JP6639940B2 - 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, in a semiconductor manufacturing apparatus, an electrostatic chuck is used as a holding device for holding a wafer. The electrostatic chuck has a configuration in which a ceramic plate and a base plate are joined by an 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 decreases, so that the temperature distribution of the wafer is made uniform in the electrostatic chuck. Performance 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. (See, for example, Patent Document 1).

JP-A-2015-103550

  However, due to product design, there are cases where heaters and coolant channels cannot be arranged uniformly in a direction parallel to the adsorption surface of the ceramic plate (hereinafter, referred to as “surface direction”). Also, due to the manufacturing process, product variations may occur on the ceramic plate and the base plate. For these reasons, even when heating by a heater or cooling by a coolant is performed, the uniformity of the temperature distribution on the adsorption surface of the ceramic plate does not become sufficiently high, and thus the uniformity of the temperature distribution of the wafer does not become sufficiently high. There is. In particular, on the outer peripheral side in the surface direction of the electrostatic chuck, when the heater is formed by, for example, screen printing, the variation in the thickness of the heater is more likely to be larger than that on the center side, and the line length of the heater is compared. Therefore, the probability of occurrence of a defect in the heater increases due to the length of the heater, and the defect of the adhesive layer (for example, bubbles in the adhesive layer) is also likely to occur. In addition, it is difficult for the uniformity of the temperature distribution on the adsorption surface of the ceramic plate to be sufficiently high.

  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 an 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 ceramics plate, further comprising an adhesive layer disposed between the ceramics plate and the base plate on an outer peripheral side of the adhesive layer; Is disposed at a position on the outer peripheral side of the adhesive layer between the first member having a different thermal conductivity and the ceramic plate and the base plate, and the adhesive layer and the first member have different thermal conductivity. A different second member. According to the present holding device, at least three members having different thermal conductivities, such as an adhesive layer, a first member, and a second member, are arranged between the ceramic plate and the base plate. Therefore, according to the present holding device, by disposing the first member and the second member at appropriate positions on the outer peripheral side of the adhesive layer between the ceramic plate and the base plate, the first surface of the ceramic plate is Can improve the uniformity of the temperature distribution.

(2) In the holding device, a thermal conductivity of the first member is higher than a thermal conductivity of the adhesive layer, and the first member overlaps with the heater when viewed in a thickness direction of the adhesive layer. It may be configured to be arranged at a position. In the first surface of the ceramic plate, the position where the heater overlaps with the heater in the thickness direction of the adhesive layer tends to have a higher temperature than other positions. According to the present holding device, the first member having a thermal conductivity higher than the thermal conductivity of the adhesive layer is disposed at a position overlapping the heater when viewed in the thickness direction of the adhesive layer. The cooling effect of the plate is enhanced, and the uniformity of the temperature distribution on the first surface of the ceramic plate can be improved.

(3) In the holding device, a thermal conductivity of the second member is lower than a thermal conductivity of the adhesive layer, and the second member is configured such that the coolant flow path is viewed in the thickness direction of the adhesive layer. May be arranged at a position overlapping with. In the first surface of the ceramic plate, the temperature at a position overlapping the coolant flow path when viewed in the thickness direction of the adhesive layer tends to be lower than at other positions. According to the present holding device, the second member having a thermal conductivity lower than the thermal conductivity of the adhesive layer is disposed at a position overlapping the refrigerant flow path when viewed in the thickness direction of the adhesive layer. Thus, the cooling effect of the ceramic plate due to the above is suppressed, and the uniformity of the temperature distribution on the first surface of the ceramic plate can be improved.

(4) In the holding device, the adhesive layer has a shape in which a plurality of concave portions are formed in an outer peripheral portion when viewed in a thickness direction of the adhesive layer, and the first member and the second member include: It may be configured to be arranged in the concave portions different from each other. According to the present holding device, it is possible to improve the uniformity of the temperature distribution on the first surface of the ceramic plate by arranging the first member and the second member while securing the bonding area by the bonding layer to some extent. it can.

(5) In the holding device, the plurality of recesses include at least one first recess, and at least one second recess in which a position in a thickness direction of the adhesive layer is different from the first recess. May be included. According to the present holding device, since the degree of freedom in the arrangement of the concave portions can be increased, the cooling effect can be finely adjusted by arranging the first member and the second member. 1 can effectively improve the uniformity of the temperature distribution on the surface.

(6) The holding device may further include an annular protective member that surrounds the adhesive layer, the first member, and the second member collectively. According to the present holding device, the first member and the second member are dropped while the uniformity of the temperature distribution on the first surface of the ceramic plate is improved by disposing the first member and the second member. Can be prevented.

(7) In the holding device, a temperature difference at each position on the first surface of the ceramic plate is within 3 ° C. during execution of heating by the heater and supply of the coolant to the coolant channel. It may be. According to the present holding device, by setting the temperature difference at each position on the first surface of the ceramic plate within 3 ° C., it is possible to sufficiently improve the uniformity of the temperature distribution on the first surface of the ceramic plate. .

(8) 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; and an adhesive layer 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. A method of manufacturing a holding device for holding an object on the first surface of the ceramic plate, the step of preparing the ceramic plate and the base plate; A step of forming an adhesive layer by arranging an adhesive between the ceramic plate and the adhesive, and after forming the adhesive layer, the temperature at each position on the first surface of the ceramic plate is reduced. A first member that is selected based on the specified temperature at a position on the outer peripheral side of the adhesive layer between the ceramics plate and the base plate, and has a different thermal conductivity from the adhesive layer. And a step of arranging, based on the specified temperature, a position on the outer peripheral side of the adhesive layer between the ceramics plate and the base plate, wherein the adhesive layer and the first member are thermally conductive. And arranging second members having different rates. According to the manufacturing method of the present holding device, the first surface of the ceramic plate is intended for a joined product in which the ceramic plate and the base plate are joined by an adhesive layer, which is very close to the finished product holding device. The first member and the second member having appropriate thermal conductivity are selected at positions on the outer peripheral side of the adhesive layer between the ceramics plate and the base plate because the temperature can be specified at each position of Can be arranged. Therefore, according to the method of manufacturing the holding device, it is possible to manufacture the holding device in which the uniformity of the temperature distribution on the first surface of the ceramic plate is improved.

  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 100 according to an embodiment. FIG. 2 is an explanatory diagram schematically showing an XZ cross-sectional configuration of the electrostatic chuck 100 according to the embodiment. FIG. 2 is an explanatory diagram schematically illustrating an XY cross-sectional configuration of the electrostatic chuck 100 according to the embodiment. 4 is a flowchart illustrating a method for manufacturing the electrostatic chuck 100 according to the embodiment. FIG. 4 is an explanatory diagram schematically illustrating a method for manufacturing the electrostatic chuck 100 according to the embodiment.

A. Embodiment:
A-1. Configuration of electrostatic chuck 100:
FIG. 1 is a perspective view schematically illustrating an external configuration of the electrostatic chuck 100 according to the present embodiment, and FIG. 2 is an explanatory diagram schematically illustrating an XZ cross-sectional configuration of the electrostatic chuck 100 according to the present embodiment. FIG. 3 is an explanatory view schematically showing an XY cross-sectional configuration of the electrostatic chuck 100 according to the present embodiment. FIG. 2 shows an XZ cross-sectional configuration of the electrostatic chuck 100 at a position II-II in FIG. 3, and FIG. 3 shows an XY cross-sectional configuration of the electrostatic chuck 100 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. However, 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 used, for example, for fixing the wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 100 includes a ceramic plate 10 and a base plate 20 which are arranged side by side in a predetermined arrangement direction (in this embodiment, a vertical direction (Z-axis direction)). The ceramic plate 10 and the base plate 20 are arranged such that the lower surface of the ceramic plate 10 (hereinafter, referred to as “ceramic-side bonding surface S2”) and the upper surface of the base plate 20 (hereinafter, referred to as “base-side bonding surface S3”) are arranged in the above-described arrangement direction. It is arranged so that it may face. The electrostatic chuck 100 further includes an adhesive layer 30 disposed between the ceramic-side bonding surface S2 of the ceramic plate 10 and the base-side bonding surface S3 of the base plate 20. The ceramic-side bonding surface S2 of the ceramic plate 10 corresponds to a second surface in the claims, and the base-side bonding surface S3 of the base plate 20 corresponds to a third surface in the claims.

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

  A pair of internal electrodes 40 formed of a conductive material (for example, tungsten or molybdenum) is provided inside the ceramic plate 10. When a voltage is applied to the pair of internal electrodes 40 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 10 by the electrostatic attraction (hereinafter, referred to as “suction surface S1”). Is fixed by suction. The suction surface S1 of the ceramic plate 10 corresponds to a first surface in the claims.

  Further, inside the ceramic plate 10, a heater 50 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 50 from a power supply (not shown), the heater 50 generates heat, thereby heating the ceramic plate 10 and the wafer W held on the suction surface S1 of the ceramic plate 10. Thereby, the temperature control of the wafer W is realized. As shown in FIG. 3, the heaters 50 are arranged substantially concentrically when viewed in the Z-axis direction in order to warm the suction surface S1 of the ceramic plate 10 as evenly as possible.

  The base plate 20 is, for example, a circular plate-shaped member having the same diameter as the ceramic plate 10 or a diameter larger than the ceramic plate 10, and is formed of a metal (for example, aluminum or an aluminum alloy). The diameter of the base plate 20 is, for example, about 220 mm to 550 mm (usually, 220 mm to 350 mm), and the thickness of the base plate 20 is, for example, about 20 mm to 40 mm.

  A coolant channel 21 is formed inside the base plate 20. When a coolant (for example, a fluorine-based inert liquid or water, etc.) flows through the coolant channel 21, the base plate 20 is cooled, and the heat is transferred from the base plate 20 to the ceramic plate 10 via the adhesive layer 30 to the ceramic plate 10. 10 is cooled, and the wafer W held on the suction surface S1 of the ceramic plate 10 is cooled. Thereby, the temperature control of the wafer W is realized.

  The adhesive layer 30 includes, for example, an adhesive such as a silicone resin, an acrylic resin, or an epoxy resin, and bonds the ceramic plate 10 and the base plate 20 together. The thickness of the adhesive layer 30 is, for example, about 0.1 mm to 1 mm.

  As shown in FIG. 2, a high thermal conductivity member 61 and a low thermal conductivity member 62 are arranged at positions on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20. Although not shown in FIG. 2, an equivalent thermal conductivity member 60 is also disposed at a position on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20. In FIG. 3, the arrangement of the high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 when viewed in the Z-axis direction are indicated by broken lines. As shown in FIGS. 2 and 3, the portion of the adhesive layer 30 on the side closer to the base plate 20 (the portion formed by a first sheet-like adhesive As1 described later) is viewed in the thickness direction of the adhesive layer 30. And a plurality of recesses (notches) Pc formed in the outer peripheral portion. The high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 are arranged in different recesses Pc. The shape of the cross section perpendicular to the vertical direction of each recess Pc may be any shape, for example, a substantially semicircular shape, a substantially semielliptical shape, a substantially rectangular shape, a polygonal shape, or the like.

  The high thermal conductivity member 61 is formed so as to include a material having a relatively high thermal conductivity (for example, aluminum or titanium), and as a result, the thermal conductivity of the high thermal conductivity member 61 is higher than that of the adhesive layer 30. Higher than thermal conductivity. The high thermal conductivity member 61 is disposed at a position overlapping the heater 50 and not overlapping the coolant channel 21 when viewed in the thickness direction of the adhesive layer 30. The heat transfer between the base plate 20 and the ceramic plate 10 is higher at the position where the high thermal conductivity member 61 is disposed than at the position where the adhesive layer 30 is disposed, and the heat transfer member is formed inside the base plate 20. The cooling effect of the ceramic plate 10 by the coolant supplied to the coolant channel 21 is enhanced. The high thermal conductivity member 61 corresponds to a first member in the claims.

  The low thermal conductivity member 62 is formed to include a material having a relatively low thermal conductivity (for example, a resin material such as PEEK (polyetheretherketone)), and as a result, the low thermal conductivity member 62 is formed. Is lower than the thermal conductivity of the adhesive layer 30. Further, the low thermal conductivity member 62 is arranged at a position overlapping with the coolant channel 21 but not overlapping with the heater 50 when viewed in the thickness direction of the adhesive layer 30. At the place where the low thermal conductivity member 62 is disposed, the heat conductivity between the base plate 20 and the ceramic plate 10 is lower than that at the place where the adhesive layer 30 is disposed, and the heat conductive member is formed inside the base plate 20. The effect of cooling the ceramic plate 10 by the coolant supplied to the coolant channel 21 is suppressed. The low thermal conductivity member 62 corresponds to a second member in the claims.

  The equivalent thermal conductivity member 60 is formed so as to include a material (for example, quartz glass or the like) having a thermal conductivity equal to the thermal conductivity of the adhesive layer 30. As a result, the equivalent thermal conductivity member 60 The thermal conductivity is equal to the thermal conductivity of the adhesive layer 30. Further, the equivalent thermal conductivity member 60 is disposed at a position where it does not overlap with the coolant channel 21 and does not overlap with the heater 50 when viewed in the thickness direction of the adhesive layer 30. At the location where the equivalent thermal conductivity member 60 is disposed, the heat conductivity between the base plate 20 and the ceramic plate 10 is equivalent to the location where the adhesive layer 30 is disposed.

  Further, as shown in FIG. 2, the electrostatic chuck 100 has an annular protection that collectively surrounds the adhesive layer 30 and the above-described high thermal conductivity member 61, low thermal conductivity member 62, and equivalent thermal conductivity member 60. A member 64 is provided. The protection member 64 is, for example, an O-ring formed of rubber. The protection member 64 protects the adhesive layer 30 from plasma and prevents the high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 from falling off.

A-2. Manufacturing method of the electrostatic chuck 100:
FIG. 4 is a flowchart illustrating a method for manufacturing the electrostatic chuck 100 according to the present embodiment. FIG. 5 is an explanatory view schematically showing a method of manufacturing the electrostatic chuck 100 according to the present embodiment. In FIG. 5, for convenience of description, there are places where the number, arrangement, and the like of the concave portions Pc, the high thermal conductivity members 61, the low thermal conductivity members 62, and the like are different from those in FIGS.

  First, the ceramic plate 10 and the base plate 20 are prepared (S110). Since the ceramic plate 10 and the base plate 20 can be manufactured by a known manufacturing method, the description of the manufacturing method is omitted here.

  Next, a substantially disk-shaped first sheet-like adhesive As1 as a material for forming the adhesive layer 30 is prepared, and a plurality of locations on the outer peripheral portion of the first sheet-like adhesive As1 are cut out to form a plurality of pieces. The recess Pc is formed (S120, see FIG. 5). The concave portion Pc is a hole that penetrates the first sheet-shaped adhesive As1 in the thickness direction (vertical direction).

  The first sheet-like adhesive As1 is obtained by mixing an adhesive component (for example, a silicone resin, an acrylic resin, an epoxy resin, etc.) and a powder component (for example, alumina, silica, silicon carbide, silicon nitride, etc.). The prepared paste is applied, for example, in the form of a film on a release sheet, and then semi-cured by a curing treatment to form a gel. The paste may include additives such as a coupling agent. Since the first sheet adhesive As1 has a relatively high viscosity, it is easy to secure a certain thickness, to make the thickness uniform, and to form the concave portion Pc. The content of the curing process differs depending on the type of the adhesive used. In the case of a thermosetting adhesive, a process of applying heat is performed as a curing process. As a process, a process of providing moisture by a method such as humidification is performed.

  Next, a substantially disk-shaped second sheet adhesive As2 as a material for forming the adhesive layer 30 is prepared, and the ceramic-side adhesive surface S2 of the ceramic plate 10 and the base-side adhesive surface S3 of the base plate 20 are separated. The first sheet-like adhesive As1 and the second sheet-like adhesive As2 are cured in a state where the second sheet-like adhesive As2 and the above-described first sheet-like adhesive As1 are pasted together. The adhesive layer 30 is formed by performing a curing process (S130). The second sheet-shaped adhesive As2 has the same configuration as the first sheet-shaped adhesive As1 described above, but no recess is formed. Further, the second sheet adhesive As2 is disposed closer to the ceramic plate 10 than the first sheet adhesive As1. 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. In addition, at least the operation of bonding the ceramic plate 10 and the base plate 20 in the step of S130 is performed in a state where the ceramic plate 10 and the base plate 20 are housed in a vacuum-sealed container. This is preferable in that air bubbles are hardly generated in the inside.

  By the processing up to S130, a joined body in which the ceramic plate 10 and the base plate 20 are joined by the adhesive layer 30 is formed. In this bonded body, a portion of the adhesive layer 30 close to the base plate 20 (a portion formed by the first sheet-like adhesive As1) has a plurality of recesses in the outer peripheral portion when viewed in the thickness direction of the adhesive layer 30. It has a shape in which Pc is formed. As described above, since no concave portion is formed in the second sheet-like adhesive As2, the space in each concave portion Pc faces the base-side adhesive surface S3 of the base plate 20, but the ceramic-side adhesive It does not face the surface S2.

  Next, in the joined body in which the ceramics plate 10 and the base plate 20 are joined, the heater 50 formed inside the ceramics plate 10 is turned on, and the coolant is supplied to the coolant flow path 21. The temperature at each position of the ten suction surfaces S1 is measured, and the low-temperature area CA and the high-temperature area HA on the suction surface S1 are specified based on the temperature measurement results (S140, see FIG. 5). Here, the low-temperature region CA on the suction surface S1 is a region including a portion overlapping with the concave portion Pc in the thickness direction of the adhesive layer 30 (hereinafter, referred to as “recess overlap portion”), and another region on the suction surface S1. This is an area where the temperature tends to be lower. The high-temperature area HA is an area including the concave portion overlapping portion, and is an area in which the temperature tends to be higher than other areas on the suction surface S1.

  In the joined body in which the ceramic plate 10 and the base plate 20 are joined, since the inside of the concave portion Pc is a space, the overlapping portion of the concave portion on the suction surface S1 is compared with other portions on the suction surface S1. The heat transfer from the substrate 20 to the ceramic plate 10 will be lower, and the temperature should be higher than that of the other parts. That is, it is predicted that the temperature T1 of the concave portion overlapping portion on the suction surface S1 will be higher by a certain temperature difference (hereinafter referred to as “predicted temperature difference ΔTp”) than the temperature T0 of the other portions. The low-temperature area CA is an area including a concave portion overlapping portion where the actual temperature is lower than the predicted temperature. That is, in the low temperature region CA, the difference between the measured value of the temperature T1 of the overlapping portion of the concave portion and the measured value of the temperature T0 of the other portion (hereinafter referred to as “measured temperature difference ΔTm”) is more than a predetermined value from the predicted temperature difference ΔTp. This is an area including a small concave overlap portion. Further, the high temperature area HA is an area including the concave portion overlapping portion where the actual temperature is higher than the predicted temperature. That is, the high temperature area HA is an area including a concave portion overlapping portion where the measured temperature difference ΔTm is larger than the predicted temperature difference ΔTp by a predetermined value or more.

  Note that the low-temperature region CA and the high-temperature region HA can occur in product design. For example, in the thickness direction of the adhesive layer 30, a region that does not overlap with the heater 50 formed inside the ceramic plate 10 (that is, a region other than a region immediately above the heater 50) can be a low-temperature region CA. Further, when viewed in the thickness direction of the adhesive layer 30, a region overlapping with the coolant flow channel 21 (that is, a region immediately above the coolant flow channel 21) can also be a low-temperature region CA. Conversely, for example, a region overlapping the heater 50 formed inside the ceramic plate 10 (that is, a region immediately above the heater 50) in the thickness direction of the adhesive layer 30 can be the high-temperature region HA. In addition, a region of the adhesive layer 30 that does not overlap with the refrigerant flow channel 21 in the thickness direction (that is, a region other than a region immediately above the refrigerant flow channel 21) can also be the high-temperature region HA. Further, the low-temperature region CA and the high-temperature region HA can also be generated due to product variations of the ceramic plate 10, the base plate 20, the adhesive layer 30, and the like in the manufacturing process.

  Next, among the plurality of concave portions Pc formed on the outer peripheral portion of the joined body in which the ceramic plate 10 and the base plate 20 are joined, low heat is generated in the concave portion Pc overlapping the low-temperature region CA in the thickness direction of the adhesive layer 30. The conductive member 62 is inserted, the high thermal conductive member 61 is inserted into the concave portion Pc overlapping the high temperature region HA, and the equivalent thermal conductive member 60 is inserted into the other concave portion Pc (S150, see FIG. 5).

  Finally, an annular protective member 64 that surrounds the adhesive layer 30, the high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 is installed (S160). Through the above steps, the manufacture of the electrostatic chuck 100 having the above-described configuration is completed.

A-3. Effects of the embodiment:
As described above, in the electrostatic chuck 100 of the present embodiment, the high thermal conductivity member 61 and the low thermal conductivity member 62 are arranged at the position on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20. Is done. The thermal conductivity of the high thermal conductivity member 61 is higher than the thermal conductivity of the adhesive layer 30, and the thermal conductivity of the low thermal conductivity member 62 is lower than the thermal conductivity of the adhesive layer 30. That is, in the electrostatic chuck 100 of the present embodiment, between the ceramic plate 10 and the base plate 20, at least three of the adhesive layers 30, the high thermal conductivity member 61, and the low thermal conductivity member 62 having different thermal conductivity. A member is arranged. The heat transfer between the base plate 20 and the ceramic plate 10 is higher at the position where the high thermal conductivity member 61 is disposed than at the position where the adhesive layer 30 is disposed, and the heat transfer member is formed inside the base plate 20. The cooling effect of the ceramic plate 10 by the coolant supplied to the coolant channel 21 is enhanced. Conversely, the heat transfer between the base plate 20 and the ceramic plate 10 is lower at the position where the low thermal conductivity member 62 is disposed than at the position where the adhesive layer 30 is disposed, and The cooling effect of the ceramic plate 10 due to the refrigerant supplied to the refrigerant flow path 21 formed in the above is suppressed. Therefore, by disposing the high thermal conductivity member 61 and the low thermal conductivity member 62 at appropriate positions on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20, the temperature on the adsorption surface S1 of the ceramic plate 10 is reduced. The uniformity of distribution can be improved.

  In addition, in the adsorption surface S1 of the ceramic plate 10, the position where the adhesive layer 30 overlaps the heater 50 when viewed in the thickness direction tends to have a higher temperature than other positions. In the electrostatic chuck 100 of the present embodiment, since the high thermal conductivity member 61 is disposed at a position overlapping the heater 50 when viewed in the thickness direction of the adhesive layer 30, the cooling effect of the refrigerant on the ceramic plate 10 is enhanced at that position. As a result, the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 10 can be improved.

  In addition, on the adsorption surface S1 of the ceramic plate 10, the position where the adhesive layer 30 overlaps the coolant flow path 21 when viewed in the thickness direction tends to have a lower temperature than other positions. In the electrostatic chuck 100 of the present embodiment, since the low thermal conductivity member 62 is disposed at a position overlapping the refrigerant flow path 21 when viewed in the thickness direction of the adhesive layer 30, the cooling effect of the refrigerant on the ceramic plate 10 at that position. Is suppressed, and the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 10 can be improved.

  Further, in the electrostatic chuck 100 of the present embodiment, the portion of the adhesive layer 30 near the base plate 20 (the portion formed by the first sheet-like adhesive As1) is viewed in the thickness direction of the adhesive layer 30. , A plurality of concave portions Pc are formed in the outer peripheral portion, and the high thermal conductivity member 61 and the low thermal conductivity member 62 are arranged in different concave portions Pc. Therefore, according to the electrostatic chuck 100 of the present embodiment, the high thermal conductivity member 61 and the low thermal conductivity member 62 are arranged to secure the bonding area of the bonding layer 30 to some extent, so that the suction surface S1 of the ceramic plate 10 is formed. The uniformity of the temperature distribution can be improved.

  Further, the electrostatic chuck 100 of the present embodiment includes an annular protective member 64 that surrounds the adhesive layer 30, the high thermal conductivity member 61, and the low thermal conductivity member 62 collectively. Therefore, according to the electrostatic chuck 100 of the present embodiment, by disposing the high thermal conductivity member 61 and the low thermal conductivity member 62, the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 10 is improved, and the high thermal conductivity is improved. The falling off of the rate member 61 and the low thermal conductivity member 62 can be prevented.

  By appropriately setting the number, shape, arrangement, heat conductivity, and the like of the high thermal conductivity member 61 and the low thermal conductivity member 62, the heating by the heater 50 and the supply of the refrigerant to the refrigerant flow path 21 are performed. In addition, the temperature difference at each position of the suction surface S1 of the ceramic plate 10 can be kept within 3 ° C. It is preferable that the temperature difference at each position of the suction surface S1 of the ceramic plate 10 be within 3 ° C., since the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 10 can be sufficiently improved.

  In the method of manufacturing the electrostatic chuck 100 according to the present embodiment, after the adhesive layers As1 and As2 disposed between the ceramic plate 10 and the base plate 20 are cured, the adhesive layer 30 is formed. The temperature at each position of the suction surface S1 is specified, and at the position on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20, each member selected based on the specified temperature (high thermal conductivity) The member 61 and the low thermal conductivity member 62) are arranged. That is, in this manufacturing method, the bonding of the ceramic plate 10 and the base plate 20 by the bonding layer 30, that is, the bonded body in a state very close to the completed electrostatic chuck 100 is targeted. Since the temperature can be specified at each position of the surface S1, a member having an appropriate thermal conductivity is selected and arranged at a position on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20. be able to. Therefore, according to this manufacturing method, it is possible to manufacture the electrostatic chuck 100 in which the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 10 is improved.

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 100 in the above embodiment is merely an example, and can be variously modified. For example, in the above embodiment, the number, position, shape, and the like of the concave portions Pc formed in the adhesive layer 30 can be arbitrarily set. Further, in the above embodiment, the concave portion Pc is formed in the portion of the adhesive layer 30 close to the base plate 20 (the portion formed by the first sheet-like adhesive As1). It may be formed on a portion closer to the plate 10 (a portion formed by the second sheet-like adhesive As2). This configuration can be realized, for example, by forming the concave portion Pc in the second sheet adhesive As2 instead of the first sheet adhesive As1 in the manufacturing process of the electrostatic chuck 100 (FIG. 5). Further, the concave portion Pc may be formed over the whole of the adhesive layer 30 in the thickness direction. This configuration is, for example, in the manufacturing process of the electrostatic chuck 100, in both the first sheet-like adhesive As1 and the second sheet-like adhesive As2, at the same position (position vertically overlapped during lamination). This can be realized by forming the concave portion Pc. Further, the concave portion Pc may be formed at a position other than both ends in the thickness direction of the adhesive layer 30. In this configuration, for example, in the manufacturing process of the electrostatic chuck 100, a third sheet-like adhesive having no concave portion Pc is further arranged below the first sheet-like adhesive As1 (on the side of the base plate 20). This can be realized by:

  In the electrostatic chuck 100, at least one concave portion Pc (hereinafter, referred to as “first concave portion Pc1”) and at least one concave portion (the position in the thickness direction of the adhesive layer 30 different from the first concave portion Pc1). Hereinafter, “second concave portion Pc2”) may be formed. For example, in the manufacturing process (FIG. 5) of the electrostatic chuck 100, the first sheet-like adhesive As1 and the second sheet-like adhesive As2 have different positions (in the vertical direction at the time of lamination). This can be realized by forming the concave portion Pc at a position that does not overlap). According to this configuration, since the degree of freedom in the arrangement of the concave portion Pc can be increased, the cooling effect by arranging the members such as the high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 is reduced. The adjustment can be performed finely, and the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 10 can be effectively improved.

  Further, for example, in the manufacturing process of the electrostatic chuck 100 (FIG. 5), the diameter of the first sheet adhesive As1 is made smaller than the diameter of the second sheet adhesive As2, so that the ceramic plate 10 and the base plate 20 are formed. In the joined body joined by the adhesive layer 30, a space is secured around the entire area of the adhesive layer 30 formed by the first sheet-like adhesive As1, and the high thermal conductivity member 61 and the low heat conductive The members such as the rate member 62 and the equivalent thermal conductivity member 60 may be arranged.

  In the above embodiment, the electrostatic chuck 100 includes one high thermal conductivity member 61 and one low thermal conductivity member 62. However, the high thermal conductivity member 61 and the low thermal conductivity included in the electrostatic chuck 100 are provided. The number of members 62 may be any number.

  Further, in the above embodiment, the high thermal conductivity member 61 is arranged at a position overlapping the heater 50 and not overlapping the refrigerant flow path 21 when viewed in the thickness direction of the adhesive layer 30. The arrangement of 61 is not limited to this. For example, even in a position other than the position where the high thermal conductivity member 61 overlaps the heater 50 and does not overlap the refrigerant flow path 21, a region where the temperature of the adsorption surface S1 of the ceramic plate 10 tends to be relatively high (high temperature region) If it is arranged in a position vertically overlapping with (HA), the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 10 can be improved.

  In the above-described embodiment, the low thermal conductivity member 62 is disposed at a position that does not overlap with the heater 50 and overlaps with the coolant flow path 21 when viewed in the thickness direction of the adhesive layer 30. The arrangement of the member 62 is not limited to this. For example, even if the low thermal conductivity member 62 does not overlap with the heater 50 but at a position other than the position where the low thermal conductivity member 62 overlaps with the coolant flow path 21, a region where the temperature tends to be relatively low on the adsorption surface S1 of the ceramic plate 10 (low temperature) If it is arranged at a position vertically overlapping the area CA), the uniformity of the temperature distribution on the suction surface S1 of the ceramic plate 10 can be improved.

  Further, in the above-described embodiment, the electrostatic chuck 100 is provided at a position on the outer peripheral side of the adhesive layer 30 between the ceramic plate 10 and the base plate 20 so as to have a high thermal conductivity higher than the thermal conductivity of the adhesive layer 30. Although it is assumed that the thermal conductivity member 61 and the low thermal conductivity member 62 having a thermal conductivity lower than the thermal conductivity of the adhesive layer 30 are provided, instead of the high thermal conductivity member 61 or the high thermal conductivity member 61 and the low thermal conductivity member, In addition to the low thermal conductivity member 62, a member having a lower thermal conductivity than the low thermal conductivity member 62 may be provided together with the low thermal conductivity member 62, or the high thermal conductivity member 61 and the low thermal conductivity Along with the member 62, a member having a higher thermal conductivity than the thermal conductivity of the high thermal conductivity member 61 may be provided. In the above embodiment, the electrostatic chuck 100 includes the equivalent thermal conductivity member 60; however, the electrostatic chuck 100 may not include the equivalent thermal conductivity member 60.

  Further, the material forming each member in the above embodiment is merely an example, and each member may be formed of another material. For example, the material for forming the high thermal conductivity member 61, the low thermal conductivity member 62, and the equivalent thermal conductivity member 60 may be a material other than the materials exemplified in the above embodiment. The material for forming these members is preferably a material that can be selected for plasma resistance and heat resistance and that does not easily cause contamination. In the above embodiment, the protection member 64 is an O-ring made of, for example, rubber. However, the protection member 64 may be made of an epoxy resin or a silicone resin.

  Further, in the above embodiment, the heater 50 is disposed inside the ceramic plate 10, but the heater 50 is not provided inside the ceramic plate 10 but on the base plate 20 side of the ceramic plate 10 (the ceramic plate 10 and the adhesive layer). 30). In this case, the bonding layer 30 bonds at least one of the ceramic plate 10 and the heater 50 to the base plate 20.

  Further, in the above embodiment, the coolant passage 21 is formed inside the base plate 20. However, the coolant passage 21 is not provided inside the base plate 20 but on the surface of the base plate 20 (for example, the base plate 20 and the base plate 20). (Between the adhesive layer 30). Further, in the above embodiment, the bipolar method in which a pair of internal electrodes 40 are provided inside the ceramic plate 10 is adopted, but the monopolar method in which one internal electrode 40 is provided inside the ceramic plate 10 is used. May be employed.

  Further, the method of manufacturing the electrostatic chuck 100 in the above embodiment is merely an example, and can be variously modified. For example, in the above embodiment, the low-temperature area CA and the high-temperature area HA on the adsorption surface S1 of the ceramic plate 10 are specified. However, only one of them (for example, only the low-temperature area CA) is specified. Is also good.

  In the above embodiment, the inside of the concave portion Pc formed on the outer peripheral portion of the joined body in which the ceramic plate 10 and the base plate 20 are joined by the adhesive layer 30 is completely filled with a member such as the high thermal conductivity member 61. It is not necessary to provide a space, and a space may remain in a part of the recess Pc. Further, among the plurality of recesses Pc, at least one recess Pc corresponding to the low-temperature region CA may be left as a space without inserting anything into the recess Pc.

  In the above embodiment, the adhesive layer 30 is formed of two sheet adhesives As, but the adhesive layer 30 may be formed of three or more sheet adhesives As, It may be formed by the paste adhesive Ap. The paste adhesive Ap 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.). Adhesive. The paste adhesive may include an additive such as a coupling agent.

  The present invention is not limited to the electrostatic chuck 100 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: Ceramic plate 20: Base plate 21: Refrigerant channel 30: Adhesive layer 40: Internal electrode 50: Heater 60: Equivalent thermal conductivity member 61: High thermal conductivity member 62: Low thermal conductivity member 64: Protective member 100: Static Electric chuck

Claims (6)

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 ceramic plate, and a coolant channel is formed;
Inside the ceramic plate, or a heater arranged on the base plate side of the ceramic plate,
An adhesive layer 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,
A holding device for holding an object on the first surface of the ceramic plate, further comprising:
A first member having a thermal conductivity different from that of the adhesive layer, which is disposed at a position on the outer peripheral side of the adhesive layer between the ceramics plate and the base plate;
A second member having a different thermal conductivity from the ceramic plate and the base plate, which is disposed at a position on the outer peripheral side of the adhesive layer, the adhesive layer and the first member;
Equipped with a,
The adhesive layer has a shape in which a plurality of recesses are formed in an outer peripheral portion when viewed in a thickness direction of the adhesive layer,
The first member and the second member are arranged in the concave portions different from each other,
The plurality of recesses include at least one first recess, and at least one second recess in which a position in a thickness direction of the adhesive layer is different from the first recess . Holding device. The holding device according to claim 1,
The thermal conductivity of the first member is higher than the thermal conductivity of the adhesive layer,
The holding device, wherein the first member is disposed at a position overlapping the heater when viewed in a thickness direction of the adhesive layer. In the holding device according to claim 1 or 2,
The thermal conductivity of the second member is lower than the thermal conductivity of the adhesive layer,
The holding device, wherein the second member is disposed at a position overlapping with the coolant flow path when viewed in a thickness direction of the adhesive layer. The holding device according to any one of claims 1 to 3 , further comprising:
A holding device, comprising: an annular protective member that surrounds the adhesive layer, the first member, and the second member collectively. In the holding device according to any one of claims 1 to 4 ,
A holding device, wherein a temperature difference at each position on the first surface of the ceramic plate is within 3 ° C. during execution of heating by the heater and supply of the coolant to the coolant channel. A plate-shaped ceramic plate having a first surface and a second surface opposite to the first surface; and a plate-shaped plate having a third surface, wherein the third surface is formed of the ceramics. A base plate having a coolant channel formed therein, disposed opposite to the second surface of the plate, and a heater disposed inside the ceramic plate or on the base plate side of the ceramic plate; An adhesive layer disposed between the ceramic plate and the base plate, for bonding at least one of the ceramic plate and the heater to the base plate, and having an object on the first surface of the ceramic plate. In a method of manufacturing a holding device for holding an object,
Preparing the ceramic plate and the base plate,
A step of disposing an adhesive between the ceramic plate and the base plate, and forming the adhesive layer by curing the adhesive,
After the formation of the adhesive layer, a step of specifying a temperature at each position on the first surface of the ceramic plate;
Disposing a first member selected based on the specified temperature and having a different heat conductivity from the adhesive layer at a position on the outer peripheral side of the adhesive layer between the ceramics plate and the base plate; ,
A second position, which is selected based on the specified temperature, at a position on the outer peripheral side of the adhesive layer between the ceramic plate and the base plate, and has a different thermal conductivity from the adhesive layer and the first member. Arranging the member;
Equipped with a,
The step of forming the adhesive layer includes, in a thickness direction of the adhesive layer, a plurality of concave portions on an outer peripheral portion, at least one first concave portion, and a position in the thickness direction of the adhesive layer. Forming at least one second recess different from the first recess, the adhesive layer having a plurality of recesses including:
The step of arranging the first member is a step of arranging the first member in at least one of the plurality of recesses,
The step of arranging the second member is a step of arranging the second member in at least one of the plurality of recesses where the first member is not arranged. To manufacture a holding device.

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