Substrate holding device and substrate holding table

Abstract

A substrate holding device according to one aspect of the present disclosure comprises: a graphite block; a temperature adjustment unit; and a heat conduction member. The graphite block is a laminate, in which a plurality of graphene layers are laminated in a first direction, and has a first surface perpendicular to the first direction, a second surface positioned opposite to the first surface, and side surfaces connecting the first surface and the second surface. A wafer is indirectly placed on the first surface. The temperature adjustment unit is thermally connected with the graphite block on the second surface, and applies heat to the graphite block or deprives the graphite block of heat. The heat conduction member is provided so as to be in contact with the side surfaces from the first surface to the second surface. In the first direction, the thermal conductivity of the heat conduction member is higher than the thermal conductivity of the graphite block. In a second direction orthogonal to the first direction, the thermal conductivity of the graphite block is higher than the thermal conductivity of the heat conduction member.

Description

Substrate holding device and substrate holding table

[0001] The present disclosure relates to a substrate holding device and a substrate holding table.

[0002] 2. Description of the Related Art Conventionally, a substrate holding apparatus for holding a semiconductor substrate is used in a manufacturing process of a semiconductor device.

[0003] This type of substrate holding device may have a function of adjusting the temperature of the held semiconductor substrate (see Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2005-136025

[0005] A substrate support device according to one embodiment of the present disclosure includes a graphite block, a temperature control unit, and a thermally conductive member. The graphite block is a laminate having a structure in which a plurality of graphenes are stacked in a first direction, and has a first surface perpendicular to the first direction, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface. A wafer is indirectly placed on the first surface. The temperature control unit is thermally connected to the graphite block at the second surface and provides heat to or removes heat from the graphite block. The thermally conductive member is provided so as to contact the side surface from the first surface to the second surface. In the first direction, the thermal conductivity of the thermally conductive member is higher than that of the graphite block. In a second direction perpendicular to the first direction, the thermal conductivity of the graphite block is higher than that of the thermally conductive member.

[0006] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a substrate holding device according to a first embodiment. FIG. 2 is a schematic plan view showing an example of the configuration of a substrate holding device according to the first embodiment. FIG. 3 is an enlarged cross-sectional view showing an example of the configuration of a first surface of a graphite block according to the first embodiment. FIG. 4 is an enlarged cross-sectional view showing an example of the configuration of a side surface of a graphite block according to the first embodiment. FIG. 5 is an enlarged cross-sectional view illustrating a configuration of the vicinity of the side surface of a graphite block according to the first embodiment. FIG. 6 is a schematic cross-sectional view showing an example of the configuration of a substrate holding device according to a second embodiment. FIG. 7 is an enlarged cross-sectional view illustrating a configuration of the vicinity of the side surface of a graphite block according to the second embodiment. FIG. 8 is a schematic cross-sectional view showing an example of the configuration of a substrate holding device according to a third embodiment. FIG. 9 is an enlarged cross-sectional view illustrating a configuration of the vicinity of the side surface of a graphite block according to the third embodiment. FIG. 10 is a schematic cross-sectional view showing a first modified example of a temperature adjustment unit. FIG. 11 is a schematic cross-sectional view showing a second modified example of a temperature adjustment unit. FIG. 12 is a schematic cross-sectional view showing an example of the configuration of a substrate holding device according to a fourth embodiment.

[0007] Hereinafter, a detailed description will be given of a substrate holding device and a substrate holding table according to the present disclosure (hereinafter referred to as an "embodiment") with reference to the drawings. Note that the present disclosure is not limited to the embodiment. Furthermore, the embodiments can be appropriately combined as long as the processing content is not contradictory. Furthermore, the same components in the following embodiments are designated by the same reference numerals, and redundant description will be omitted.

[0008] In addition, in the drawings referred to below, for ease of understanding, an orthogonal coordinate system may be shown in which the X-axis direction, Y-axis direction, and Z-axis direction, which are perpendicular to each other, are defined, and the Z-axis direction is the vertically upward direction.

[0009] Conventionally, in the manufacture of semiconductor devices, various processes, such as drawing fine patterns on a semiconductor substrate (wafer), are performed. During these processes, the wafer is indirectly placed on a mounting surface of a substrate holding device, and the various processes are performed on the wafer. Examples of the wafer holding means include a vacuum suction system and an electrostatic suction system.

[0010] In recent years, in the field of semiconductor device manufacturing, non-uniformity in processing accuracy has become a concern due to the increasing diameter of wafers and the increasing precision and miniaturization of processing. For example, problems such as varying etching accuracy across the wafer surface have been pointed out. In such cases, product quality and manufacturing yields are likely to decline. Such non-uniformity in processing accuracy is primarily caused by non-uniformity in the wafer surface temperature during processing.

[0011] For example, Patent Document 1 discloses a substrate holding device having a plurality of chucking areas with independently controllable chucking forces, and including a temperature measuring means for measuring the wafer temperature in each chucking area, an electrostatic chucking means for exerting an electrostatic chucking force on the wafer, and a heat medium supplying means for flowing a heat medium between the wafer and the chucking area. This substrate holding device eliminates non-uniformity in the wafer temperature by controlling the temperature within the wafer surface by changing the electrostatic chucking forces of the plurality of chucking areas provided on the wafer stage in accordance with the temperature distribution of the wafer measured while it is electrostatically attracted to the wafer stage.

[0012] However, the wafer stage in the substrate holding device described in Patent Document 1 is made of metal, and when the thermal conductivity is similar to that of metal, there is a problem in that temperature variations are likely to occur within the wafer surface. Generally, the lower the thermal conductivity of a material, the more likely temperature variations are to occur. For this reason, the substrate holding device described in Patent Document 1 requires accurate temperature control within the wafer surface, making it difficult to reduce such temperature variations. Therefore, technology that can improve the uniformity of wafer temperature within the wafer surface without accurate temperature control is desired.

[0013] According to the present disclosure, it is possible to improve the temperature uniformity within the surface of a wafer such as a semiconductor substrate.

[0014] In the present disclosure, the wafer is not limited to a semiconductor substrate, but may include wafers other than semiconductor substrates, such as glass plates and ceramic plates. The temperature control within the wafer described above is also important for wafers other than semiconductor substrates. Semiconductor substrates require more precise temperature control than wafers other than semiconductor substrates.

[0015] First Embodiment First, a configuration example of a substrate holding device according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a schematic cross-sectional view showing the configuration example of the substrate holding device according to the first embodiment. Fig. 2 is a schematic plan view showing the configuration example of the substrate holding device according to the first embodiment.

[0016] As shown in FIGS. 1 and 2, the substrate holding device 1 may include a graphite block 10, a heat conducting member 20, and a temperature adjusting unit 30.

[0017] (Graphite Block) The graphite block 10 may be a laminate having a structure in which a plurality of graphenes 11 are stacked in one direction. The graphenes 11 may be a sheet-like substance in which a honeycomb structure formed by bonding carbon atoms extends in a two-dimensional direction. The graphenes 11 may be bonded to each other by intermolecular forces, such as van der Waals forces.

[0018] In the first embodiment, the plurality of graphenes 11 are stacked in the Z-axis direction (an example of a first direction). The honeycomb structure of the graphenes 11 may extend along an XY plane perpendicular to the Z-axis direction. For ease of understanding, FIG. 2 schematically illustrates the honeycomb structure of the graphenes 11. Note that FIG. 2 does not illustrate a holding member 40, which will be described later. Hereinafter, an in-plane direction in the XY plane (an example of a second direction) may be referred to as an XY plane direction.

[0019] Graphite block 10 may have, for example, a thin circular plate shape in a planar view. Specifically, graphite block 10 may have a first surface 10a perpendicular to the Z-axis direction, a second surface 10b located opposite first surface 10a, and a side surface 10c connecting first surface 10a and second surface 10b. First surface 10a extends along the XY plane. First surface 10a may be a surface located at one end (here, the end on the positive Z-axis direction side) in the stacking direction of multiple graphenes 11. Second surface 10b extends along the XY plane. Second surface 10b may be a surface located at the other end (here, the end on the negative Z-axis direction side) in the stacking direction of graphenes 11.

[0020] The thickness of graphite block 10 in the Z-axis direction may be, for example, 0.5 mm or more and 10 mm or less. Alternatively, the thickness of graphite block 10 in the Z-axis direction may be, for example, 1 mm or more and 8 mm or less. Furthermore, the diameter of graphite block 10 in the XY plane direction may be, for example, 100 mm or more and 400 mm or less.

[0021] A wafer W may be indirectly placed on the first surface 10a of the graphite block 10. For example, the wafer W may be indirectly placed via a holding member 40 (described later) or the like. When a temperature adjustment unit 30 (described later) functions as a heating mechanism, the wafer W is heated by heat conducted from the graphite block 10. When the temperature adjustment unit 30 (described later) functions as a cooling mechanism, the wafer W is dissipated by heat conducted from the wafer W to the graphite block 10. In this embodiment, the wafer W may be a semiconductor substrate.

[0022] The graphite block 10 has anisotropic thermal conductivity. Specifically, the graphite block 10 may have extremely high thermal conductivity in the direction along the crystal plane, i.e., in the XY plane direction.

[0023] The thermal conductivity of graphite block 10 in the XY plane direction may be, for example, 200 W / m·K or more. On the other hand, the thermal conductivity of graphite block 10 in the stacking direction of graphene 11, i.e., the Z-axis direction, may be, for example, 7 W / m·K.

[0024] The thermal conductivity of the graphite block 10 in the XY plane direction may preferably be 370 W / m·K or more. More preferably, the thermal conductivity of the graphite block 10 in the XY plane direction may be 450 W / m·K or more. Even more preferably, the thermal conductivity of the graphite block 10 in the XY plane direction may be 800 W / m·K or more. In the first embodiment, the thermal conductivity of the graphite block 10 in the XY plane direction may be 1200 W / m·K or more, more specifically, approximately 1700 W / m·K.

[0025] As described above, the graphite block 10 has a higher thermal conductivity in the XY plane than metal. Generally, the higher the thermal conductivity of a material, the less likely temperature unevenness occurs. This is because, when a temperature difference occurs, the higher the thermal conductivity of the material, the faster the temperature difference is resolved. In other words, the graphite block 10 has a higher thermal uniformity in the XY plane than metal. Therefore, the substrate holding device 1 having such a graphite block 10 can improve the in-plane temperature uniformity of the wafer W compared to conventional substrate holding devices that conduct heat to the wafer through metal members.

[0026] The graphite block 10 has an anisotropic thermal expansion coefficient. Specifically, the thermal expansion coefficient of the graphite block 10 in the XY plane is smaller than the thermal expansion coefficient of the graphite block 10 in the Z-axis direction. Therefore, thermal expansion and contraction are unlikely to occur on the first surface 10a on which the wafer W is indirectly placed, and the wafer W can be stably placed thereon.

[0027] The thermal expansion coefficient of the graphite block 10 in the Z-axis direction is, for example, 20×10 －６ / K or more. Preferably, the thermal expansion coefficient of the graphite block 10 in the Z-axis direction is 24×10 －６ / K. Alternatively, the thermal expansion coefficient of the graphite block 10 in the Z-axis direction may be 27×10 －６ / K or less. In the present disclosure, when the term "coefficient of thermal expansion" is simply mentioned, it means the linear expansion coefficient.

[0028] On the other hand, the thermal expansion coefficient of the graphite block 10 in the XY plane direction is, for example, 0.050×10 －６ Alternatively, the thermal expansion coefficient of the graphite block 10 in the XY plane direction may be a negative value, specifically, −0.001×10 －６ / K or less. Alternatively, the thermal expansion coefficient of the graphite block 10 in the XY plane direction may be −0.01×10 －６ / K or more.

[0029] As a specific material, the graphite block 10 may be mainly composed of pyrolytic graphite. In the present disclosure, the term "main component" means that the volume ratio is 50% or more.

[0030] Pyrolytic graphite may be produced, for example, by decomposing, depositing and laminating hydrocarbons, followed by pressure annealing.

[0031] First surface 10a and second surface 10b of graphite block 10 may be wider than the other surfaces of graphite block 10. Specifically, the area of ​​first surface 10a and second surface 10b may be larger than the area of ​​side surface 10c. In other words, the dimension of graphite block 10 in the Z-axis direction may be smaller than the dimension of graphite block 10 in the XY plane.

[0032] In this way, by reducing the dimension of the graphite block 10 in the Z-axis direction, in which the thermal conductivity is relatively low, heat can be efficiently diffused throughout the graphite block 10 .

[0033] (Regarding the Heat Conduction Member) Heat conduction member 20 is provided so as to contact side surface 10c of graphite block 10 from first surface 10a to second surface 10b, and is thermally connected to graphite block 10 at side surface 10c. Heat conduction member 20 according to the first embodiment may be, for example, a metal film, as will be described later.

[0034] In the Z-axis direction, the thermal conductivity of heat conduction member 20 is higher than that of graphite block 10. In addition, in the XY plane direction, the thermal conductivity of heat conduction member 20 is lower than that of graphite block 10. Examples of such heat conduction member 20 include metal materials such as copper, silver, aluminum-based metals, and stainless steel.

[0035] Furthermore, the difference between the thermal expansion coefficient of graphite block 10 and the thermal expansion coefficient of heat conduction member 20 in the Z-axis direction is smaller than the difference between the thermal expansion coefficient of graphite block 10 and the thermal expansion coefficient of heat conduction member 20 in the XY plane. In other words, the thermal expansion coefficient of heat conduction member 20 has a value close to the thermal expansion coefficient of graphite block 10 in the Z-axis direction. With such heat conduction member 20, thermal stress is less likely to occur in the Z-axis direction at the connection between heat conduction member 20 and side surface 10c of graphite block 10, and the connection is less likely to peel off.

[0036] In the first embodiment, heat conduction member 20 may be a metal film made of, for example, the above-mentioned metal material. In such a case, the metal film may be formed directly on side surface 10c of graphite block 10 by various processing methods such as plating, vapor deposition, and thermal spraying. Note that a ceramic material such as AlN (aluminum nitride) may also be used as heat conduction member 20. In such a case, the above-mentioned ceramic raw material may be directly thermally sprayed onto side surface 10c of graphite block 10.

[0037] As described above, the graphite block 10 having a structure in which a plurality of graphenes 11 are stacked has anisotropic thermal conductivity, and has very high thermal conductivity in the XY plane direction but relatively low thermal conductivity in the Z-axis direction. In contrast, the substrate holding device 1 according to the first embodiment has a thermal conductive member 20 whose thermal conductivity in the Z-axis direction is higher than that of the graphite block 10.

[0038] Such heat conduction member 20 functions as a heat conduction path in the Z-axis direction. That is, for example, heat generated in a temperature adjustment unit 30 (described later) moves along the Z-axis direction through heat conduction member 20, which has a relatively high thermal conductivity, and is then conducted from heat conduction member 20 to graphite block 10, and moves through graphite block 10 in the XY plane direction. In this way, heat generated in, for example, temperature adjustment unit 30 (described later) is efficiently conducted throughout graphite block 10. Therefore, with a substrate holding device 1 having such heat conduction member 20, it is possible to effectively heat and dissipate heat from wafer W using graphite block 10.

[0039] Heat conduction member 20 may be provided around the entire periphery of side surface 10c of graphite block 10. That is, heat conduction member 20 may be provided so as to cover the entire side surface 10c of graphite block 10. With this configuration, the number of heat conduction paths between heat conduction member 20 and graphite block 10 increases compared to when heat conduction member 20 is provided only around a portion of the periphery of the side surface of graphite block 10, and heat can be conducted to graphite block 10 more effectively.

[0040] (Regarding the Temperature Adjustment Unit) Temperature adjustment unit 30 is provided so as to be in contact with second surface 10b of graphite block 10, and is thermally connected to graphite block 10 at second surface 10b. Temperature adjustment unit 30 functions as a temperature adjustment mechanism that applies heat to graphite block 10 or removes heat from graphite block 10.

[0041] The temperature adjustment unit 30 according to the first embodiment may be, for example, a metal or ceramic disk having a heater 31 therein. The heater 31 may include, for example, an electric heating wire. The temperature adjustment unit 30 functions as a heating mechanism that applies heat to the graphite block 10. Note that the temperature adjustment unit 30 is not limited to a configuration having a heater 31. This point will be described later with reference to FIGS. 10 and 11 .

[0042] In the first embodiment, graphite block 10 is placed on the surface of temperature adjustment unit 30. Heat generated in temperature adjustment unit 30 first moves in the XY plane along second surface 10b of graphite block 10. Then, the heat moves in the Z-axis direction through heat conduction member 20 and throughout graphite block 10.

[0043] The second surface 10b of the temperature adjustment unit 30 may be in contact with the heat conduction member 20. With this configuration, the heat generated in the temperature adjustment unit 30 can be conducted directly to the heat conduction member 20, and therefore the heat can be conducted to the graphite block 10 more effectively.

[0044] In addition, according to the substrate holding device 1 of the first embodiment, by using the graphite block 10 having a higher thermal conductivity in the in-plane direction than metal, even if the temperature adjustment unit 30 has temperature unevenness in the in-plane direction, such temperature unevenness is less likely to be transmitted to the wafer W. Therefore, according to the substrate holding device 1 of the present disclosure, compared to conventional substrate holding devices, even a member having poor thermal uniformity in the in-plane direction can be used as the temperature adjustment unit 30. When the wafer W is a semiconductor substrate, it is more important to suppress a decrease in manufacturing accuracy due to the occurrence of temperature unevenness than when the wafer W is a glass plate or the like.

[0045] (Regarding the Holding Member) The substrate holding device 1 according to the first embodiment may have a holding member 40 for placing the wafer W on it. The holding member 40 is located on the first surface 10a of the graphite block 10 and is thermally connected to the graphite block 10 at the first surface 10a. The holding member 40 may have, for example, a circular thin plate shape in a plan view, and has a placement surface on which the wafer W is placed. The wafer W may be indirectly placed on the first surface 10a of the graphite block 10 by the holding member 40.

[0046] The thermal conductivity of holding member 40 may be higher than that of graphite block 10 in the stacking direction and lower than that of graphite block 10 in the direction along the crystal plane. Holding member 40 may be a metal substrate made of a metal material such as copper, silver, aluminum, or stainless steel. Alternatively, holding member 40 may be a ceramic substrate made of a ceramic material such as AlN (aluminum nitride).

[0047] According to the substrate holding device 1 having such a holding member 40, even if the temperature adjustment unit 30 has temperature unevenness in the in-plane direction, such temperature unevenness is unlikely to be transmitted to the wafer W. Therefore, there is less need to reduce temperature unevenness in the members constituting the temperature adjustment unit 30. This allows for a reduction in the manufacturing cost of the substrate holding device 1 having the temperature adjustment unit 30.

[0048] Next, the configuration of the graphite block 10 will be described in more detail with reference to Figures 3 and 4. Figure 3 is an enlarged cross-sectional view showing an example of the configuration of the first surface 10a of the graphite block according to the first embodiment. Figure 4 is an enlarged cross-sectional view showing an example of the configuration of the side surface 10c of the graphite block according to the first embodiment. Note that the heat conduction member 20 is not shown in Figure 4.

[0049] Graphite block 10 may have anisotropy in terms of brittleness. That is, graphite block 10 may have a property such that, when stress is applied along the plane direction of a crystal plane, graphene 11 located on the crystal plane is easily peeled off.

[0050] 3, graphene 11 may have an edge portion E1 on first surface 10a of graphite block 10. As a result, graphite block 10 may have a property of being easily broken from edge portion E1 on first surface 10a.

[0051] Furthermore, the side surface 10c of the graphite block 10 may include relatively large irregularities. Specifically, as shown in FIG. 4, the side surface 10c may have a recess F1. In the first embodiment, the irregularities included in the side surface 10c may be fine irregularities. This configuration allows the heat conduction member 20 as a metal film and the bonding material 60 (described later) to enter the recess F1. This point will be described later with reference to FIGS. 5 and 9.

[0052] In graphite block 10, the surface roughness of side surface 10c may be greater than the surface roughness of first surface 10a, which is a crystal plane. Specifically, the surface roughness of side surface 10c may be 20 times or more, 10 times or more but less than 20 times, or 5 times or more but less than 10 times the surface roughness of first surface 10a. In this disclosure, "surface roughness" refers to the arithmetic mean roughness Ra defined in JIS_B_0601:2001.

[0053] With this configuration, the surface roughness of the first surface 10a is small, and the edge portions E1 of the graphenes 11 appearing on the first surface 10a are small, so that the brittleness of the first surface 10a can be reduced.

[0054] Next, the configuration of the joint between graphite block 10 and heat conduction member 20 will be described in more detail with reference to Fig. 5. Fig. 5 is an enlarged cross-sectional view illustrating the configuration of the vicinity of side surface 10c of graphite block 10 according to the first embodiment.

[0055] As described above, the heat conduction member 20 according to the first embodiment may be a metal film. In this case, the heat conduction member 20 may be provided so as to fit into the recess F1 in the side surface 10c of the graphite block 10, as shown in FIG. 5 . This configuration increases the contact area between the heat conduction member 20 and the side surface 10c of the graphite block 10, thereby increasing the connection strength and making the heat conduction member 20 less likely to peel off from the side surface 10c. Furthermore, this configuration increases the thermal contact area between the heat conduction member 20 and the side surface 10c of the graphite block 10, thereby improving the efficiency of heating and heat dissipation of the wafer W.

[0056] Second Embodiment Next, a configuration example of a substrate holding device 1 according to a second embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a schematic cross-sectional view showing a configuration example of a substrate holding device 1 according to the second embodiment. Fig. 7 is an enlarged cross-sectional view for explaining the configuration of the vicinity of side surface 10c of graphite block 10 according to the second embodiment.

[0057] 6 and 7, the substrate holding device 1 according to the second embodiment may have a protective member 50 that protects the heat conductive member 20. That is, the substrate holding device 1 according to the second embodiment corresponds to a configuration in which the protective member 50 is added to the substrate holding device 1 according to the first embodiment.

[0058] The protective member 50 is a metal member that protects the heat conduction member 20, and may have a first portion 51 that contacts the side surface of the heat conduction member 20 and a second portion 52 that contacts a part of the mounting surface of the holding member 40. The protective member 50 may have, for example, an L-shape made up of the first portion 51 and the second portion 52 in a cross-sectional view of the substrate holding device 1.

[0059] Examples of the metal constituting the protective member 50 include metal materials such as copper, silver, aluminum-based metals, and stainless steel. That is, the protective member 50 may be made of the same metal material as the heat conduction member 20.

[0060] According to the substrate holding device 1 having such a protective member 50, the second part 52 can press and fix the above-mentioned holding member 40 against the graphite block 10, thereby reducing the positional deviation of the holding member 40 on the first surface 10a of the graphite block 10.

[0061] Furthermore, according to the substrate holding device 1 having such a protective member 50, the heat conduction member 20 and the protective member 50 conduct heat in the Z-axis direction, thereby increasing the heat conduction paths in the Z-axis direction, thereby improving the efficiency of heating and heat dissipation of the wafer W.

[0062] Furthermore, according to the substrate holding device 1 having the holding member 40 and the protective member 50, by surrounding the graphite block 10 with the holding member 40 and the protective member 50, it is possible to prevent fragments or powder of graphite that have fallen off the graphite block 10 from diffusing into the surrounding area.

[0063] The protective member 50 may be in contact with the temperature adjustment unit 30. This configuration increases the number of heat conduction paths between the temperature adjustment unit 30 and the graphite block 10, thereby further increasing the efficiency of heating or dissipating heat from the wafer W.

[0064] <Third Embodiment> Next, a configuration example of a substrate holding device 1 according to a third embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a schematic cross-sectional view showing a configuration example of a substrate holding device 1 according to the third embodiment. Fig. 9 is an enlarged cross-sectional view for explaining the configuration of the vicinity of side surface 10c of graphite block 10 according to the third embodiment.

[0065] 8 and 9, the substrate holding device 1 according to the third embodiment may have a bonding material 60 positioned between the heat conducting member 20 and the graphite block 10. In the first embodiment, the heat conducting member 20 is a metal film, but in the third embodiment, the heat conducting member 20 may be a rigid body made of metal.

[0066] Bonding material 60 may be a thermally conductive bonding material, such as a brazing material containing a metal. Bonding material 60 thermally connects heat conduction member 20 and side surface 10 c of graphite block 10. Bonding material 60 also adhesively fixes heat conduction member 20 to side surface 10 c of graphite block 10.

[0067] As described above, graphite block 10 has recess F1 on side surface 10c. Therefore, if heat conduction member 20 is a rigid body made of metal, a gap is likely to occur between heat conduction member 20 and side surface 10c. In such a case, the thermal contact area between heat conduction member 20 and graphite block 10 becomes small, which may reduce the efficiency of heating and heat dissipation of wafer W.

[0068] On the other hand, with the configuration including bonding material 60, even if there is a gap between heat conduction member 20 and side surface 10c, heat conduction member 20 and side surface 10c can be bonded together while sealing the gap with bonding material 60. This increases the thermal connection area between heat conduction member 20 and graphite block 10 compared to a case without bonding material 60, thereby improving the efficiency of heating and heat dissipation of wafer W.

[0069] <Modifications of Temperature Adjustment Unit> Next, modifications of the temperature adjustment unit 30 will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a schematic cross-sectional view showing a first modification of the temperature adjustment unit 30. Fig. 11 is a schematic cross-sectional view showing a second modification of the temperature adjustment unit 30.

[0070] In the first to third embodiments, an example has been described in which the temperature adjustment unit 30 has an internal heater 31. However, the present invention is not limited to this, and the temperature adjustment unit 30 may have, for example, an internal water-cooled pipe 32 as shown in Fig. 10. The temperature adjustment unit 30 functions as a cooling mechanism that removes heat from the graphite block 10 by circulating a cooling medium such as water through the water-cooled pipe 32.

[0071] 11, temperature adjustment unit 30 may be a rigid body made of metal or ceramic and having a plurality of fins 33. Such temperature adjustment unit 30 functions as a cooling mechanism that removes heat from graphite block 10 by air-cooling fins 33 with air.

[0072] Alternatively, temperature adjustment unit 30 may be, for example, a Peltier element. Such a Peltier element can be used as a heating mechanism that applies heat to graphite block 10 or a cooling mechanism that removes heat from graphite block 10.

[0073] Fourth Embodiment Next, a configuration example of a substrate holding device 1 according to a fourth embodiment will be described with reference to Fig. 12. Fig. 12 is a schematic cross-sectional view showing the configuration example of a substrate holding device 1 according to the fourth embodiment.

[0074] In the first to third embodiments, an example has been described in which temperature adjustment unit 30 is thermally connected to graphite block 10 at second surface 10b of graphite block 10. However, the present invention is not limited to this, and temperature adjustment unit 30 may be provided, for example, on a side surface of heat conduction member 20. In such a case, temperature adjustment unit 30 may be thermally connected to heat conduction member 20 at the side surface of heat conduction member 20. In such a case, temperature adjustment unit 30 may be directly connected to heat conduction member 20 at the side surface of heat conduction member 20, or may be indirectly connected via protective member 50 or a thermally conductive bonding material, etc.

[0075] In this configuration, temperature adjustment unit 30 may be provided around the entire periphery of the side surface of heat conduction member 20, or may be provided only on a portion of the periphery of heat conduction member 20. Furthermore, in this configuration, a metal plate 70 for placing graphite block 10 may be provided on second surface 10b of graphite block 10. Metal plate 70 protects graphite block 10 and prevents dust generation from graphite block 10. Metal plate 70 may be made of, for example, aluminum, iron, copper, or an alloy containing one or more of the above metals. A plate made of a ceramic material may be used instead of metal plate 70.

[0076] <Application Example of Substrate Holding Device of Present Disclosure> The configuration of the substrate holding device 1 according to this embodiment has been described above, but the technology of the present disclosure can be widely applied as a substrate holding table in substrate processing apparatuses and the like that require wafer temperature control. In such cases, the substrate holding table may be configured in the substrate holding device 1 without the temperature adjustment unit 30.

[0077] Examples of substrate processing apparatuses requiring wafer temperature control include exposure apparatuses, resist coaters, dry etching apparatuses, inspection apparatuses that perform electrical inspections on wafers, and jigs that correct wafer warpage. In such substrate processing apparatuses, the substrate holder may be thermally connected to a temperature control member or the like that is provided for wafer temperature control. By using such a substrate holder, wafer temperature control can be performed while improving the in-plane temperature uniformity of the wafer.

[0078] The present disclosure has been described in detail above, but the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible within the scope that does not deviate from the gist of the present disclosure.

[0079] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0080] The present technology may also be configured as follows: (1) A substrate holding device including: a graphite block having a stack structure in which a plurality of graphenes are stacked in a first direction, the graphite block having a first surface perpendicular to the first direction, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface, the graphite block having a wafer indirectly placed on the first surface; a temperature control unit thermally connected to the graphite block at the second surface and supplying heat to the graphite block or removing heat from the graphite block; and a heat conduction member provided in contact with the side surface from the first surface to the second surface, wherein the heat conduction member has a higher thermal conductivity than the graphite block in the first direction, and the heat conduction member has a higher thermal conductivity than the graphite block in a second direction orthogonal to the first direction. (2) The substrate holding device according to (1), wherein the heat conduction member is provided around the entire periphery of the side surface. (3) The substrate holding device according to (2), comprising: a holding member located on the first surface and having a mounting surface on which the wafer is placed; and a protective member in contact with the thermally conductive member and protecting the thermally conductive member, wherein the thermally conductive member is a metal film formed on a side surface of the graphite block, and the protective member is made of metal and has a first portion in contact with the side surface of the thermally conductive member and a second portion in contact with a part of the mounting surface of the holding member. (4) The substrate holding device according to any one of (1) to (3), comprising: a holding member located on the first surface and having a mounting surface on which the wafer is placed, wherein the thermal conductivity of the holding member is higher than the thermal conductivity of the graphite block in the first direction and lower than the thermal conductivity of the graphite block in the second direction. (5) The substrate holding device according to any one of (1) to (4), wherein the thermal expansion coefficient of the graphite block in the second direction is lower than the thermal expansion coefficient of the graphite block in the first direction.(6) The substrate holding device according to any one of (1) to (5), wherein a difference between the thermal expansion coefficient of the graphite block and the thermal expansion coefficient of the heat conduction member in the first direction is smaller than a difference between the thermal expansion coefficient of the graphite block and the thermal expansion coefficient of the heat conduction member in the second direction. (7) The substrate holding device according to any one of (1) to (6), wherein a surface roughness of the side surface of the graphite block is larger than a surface roughness of the first surface of the graphite block. (8) The substrate holding device according to any one of (1) and (2) or (4) to (7), wherein the heat conduction member is a rigid metal body in contact with a side surface of the graphite block, and includes a bonding material positioned between the heat conduction member and the graphite block, and the heat conduction member and the graphite block are thermally connected via the bonding material. (9) A substrate holding table comprising: a graphite block having a stacked structure in which a plurality of graphenes are stacked in a first direction, the graphite block having a first surface perpendicular to the first direction, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface, a wafer being indirectly placed on the first surface and a temperature adjustment member being connected to the second surface; and a heat conduction member provided in contact with the side surface from the first surface to the second surface, wherein the heat conduction member has a higher thermal conductivity than the graphite block in the first direction, and the graphite block has a higher thermal conductivity than the heat conduction member in a second direction perpendicular to the first direction.

[0081] REFERENCE SIGNS LIST 1 substrate holding device 10 graphite block 10a first surface 10b second surface 10c side surface 11 graphene 20 heat conducting member 30 temperature control unit 31 heater 32 water cooling pipe 33 fin 40 holding member 50 protective member 51 first portion 52 second portion 60 bonding material E1 edge portion F1 recess W wafer

Claims

1. A substrate holding device comprising: a graphite block having a stack structure in which a plurality of graphenes are stacked in a first direction, the graphite block having a first surface perpendicular to the first direction, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface, the graphite block having a wafer indirectly placed on the first surface; a temperature control unit thermally connected to the graphite block on the second surface and supplying heat to the graphite block or removing heat from the graphite block; and a heat conduction member provided in contact with the side surface from the first surface to the second surface, wherein the heat conduction member has a higher thermal conductivity than the graphite block in the first direction, and the graphite block has a higher thermal conductivity than the heat conduction member in a second direction perpendicular to the first direction.

2. The substrate holding device according to claim 1, wherein the heat conducting member is provided over the entire periphery of the side surface.

3. A substrate holding device as described in claim 2, comprising: a holding member located on the first surface and having a mounting surface on which the wafer is placed; and a protective member in contact with the heat conduction member and protecting the heat conduction member, wherein the heat conduction member is a metal film formed on the side surface of the graphite block, and the protective member is made of metal and has a first portion in contact with the side surface of the heat conduction member and a second portion in contact with a part of the mounting surface of the holding member.

4. A substrate holding device as described in any one of claims 1 to 3, comprising a holding member located on the first surface and having a mounting surface on which the wafer is placed, the thermal conductivity of the holding member being higher than the thermal conductivity of the graphite block in the first direction and lower than the thermal conductivity of the graphite block in the second direction.

5. A substrate holding device according to any one of claims 1 to 4, wherein the coefficient of thermal expansion of said graphite block in said second direction is smaller than the coefficient of thermal expansion of said graphite block in said first direction.

6. A substrate holding device as described in any one of claims 1 to 5, wherein the difference between the thermal expansion coefficient of the graphite block and the thermal expansion coefficient of the heat conduction member in the first direction is smaller than the difference between the thermal expansion coefficient of the graphite block and the thermal expansion coefficient of the heat conduction member in the second direction.

7. A substrate holding device according to any one of claims 1 to 6, wherein the surface roughness of the side surface of the graphite block is greater than the surface roughness of the first surface of the graphite block.

8. A substrate holding device as described in any one of claims 1 and 2 or claims 4 to 7, wherein the heat conducting member is a rigid metal body that contacts the side of the graphite block, and has a bonding material positioned between the heat conducting member and the graphite block, and the heat conducting member and the graphite block are thermally connected via the bonding material.

9. A substrate holder comprising: a graphite block having a structure in which a plurality of graphenes are stacked in a first direction, the graphite block having a first surface perpendicular to the first direction, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface, a wafer being indirectly placed on the first surface and a temperature control member being connected to the second surface; and a heat conduction member provided so as to contact the side surface from the first surface to the second surface, wherein the heat conduction member has a higher thermal conductivity than the graphite block in the first direction, and the graphite block has a higher thermal conductivity than the heat conduction member in a second direction perpendicular to the first direction.

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