Substrate holding member and manufacturing method thereof

Abstract

To provide a substrate holding member capable of heating a substrate quickly and evenly and capable of becoming a steady-state faster and a manufacturing method thereof.SOLUTION: A substrate holding member 100 includes: a substrate holding member body 110 having a placement surface 112 of a flat plate made of a ceramic sintered body; and a heating resistance 120 embedded in the substrate holding member body 110. The substrate holding member body 110 is formed of a first area 131 and a second area 132. The first area 131 constitutes at least a part of the placement surface 112, and the second area 132 constitutes at least a side face 114 of the substrate holding member body 110. The thermal conductivity of the first area 131 is lower than that of the second area 132.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a substrate holding member and a method for manufacturing the same. [Background technology]

[0002] Heater plates (substrate holding members) with embedded heating resistors have been used as semiconductor manufacturing equipment components, and are capable of heating the substrate placed on the heater plate.

[0003] Patent Document 1 discloses a method for producing an electrode-embedded ceramic sintered body (molded body hot pressing method), which comprises a first step in which a plurality of ceramic molded bodies are prepared, and a second step in which one ceramic molded body has a groove shaped to match the shape of an electrode on the joining surface with another ceramic molded body, and the multiple ceramic molded bodies are stacked so that the electrode is accommodated in the space formed by the groove, and then the ceramic molded bodies are pressurized, sintered, and joined.

[0004] Patent Document 2 discloses a substrate mounting device comprising a plate-shaped ceramic substrate having a substrate mounting surface on one side and a bonding layer formed on the other side of the ceramic substrate, the surface being divided into a plurality of regions with bonding having different thermal conductivity arranged in each region, and a method for adjusting the in-plane temperature distribution of a substrate mounted on the ceramic substrate by adjusting the in-plane distribution of thermal conductivity in the bonding layer formed on the other side of the ceramic substrate having a substrate mounting surface on one side. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6148845 [Patent Document 2] Patent No. 4409373 Summary of the Invention [Problem to be solved by the invention]

[0006] A heater plate with high thermal conductivity is desirable for heating a substrate quickly and uniformly. However, if the overall thermal conductivity of the heater plate is simply increased, the amount of heat generated by the heating resistor that escapes from the outer periphery of the plate to the environment through thermal radiation and convection also increases, so that for the same amount of heat generated, it takes longer for the temperature of the substrate-mounting surface of the heater plate to reach the set value.

[0007] Also, in order to maintain the heater plate at a specified temperature, a shaft structure (support member) has been adopted that supports the heater plate on the back side for the purpose of insulation. However, in the case of a heater with a shaft, the heat generated by the heating resistor not only escapes from the outer periphery of the plate to the environment by thermal radiation, etc., but also a large amount of heat is conducted to the shaft, so the temperature distribution on the substrate mounting surface of the heater plate is low at the center and outer periphery where the shaft is located, and high in the middle, resulting in an M-shaped temperature distribution symmetrical about the center of the heater plate, which hinders temperature uniformity.

[0008] However, Patent Document 1 does not focus on the temperature rise characteristics of the substrate mounting surface. In addition, Patent Document 2 adjusts the temperature distribution on the substrate mounting surface by using bonding materials with different thermal conductivities, but does not consider improving the temperature rise characteristics by reducing heat radiation from the outer periphery or the amount of heat conducted to the shaft by a heater with a shaft.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a substrate holding member that can heat a substrate quickly and uniformly and reach a steady state more quickly, and a method for manufacturing the same. [Means for solving the problem]

[0010] (1) In order to achieve the above object, a substrate holding member of the present invention is a substrate holding member comprising: a flat substrate holding member body having a mounting surface and made of a ceramic sintered body; and a heating resistor embedded in the substrate holding member body, the substrate holding member body being formed of a first region and a second region, the first region constituting at least a part of the mounting surface, the second region constituting at least a side surface of the substrate holding member body, and the thermal conductivity of the second region being lower than the thermal conductivity of the first region. The ceramic sintered body forming the substrate holding member body is mainly composed of AlN, and the oxide-equivalent concentration of the sintering aid element contained in the first region is higher than the oxide-equivalent concentration of the sintering aid element contained in the second region. It is characterized by the following.

[0011] In this way, by constructing the substrate holding member body from a combination of a first region with high thermal conductivity and a second region with low thermal conductivity, heat is quickly conducted in the first region and is less likely to escape to the outside in the second region. As a result, the substrate can be heated quickly and uniformly and reaches a steady state more quickly than if the entire substrate holding member body was made from a material with high thermal conductivity.

[0012] (2) The substrate holding member of the present invention further includes a support member supporting the substrate holding member body made of a sintered ceramic body, and the second region constitutes at least a joint portion of the substrate holding member body with the support member.

[0013] In this way, by configuring the joint with the support member from the second region having low thermal conductivity, less heat is conducted to the support member than when the joint is configured from the first region, and the range of temperature distribution on the mounting surface can be kept small.

[0014] (3) In the substrate holding member of the present invention, the second region forms the side surface and the entire lower surface of the substrate holding member body that faces the mounting surface.

[0015] In this way, by disposing the second region over the entire bottom surface of the substrate holding member body, heat is less likely to escape to the outside from the side and bottom surfaces, improving energy efficiency.

[0016] (4) Furthermore, in the substrate holding member of the present invention, the ceramic sintered body forming the substrate holding member main body is characterized in that the ceramic sintered body has AlN as its main component, and that the oxide-equivalent concentration of the sintering aid element contained in the first region is different from the oxide-equivalent concentration of the sintering aid element contained in the second region, or that the type of sintering aid contained in the first region is different from the type of sintering aid contained in the second region.

[0017] Ceramic sintered bodies whose main component is AlN have high thermal conductivity and excellent heat resistance and plasma resistance, and their thermal conductivity can be easily adjusted by changing the concentration and type of sintering aid. Therefore, by forming the first and second regions from ceramic sintered bodies whose main component is AlN, it is possible to construct a substrate holding member whose thermal conductivity can be adjusted and which has excellent heat resistance and plasma resistance.

[0018] (5) In the substrate holding member of the present invention, the sintering aid element is yttrium.

[0019] When the sintering aid element used in the ceramic sintering process is yttrium, the thermal conductivity of the sintered body containing AlN as the main component can be adjusted by changing the concentration, provided that the oxide-equivalent concentration is within a range of 10 wt% or less, making it easier to adjust the thermal conductivity.

[0020] (6) Furthermore, in the substrate holding member of the present invention, the ceramic sintered body forming the substrate holding member body and the support member is mainly composed of AlN, the oxide-equivalent concentration of the sintering aid element contained in the first region is different from the oxide-equivalent concentration of the sintering aid element contained in the second region, or the type of sintering aid contained in the first region is different from the type of sintering aid contained in the second region, and the ceramic sintered body forming the support member does not contain a sintering aid.

[0021] This allows the thermal conductivity of the support member to be sufficiently low, so that the amount of heat escaping from the support member can be reduced, and the range of the temperature distribution on the mounting surface can be further reduced.

[0022] (7) The method for producing a substrate holding member of the present invention further comprises the steps of: Main component is AlN a step of forming one or more first ceramics molded bodies from a first ceramics raw material powder; a step of forming one or more second ceramics molded bodies from a second ceramics raw material powder having the same main component as the first ceramics raw material powder but a different amount or type of sintering aid added thereto; a step of degreasing the one or more first ceramics molded bodies and the one or more second ceramics molded bodies at a predetermined temperature or more and for a predetermined time or more to produce one or more first ceramics degreased bodies and one or more second ceramics degreased bodies; a step of preparing a heating resistor, and combining the heating resistor, the one or more first ceramics degreased bodies, and the one or more second ceramics degreased bodies to form a substrate holding member main body precursor that is formed in a flat plate shape, has a mounting surface on one main surface, and has a heating resistor embedded therein; and a step of uniaxially pressing and firing the substrate holding member main body precursor in a direction perpendicular to the main surface to fire the substrate holding member main body, a weight percent concentration of the sintering aid added to the first ceramic raw material powder is greater than a weight percent concentration of the sintering aid added to the second ceramic raw material powder; In the substrate holding member body, a second region in which a ceramic sintered body formed by sintering the second ceramic raw material powder is placed has a relatively low thermal conductivity compared to a first region in which a ceramic sintered body formed by sintering the first ceramic raw material powder is placed, the first region is placed on at least a part of the mounting surface, and the second region is placed on at least a side of the substrate holding member body.

[0023] In this way, by constructing the substrate holding member body from a combination of a first region with high thermal conductivity and a second region with low thermal conductivity, heat is quickly conducted in the first region and is less likely to escape to the outside in the second region. As a result, the substrate can be heated quickly and uniformly and reaches a steady state more quickly than if the entire substrate holding member body was made from a material with high thermal conductivity.

[0024] (8) Furthermore, in the method for manufacturing the substrate holding member of the present invention, the method further includes the steps of: forming a third ceramic formed body from a third ceramic raw material powder having the same main component as the first ceramic raw material powder but a different amount or type of sintering aid added; degreasing the third ceramic formed body at a predetermined temperature or for a predetermined time to produce a third ceramic degreased body; firing the third ceramic degreased body to fire a support member supporting the substrate holding member body; and arranging the support member at a predetermined position on an underside of the substrate holding member body facing the mounting surface, and heating the support member while applying pressure perpendicular to the main surface, thereby joining the substrate holding member body and the support member, wherein at least a joint portion with the support member on the underside of the substrate holding member body facing the mounting surface is located in the second region.

[0025] In this way, by forming the joint with the support member in the second region with low thermal conductivity, heat conduction to the support member is reduced, and the range of temperature distribution on the mounting surface can be kept small. Effect of the Invention

[0026] According to the present invention, it is possible to provide a substrate holding member that can heat a substrate quickly and uniformly and reach a steady state more quickly, and a method for manufacturing the same. [Brief description of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view showing an example of a substrate holding member according to a first embodiment. [Diagram 2] 5 is a cross-sectional view showing a modified example of the substrate holding member according to the first embodiment. FIG. [Diagram 3] 5 is a flowchart showing a method for manufacturing a substrate holding member according to the first embodiment. [Figure 4] 1(a) to 1(c) are cross-sectional views each showing a schematic diagram of one stage of the manufacturing process of the first embodiment. [Diagram 5] 1(a) to 1(c) are cross-sectional views each showing a schematic diagram of one stage of the manufacturing process of the first embodiment. [Figure 6] 10 is a cross-sectional view showing an example of a substrate holding member according to a second embodiment. FIG. [Figure 7] FIG. 11 is a cross-sectional view showing a modified example of the substrate holding member according to the second embodiment. [Figure 8] FIG. 11 is a cross-sectional view showing a modified example of the substrate holding member according to the second embodiment. [Figure 9] 10 is a flowchart showing a method for manufacturing a substrate holding member according to a second embodiment. [Figure 10] 1 is a table showing the production conditions and measurement results of Examples and Comparative Examples. [Figure 11] FIG. 11 is a cross-sectional view showing a substrate holding member of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Next, an embodiment of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are used for the same components in each drawing, and duplicated descriptions will be omitted. In the configuration diagrams, the size of each component is conceptually shown, and does not necessarily represent the actual dimensional ratio.

[0029] [First embodiment] [Configuration of the substrate holding member] First, the configuration of a substrate holding member according to a first embodiment will be described. Fig. 1 is a cross-sectional view showing an example of a substrate holding member according to this embodiment. The substrate holding member 100 according to this embodiment includes a substrate holding member main body 110 and a heating resistor 120. The substrate holding member 100 is applied to a heater, an electrostatic chuck, etc.

[0030] The substrate holding member body 110 is made of a ceramic sintered body, formed in a flat plate shape, and has a mounting surface 112 on one of its main surfaces for mounting a substrate. Various materials can be used for the substrate holding member body 110 depending on the application. For example, AlN, Al2O3, Si3N4, SiC, etc. can be used. The shape of the substrate holding member body 110 can be various shapes such as a disk shape, a polygonal shape, an ellipse shape, etc.

[0031] The substrate holding member body 110 is formed of a first region 131 and a second region 132, and the thermal conductivity of the second region 132 is lower than that of the first region 131. By configuring the substrate holding member body 110 with the first region 131 and the second region 132 having different thermal conductivities in this manner, it is possible to adjust the temperature distribution of the mounting surface 112 and the amount of heat escaping from the surface of the substrate holding member body 110. The thermal conductivity of the first region 131 and the second region 132 is high or low at room temperature.

[0032] The first region 131 constitutes at least a part of the mounting surface 112, and the second region 132 constitutes at least the side surface 114 of the substrate holding member body 110. As a result, heat is quickly conducted in the first region 131, and heat is less likely to escape to the outside in the second region 132. Therefore, the substrate can be heated quickly and uniformly and reaches a steady state more quickly, compared to a case in which the entire substrate holding member body 110 is made of a material with high thermal conductivity. The second region 132 constitutes at least the side surface 114 of the substrate holding member body 110 means that the entire side surface 114 of the substrate holding member body 110 is formed of the second region 132. It is preferable that the second region 132 constituting the side surface 114 has a thickness from the surface of the side surface of 5 mm to 50 mm.

[0033] FIG. 2 is a cross-sectional view showing a modified example of the substrate holding member according to the present embodiment. As shown in FIG. 2, the second region 132 preferably constitutes the entire lower surface 116 facing the side surface 114 and the mounting surface 112 of the substrate holding member body 110. In this way, by disposing the second region 132 on the entire lower surface 116 of the substrate holding member body 110, heat is less likely to escape from the lower surface 116 to the outside, improving energy efficiency. Note that the lower surface 116 means that it is the lower side when the mounting surface 112 is used as the upper surface, and the mounting surface 112 is not necessarily always the upper surface. The second region 132 constituting the lower surface 116 preferably has a thickness from the surface of the lower surface of 5 mm to 30 mm.

[0034] It is preferable that the ceramic sintered bodies forming the first region 131 and the second region 132 have the same main component. This allows the different regions to be integrated without distortion because the shrinkage rates during sintering are similar, and the bond at the interface between the first region 131 and the second region 132 becomes stronger. In addition, the thermal expansion coefficients of the first region 131 and the second region 132 when the substrate holding member 100 is used are also similar, so that the risk of cracks or the like occurring at the interface can be reduced even with repeated use.

[0035] The ceramic sintered body forming the substrate holding member body 110 preferably has AlN as its main component, and the oxide-equivalent concentration of the sintering aid element contained in the first region 131 may be different from the oxide-equivalent concentration of the sintering aid element contained in the second region 132, or the type of sintering aid contained in the first region 131 may be different from the type of sintering aid contained in the second region 132.

[0036] A ceramic sintered body mainly composed of AlN has high thermal conductivity and excellent heat resistance and plasma resistance, and the thermal conductivity can be easily adjusted by changing the oxide-equivalent concentration of the sintering aid element or the type of sintering aid. Therefore, by forming the first region 131 and the second region 132 from a ceramic sintered body mainly composed of AlN, the thermal conductivity can be adjusted and the substrate holding member body 110 with excellent heat resistance and plasma resistance can be configured. Note that being the main component means that the ceramic is contained in an amount of 90 wt% or more.

[0037] The sintering aid element of the ceramic sintered body mainly composed of AlN can be a rare earth element such as yttrium, an alkaline earth metal such as calcium, or a transition metal such as titanium. The oxide-equivalent concentration of the sintering aid element is different between the first region 131 and the second region 132 when the same sintering aid element is contained and the concentration of the sintering aid element converted into an oxide is different. For example, when the sintering aid element is yttrium, the concentration converted into its oxide Y2O3 may be different between the first region 131 and the second region 132. The case where one region does not contain the sintering aid element is also included as the case where the oxide-equivalent concentration of the sintering aid element is different. In addition, the type of sintering aid is different between the first region 131 and the second region 132, and the type of sintering aid is different between the first region 131 and the second region 132. The case where one region contains one type of sintering aid and the other region contains two types of sintering aids, and the number of types of sintering aids contained is different is also included.

[0038] Of the above, the sintering aid element of the ceramic sintered body mainly composed of AlN is preferably yttrium. When the sintering aid element of the ceramic sintered body mainly composed of AlN is yttrium, the thermal conductivity of the ceramic sintered body mainly composed of AlN can be adjusted by the concentration in the range of 10wt% or less in terms of oxide, which makes it easier to adjust the thermal conductivity.

[0039] The heating resistor 120 is embedded inside the substrate holding member main body 110. The heating resistor 120 may be formed in various shapes, such as a mesh shape or a foil shape. The heating resistor 120 may be formed from various materials, such as molybdenum and tungsten. The heating resistor 120 is preferably embedded inside the first region 131 constituting the mounting surface 112, or embedded in the boundary between the first region 131 constituting the mounting surface 112 and the second region 132 disposed thereunder. This allows the heat generated from the heating resistor 120 to be rapidly transferred to the mounting surface 112 and the substrate, and the substrate can be rapidly and uniformly heated.

[0040] The heating resistor 120 is preferably embedded inside the second region 132 constituting the side surface 114. This allows for easier temperature uniformity compared to the conventional method that requires a complicated structure and system, such as providing a separate heating resistor. In addition, when the ceramic sintered bodies forming the first region 131 and the second region 132 are sintered integrally, discontinuity and non-uniform heat transfer at the boundary between the first region 131 and the second region 132 are suppressed, improving the symmetry of heat transfer within the surface. Therefore, the temperature distribution can be improved simply by arranging a heating resistor in the first region 131.

[0041] The substrate holding member body 110 may have an electrode other than the heating resistor 120 inside the first region 131. For example, by providing an electrode for electrostatic attraction, the substrate holding member 100 can be used as an electrostatic chuck with a heater.

[0042] In addition to the above, the substrate holding member 100 is provided with necessary terminals 140 and terminal holes 142. This allows power to be supplied to the heating resistor 120 and the electrodes.

[0043] The substrate holding member of the present invention has a first region where heat is quickly conducted and a second region where heat is less likely to escape to the outside, and therefore can heat the substrate quickly and uniformly and reach a steady state more quickly, compared to a substrate holding member in which the entire body is made of a material with high thermal conductivity.

[0044] [Method of manufacturing the substrate holding member] Next, a method for manufacturing a substrate holding member according to this embodiment will be described. Fig. 3 is a flow chart showing a method for manufacturing a substrate holding member according to a first embodiment of the present invention. As shown in Fig. 3, the method for manufacturing a substrate holding member according to the first embodiment of the present invention includes a first ceramics molded body forming step STEP 1, a second ceramics molded body forming step STEP 2, a first and second ceramics degreased body preparing step STEP 3, a substrate holding member main body precursor forming step STEP 4, and a firing step STEP 5.

[0045] 4(a) to (c) and 5(a) to (c) are cross-sectional views each showing a schematic diagram of one stage of the manufacturing process of this embodiment. FIG. 4(a) to (c) and FIG. 5(a) to (c) show the manufacturing process of the substrate holding member of FIG. 2.

[0046] In the first ceramic molded body forming step STEP 1, one or more first ceramic molded bodies 11 are formed from the first ceramic raw material powder. For example, additives such as a binder, a plasticizer, a dispersant, etc. are appropriately added to the ceramic raw material powder and mixed to prepare a slurry, which is then granulated by a spray-drying method or the like to produce granules (first ceramic raw material powder), and then pressed to form one or more first ceramic molded bodies 11. A powder serving as a sintering aid may be added to the first ceramic raw material powder as necessary.

[0047] The ceramic raw material powder is preferably of high purity, preferably 96% or more, more preferably 98% or more, and preferably has an average particle size of 0.1 μm or more and 1.0 μm or less.

[0048] The mixing method may be either wet or dry, and a mixer such as a ball mill or a vibration mill may be used. As a molding method, a known method such as uniaxial pressing or cold isostatic pressing (CIP) may be used. The method for forming the first ceramic molded body is not limited to pressing, and may be, for example, green sheet lamination or casting, which may be appropriately degreased or further calcined to produce the first ceramic molded body.

[0049] After molding, one or more first ceramic molded bodies 11 may be machined to adjust the shape of the molded body. As shown in Fig. 4(b), a groove having a shape matching the shape of the heating resistor may be formed on one side of the first ceramic molded body 11 (the surface to be joined with another ceramic molded body). The machining may be performed after degreasing.

[0050] In the second ceramics molded body forming step STEP 2, one or more second ceramics molded bodies 12 are formed from the second ceramics raw material powder. The second ceramics raw material powder has the same main components as the first ceramics raw material powder, but differs in the amount or type of sintering aid added. Details of the method for producing the second ceramics raw material powder and the method for forming the second ceramics molded body may be the same as those of the first ceramics molded body forming step STEP 1.

[0051] After molding, the one or more second ceramic bodies 12 may be machined to adjust the shape of the body. Figure 4(a) shows the second ceramic body 12 machined to accommodate two first ceramic bodies 11.

[0052] In STEP 3, the first and second ceramic degreased bodies production process, one or more first ceramic moldings 11 and one or more second ceramic moldings 12 are degreased at a predetermined temperature or higher for a predetermined period of time or longer to produce one or more first ceramic degreased bodies 21 and one or more second ceramic degreased bodies 22.

[0053] The first ceramic molded body 11 and the second ceramic molded body 12 are heat-treated at a temperature of, for example, 400°C or more and 800°C or less to become the first ceramic degreased body 21 and the second ceramic degreased body 22. The degreasing time is preferably 1 hour or more and 120 hours or less. For degreasing, an atmospheric furnace or a nitrogen atmosphere furnace can be used, but since it is important to remove the organic components of the binder, an atmospheric furnace is preferable. In the first and second ceramic degreased body manufacturing step STEP 3, the degreasing temperature and degreasing time of the first ceramic molded body 11 and the second ceramic molded body 12 may be the same or different.

[0054] In the substrate holding member main body precursor formation process STEP 4, a heating resistor 120 is prepared, and the heating resistor 120, one or more first ceramic degreased bodies 21, and one or more second ceramic degreased bodies 22 are combined to form a substrate holding member main body precursor 30 which is formed in a flat plate shape, has a mounting surface 112 on one main surface, and has the heating resistor 120 embedded therein.

[0055] Here, the region where the ceramic sintered body obtained by sintering the first ceramic raw material powder is arranged is called the first region, and the region where the ceramic sintered body obtained by sintering the second ceramic raw material powder is arranged is called the second region. That is, in the substrate holding member main body precursor forming step, the region where the first ceramic degreased body is arranged becomes the first region 131 after sintering, and the region where the second ceramic degreased body is arranged becomes the second region 132 after sintering. The amount or type of sintering aid is adjusted so that the second region 132 has a relatively lower thermal conductivity than the first region 131.

[0056] At this time, the first ceramic degreased body 21 is positioned so that at least the first region 131 constitutes a part of the mounting surface 112, and the second ceramic degreased body 22 is positioned so that at least the second region 132 constitutes the side surface 114 of the substrate holding member main body 110.

[0057] The heating resistor 120 is prepared by processing the resistor 120 into a shape according to the design of the substrate holding member 100. The heating resistor 120 may be formed into various shapes, such as a mesh shape or a foil shape. The heating resistor 120 may be formed from various materials, such as molybdenum and tungsten. The heating resistor 120 is preferably embedded in the first region 131 constituting the mounting surface 112 by being sandwiched between the first ceramic degreased body constituting the mounting surface 112 and another first ceramic degreased body, or embedded in the boundary between the first region 131 constituting the mounting surface 112 and the second region 132 disposed therebelow by being sandwiched between the first ceramic degreased body constituting the mounting surface 112 and the second region 132 disposed therebelow.

[0058] In the firing step STEP5, the formed substrate holding member main body precursor 30 is uniaxially pressurized and fired in a direction perpendicular to the mounting surface to fire the substrate holding member main body 110. The pressure is preferably 1 MPa or more. The firing temperature is preferably 1500°C or more and 2000°C or less. The firing time is preferably 1 hour or more and 12 hours or less. The firing atmosphere is, for example, a nitrogen or inert gas atmosphere, but may also be a vacuum atmosphere. As a result, the first ceramic degreased body 21 and the second ceramic degreased body 22 are sintered to become the first and second ceramic sintered bodies, respectively, which are integrated to obtain the substrate holding member 100 in which the heating resistor 120 is embedded.

[0059] Then, necessary terminal holes 142 are provided in the fired substrate holding member 100, and the terminals 140 are connected with brazing material or the like. The terminals may be made of Ni or the like. The brazing material may be Au brazing material or the like.

[0060] In this way, it is possible to manufacture a substrate holding member 100 that includes a first region with high thermal conductivity on the mounting surface and a second region with low thermal conductivity on the outer periphery.

[0061] In addition, between the first and second ceramic degreased body preparation step STEP 3 and the substrate holding member main body precursor formation step STEP 4, the first and second ceramic calcined body preparation steps may be provided. When the first and second ceramic calcined body preparation steps are provided, the first and second ceramic degreased bodies are calcined at a temperature of 1200°C or more and 1700°C or less to prepare the first and second ceramic calcined bodies. This makes it possible to further improve the dimensional accuracy of the first and second regions of the substrate holding member. The calcination time is preferably 0.5 hours or more and 12 hours or less. The calcination atmosphere is preferably a nitrogen or inert gas atmosphere, but may be a vacuum atmosphere or the like. In the first and second ceramic calcined body preparation steps, the calcination temperature and the calcination time of the first and second ceramic degreased bodies may be the same or different. When the calcined body preparation step is provided, the machining may be performed after the calcined body preparation step.

[0062] [Second embodiment] Next, the configuration of a substrate holding member according to the second embodiment will be described. Fig. 6 is a cross-sectional view showing an example of a substrate holding member according to this embodiment. A substrate holding member 200 according to this embodiment includes a substrate holding member main body 110, a heating resistor 120, and a support member 210. The basic configurations of the substrate holding member main body 110 and the heating resistor 120 are similar to those of the first embodiment, so only the different parts will be described.

[0063] The support member 210 is made of a sintered ceramic body, and supports the substrate holding member body 110. This makes the substrate holding member 200 applicable to a heater with a shaft, an electrostatic chuck with a shaft, and the like.

[0064] The second region 132 of the substrate holding member body 110 constitutes at least the joint portion 118 with the support member 210 of the substrate holding member body 110. In this manner, the joint portion 118 between the substrate holding member body 110 and the support member 210 is formed in the second region 132 having a low thermal conductivity, so that less heat is conducted to the support member 210 compared to when the joint portion 118 is constituted by the first region 131, and the width of the temperature distribution of the mounting surface 112 can be suppressed to be small.

[0065] Fig. 7 is a cross-sectional view showing a modified example of the substrate holding member according to this embodiment. As shown in Fig. 7, the second region 132 preferably constitutes the entire lower surface 116 facing the side surface 114 and the mounting surface 112 of the substrate holding member main body 110. In this embodiment, too, by disposing the second region 132 on the entire lower surface 116 of the substrate holding member main body 110, heat is less likely to escape from the lower surface 116 to the outside, improving energy efficiency.

[0066] Fig. 8 is a cross-sectional view showing a modified example of the substrate holding member according to this embodiment. As shown in Fig. 8, the second region 132 may constitute a part of the mounting surface 112 or a part of the lower surface 116 facing the mounting surface 112. This allows the arrangement of the first region 131 and the second region 132 to design the temperature distribution of the mounting surface 112 and the thermal conductivity of the entire substrate holding member according to the arrangement.

[0067] It is preferable that the ceramic sintered bodies forming the first region 131, the second region 132, and the support member 210 have the same main component. As a result, the substrate holding member body 110 has the same shrinkage rate during sintering, so that the different regions can be integrated without distortion, and the bond at the interface between the first region 131 and the second region 132 becomes stronger. In addition, the bonding strength of the bonding interface between the joint portion 118 of the substrate holding member body 110 and the support member 210 is also increased when the substrate holding member 100 is bonded by solid-state bonding or the like. In addition, the thermal expansion coefficients of the substrate holding member 100 during use are also the same in the first region 131, the second region 132, and the support member 210, so that the risk of cracks or the like occurring at the interface between the first region 131 and the second region 132 and the bonding interface between the joint portion 118 of the substrate holding member body 110 and the support member 210 can be reduced even when the substrate holding member 100 is used repeatedly.

[0068] The ceramic sintered body forming the substrate holding member main body 110 and the support member 210 has AlN as its main component, and the oxide-equivalent concentration of the sintering aid element contained in the first region 131 is different from the oxide-equivalent concentration of the sintering aid element contained in the second region 132, or the type of sintering aid contained in the first region 131 is different from the type of sintering aid contained in the second region 132, and further, it is preferable that the ceramic sintered body forming the support member 210 does not contain a sintering aid.

[0069] An AlN ceramic sintered body that does not contain a sintering aid can have a sufficiently low thermal conductivity. Therefore, by forming the support member 210 from a ceramic sintered body that contains AlN as the main component and does not contain a sintering aid, the thermal conductivity of the support member 210 can be sufficiently low, so that the loss of heat from the support member 210 can be reduced and the temperature distribution width of the mounting surface 112 can be further suppressed. The sintering aid element contained in the first region 131 or the second region 132 is preferably yttrium.

[0070] The substrate holding member of the present invention has a first region in which heat is quickly conducted and a second region in which heat is less likely to escape to the outside, and the joint with the support member is formed in the second region which has low thermal conductivity.As a result, compared to a substrate holding member in which the entire substrate holding member body is formed from a material with high thermal conductivity, the substrate can be heated quickly and uniformly, the steady state is reached more quickly, and less heat is conducted to the support member, thereby making it possible to reduce the range of the temperature distribution on the mounting surface.

[0071] [Method of manufacturing the substrate holding member] Next, a method for manufacturing a substrate holding member according to this embodiment will be described. FIG. 9 is a flow chart showing a method for manufacturing a substrate holding member according to a second embodiment of the present invention. As shown in FIG. 9, the method for manufacturing a substrate holding member according to the second embodiment of the present invention includes a first ceramic molded body forming step STEP 1, a second ceramic molded body forming step STEP 2, a first and second ceramic degreased body preparing step STEP 3, a substrate holding member main body precursor forming step STEP 4, a firing step STEP 5, a third ceramic molded body forming step STEP 6, a third ceramic degreased body preparing step STEP 7, a support member firing step STEP 8, and a joining step STEP 9. The method for manufacturing a substrate holding member according to this embodiment is manufactured in the same manner as the method for manufacturing a substrate holding member according to the first embodiment until halfway, so that the following will explain the differences from the method for manufacturing a substrate holding member according to the first embodiment.

[0072] In the substrate holding member main body precursor formation process STEP 4, in addition to the configuration of the first embodiment, a second ceramic degreased body is arranged on the underside facing the mounting surface of the substrate holding member main body so that at least the joining portion to be joined with the support member becomes the second region.

[0073] In the third ceramic molded body forming step STEP 6, a third ceramic molded body is formed from the third ceramic raw material powder. The third ceramic raw material powder has the same main component as the first ceramic raw material powder, but the amount or type of sintering aid added is different. The method for producing the third ceramic raw material powder and the method for forming the third ceramic molded body may be the same as those in the first ceramic molded body forming step STEP 1. It is preferable that the third ceramic raw material powder does not contain a sintering aid. In addition, it is preferable that the third ceramic raw material powder is a ceramic whose main component is AlN.

[0074] In the third ceramic degreased body preparation step STEP 7, the third ceramic molded body is degreased at a predetermined temperature or higher for a predetermined time or longer to prepare a third ceramic degreased body. The numerical ranges of the degreasing conditions for the third ceramic molded body may be the same as those of the first and second ceramic degreased body preparation steps STEP 3. The third ceramic degreased body preparation step STEP 7 may be performed simultaneously with the first and second ceramic degreased body preparation steps STEP 3.

[0075] In the support member firing step (STEP 8), the third ceramic degreased body is fired to fire the support member that supports the substrate holding member body. The support member is preferably fired at normal pressure. The firing temperature is preferably 1500°C or higher and 2000°C or lower. The firing time is more preferably 1 hour or higher and 12 hours or lower. The firing atmosphere is, for example, a nitrogen or inert gas atmosphere, but may also be a vacuum atmosphere.

[0076] In the bonding step STEP 9, the support member is placed at a predetermined position on the lower surface of the substrate holding member body facing the mounting surface, and the substrate holding member body and the support member are bonded by applying pressure perpendicular to the main surface while heating. The predetermined position on the lower surface is included in the bonding portion. The pressure is preferably 1 MPa or more. The heating temperature is preferably 1500°C or more and 2000°C or less. The heating time is preferably 0.5 hours or more and 5 hours or less. The heating atmosphere is, for example, a nitrogen or inert gas atmosphere, but may be a vacuum atmosphere or the like. This causes the substrate holding member body and the support member to be solid-phase bonded. The terminal 140 is brazed after the substrate holding member body and the support member are bonded. The bonding means is not limited to solid-phase bonding, and may be a means in which an inorganic bonding material is interposed.

[0077] In this way, a substrate holding member 200 can be manufactured which includes a first region with high thermal conductivity on the mounting surface, a second region with low thermal conductivity on the outer periphery and at the joint, and in which the substrate holding member body and the support member are joined.

[0078] [Examples and Comparative Examples] Example 1 A first ceramics compact with a diameter of 300 mm and a thickness of 10 mm and a second ceramics compact with a diameter of 300 mm and a thickness of 5 mm were formed using a first ceramics raw material powder mainly composed of AlN to which 5 wt% Y2O3 was added. A second ceramics compact with a diameter of 340 mm and a thickness of 25 mm and a recessed portion with a diameter of 300 mm and a depth of 15 mm was formed using a second ceramics raw material powder mainly composed of AlN to which no sintering aid was added. A groove for accommodating a heating resistor was then formed on one surface of the first ceramics compact with a thickness of 10 mm.

[0079] Next, the first ceramic molded body and the second ceramic molded body were degreased at 550°C for 12 hours to produce a first ceramic degreased body and a second ceramic degreased body. Next, a molybdenum mesh (wire diameter 0.1 mm, mesh size 50 mesh) made of molybdenum with a diameter of 290 mm was prepared as a heating resistor. Then, the heating resistor was placed in the groove of the first ceramic degreased body in which a groove was formed, sandwiched between the other first ceramic degreased body, and stored in the second ceramic degreased body to produce a substrate holding member main body precursor.

[0080] Next, the substrate holding member main body precursor was subjected to uniaxial hot press sintering at 1800°C for 5 hours while applying a force of 6 MPa in a direction perpendicular to the mounting surface. In this manner, the substrate holding member main body was sintered. The size of the substrate holding member main body after sintering was 300 mm in diameter and 20 mm in thickness. The arrangement of the first and second regions of the substrate holding member main body is the same as that of the substrate holding member shown in FIG. 2.

[0081] Separately, a third ceramics molded body having an outer diameter of 80 mm, an inner diameter of 60 mm, and a height of 120 mm was formed from a third ceramics raw material powder containing AlN as the main component without the addition of a sintering aid. This was degreased at 550°C for 12 hours to produce a third ceramics degreased body. The third ceramics degreased body was fired at 1900°C for 5 hours at normal pressure to fire the support member.

[0082] The substrate holding member body and the support member were then joined by heating at 1700°C for 1 hour while applying a force of 1 MPa in the direction perpendicular to the mounting surface. In addition, the necessary Ni terminals were brazed with Au solder. In this manner, the heater with a shaft of Example 1 was produced.

[0083] Example 2 In Example 2, except that 1 wt % of Y2O3 was added to the second ceramic raw material powder, a substrate holding member was produced under the same conditions and with the same size as in Example 1. The joining of the support member was the same as in Example 1.

[0084] Example 3 In Example 3, a substrate holder was produced under the same conditions and with the same size as in Example 1, except that 3 wt% of Y2O3 and 1 wt% of CaO were added to the first ceramic raw material powder. The joining of the support member was the same as in Example 1.

[0085] Comparative Example 1 In Comparative Example 1, a substrate holding member body was produced by powder hot pressing using ceramic raw material powder mainly composed of AlN to which 5 wt% Y2O3 was added. First, the ceramic raw material powder was filled into a mold and subjected to uniaxial pressure treatment. This resulted in a first layer having a diameter of 340 mm and a thickness of 5 mm. Next, a molybdenum mesh (wire diameter 0.1 mm, mesh size 50 mesh) made of molybdenum and having a diameter of 290 mm, which would serve as a heating resistor, was placed on the first layer. Next, the ceramic raw material powder was filled on the heating resistor and subjected to uniaxial pressure treatment to form a second layer, thereby forming a molded body before firing.

[0086] Next, the laminated compact up to the second layer was hot-pressed at a pressure of 10 MPa, a firing temperature of 1800°C, and a firing time of 2 hours to fire a substrate holding member body having a diameter of 340 mm and a thickness of 20 mm. Then, a support member was produced and bonded in the same manner as in Example 1. FIG. 11 is a cross-sectional view showing the substrate holding member of Comparative Example 1. As shown in FIG. 11, Comparative Example 1 is entirely formed of an AlN sintered body with high thermal conductivity.

[0087] Comparative Example 2 In Comparative Example 2, a substrate holding member body was fabricated by a compact hot press method using ceramic raw material powder mainly composed of AlN to which 5 wt% Y2O3 was added. That is, the substrate holding member body was fabricated by subjecting the ceramic raw material powder to CIP molding, degreasing, and uniaxial hot press sintering in the same manner as in Example 1. As shown in FIG. 11, in Comparative Example 2, the substrate holding member body is not divided into a first region and a second region, and is entirely formed of an AlN sintered body with high thermal conductivity. The joining of the support member is the same as in Example 1.

[0088] (Measurement of temperature distribution) The temperature distribution of the heater with a shaft that was fabricated was measured. The heater with a shaft was installed in a chamber and evaluated in a N2 atmosphere of 10 Torr. Power was supplied to the power supply terminal of the substrate holder, and the temperature was controlled so that the temperature of the substrate holder body was 400°C. The temperature distribution on the mounting surface at that time was measured with an IR camera. The maximum-minimum value of the measurement points on any line passing through the center of the mounting surface was taken as the temperature distribution (°C).

[0089] 10 is a table showing the manufacturing conditions and the measurement results of the examples and the comparative examples. In all of the examples 1 to 3, the temperature distribution of the mounting surface was smaller than that of the comparative examples 1 and 2. This is presumably because the center of the mounting surface of the substrate holding member body is formed in the first region with high thermal conductivity, and the outer periphery and the joint portion are formed in the second region with low thermal conductivity, thereby suppressing heat dissipation and heat conduction from the outer periphery and the joint portion, and further, the joint portion with the support member is composed of the second region with low thermal conductivity, so that compared to the case where the joint portion is composed of the first region, the heat conduction to the support member is reduced and the thermal conductivity of the mounting surface is maintained high, thereby improving the uniformity of the temperature distribution on the surface of the mounting surface.

[0090] Even in the case of a substrate holding member without a shaft, the effect of suppressing heat dissipation from the outer periphery and the effect of maintaining high thermal conductivity of the mounting surface are similar, so it is presumed that the substrate holding member will reach a steady state more quickly than if the entire body of the substrate holding member was made of a material with high thermal conductivity.

[0091] From the above, it was confirmed that the substrate holding member of the present invention is a substrate holding member that can heat the substrate quickly and uniformly and reach a steady state more quickly, compared to a substrate holding member whose entire body is made of a material with high thermal conductivity, because the substrate holding member of the present invention quickly conducts heat in the first region and the second region makes it difficult for heat to escape to the outside. It was also confirmed that the manufacturing method of the present invention can manufacture such a substrate holding member.

[0092] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and equivalents are included within the spirit and scope of the present invention. In addition, the structure, shape, number, position, size, etc. of the components shown in each drawing are for convenience of explanation and may be changed as appropriate. [Explanation of symbols]

[0093] 11 First ceramic molded body 12 Second ceramic molded body 21 First ceramic degreaser 22 Second ceramic degreaser 30 Substrate holding member main body precursor 100, 200 Substrate holding member 110 Substrate holding member body 112 Placement surface 114 Side 116 Bottom surface 118 Joint part 120 Heating resistor 131 First Area 132 The Second Region 140 Terminals 142 Terminal hole

Claims

1. A substrate holding member, a flat-plate-shaped substrate holding member body having a mounting surface and made of a ceramic sintered body; a heating resistor embedded in the substrate holding member body, the substrate holding member body is formed with a first region and a second region; The first region constitutes at least a part of the placement surface, the second region constitutes at least a side surface of the substrate holding member body, the thermal conductivity of the second region is lower than the thermal conductivity of the first region; The ceramic sintered body forming the substrate holding member body is mainly composed of AlN, A substrate holding member, characterized in that the oxide-equivalent concentration of a sintering aid element contained in the first region is greater than the oxide-equivalent concentration of a sintering aid element contained in the second region.

2. The substrate holding member further includes a support member for supporting the substrate holding member body made of a sintered ceramic body, 2. The substrate holding member according to claim 1, wherein the second region constitutes at least a joint portion of the substrate holding member body that is joined to the support member.

3. 3. The substrate holding member according to claim 1, wherein the second region constitutes the side surface and the entire lower surface of the substrate holding member body that faces the placement surface.

4. The ceramic sintered body forming the substrate holding member body is mainly composed of AlN, A substrate holding member as described in any one of claims 1 to 3, characterized in that the oxide-equivalent concentration of the sintering aid element contained in the first region is different from the oxide-equivalent concentration of the sintering aid element contained in the second region, or the type of sintering aid contained in the first region is different from the type of sintering aid contained in the second region.

5. 5. The substrate holder according to claim 4, wherein the sintering aid element is yttrium.

6. The ceramic sintered body forming the substrate holding member body and the support member is mainly composed of AlN, The oxide-equivalent concentration of the sintering aid element contained in the first region is different from the oxide-equivalent concentration of the sintering aid element contained in the second region, or the type of the sintering aid contained in the first region is different from the type of the sintering aid contained in the second region, 3. The substrate holding member according to claim 2, wherein the ceramic sintered body forming the support member does not contain a sintering additive.

7. A method for manufacturing a substrate holding member formed of a ceramic sintered body, comprising the steps of: forming one or more first ceramic bodies from a first ceramic raw material powder containing AlN as a main component; forming one or more second ceramic bodies from a second ceramic raw material powder having the same main component as the first ceramic raw material powder but a different amount or type of sintering aid added thereto; a step of subjecting the one or more first ceramic molded bodies and the one or more second ceramic molded bodies to a degreasing treatment at a predetermined temperature or higher and for a predetermined time or longer to produce one or more first ceramic degreased bodies and one or more second ceramic degreased bodies; preparing a heating resistor, and combining the heating resistor, the one or more first ceramic degreased bodies, and the one or more second ceramic degreased bodies to form a substrate holding member main body precursor having a flat plate shape, a mounting surface on one main surface, and an embedded heating resistor; and sintering the substrate holding member body precursor under uniaxial pressure in a direction perpendicular to the main surface to form a substrate holding member body, a weight percent concentration of the sintering aid added to the first ceramic raw material powder is greater than a weight percent concentration of the sintering aid added to the second ceramic raw material powder; a second region in the substrate holding member body, in which a ceramic sintered body obtained by sintering the second ceramic raw material powder is disposed, has a relatively low thermal conductivity compared to a first region in which a ceramic sintered body obtained by sintering the first ceramic raw material powder is disposed; The first area is disposed on at least a portion of the placement surface, A method for manufacturing a substrate holding member, wherein the second region is disposed on at least a side surface of the substrate holding member body.

8. In the method for manufacturing the substrate holding member, forming a third ceramic molded body from a third ceramic raw material powder having the same main component as the first ceramic raw material powder but a different amount or type of sintering aid added thereto; a step of subjecting the third ceramic formed body to a degreasing treatment at a predetermined temperature or higher for a predetermined time or longer to prepare a third ceramic degreased body; sintering the third ceramic degreased body to form a support member that supports the substrate holding member body; and placing the support member at a predetermined position on a lower surface of the substrate holding member body that faces the mounting surface, and applying heat while applying pressure in a direction perpendicular to the main surface to bond the substrate holding member body and the support member together.

8. The method for manufacturing a substrate holding member according to claim 7, wherein the second region is disposed on at least a portion of the lower surface of the substrate holding member body facing the mounting surface and joined to the support member.

9. A substrate holding member, comprising: a flat-plate-shaped substrate holding member body having a mounting surface and made of a ceramic sintered body; a heating resistor embedded in the substrate holding member body, the substrate holding member body is formed with a first region and a second region; The first region constitutes at least a part of the placement surface, the second region constitutes at least a side surface of the substrate holding member body, the thermal conductivity of the second region is lower than the thermal conductivity of the first region; The ceramic sintered body forming the substrate holding member body is mainly composed of AlN, The first region and the second region both contain a sintering aid element, A substrate holding member characterized in that the oxide-equivalent concentration of a sintering aid element contained in the first region is different from the oxide-equivalent concentration of a sintering aid element contained in the second region, or the type of sintering aid contained in the first region is different from the type of sintering aid contained in the second region.

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