Substrate fixing device and method for manufacturing a substrate fixing device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SHINKO ELECTRIC IND CO LTD
- Filing Date
- 2022-06-09
- Publication Date
- 2026-08-05
Smart Images
Figure 0007900955000001 
Figure 0007900955000002 
Figure 0007900955000003
Abstract
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, a substrate fixing device that adsorbs and holds a wafer, for example, when manufacturing semiconductor components, 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 the 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, in order to improve the heat uniformity on the adsorption surface of the wafer, a temperature adjustment function may be imparted to the ceramic plate. Specifically, for example, a heater electrode is formed by screen printing a metal paste such as tungsten, and this heater electrode may be fired simultaneously when the ceramic plate is formed.
[0004] When the heater electrode is formed by screen printing, the width and thickness of the formed heater electrode may be non-uniform, and the temperature of the adsorption surface of the ceramic plate may not be sufficiently uniform. On the other hand, in order to obtain high heat uniformity on the adsorption surface of the ceramic plate, a technique has been proposed in which a concave portion is provided on the adhesion surface of the ceramic plate with the base plate, and a temperature adjustment resin having a lower thermal conductivity than the ceramic plate is filled in such a concave portion.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
[0006] However, the above technology has a problem in that the transfer of heat from the ceramic plate to the base plate is hindered by the temperature-controlling resin, resulting in an uneven temperature on the adsorption surface of the ceramic plate and insufficient heat uniformity.
[0007] Specifically, because the temperature-controlling resin has a lower thermal conductivity than the ceramic plate, when the heater electrodes generate heat, heat does not transfer sufficiently from the ceramic plate to the base plate at the location of the temperature-controlling resin, resulting in the creation of hot spots on the adsorption surface of the ceramic plate that are hotter than other areas. As a result, the uniformity of heat distribution across the entire adsorption surface of the ceramic plate may decrease.
[0008] The disclosed technology was developed in view of the above, and aims to provide a substrate fixing device and a method for manufacturing a substrate fixing device that can achieve sufficiently high heat uniformity. [Means for solving the problem]
[0009] In one embodiment, the substrate fixing device disclosed in this application comprises a base plate, a ceramic plate, and a thermal conductive member. The ceramic plate is bonded to the base plate via an adhesive layer and contains heat-generating electrodes, which attract the substrate by electrostatic force. The thermal conductive member is disposed at least one of the bonding surface of the ceramic plate, the bonding surface of the base plate, and inside the adhesive layer, and the thermal conductivity of the base plate and the ceramic plate in the lamination direction is higher than the thermal conductivity in the planar direction perpendicular to the lamination direction. [Effects of the Invention]
[0010] One embodiment of the substrate fixing device disclosed in this application has the effect of achieving sufficiently high heat uniformity. [Brief explanation of the drawing]
[0011] [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 plan view showing a specific example of the arrangement of heat conductive members. [Figure 4] Figure 4 is a flowchart showing a method for manufacturing a substrate fixing device according to the first embodiment. [Figure 5] Figure 5 shows a specific example of a ceramic plate. [Figure 6] Figure 6 shows a specific example of the hotspot identification process. [Figure 7] Figure 7 shows a specific example of the recess formation process. [Figure 8] Figure 8 shows a specific example of the heat conduction component placement process. [Figure 9] Figure 9 is a schematic diagram showing a cross-section of the substrate fixing device according to the second embodiment. [Figure 10] Figure 10 is a flowchart showing a method for manufacturing a substrate fixing device according to the second embodiment. [Figure 11] Figure 11 shows a specific example of the recess formation process. [Figure 12] Figure 12 shows a specific example of the heat conduction member placement process. [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 first adhesive application process. [Figure 16] Figure 16 shows a specific example of the heat conduction member placement process. [Figure 17] Figure 17 shows a specific example of the second adhesive application process. [Figure 18] Figure 18 is a schematic diagram showing a cross-section of the substrate fixing device according to the fourth embodiment. [Figure 19]FIG. 19 is a flowchart showing a manufacturing method of a substrate fixing device according to the fourth embodiment. [Figure 20] FIG. 20 is a diagram showing a specific example of the heat conductive member bonding step. [Figure 21] FIG. 21 is a diagram showing a specific example of the second adhesive application step.
Embodiments for Carrying Out the Invention
[0012] Hereinafter, embodiments of the substrate fixing device and the manufacturing method of 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.
[0013] (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.
[0014] 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 with the substrate fixing device 100.
[0015] 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 being adhered to the base plate 110 with an adhesive layer made of, for example, a silicone resin on the adhesive surface. 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.
[0016] The ceramic plate 120 incorporates conductive electrodes, and utilizes the electrostatic force generated when a voltage is applied to these electrodes to attract objects such as wafers to its adsorption surface. The ceramic plate 120 also incorporates heater electrodes, and the heater electrodes, which generate heat when a voltage is applied, regulate the temperature of the ceramic plate 120 and the objects such as wafers that are attracted to the ceramic plate 120.
[0017] Figure 2 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to an 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.
[0018] 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 onto 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] A recess 120c is formed on the lower surface 120a of the ceramic plate 120, and the heat conductive member 140 is placed within this recess 120c.
[0023] The heat conductive member 140 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 the "lamination direction") is higher than the thermal conductivity in the planar direction perpendicular to the lamination direction. Specifically, the heat conductive member 140 has a structure in which a plurality of carbon nanotubes 141, in which the thermal conductivity in the longitudinal direction is higher than the thermal conductivity in other directions, are embedded in the resin 142. The carbon nanotubes 141 are cylindrical crystals made of carbon and are arranged so that their longitudinal direction faces the lamination direction. The thermal conductivity of the carbon nanotubes 141 in the longitudinal direction is higher than the thermal conductivity of the ceramic plate 120. The resin 142 coats the carbon nanotubes 141 with both longitudinal end faces of the carbon nanotubes 141 exposed. As the resin 142, for example, a thermosetting resin such as epoxy resin or a thermoplastic resin such as polyethylene resin can be used.
[0024] By placing a thermally anisotropic heat conductive member 140 on the lower surface 120a (or recess 120c) of the ceramic plate 120, heat can be smoothly transferred from the ceramic plate 120 to the base plate 110 compared to the case where a temperature-controlling resin is placed. This suppresses the occurrence of hot spots on the adsorption surface of the ceramic plate 120 (i.e., the upper surface 120b) where the temperature is higher than other areas. As a result, the temperature distribution on the adsorption surface of the ceramic plate 120 can be made uniform, and sufficiently high heat uniformity can be obtained.
[0025] Furthermore, by arranging the carbon nanotubes 141 of the heat conductive member 140 so that their longitudinal direction faces the stacking direction, and by covering both ends in the longitudinal direction with resin 142 while leaving them exposed, heat transfer along the stacking direction can be facilitated.
[0026] Here, a specific example of the arrangement of the heat conduction members 140 will be explained with reference to Figure 3. Figure 3 is a plan view showing a specific example of the arrangement of the heat conduction members 140. In Figure 3, the arrangement of the two heat conduction members 140 shown in Figure 2 is illustrated.
[0027] As shown in Figure 3, the heat conductive member 140 is positioned on the adsorption surface (i.e., the upper surface 120b) of the ceramic plate 120 in a position that coincides in plan view with the hot spot HS, which is a temperature singularity when the heater electrode 122 generates heat. That is, a recess 120c (see Figure 2) is formed on the lower surface 120a (see Figure 2) of the ceramic plate 120 corresponding to the position of the hot spot HS, and the heat conductive member 140 is placed within this recess 120c. The hot spot HS is identified in advance by measuring the temperature distribution on the upper surface 120b of the ceramic plate 120 using a measuring device while a voltage is applied to the heater electrode 122, as will be described later.
[0028] In this way, by positioning the heat conduction member 140 so as to overlap with the identified hot spot HS in a plan view, heat transfer from the hot spot HS to the base plate 110 can be facilitated compared to the case where the heat conduction member 140 and the hot spot HS do not overlap. As a result, since cooling by the base plate 110 can be applied precisely to the hot spot HS, the temperature difference on the adsorption surface of the ceramic plate 120 can be further reduced.
[0029] Returning to the explanation of Figure 2, the adhesive layer 130 is a layer, for example, 0.05 mm to 3.0 mm thick, made of a silicone resin-based adhesive or an epoxy resin-based adhesive, and adheres the lower surface 120a of the ceramic plate 120 to the upper surface 110a of the base plate 110.
[0030] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 4. Figure 4 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the first embodiment.
[0031] 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 5. Figure 5 is a diagram showing a specific example of the ceramic plate 120.
[0032] Once the ceramic plate 120 is formed, hot spots on the adsorption surface of the ceramic plate 120 are identified (step S102). Specifically, as shown in Figure 6, for example, the hot spots are identified using measurement results obtained by measuring the temperature distribution on the upper surface 120b of the ceramic plate 120 with a measuring device 200 while a voltage is applied to the heater electrode 122. Figure 6 is a diagram showing a specific example of the hot spot identification process. As the measuring device 200, for example, a non-contact thermometer such as an infrared camera can be used. The measuring device 200 may also be equipped with a computing device such as a processor that identifies hot spots by comparing the measurement results of the temperature distribution obtained from a non-contact thermometer such as an infrared camera with a predetermined threshold.
[0033] Once a hot spot is identified, a recess is formed on the bonding surface (i.e., the lower surface 120a) of the ceramic plate 120 corresponding to the location of the hot spot (step S103). Specifically, as shown in Figure 7, for example, the ceramic plate 120 is cut from the lower surface 120a side to a position where it does not reach the heater electrode 122 to form a recess 120c. Figure 7 shows a specific example of the recess formation process. The recess 120c is formed, for example, by laser processing or drilling.
[0034] Once the recess 120c is formed, the heat conductive member 140 is placed inside the recess 120c (step S104). Specifically, as shown in Figure 8, for example, a heat conductive member 140 having a cylindrical shape with approximately the same diameter as the recess 120c is fitted into the recess 120c. Figure 8 is a diagram showing a specific example of the heat conductive member placement process. The heat conductive member 140 is placed inside the recess 120c such that the longitudinal direction of the carbon nanotube 141 coincides with the stacking direction of the base plate 110 and the ceramic plate 120 (in other words, the thickness direction of the ceramic plate 120). At this time, the carbon nanotube 141 penetrates the resin 142 in the thickness direction, the upper end surface of the carbon nanotube 141 is in contact with the bottom surface of the recess 120c, and the lower end surface of the carbon nanotube 141 is exposed from the lower surface 120a side of the ceramic plate 120. By placing the heat conductive member 140 within the recess 120c, a ceramic plate 120 is obtained in which thermal anisotropy due to the heat conductive member 140 is locally imparted to the adhesive surface (i.e., the lower surface 120a).
[0035] The ceramic plate 120 is bonded to the base plate 110 by the adhesive layer 130 (step S105). Specifically, the lower surface 120a of the ceramic plate 120 on which the heat conductive member 140 is placed is bonded to the upper surface 110a of the base plate 110 by the adhesive layer 130. At this time, the lower end surface of the carbon nanotube 141 exposed from the lower surface 120a side of the ceramic plate 120 is connected to the upper surface 110a of the base plate 110 via the adhesive layer 130, and the upper surface 110a of the base plate 110 and the bottom surface of the recess 120c are thermally conductive. This makes it possible to facilitate the transfer of heat from the hot spot corresponding to the recess 120c to the base plate 110. The substrate fixing device 100 is completed when the ceramic plate 120 is bonded to the base plate 110. Note that the upper and lower end surfaces of the carbon nanotube 141 may be embedded in the resin 142 or the adhesive layer 130.
[0036] 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, the base plate 110), a ceramic plate (for example, the ceramic plate 120), and a heat conductive member (for example, the heat conductive member 140). The ceramic plate is bonded to the base plate via an adhesive layer (for example, the adhesive layer 130) and incorporates a heat-generating electrode (for example, a heater electrode 122) to attract a substrate (for example, a wafer) by electrostatic force. The heat conductive member is placed on the bonding surface of the ceramic plate (for example, the lower surface 120a), and the thermal conductivity in the stacking direction between the base plate and the ceramic plate is higher than the thermal conductivity in the planar direction perpendicular to the stacking direction. As a result, the substrate fixing device according to the first embodiment can obtain sufficiently high heat uniformity.
[0037] Furthermore, the heat conductive member may be positioned on the adsorption surface (e.g., the upper surface 120b) of the ceramic plate capable of adsorbing the substrate, in a plan view, at a location that coincides with the hot spot, which becomes a temperature singularity when the electrode generates heat. As a result, according to the substrate fixing device of the first embodiment, pinpoint cooling by the base plate can be applied to the hot spot, thereby further reducing the temperature difference on the adsorption surface of the ceramic plate.
[0038] Furthermore, recesses (for example, recess 120c) may be formed on the bonding surface of the ceramic plate corresponding to the location of the hot spot. The heat conductive member may then be placed within the recess. As a result, according to the substrate fixing device of the first embodiment, pinpoint cooling by the base plate can be applied to the hot spot, thereby further reducing the temperature difference on the adsorption surface of the ceramic plate.
[0039] Furthermore, the heat conductive member may include carbon nanotubes (e.g., carbon nanotube 141) and a resin (e.g., resin 142). The carbon nanotubes may be arranged so that their longitudinal direction faces the stacking direction. The resin may cover the carbon nanotubes so that both ends of the carbon nanotubes in the longitudinal direction are exposed. As a result, according to the substrate fixing device of the first embodiment, heat transfer along the stacking direction between the base plate and the ceramic plate can be facilitated.
[0040] (Second Embodiment) The second embodiment relates to a variation in the arrangement of the heat conductive member 140 in the first embodiment.
[0041] Figure 9 is a schematic diagram showing a cross-section of the substrate fixing device 100 according to the second embodiment. In Figure 9, the same reference numerals are used for the same parts as in Figure 2.
[0042] In the substrate fixing device 100 shown in Figure 9, the heat conductive member 140 is placed on the adhesive surface (i.e., the upper surface 110a) of the base plate 110 instead of the adhesive surface (i.e., the lower surface 120a) of the ceramic plate 120. That is, a recess 110c is formed on the upper surface 110a of the base plate 110, not on the lower surface 120a of the ceramic plate 120, and the heat conductive member 140 is placed within this recess 110c. In this way, even when the heat conductive member 140 is placed on the upper surface 110a of the base plate 110 instead of the lower surface 120a of the ceramic plate 120, heat can be smoothly transferred from the ceramic plate 120 to the base plate 110 compared to when a temperature-controlling resin is placed. Therefore, it is possible to suppress the occurrence of hot spots on the adsorption surface (i.e., the upper surface 120b) of the ceramic plate 120 where the temperature is higher than in other areas. As a result, the temperature distribution on the adsorption surface of the ceramic plate 120 can be made uniform, and sufficiently high heat uniformity can be obtained.
[0043] Next, the manufacturing method of the substrate fixing device 100 configured as described above will be explained with reference to Figure 10. Figure 10 is a flowchart showing the manufacturing method of the substrate fixing device 100 according to the second embodiment. In the processes illustrated in Figure 10, the processes that are denoted by the same reference numerals as in Figure 4 are the same as the processes explained using Figure 4, so a detailed explanation will be omitted.
[0044] When a hot spot is identified in step S102, a recess is formed on the adhesive surface (i.e., the upper surface 110a) of the base plate 110 corresponding to the location of the hot spot (step S203). Specifically, as shown in Figure 11, for example, the base plate 110 is cut away from the upper surface 110a side to a position where it does not reach the refrigerant passage 111 to form a recess 110c. Figure 11 shows a specific example of the recess formation process. The recess 110c is formed, for example, by laser processing or drilling.
[0045] Once the recess 110c is formed, the heat conductive member 140 is placed inside the recess 110c (step S204). Specifically, as shown in Figure 12, for example, a heat conductive member 140 having a cylindrical shape with approximately the same diameter as the recess 110c is fitted into the recess 110c. Figure 12 is a diagram showing a specific example of the heat conductive member placement process. The heat conductive member 140 is placed inside the recess 110c such that the longitudinal direction of the carbon nanotube 141 coincides with the stacking direction of the base plate 110 and the ceramic plate 120 (in other words, the thickness direction of the base plate 110). At this time, the carbon nanotube 141 penetrates the resin 142 in the thickness direction, the lower end surface of the carbon nanotube 141 is in contact with the bottom surface of the recess 110c, and the upper end surface of the carbon nanotube 141 is exposed from the upper surface 110a side of the base plate 110. By placing the heat conductive member 140 within the recess 110c, a base plate 110 is obtained in which thermal anisotropy due to the heat conductive member 140 is locally imparted to the adhesive surface (i.e., the upper surface 110a).
[0046] The ceramic plate 120 is bonded to the base plate 110 by an adhesive layer 130 (step S205). Specifically, the lower surface 120a of the ceramic plate 120 is bonded to the upper surface 110a of the base plate 110, on which the heat conductive member 140 is placed, by the adhesive layer 130. At this time, the upper end surface of the carbon nanotube 141 exposed from the upper surface 110a side of the base plate 110 is connected to the lower surface 120a of the ceramic plate 120 via the adhesive layer 130, and the lower surface 120a of the ceramic plate 120 and the bottom surface of the recess 110c are thermally conductive. This makes it possible to facilitate the transfer of heat from the hot spot corresponding to the recess 110c to the base plate 110. The substrate fixing device 100 is completed when the ceramic plate 120 is bonded to the base plate 110. Note that the upper and lower end surfaces of the carbon nanotube 141 may be embedded in the resin 142 or the adhesive layer 130.
[0047] As described above, in the substrate fixing device according to the second embodiment, the heat conductive member is placed on the adhesive surface (for example, the upper surface 110a) of the base plate. As a result, the substrate fixing device according to the second embodiment can obtain sufficiently high heat uniformity.
[0048] Furthermore, recesses (for example, recess 110c) may be formed on the adhesive surface of the base plate corresponding to the location of the hot spot. The heat conductive member may then be placed within the recess. As a result, according to the substrate fixing device of the second embodiment, pinpoint cooling by the base plate can be applied to the hot spot, thereby further reducing the temperature difference on the adsorption surface of the ceramic plate.
[0049] (Third embodiment) The third embodiment relates to a variation in the arrangement of the heat conductive member 140 in the first embodiment.
[0050] 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.
[0051] In the substrate fixing device 100 shown in Figure 13, the heat conductive member 140 is placed inside the adhesive layer 130 instead of on the bonding surface (i.e., the bottom surface 120a) of the ceramic plate 120. Even when the heat conductive member 140 is placed inside the adhesive layer 130 instead of on the bottom surface 120a of the ceramic plate 120, heat can be smoothly transferred from the ceramic plate 120 to the base plate 110 compared to when a temperature-controlling resin is placed. Therefore, it is possible to suppress the occurrence of hot spots on the adsorption surface (i.e., the top surface 120b) of the ceramic plate 120 that have a higher temperature than other areas. As a result, the temperature distribution on the adsorption surface of the ceramic plate 120 can be made uniform, and sufficiently high heat uniformity can be obtained.
[0052] The adhesive layer 130 comprises a first adhesive 131 and a second adhesive 132. The first adhesive 131 is in sheet form and is laminated over the entire adhesive surface (i.e., the upper surface 110a) of the base plate 110 to bond the heat conductive member 140. The second adhesive 132 is laminated between the first adhesive 131 and the adhesive surface (i.e., the lower surface 120a) of the ceramic plate 120 to cover the heat conductive member 140. The second adhesive 132 may be made of the same resin as the resin that constitutes the first adhesive 131, or it may be made of a different resin. In this way, the first adhesive 131 is laminated over the entire upper surface 110a of the base plate 110, and the heat conductive member 140 to which the first adhesive 131 is bonded is covered by the second adhesive 132, thereby fixing the position of the heat conductive member 140 within the adhesive layer 130. Therefore, the heat conductive member 140 is positioned inside the adhesive layer 130 without the need to go through the process of forming a recess in the adhesive surface (i.e., the lower surface 120a) of the ceramic plate 120. In other words, the heat conductive member 140 can be positioned inside the adhesive layer 130 in a simple process, thereby improving the manufacturing efficiency of the substrate fixing device 100.
[0053] 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 the processes illustrated in Figure 14, the processes that are denoted by the same reference numerals as in Figure 4 are the same as the processes explained using Figure 4, so a detailed explanation will be omitted.
[0054] When a hot spot is identified in step S102, the first adhesive is applied to the entire surface of the bonding surface (i.e., the upper surface 110a) of the base plate 110 (step S303). Specifically, as shown in Figure 15, for example, the first adhesive 131 is applied to the entire surface of the upper surface 110a of the base plate 110. Figure 15 is a diagram showing a specific example of the first adhesive application process. At the point when the first adhesive 131 is applied to the entire surface of the upper surface 110a of the base plate 110, the resin constituting the first adhesive 131 is in a semi-cured state.
[0055] When the first adhesive 131 is applied, the heat conductive member 140 is positioned on the first adhesive 131 corresponding to the location of the hot spot (step S304). Specifically, as shown in Figure 16, for example, a heat conductive member 140 having a cylindrical shape with approximately the same diameter as the width of the hot spot is positioned on the first adhesive 131. Figure 16 is a diagram showing a specific example of the heat conductive member positioning process. The heat conductive member 140 is positioned on the first adhesive 131 such that the longitudinal direction of the carbon nanotube 141 coincides with the lamination direction of the base plate 110 and the ceramic plate 120 (in other words, the thickness direction of the base plate 110). At this time, the carbon nanotube 141 penetrates the resin 142 in the thickness direction, the lower end surface of the carbon nanotube 141 is in contact with the first adhesive 131, and the upper end surface of the carbon nanotube 141 is exposed from the upper surface of the resin 142.
[0056] Then, the second adhesive is applied to the bonding surface (i.e., the bottom surface 120a) of the ceramic plate 120 (step S305). Specifically, as shown in Figure 17, for example, the second adhesive 132 is applied to the entire surface of the bottom surface 120a of the ceramic plate 120. Figure 17 is a diagram showing a specific example of the second adhesive application process. At the point when the second adhesive 132 is applied to the entire surface of the bottom surface 120a of the ceramic plate 120, the resin constituting the second adhesive 132 is in a semi-cured state.
[0057] When the second adhesive 132 is applied, the ceramic plate 120 is bonded to the base plate 110 by an adhesive layer 130 consisting of the first adhesive 131 and the second adhesive 132, which cover the heat conductive member 140 (step S306). Specifically, the semi-cured first adhesive 131 is laminated with the semi-cured second adhesive 132 so as to cover the heat conductive member 140, and the first adhesive 131 and the second adhesive 132 harden by heating and pressurizing. As a result, the heat conductive member 140 is positioned inside the adhesive layer 130 consisting of the first adhesive 131 and the second adhesive 132, and the lower surface 120a of the ceramic plate 120 is bonded to the upper surface 110a of the base plate 110 by the adhesive layer 130. At this time, the upper end surface of the carbon nanotube 141 exposed from the upper surface of the resin 142 is connected to the lower surface 120a of the ceramic plate 120 via the second adhesive 132, and is thermally conductive with the lower surface 120a of the ceramic plate 120. This facilitates the transfer of heat from the hot spot to the base plate 110. The substrate fixing device 100 is completed when the ceramic plate 120 is bonded to the base plate 110. The upper and lower ends of the carbon nanotube 141 may be embedded in the resin 142 or the adhesive layer 130.
[0058] As described above, in the substrate fixing apparatus according to the third embodiment, the heat conductive member is placed inside the adhesive layer (for example, adhesive layer 130). As a result, the substrate fixing apparatus according to the third embodiment can obtain sufficiently high heat uniformity.
[0059] Furthermore, the adhesive layer may have a first adhesive (e.g., first adhesive 131) and a second adhesive (e.g., second adhesive 132). The first adhesive may be laminated over the entire adhesive surface of the base plate to bond the heat conductive member. The second adhesive may be laminated between the first adhesive and the adhesive surface of the ceramic plate to cover the heat conductive member. As a result, according to the substrate fixing device of the third embodiment, the step of forming recesses for arranging the heat conductive member can be omitted, and manufacturing efficiency can be improved.
[0060] In the substrate fixing device 100 according to the third embodiment, the positions of the first adhesive 131 and the second adhesive 132 may be swapped. That is, the first adhesive 131 may be laminated over the entire bonding surface (i.e., the lower surface 120a) of the ceramic plate 120 to bond the heat conductive member 140. Alternatively, the second adhesive 132 may be laminated between the first adhesive 131 and the bonding surface (i.e., the upper surface 110a) of the base plate to cover the heat conductive member 140.
[0061] (Fourth Embodiment) The fourth embodiment relates to a variation in the structure of the adhesive layer 130 in the third embodiment.
[0062] 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.
[0063] In the substrate fixing device 100 shown in Figure 18, the adhesive layer 130 has a first adhesive 131 and a second adhesive 132. The first adhesive 131 is pad-shaped and adheres the heat conductive member 140 to the adhesive surface (i.e., the lower surface 120a) of the ceramic plate 120. The second adhesive 132 is laminated between the adhesive surface (i.e., the upper surface 110a) of the base plate 110 and the adhesive surface (i.e., the lower surface 120a) of the ceramic plate 120, covering the heat conductive member 140 and the first adhesive 131. The second adhesive 132 may be made of the same resin as the resin constituting the first adhesive 131, or it may be made of a different resin than the resin constituting the first adhesive 131. In this way, the heat conductive member 140 is bonded to the lower surface 120a of the ceramic plate 120 via the first adhesive 131, and the heat conductive member 140 and the first adhesive 131 are covered with the second adhesive 132, thereby fixing the position of the heat conductive member 140 within the adhesive layer 130. Therefore, the heat conductive member 140 is positioned inside the adhesive layer 130 without going through the process of forming a recess in the bonding surface (i.e., the lower surface 120a) of the ceramic plate 120. In other words, the heat conductive member 140 can be positioned inside the adhesive layer 130 in a simple process, and the manufacturing efficiency of the substrate fixing device 100 can be improved.
[0064] 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 the processes illustrated in Figure 19, the processes that are denoted by the same reference numerals as in Figure 14 are the same as the processes explained using Figure 14, so a detailed explanation will be omitted.
[0065] In step S102, once the hot spot is identified, the heat conduction member 140 is bonded to the bonding surface (i.e., the lower surface 120a) of the ceramic plate 120 at the position corresponding to the hot spot (step S403). Specifically, as shown in Figure 20, for example, a heat conduction member 140 having a cylindrical shape with approximately the same diameter as the width of the hot spot is bonded to the lower surface 120a of the ceramic plate 120 via the first adhesive 131. Figure 20 is a diagram showing a specific example of the heat conduction member bonding process. At the time the heat conduction member 140 is bonded to the lower surface 120a of the ceramic plate 120, the resin constituting the first adhesive 131 is in a semi-cured state. The heat conduction member 140 is bonded to the lower surface 120a of the ceramic plate 120 such that the longitudinal direction of the carbon nanotube 141 coincides with the lamination direction of the base plate 110 and the ceramic plate 120 (in other words, the thickness direction of the ceramic plate 120). At this time, the carbon nanotube 141 penetrates the resin 142 in the thickness direction, the upper end surface of the carbon nanotube 141 is in contact with the first adhesive 131, and the lower end surface of the carbon nanotube 141 is exposed from the lower surface of the resin 142.
[0066] Furthermore, if the resin constituting the first adhesive 131 is different from the resin constituting the second adhesive 132, it is preferable that the first adhesive 131 has a higher thermal conductivity than the second adhesive 132. This makes it possible to facilitate the transfer of heat from the ceramic plate 120 to the heat conductive member 140.
[0067] Then, the second adhesive is applied to the bonding surface (i.e., the upper surface 110a) of the base plate 110 (step S404). Specifically, as shown in Figure 21, for example, the second adhesive 132 is applied to the entire surface of the upper surface 110a of the base plate 110. Figure 21 is a diagram showing a specific example of the second adhesive application process. At the point when the second adhesive 132 is applied to the entire surface of the upper surface 110a of the base plate 110, the resin constituting the second adhesive 132 is in a semi-cured state.
[0068] When the second adhesive 132 is applied, the ceramic plate 120 is bonded to the base plate 110 by an adhesive layer 130 consisting of the first adhesive 131 and the second adhesive 132, which cover the heat conductive member 140 (step S405). The semi-cured second adhesive 132 is laminated on the lower surface 120a of the ceramic plate 120 so as to cover the heat conductive member 140 and the first adhesive 131, and the first adhesive 131 and the second adhesive 132 harden through heating and pressurization. As a result, the heat conductive member 140 is positioned inside the adhesive layer 130 consisting of the first adhesive 131 and the second adhesive 132, and the lower surface 120a of the ceramic plate 120 is bonded to the upper surface 110a of the base plate 110 by the adhesive layer 130. At this time, the lower end surface of the carbon nanotube 141 exposed from the lower surface of the resin 142 is connected to the upper surface 110a of the base plate 110 via the second adhesive 132, and is thermally conductive with the upper surface 110a of the base plate 110. This makes it possible to facilitate the transfer of heat from the hot spot to the base plate 110. The substrate fixing device 100 is completed when the ceramic plate 120 is bonded to the base plate 110. The upper and lower end surfaces of the carbon nanotube 141 may be embedded in the resin 142 or the adhesive layer 130.
[0069] As described above, in the substrate fixing apparatus according to the fourth embodiment, the adhesive layer comprises a first adhesive (e.g., first adhesive 131) and a second adhesive (e.g., second adhesive 132). The first adhesive is pad-shaped and adheres the heat conductive member to the bonding surface of the ceramic plate. The second adhesive is laminated between the bonding surface of the base plate and the bonding surface of the ceramic plate, covering the heat conductive member and the first adhesive. As a result, according to the substrate fixing apparatus according to the fourth embodiment, the step of forming a recess for arranging the heat conductive member can be omitted, and manufacturing efficiency can be improved.
[0070] Furthermore, the first adhesive may have a higher thermal conductivity than the second adhesive. This makes it possible to facilitate the transfer of heat from the ceramic plate to the heat conductive member according to the substrate fixing device of the fourth embodiment.
[0071] In the substrate fixing device according to the fourth embodiment, the pad-shaped first adhesive 131 may be used to bond the heat conductive member 140 to the adhesive surface of the base plate 110 (i.e., the upper surface 110a) instead of the adhesive surface of the ceramic plate 120 (i.e., the lower surface 120a).
[0072] (Other variations) In the above embodiment, the case in which the heat conductive member 140 is placed on the bonding surface of the ceramic plate 120, the bonding surface of the base plate 110, or inside the adhesive layer 130 was described as an example, but the placement position of the heat conductive member 140 can be changed as appropriate. For example, the heat conductive member 140 may be placed on any two of the bonding surfaces of the ceramic plate 120, the bonding surface of the base plate 110, and inside the adhesive layer 130. Alternatively, the heat conductive member 140 may be placed on the bonding surface of the ceramic plate 120, the bonding surface of the base plate 110, and inside the adhesive layer 130. In short, the heat conductive member 140 may be placed on at least one of the bonding surfaces of the ceramic plate 120, the bonding surface of the base plate 110, and inside the adhesive layer 130. [Explanation of Symbols]
[0073] 100 Board fixing device 110 Base Plate 110a top side 110c recess 111 Refrigerant passage 120 ceramic plates 120a Bottom 120b top surface 120c recess 121 Electrode 122 Heater electrodes 130 Adhesive layer 131 First Adhesive 132 Second Adhesive 140 Heat conductive material 141 Carbon nanotubes 142 Resin
Claims
1. base plate and A ceramic plate is bonded to the base plate via an adhesive layer and incorporates a heat-generating electrode, which attracts the substrate by electrostatic force, A thermal conductive member is disposed on at least one of the bonding surfaces of the ceramic plate, the bonding surface of the base plate, and inside the adhesive layer, wherein the thermal conductivity in the lamination direction between the base plate and the ceramic plate is higher than the thermal conductivity in the planar direction perpendicular to the lamination direction. Yes, At least one of the adhesive surface of the ceramic plate, the adhesive surface of the base plate, and the interior of the adhesive layer has a recess formed in a position that overlaps in a plan view with a hot spot, which is a temperature singularity when the electrode generates heat on the adsorption surface of the ceramic plate capable of adsorbing the substrate, and which is identified based on measurement results obtained by measuring the temperature distribution of the adsorption surface with a measuring device while a voltage is applied to the electrode. The heat conductive member is disposed within the recess. A substrate fixing device characterized by the following features.
2. The aforementioned heat conductive member is Carbon nanotubes arranged such that their longitudinal direction faces the stacking direction, A resin that coats the carbon nanotube with both longitudinal ends of the carbon nanotube exposed. A substrate fixing device according to claim 1, characterized by having the following features.
3. The adhesive layer is A first adhesive is laminated onto the entire surface of either the bonding surface of the ceramic plate or the bonding surface of the base plate to bond the heat conductive member, A second adhesive is laminated between the first adhesive and the other of the bonding surface of the ceramic plate and the bonding surface of the base plate, and covers the heat conductive member. A substrate fixing device according to claim 1, characterized by having the following features.
4. The adhesive layer is A pad-shaped first adhesive is used to bond the heat conductive member to either the bonding surface of the ceramic plate or the bonding surface of the base plate. A second adhesive is laminated between the adhesive surface of the ceramic plate and the adhesive surface of the base plate, and covers the heat conductive member and the first adhesive. A substrate fixing device according to claim 1, characterized by having the following features.
5. The substrate fixing device according to claim 4, characterized in that the first adhesive has a higher thermal conductivity than the second adhesive.