where the filling member 160 is disposed can be suppressed, and the suction surface S1 of the ceramic plate 100 can be suppressed. A decrease in the uniformity of the temperature distribution in the above can be more effectively suppressed. Further, in the electrostatic chuck 10 of the present embodiment, since the filling member 160 and the bottom surface 144 of the concave portion 140 are in contact with each other, compared with the configuration in which the space Sp exists between the filling member 160 and the bottom surface 144 of the concave portion 140. Thus, the discharge between the ceramic plate 100 and the base plate 200 via the inside of the concave portion 140 can be effectively suppressed.

  Further, in the electrostatic chuck 10 of the present embodiment, the dimension D1 in the depth direction of the recess 140 is larger than the dimension R1 in the radial direction of the recess 140. Therefore, in the electrostatic chuck 10 of the present embodiment, the second adhesive layer disposed between the filling member 160 and the side surface 142 of the recess 140 is formed by relatively increasing the depth dimension D1 of the recess 140. The area of 170 can be made relatively large, and the discharge between ceramic plate 100 and base plate 200 via the inside of recess 140 can be suppressed more reliably. Further, in the electrostatic chuck 10 of the present embodiment, by making the radial dimension R1 of the concave portion 140 relatively small, the area of the ceramic plate 100 that is not in contact with the first adhesive layer 300 can be reduced. A decrease in the uniformity of the temperature distribution on the suction surface S1 of the plate 100 can be more effectively suppressed.

  Further, in the method of manufacturing the electrostatic chuck 10 according to the present embodiment, a step of applying the adhesive Ad2 to the side surface of the filling member 160 (S130 in FIG. 5) and inserting the filling member 160 into the recess 140 of the ceramic plate 100. The method includes the step (S140) and the step of curing the adhesive Ad2 to form the second adhesive layer 170 (S150). According to this manufacturing method, the second adhesive layer 170 is arranged between the filling member 160 and the side surface 142 of the recess 140, and is not arranged between the filling member 160 and the bottom surface 144 of the recess 140. Then, the second adhesive layer 170 can be formed.

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

  The configuration of the electrostatic chuck 10 in the above embodiment is merely an example, and can be variously modified. For example, in the above embodiment, the configuration for supplying the helium gas (the gas source connection hole 221, the gas supply path 220, the gas supply hole 222, the through hole 310, the concave portion 140, the first vertical channel 132, the horizontal channel 112, The shape, position, number, and the like of the second vertical flow path 122, the gas ejection holes 102, and the like can be arbitrarily set.

  Further, in the above embodiment, the upper surface of the filling member 160 is in contact with the bottom surface 144 of the recess 140, but a space may exist between the upper surface of the filling member 160 and the bottom surface 144 of the recess 140. Further, an adhesive layer may be arranged in all or a part of this space.

  Further, the material forming each member in the above embodiment is merely an example, and each member may be formed of another material. In the above embodiment, the heater 500 is disposed inside the ceramic plate 100. However, the heater 500 is not disposed inside the ceramic plate 100 but on the base plate 200 side of the ceramic plate 100 (the ceramic plate 100 and the first plate). (Between the adhesive layer 300). In this case, the first bonding layer 300 bonds at least one of the ceramic plate 100 and the heater 500 to the base plate 200.

  Further, in the above embodiment, the coolant passage 210 is formed inside the base plate 200. However, the coolant passage 210 is not provided inside the base plate 200 but on the surface of the base plate 200 (for example, the base plate 200 and the base plate 200). (Between the first adhesive layer 300). Further, in the above embodiment, the bipolar method in which the pair of internal electrodes 400 are provided inside the ceramic plate 100 is adopted, but the monopolar method in which one internal electrode 400 is provided inside the ceramic plate 100 is used. May be employed.

  Further, the method of manufacturing the electrostatic chuck 10 in the above embodiment is merely an example, and can be variously modified. For example, in the above embodiment, the concave portion 140 is formed by polishing after manufacturing the ceramic plate 100, but the concave portion 140 may be formed by punching a ceramic green sheet before firing. .

  The present invention is not limited to the electrostatic chuck 10 that holds the wafer W using electrostatic attraction, but includes another holding device that includes a ceramic plate and a base plate and holds an object on the surface of the ceramic plate (for example, , Vacuum chuck, etc.).

10: Electrostatic chuck 100: Ceramic plate 102: Gas ejection hole 112: Horizontal flow path 122: Second vertical flow path 132: First vertical flow path 140: Concavity 142: Side surface 144: Bottom surface 160: Filling member 170: First 2 adhesive layer 200: base plate 210: refrigerant flow path 220: gas supply path 221: gas source connection hole 222: gas supply hole 300: first adhesive layer 310: through hole 400: internal electrode 500: heater

Claims (4)

A plate-shaped ceramic plate having a first surface and a second surface opposite to the first surface;
A base plate having a plate shape having a third surface, wherein the third surface is disposed so as to face the second surface of the ceramics plate, and a coolant channel is formed;
Inside the ceramic plate, or a heater disposed on the base plate side of the ceramic plate,
A first adhesive layer disposed between the ceramic plate and the base plate, for bonding at least one of the ceramic plate and the heater and the base plate;
A holding device for holding an object on the first surface of the ceramic plate,
Inside the base plate, a gas supply passage communicating with a gas supply hole opened on the third surface of the base plate is formed,
In the first adhesive layer, a through hole communicating with the gas supply hole and penetrating the first adhesive layer in a thickness direction is formed,
On the second surface side of the ceramic plate, a concave portion communicating with the through hole and having a bottom surface and side surfaces is formed,
Inside the ceramic plate, a gas ejection channel connecting the bottom surface of the concave portion and a gas ejection hole opened on the first surface of the ceramic plate is formed,
The holding device further comprises:
A filling member formed of an insulating material and having air permeability filled in the concave portion,
A second adhesive layer that is disposed between the filling member and the side surface of the concave portion and adheres the filling member and the ceramic plate;
Equipped with a,
The holding device, wherein the second adhesive layer that bonds the filling member and the ceramic plate is disposed only between the filling member and the side surface of the concave portion . A plate-shaped ceramic plate having a first surface and a second surface opposite to the first surface;
  A base plate having a plate shape having a third surface, wherein the third surface is disposed so as to face the second surface of the ceramics plate, and a coolant channel is formed;
  Inside the ceramic plate, or a heater arranged on the base plate side of the ceramic plate,
  A first adhesive layer disposed between the ceramic plate and the base plate, for bonding at least one of the ceramic plate and the heater and the base plate;
A holding device for holding an object on the first surface of the ceramic plate,
  Inside the base plate, a gas supply passage communicating with a gas supply hole opened in the third surface of the base plate is formed,
  In the first adhesive layer, a through hole communicating with the gas supply hole and penetrating the first adhesive layer in a thickness direction is formed,
  On the second surface side of the ceramic plate, a concave portion having a bottom surface and a side surface is formed, communicating with the through hole,
  Inside the ceramic plate, a gas ejection channel connecting the bottom surface of the concave portion and a gas ejection hole opened on the first surface of the ceramic plate is formed,
  The holding device further comprises:
  A filling member formed of an insulating material and having air permeability filled in the concave portion,
  A second adhesive layer that is disposed between the filling member and the side surface of the concave portion and adheres the filling member and the ceramic plate;
With
  The holding device, wherein the filling member is in contact with the bottom surface of the concave portion. A plate-shaped ceramic plate having a first surface and a second surface opposite to the first surface;
  A base plate having a plate shape having a third surface, wherein the third surface is disposed so as to face the second surface of the ceramics plate, and a coolant channel is formed;
  Inside the ceramic plate, or a heater arranged on the base plate side of the ceramic plate,
  A first adhesive layer disposed between the ceramic plate and the base plate, for bonding at least one of the ceramic plate and the heater and the base plate;
A holding device for holding an object on the first surface of the ceramic plate,
  Inside the base plate, a gas supply passage communicating with a gas supply hole opened on the third surface of the base plate is formed,
  In the first adhesive layer, a through hole communicating with the gas supply hole and penetrating the first adhesive layer in a thickness direction is formed,
  On the second surface side of the ceramic plate, a concave portion communicating with the through hole and having a bottom surface and side surfaces is formed,
  Inside the ceramic plate, a gas ejection channel connecting the bottom surface of the concave portion and a gas ejection hole opened on the first surface of the ceramic plate is formed,
  The holding device further comprises:
  A filling member formed of an insulating material and having air permeability filled in the concave portion,
  A second adhesive layer that is disposed between the filling member and the side surface of the concave portion and adheres the filling member and the ceramic plate;
With
  The holding device according to claim 1, wherein a size of the recess in a depth direction is larger than a size of the recess in a radial direction. The method of manufacturing a holding device according to any one of claims 1 to 3 ,
Applying an adhesive to the side surface of the filling member,
Inserting the filling member coated with the adhesive into the recess of the ceramic plate,
Curing the adhesive to form the second adhesive layer;
A method for manufacturing a holding device, comprising:

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