Substrate fixing device and method for manufacturing a substrate fixing device

Abstract

To improve thermal response and adhesion in the adhesive layer.SOLUTION: A substrate fixing device has a base plate, a ceramic plate, and an adhesive layer. The ceramic plate is fixed to the base plate and adsorbs the substrate by electrostatic force. The adhesive layer bonds the base plate to the ceramic plate. The adhesive layer has a plurality of linear heat transfer elements and resin. The plurality of heat transfer elements are arranged adjacent to each other so that their longitudinal direction faces the stacking direction of the ceramic plate and the base plate. The resin is filled between the adjacent heat transfer elements and bonded to the ceramic plate and base plate.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a substrate fixing device and a method for manufacturing the substrate fixing device.

Background Art

[0002] Generally, for example, when manufacturing semiconductor components, a substrate fixing device that adsorbs and holds a wafer is also called an electrostatic chuck (ESC) and includes a ceramic plate with built-in electrodes. The substrate fixing device has a structure in which the ceramic plate is adhered to a base plate, and by applying a voltage to the electrodes built into the ceramic plate, the wafer is adsorbed to the ceramic plate using electrostatic force. By adsorbing and holding the wafer on the ceramic plate, processes such as microfabrication and etching on the wafer can be efficiently performed.

[0003] In such a substrate fixing device, the ceramic plate is adhered to the base plate by, for example, a silicone resin-based adhesive. When the ceramic plate and the base plate are adhered by an adhesive, since the thermal resistance in the thickness direction of the adhesive is relatively large, the transfer of heat from the ceramic plate that adsorbs the wafer to the base plate is inhibited, and the rapidity of temperature adjustment of the wafer may decrease. On the other hand, in order to improve the heat transfer property from the ceramic plate to the base plate, a technique has been proposed in which the ceramic plate is adhered to the base plate by an adhesive layer composed of an aggregate of carbon nanotubes having a high longitudinal thermal conductivity instead of an adhesive.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when an adhesive layer made of carbon nanotube aggregates is used, while the thermal responsiveness of the adhesive layer is improved, there is a problem that the adhesive strength may decrease. Specifically, when the ceramic plate and the base plate are bonded based solely on the intermolecular forces of the carbon nanotubes in the adhesive layer, the adhesive strength between the ceramic plate and the base plate is relatively low. As a result, the adhesive layer may peel off from the ceramic plate or the base plate due to stress caused by the difference in thermal expansion coefficients between the ceramic plate and the base plate.

[0006] The disclosed technology has been made in view of the above, and aims to provide a substrate fixing device and a method for manufacturing a substrate fixing device that can improve the thermal responsiveness and adhesion of the adhesive layer. [Means for solving the problem]

[0007] In one embodiment, the substrate fixing device disclosed in this application comprises a base plate, a ceramic plate, and an adhesive layer. The ceramic plate is fixed to the base plate and attracts the substrate by electrostatic force. The adhesive layer bonds the base plate and the ceramic plate. The adhesive layer comprises a plurality of linear heat transfer elements and a resin. The plurality of heat transfer elements are arranged adjacent to each other so that their longitudinal direction faces the stacking direction of the ceramic plate and the base plate. The resin is filled between adjacent heat transfer elements and bonded to the ceramic plate and the base plate. [Effects of the Invention]

[0008] According to one embodiment of the substrate fixing device disclosed in this application, the thermal responsiveness and adhesion of the adhesive layer can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing the configuration of a substrate fixing device according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing a cross-section of the substrate fixing device according to the first embodiment. [Figure 3] Figure 3 is a flowchart showing a method for manufacturing a substrate fixing device according to the first embodiment. [Figure 4] Figure 4 shows a specific example of a ceramic plate. [Figure 5] Figure 5 shows a specific example of the adhesive layer lamination process. [Figure 6] Figure 6 shows a specific example of the ceramic plate lamination process. [Figure 7] Figure 7 is a schematic diagram showing a cross-section of the substrate fixing device according to the second embodiment. [Figure 8] Figure 8 is a flowchart showing a method for manufacturing a substrate fixing device according to the second embodiment. [Figure 9] Figure 9 shows a specific example of the adhesive layer lamination process. [Figure 10] Figure 10 shows a specific example of the ceramic plate lamination process. [Figure 11] Figure 11 shows a first modified example of the substrate fixing device according to the second embodiment. [Figure 12] Figure 12 shows a second modified example of the substrate fixing device according to the second embodiment. [Figure 13] Figure 13 is a schematic diagram showing a cross-section of the substrate fixing device according to the third embodiment. [Figure 14] Figure 14 is a flowchart showing a method for manufacturing a substrate fixing device according to the third embodiment. [Figure 15] Figure 15 shows a specific example of the adhesive layer lamination process. [Figure 16] Figure 16 shows a specific example of the ceramic plate lamination process. [Figure 17] Figure 17 shows a specific example of an intermediate structure. [Figure 18] Figure 18 is a schematic diagram showing a cross-section of the substrate fixing device according to the fourth embodiment. [Figure 19] Figure 19 is a flowchart showing a method for manufacturing a substrate fixing device according to the fourth embodiment. [Figure 20] Figure 20 shows a specific example of the sealing member placement process.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the substrate fixing device and the method for manufacturing the substrate fixing device disclosed in the present application will be described in detail based on the drawings. Note that the disclosed technology is not limited by this embodiment.

[0011] (First Embodiment) FIG. 1 is a perspective view showing the configuration of a substrate fixing device 100 according to the first embodiment. The substrate fixing device 100 shown in FIG. 1 has a structure in which a ceramic plate 120 is adhered to a base plate 110.

[0012] The base plate 110 is a circular member made of metal such as aluminum, for example. The base plate 110 is a base material for fixing the ceramic plate 120. The base plate 110 is attached to, for example, a semiconductor manufacturing apparatus, and functions as a semiconductor holding device for holding a wafer by the substrate fixing device 100.

[0013] The ceramic plate 120 is a circular member made of insulating ceramic. The diameter of the ceramic plate 120 is smaller than the diameter of the base plate 110, and the ceramic plate 120 is fixed at the center of the base plate 110. That is, the lower surface of the ceramic plate 120 becomes an adhesive surface adhered to the base plate 110, and the ceramic plate 120 is fixed by adhering the adhesive surface to the base plate 110. The upper surface of the ceramic plate 120 is an adsorption surface for adsorbing an object to be adsorbed such as a wafer, for example.

[0014] The ceramic plate 120 incorporates a conductive electrode, and uses the electrostatic force generated when a voltage is applied to such an electrode to adsorb an object such as a wafer to the adsorption surface. Further, the ceramic plate 120 incorporates a heater electrode, and the temperature of the ceramic plate 120 and an object such as a wafer adsorbed to the ceramic plate 120 is adjusted by the heater electrode that generates heat when a voltage is applied.

[0015] Figure 2 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to the first embodiment. Figure 2 shows a cross-section viewed along the line II-II in Figure 1. As shown in Figure 2, the substrate fixing device 100 is constructed by bonding a base plate 110 and a ceramic plate 120 together with an adhesive layer 130.

[0016] The base plate 110 is, for example, a circular metal member with a thickness of about 20 to 50 mm. Inside the base plate 110, a refrigerant passage 111 is formed, which serves as a passage for a refrigerant such as cooling water or cooling gas. The ceramic plate 120 is cooled as the refrigerant passes through the refrigerant passage 111. As a result of the cooling of the ceramic plate 120, objects such as wafers that are adsorbed on the adsorption surface of the ceramic plate 120 are cooled. The upper surface 110a of the base plate 110 is an adhesive surface that is bonded to the ceramic plate 120, and is bonded to the lower surface 120a of the ceramic plate 120 by an adhesive layer 130.

[0017] The ceramic plate 120 is a circular plate made of ceramic, for example, 4 to 6 mm thick. The ceramic plate 120 is obtained by firing a green sheet made using aluminum oxide, for example. The lower surface 120a of the ceramic plate 120 is an adhesive surface that is bonded to the base plate 110, and is bonded to the upper surface 110a of the base plate 110 by an adhesive layer 130. An electrode 121 and a heater electrode 122 are formed inside the ceramic plate 120.

[0018] The electrode 121 is placed inside the ceramic plate 120 and generates an electrostatic force when a voltage is applied. Due to this electrostatic force, the ceramic plate 120 attracts an object, such as a wafer, to its upper surface 120b, which serves as the adsorption surface.

[0019] The heater electrode 122 is positioned below the electrode 121 inside the ceramic plate 120 and generates heat when a voltage is applied. This heat generated by the heater electrode 122 heats the ceramic plate 120 and the object such as a wafer that is adsorbed onto the upper surface 120b of the ceramic plate 120.

[0020] The adhesive layer 130 adheres the base plate 110 and the ceramic plate 120. The adhesive layer 130 has the property (hereinafter referred to as "thermal anisotropy") that the thermal conductivity in the lamination direction between the base plate 110 and the ceramic plate 120 (hereinafter sometimes simply referred to as "lamination direction") is higher than the thermal conductivity in the planar direction perpendicular to the lamination direction. Specifically, the adhesive layer 130 has a structure in which a plurality of carbon nanotubes 131, in which the thermal conductivity in the longitudinal direction is higher than the thermal conductivity in other directions, are embedded in the resin 132.

[0021] Multiple carbon nanotubes 131 are linear crystals made of carbon, arranged adjacent to each other so that their longitudinal directions are aligned with the stacking direction between the base plate 110 and the ceramic plate 120. The longitudinal thermal conductivity of the carbon nanotubes 131 is higher than that of the ceramic plate 120. The carbon nanotubes 131 are an example of a heat transfer material.

[0022] The resin 132 is filled between adjacent carbon nanotubes 131 and bonded to the ceramic plate 120 and the base plate 110. For example, the resin 132 can be a thermosetting resin or a thermoplastic resin. Examples of thermosetting resins include epoxy resins, polyimide resins, phenolic resins, or silicone resins. Examples of thermoplastic resins include polyethylene resins, polyphenylene resins, polyether resins, acrylic resins, or fluoropolymer resins.

[0023] By bonding the base plate 110 and the ceramic plate 120 with an adhesive layer 130 having a structure in which multiple carbon nanotubes 131 are embedded in resin 132, heat transfer through the adhesive layer 130 can be made smoother compared to when an adhesive is used. As a result, the heat transfer from the ceramic plate 120 to the base plate 110 via the adhesive layer 130 is improved, and the thermal responsiveness of the adhesive layer 130 can be improved. In addition, since the resin 132 is bonded to the ceramic plate 120 and the base plate 110, the adhesive strength between the ceramic plate 120 and the base plate 110 is higher compared to when an adhesive layer consisting of an aggregate of carbon nanotubes is used. This suppresses peeling of the adhesive layer 130 and improves the adhesion of the adhesive layer 130, even when stress due to the difference in thermal expansion coefficients between the ceramic plate 120 and the base plate 110 acts on the adhesive layer 130.

[0024] Furthermore, the resin 132 coats the carbon nanotubes 131 with their longitudinal upper and lower end faces exposed. This allows the longitudinal upper end face of the carbon nanotubes 131 to be in contact with the ceramic plate 120 and the lower end face to be in contact with the base plate 110, thereby facilitating smoother heat transfer through the adhesive layer 130.

[0025] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 3. Figure 3 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the first embodiment.

[0026] First, a ceramic plate 120 for adsorbing an object such as a wafer is formed (step S101). Specifically, for example, multiple green sheets mainly made of aluminum oxide are prepared, and an electrode 121 is formed on one surface of a green sheet as appropriate, and a heater electrode 122 is formed on one surface of another green sheet. The electrode 121 and heater electrode 122 can be formed, for example, by screen printing a metal paste onto the surface of a green sheet. Then, the multiple green sheets are stacked and fired to form the ceramic plate 120. The ceramic plate 120 incorporates layers of electrodes 121 and layers of heater electrodes 122, for example, as shown in Figure 4. Figure 4 is a diagram showing a specific example of the ceramic plate 120. Note that the heater electrode 122 may be omitted if necessary.

[0027] Once the ceramic plate 120 is formed, an adhesive layer is laminated onto the ceramic plate 120 (step S102). Specifically, as shown in Figure 5, for example, an adhesive layer 130 consisting of multiple carbon nanotubes 131 and resin sheets 132a and 132b is temporarily bonded to the lower surface 120a of the ceramic plate 120 from the resin sheet 132a side. Figure 5 is a diagram showing a specific example of the adhesive layer lamination process. The resin sheets 132a and 132b are sheet-like members formed using a semi-cured resin for forming the resin 132, and they support multiple carbon nanotubes 131 by sandwiching them. The resin sheet 132a is connected to the upper end of the carbon nanotubes 131, and the resin sheet 132b is connected to the lower end of the carbon nanotubes 131. At the stage when the adhesive layer 130 is laminated onto the ceramic plate 120, the resin 132 has not yet filled the spaces between adjacent carbon nanotubes 131 in the adhesive layer 130.

[0028] Then, the ceramic plate 120 with the adhesive layer 130 laminated on it is laminated onto the base plate 110 via the adhesive layer 130 (step S103). Specifically, as shown in Figure 6 for example, the ceramic plate 120 with the adhesive layer 130 laminated on it is temporarily bonded to the upper surface 110a of the base plate 110 from the resin sheet 132b side of the adhesive layer 130. Figure 6 is a diagram showing a specific example of the ceramic plate lamination process.

[0029] Then, the ceramic plate 120 laminated on the base plate 110 via the adhesive layer 130 is bonded to the base plate 110 (step S104). Specifically, the semi-cured resin that forms the resin sheets 132a and 132b is filled between adjacent carbon nanotubes 131 in the adhesive layer 130 by heating and pressurizing, and the filled resin hardens while in contact with the ceramic plate 120 and the base plate 110. As a result, resin 132 is formed that is filled between adjacent carbon nanotubes 131 and bonded to the ceramic plate 120 and the base plate 110.

[0030] In this substrate fixing device 100, the base plate 110 and the ceramic plate 120 are bonded together by an adhesive layer 130 having a structure in which multiple carbon nanotubes 131 are embedded in a resin 132, thereby improving the thermal responsiveness and adhesion of the adhesive layer 130.

[0031] As described above, the substrate fixing device according to the first embodiment (for example, the substrate fixing device 100) comprises a base plate (for example, base plate 110), a ceramic plate (for example, ceramic plate 120), and an adhesive layer (for example, adhesive layer 130). The ceramic plate is fixed to the base plate and attracts a substrate (for example, a wafer) by electrostatic force. The adhesive layer bonds the base plate and the ceramic plate. The adhesive layer comprises a plurality of linear heat transfer elements (for example, carbon nanotubes 131) and a resin (for example, resin 132). The plurality of heat transfer elements are arranged adjacent to each other so that their longitudinal direction faces the stacking direction of the ceramic plate and the base plate. The resin is filled between adjacent heat transfer elements and bonded to the ceramic plate and the base plate. As a result, according to the substrate fixing device according to the first embodiment, the thermal responsiveness and adhesion of the adhesive layer can be improved.

[0032] Furthermore, the ceramic plate may incorporate a heat-generating electrode (for example, a heater electrode 122). This allows the substrate fixing device according to the first embodiment to adjust the temperature of the ceramic plate and the temperature of the substrate adsorbed onto the ceramic plate to a desired temperature.

[0033] (Second Embodiment) The second embodiment differs from the first embodiment in that, in addition to the adhesive layer, an adhesive is used to bond the ceramic plate and the base plate.

[0034] Figure 7 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to the second embodiment. In Figure 7, the same reference numerals are used for the same parts as in Figure 2. The substrate fixing device 100 shown in Figure 7 includes a first adhesive 140 and a second adhesive 150 in addition to the parts shown in Figure 2.

[0035] The first adhesive 140 is placed between the ceramic plate 120 and the adhesive layer 130. The second adhesive 150 is placed between the base plate 110 and the adhesive layer 130. The first adhesive 140 and the second adhesive 150 may be formed from the same resin as the resin 132 of the adhesive layer 130, or from a different resin. As the resins forming the first adhesive 140 and the second adhesive 150, for example, thermosetting resins or thermoplastic resins can be used. As thermosetting resins, for example, epoxy resins, polyimide resins, phenolic resins, or silicone resins can be used. As thermoplastic resins, for example, polyethylene resins, polyphenylene resins, polyether resins, acrylic resins, or fluororesins can be used.

[0036] The adhesive layer 130 is bonded to the ceramic plate 120 via the first adhesive 140 and to the base plate 110 via the second adhesive 150. In other words, the ceramic plate 120 is bonded to the base plate 110 by the adhesive layer 130, the first adhesive 140, and the second adhesive 150. With this configuration, the adhesive strength between the ceramic plate 120 and the base plate 110 is higher compared to the case where the ceramic plate 120 is bonded to the base plate 110 by the adhesive layer 130 alone.

[0037] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 8. Figure 8 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the second embodiment. In Figure 8, the same parts as in Figure 3 are denoted by the same reference numerals.

[0038] In step S101, when the ceramic plate 120 is formed, an adhesive layer is laminated onto the ceramic plate 120 (step S202). Specifically, as shown in Figure 9, for example, an adhesive layer 130 consisting of multiple carbon nanotubes 131 and resin sheets 132a and 132b is temporarily bonded to the lower surface 120a of the ceramic plate 120 from the resin sheet 132a side via the first adhesive 140. Figure 9 is a diagram showing a specific example of the adhesive layer lamination process. At the stage when the adhesive layer 130 is laminated onto the ceramic plate 120, the resin 132 has not yet filled the spaces between adjacent carbon nanotubes 131 in the adhesive layer 130.

[0039] Then, the ceramic plate 120 with the adhesive layer 130 laminated on it is laminated onto the base plate 110 via the first adhesive 140, the adhesive layer 130, and the second adhesive 150 (step S203). Specifically, as shown in Figure 10, for example, the ceramic plate 120 with the adhesive layer 130 laminated on it is temporarily bonded to the upper surface 110a of the base plate 110 via the second adhesive 150 from the resin sheet 132b side of the adhesive layer 130. Figure 10 is a diagram showing a specific example of the ceramic plate lamination process.

[0040] Then, the ceramic plate 120, which is laminated on the base plate 110 via the first adhesive 140, the adhesive layer 130, and the second adhesive 150, is bonded to the base plate 110 (step S204). Specifically, the semi-cured resin that forms the resin sheets 132a and 132b is filled between adjacent carbon nanotubes 131 in the adhesive layer 130 by heating and pressurizing, and the filled resin hardens while in contact with the first adhesive 140 and the second adhesive 150. As a result, the resin 132 that is filled between adjacent carbon nanotubes 131 is bonded to the ceramic plate 120 via the first adhesive 140 and to the base plate 110 via the second adhesive 150. As a result, the base plate 110 and the ceramic plate 120 are bonded by the first adhesive 140, the adhesive layer 130, and the second adhesive 150, and the substrate fixing device 100 is completed.

[0041] As described above, the substrate fixing device according to the second embodiment further comprises a first adhesive (e.g., first adhesive 140) and a second adhesive (e.g., second adhesive 150). The first adhesive is placed between the ceramic plate and the adhesive layer. The second adhesive is placed between the base plate and the adhesive layer. The adhesive layer is bonded to the ceramic plate via the first adhesive and to the base plate via the second adhesive. As a result, the substrate fixing device according to the second embodiment provides a higher adhesive strength between the ceramic plate and the base plate compared to the case where the ceramic plate is bonded to the base plate by the adhesive layer alone.

[0042] In this embodiment, the ceramic plate 120 incorporates the heater electrode 122, but the arrangement of the heater electrode is not limited to this and can be changed in various ways. Hereinafter, specific modifications of the substrate fixing device 100 will be described.

[0043] Figure 11 shows a first modified example of the substrate fixing device 100 according to the second embodiment. In Figure 11, the same parts as in Figure 7 are denoted by the same reference numerals.

[0044] In the modified example shown in Figure 11, a heater electrode 141 is placed inside the first adhesive 140. The heater electrode 141 generates heat when a voltage is applied. This heat generated by the heater electrode 122 heats the ceramic plate 120 and the object such as a wafer that is adsorbed onto the upper surface 120b of the ceramic plate 120. In this way, the temperature of the ceramic plate 120 and the temperature of the object such as a wafer adsorbed onto the ceramic plate 120 can be adjusted to a desired temperature.

[0045] Figure 12 shows a second modified example of the substrate fixing device 100 according to the second embodiment. In Figure 12, the same reference numerals are used for the same parts as in Figure 7.

[0046] In the modified example shown in Figure 12, a heater electrode 151 is placed inside the second adhesive 150. The heater electrode 151 generates heat when a voltage is applied. This heat generated by the heater electrode 151 heats the second adhesive 150, as well as the object such as a wafer that is adsorbed onto the upper surface 120b of the ceramic plate 120. In this way, the temperature of the ceramic plate 120 and the temperature of the object such as a wafer adsorbed onto the ceramic plate 120 can be adjusted to a desired temperature.

[0047] Furthermore, the heater electrodes may be placed not only individually inside the ceramic plate 120, the first adhesive 140, and the second adhesive 150, but also inside at least one of the ceramic plate 120, the first adhesive 140, and the second adhesive 150.

[0048] (Third embodiment) The third embodiment differs from the first embodiment in its structure for protecting the outer surface of the adhesive layer from plasma.

[0049] Figure 13 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to the third embodiment. In Figure 13, the same reference numerals are used for the same parts as in Figure 2. In the substrate fixing device 100 shown in Figure 13, the outer surface of the adhesive layer 130 is located inward from the outer surface of the ceramic plate 120. The outer surface of the adhesive layer 130, together with the lower surface 120a of the ceramic plate and the upper surface 110a of the base plate 110, which are opposite each other on the outer circumference of the substrate fixing device 100, form a recess 135. A sealing member 160 is placed in this recess 135 to close the recess 135. In this way, the outer surface of the adhesive layer 130 can be protected from plasma.

[0050] In other words, if the sealing member 160 is not placed, the outer surface of the adhesive layer 130 may be exposed to plasma and worn down when the substrate fixing device 100 is used, for example, for plasma etching of a wafer. In contrast, by placing the sealing member 160 in the recess 135 formed by the outer surface of the adhesive layer 130 and the lower surface 120a of the ceramic plate and the upper surface 110a of the base plate 110, the plasma is prevented from reaching the outer surface of the adhesive layer 130. As a result, contact between the plasma and the adhesive layer 130 can be suppressed, thereby suppressing wear of the adhesive layer 130 due to the plasma.

[0051] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 14. Figure 14 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the third embodiment. In Figure 14, the same parts as in Figure 3 are denoted by the same reference numerals.

[0052] In step S101, when the ceramic plate 120 is formed, an adhesive layer is laminated onto the ceramic plate 120 (step S302). Specifically, as shown in Figure 15, for example, an adhesive layer 130 consisting of multiple carbon nanotubes 131 and resin sheets 132a and 132b is temporarily bonded to the lower surface 120a of the ceramic plate 120 from the resin sheet 132a side. Figure 15 is a diagram showing a specific example of the adhesive layer lamination process. The outer surface of the adhesive layer 130 is located inward from the outer surface of the ceramic plate 120. At the stage when the adhesive layer 130 is laminated onto the ceramic plate 120, the resin 132 has not yet filled the spaces between adjacent carbon nanotubes 131 in the adhesive layer 130.

[0053] Then, the ceramic plate 120 with the adhesive layer 130 laminated on it is laminated onto the base plate 110 via the adhesive layer 130 (step S303). Specifically, for example as shown in Figure 16, the ceramic plate 120 with the adhesive layer 130 laminated on it is temporarily bonded to the upper surface 110a of the base plate 110 from the resin sheet 132b side of the adhesive layer 130. Figure 16 is a diagram showing a specific example of the ceramic plate lamination process.

[0054] Then, the ceramic plate 120 laminated on the base plate 110 via the adhesive layer 130 is bonded to the base plate 110 (step S304). Specifically, the semi-cured resin that forms the resin sheets 132a and 132b is filled between adjacent carbon nanotubes 131 in the adhesive layer 130 by heating and pressurizing, and the filled resin hardens while in contact with the first adhesive 140 and the second adhesive 150. As a result, resin 132 is formed that is filled between adjacent carbon nanotubes 131 and bonded to the ceramic plate 120 and the base plate 110. As a result, an intermediate structure of the substrate fixing device 100 is obtained in which the base plate 110 and the ceramic plate 120 are bonded by the adhesive layer 130, as shown in Figure 17, for example. Figure 17 is a diagram showing a specific example of the intermediate structure. In such an intermediate structure, a recess 135 is formed on the outer periphery of the intermediate structure by the outer surface of the adhesive layer 130 and the lower surface 120a of the opposing ceramic plates 120 and the upper surface 110a of the base plate 110.

[0055] Once the intermediate structure is obtained, a sealing member 160 is placed in the recess 135 on the outer circumference of the intermediate structure to close the recess 135 (step S305). Specifically, for example, an annular sealing member 160 is fitted into the recess 135. As the annular sealing member 160, for example, an O-ring or potting resin can be used. As the potting resin, for example, epoxy resin, silicone resin or urethane resin can be used. With the sealing member 160 placed in the recess 135, the substrate fixing device 100 is completed.

[0056] As described above, in the substrate fixing apparatus according to the third embodiment, the outer surface of the adhesive layer is located inward from the outer surface of the ceramic plate. The outer surface of the adhesive layer, together with the adhesive surfaces of the ceramic plate (e.g., the lower surface 120a) and the adhesive surface of the base plate (e.g., the upper surface 110a) that face each other on the outer circumference of the substrate fixing apparatus, forms a recess (e.g., recess 135). A sealing member (e.g., sealing member 160) that closes the recess is placed in the recess. As a result, according to the substrate fixing apparatus according to the third embodiment, even when the substrate fixing apparatus 100 is used for plasma etching of a wafer, for example, the wear of the adhesive layer by plasma can be suppressed.

[0057] (Fourth Embodiment) The fourth embodiment relates to a variation in the structure of the adhesive layer 130 and the sealing member 160 in the third embodiment.

[0058] Figure 18 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to the fourth embodiment. In Figure 18, the same reference numerals are used for the same parts as in Figure 13. In the substrate fixing device 100 shown in Figure 18, the adhesive layer 130 has a resin 132 consisting of a first resin 132A and a second resin 132B that are separated from each other. The first resin 132A covers the upper end of the carbon nanotube 131 and is bonded to the ceramic plate 120. The second resin 132B covers the lower end of the carbon nanotube 131 and is bonded to the base plate 110. The sealing member 160 maintains the distance between the ceramic plate 120 and the base plate 110 so that a gap is formed between the first resin 132A and the second resin 132B. That is, the sealing member 160 has a thickness such that the first resin 132A and the second resin 132B do not come into contact with each other. In this way, even when stress due to the difference in thermal expansion coefficients between the ceramic plate 120 and the base plate 110 acts on the adhesive layer 130, the stress can be absorbed into the void between the first resin 132A and the second resin 132B, thereby preventing damage to the adhesive layer 130.

[0059] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 19. Figure 19 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the fourth embodiment. In Figure 19, the same parts as in Figure 14 are denoted by the same reference numerals.

[0060] In step S303, the ceramic plate 120 is laminated onto the base plate 110 via the adhesive layer 130, so that the outer surface of the adhesive layer 130 forms a recess 135 together with the lower surface 120a of the ceramic plate and the upper surface 110a of the base plate 110 that are opposite each other. A sealing member 160 that closes the recess 135 is placed in this recess 135 (step S404). Specifically, for example as shown in Figure 20, an annular sealing member 160 is placed on the bottom surface of the recess 135. Figure 20 is a diagram showing a specific example of the sealing member placement process. As the annular sealing member 160, for example, an O-ring or a resin spacer can be used.

[0061] When the sealing member 160 is placed, the ceramic plate 120 is bonded to the base plate 110 (step S405). Specifically, the semi-cured resin that forms the resin sheet 132a is filled between the upper ends of adjacent carbon nanotubes 131 in the adhesive layer 130 by heating and pressurizing, and the filled resin hardens while in contact with the ceramic plate 120. This forms a first resin 132A that is filled between the upper ends of adjacent carbon nanotubes 131 and bonded to the ceramic plate 120. In addition, the semi-cured resin that forms the resin sheet 132b is filled between the lower ends of adjacent carbon nanotubes 131 in the adhesive layer 130 by heating and pressurizing, and the filled resin hardens while in contact with the base plate 110. This forms a second resin 132B that is filled between the lower ends of adjacent carbon nanotubes 131 and bonded to the base plate 110. When the first resin 132A and the second resin 132B are formed, the gap between the base plate 110 and the ceramic plate 120 is maintained by the sealing member 160 so that a gap is formed between the first resin 132A and the second resin 132B. When the gap between the base plate 110 and the ceramic plate 120 reaches the desired distance, the heating and pressurizing are released, and the substrate fixing device 100 is completed with the base plate 110 and the ceramic plate 120 bonded together by the adhesive layer 130.

[0062] As described above, in the substrate fixing device according to the fourth embodiment, the adhesive layer has a first resin (e.g., first resin 132A) and a second resin (e.g., second resin 132B) that are separated from each other. The first resin covers one end (e.g., the upper end) of the heat transfer element (e.g., carbon nanotube 131) and is bonded to the ceramic plate. The second resin covers the other end (e.g., the lower end) of the heat transfer element and is bonded to the base plate. The sealing member maintains the distance between the ceramic plate and the base plate so that a gap is formed between the first resin and the second resin. As a result, according to the substrate fixing device according to the fourth embodiment, damage to the adhesive layer can be suppressed. [Explanation of symbols]

[0063] 100 Board fixing device 110 Base Plate 110a top side 111 Refrigerant passage 120 ceramic plates 120a Bottom side 120b top surface 121 Electrode 122 Heater electrodes 130 Adhesive layer 131 Carbon nanotubes 132 Resin 132a Resin sheet 132A First resin 132b Resin sheet 132B 2nd resin 135 recess 140 First adhesive 141 Heater electrode 150 Second Adhesive 151 Heater electrode 160 sealing member

Claims

1. base plate and A ceramic plate fixed to the base plate and adsorbing the substrate by electrostatic force, An adhesive layer that bonds the base plate and the ceramic plate. It has, The aforementioned adhesive layer is A plurality of linear heat transfer elements are arranged adjacent to each other such that their longitudinal direction faces the stacking direction of the ceramic plate and the base plate, A resin is filled between adjacent heat transfer elements and bonded to the ceramic plate and the base plate. It has, The outer surface of the adhesive layer is Located on the inner side of the outer surface of the ceramic plate, the recess is formed together with the adhesive surfaces of the ceramic plate and the base plate that face each other on the outer circumference of the substrate fixing device. A sealing member is placed in the recess to close the recess. The adhesive layer comprises a first resin and a second resin, which are separated from each other, as the resin. The first resin is One end of the heat transfer element is covered and bonded to the ceramic plate, The second resin is The other end of the heat transfer element is covered and bonded to the base plate, The sealing member maintains the distance between the ceramic plate and the base plate such that a gap is formed between the first resin and the second resin. A substrate fixing device characterized by the following features.

2. A first adhesive is placed between the ceramic plate and the adhesive layer, The second adhesive is placed between the base plate and the pre-adhesive layer. It further possesses, The substrate fixing device according to claim 1, wherein the adhesive layer is bonded to the ceramic plate via the first adhesive and to the base plate via the second adhesive.

3. The substrate fixing device according to claim 2, wherein at least one of the ceramic plate, the first adhesive, and the second adhesive incorporates a heat-generating electrode.

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