Electrode embedding member and substrate holding member

Abstract

To provide an electrode embedding member and a substrate holding member that can provide a temperature distribution in the radial direction of a mounted substrate.SOLUTION: An electrode embedding material 100 includes a base material 10 formed of a ceramic sintered body, and a heater electrode 20 embedded in the base material 10, the base material 10 has one or more cavities 30 inside the base material 10, and in a vertical cross section of the base material 10, the cavity 30 is located closer to the upper surface 12 of the base material 10 than a heater electrode layer 24 in which the heater electrode 20 is embedded, and the cavity 30 has an annular shape when seen through from the upper surface 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electrode-embedded member and a substrate holding member.

Background Art

[0002] As a member for a semiconductor manufacturing apparatus, a heater plate (electrode-embedded member) in which an electrode (heating resistor) is embedded has been used. The heater plate can heat the placed substrate.

[0003] Conventionally, for a ceramic base material such as AlN used for a heater plate, the heat generated inside the base material is isotropically conducted and diffused through the base material. Therefore, the base material itself is homogenized according to the thermal conductivity, and correspondingly, the substrate also tends to be homogenized. However, in a specific semiconductor manufacturing process, it may be required to provide a specific temperature distribution in the radial direction of the substrate rather than homogenizing the substrate.

[0004] Patent Document 1 aims to provide a ceramic heater that realizes precise uniform heat control of wafers and the like in various environments in a semiconductor process. It includes a plurality of heating resistors embedded inside a ceramic base material, a placement surface for placing the heated object formed on the surface of the ceramic base material, and at least one partition groove provided so as to penetrate a substantially flat surface where the plurality of heating resistors are embedded on the opposite surface side of the placement surface, and partitioning the action region of the heating resistor. A ceramic heater characterized by this is disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 describes a design in which heating resistors are separated by grooves, and while the heat generated from the heater electrodes is suppressed from diffusing horizontally, it requires forming deep grooves in the direction of the mounting surface from the back surface of the ceramic substrate, which reduces the strength of the substrate itself. Therefore, in environments where it is used at high temperatures, the risk of substrate breakage increases. In addition, electrical connection between the separated heater electrodes and electrical wiring from the inside of the shaft provided in the center of the bottom surface of the substrate were difficult.

[0007] Therefore, there has been a demand for a heater that can provide a temperature distribution in the radial direction of the mounted substrate, and that is also practical and highly reliable.

[0008] This invention has been made in view of these circumstances, and aims to provide an electrode embedding member and a substrate holding member that can provide a temperature distribution in the radial direction of the substrate on which it is placed. [Means for solving the problem]

[0009] (1) In order to achieve the above objective, the present invention employs the following means. That is, the electrode embedding member of the present invention is an electrode embedding member comprising a base material formed of a ceramic sintered body and a heater electrode embedded in the base material, wherein the base material is located inside the base material In the vertical direction, it is located in a position that overlaps with the heater electrode. The substrate has one or more cavities, and in a vertical cross-section of the substrate, the cavities are located closer to the upper surface of the substrate than the heater electrode layer in which the heater electrodes are embedded, and the cavities, when viewed through from the upper surface, include an annular shape.

[0010] In this way, by forming a circular cavity that acts as an insulating region above the heater electrode layer, radial heat diffusion is suppressed, and heat is transferred upward. As a result, it is possible to design the substrate so that a temperature distribution occurs radially on the substrate surface, making it easy to create a temperature distribution in the radial direction of the substrate. Furthermore, since the placement of the heater electrodes and the insulating region can be set independently, the degree of freedom in designing the surface temperature distribution of the substrate is increased.

[0011] (2) Furthermore, the electrode embedding member of the present invention is the electrode embedding member described in (1) above, The one or more cavities are located inside the substrate, in a position that overlaps with the heater electrode in the vertical direction. Multiple cavities and The plurality of cavities are characterized by being arranged in a concentric pattern, as seen through the top surface.

[0012] By arranging multiple cavities concentrically in this way, the surface temperature of the substrate can be finely distributed in the radial direction, making it easy to create a precise radial temperature distribution on the substrate.

[0013] (3) Furthermore, the electrode embedding member of the present invention is the electrode embedding member described in (1) above, and 1 or more Area of ​​the cavity viewed through the upper surface sum The material is characterized by the fact that, when Si is the material and S is the area of ​​the substrate mounting surface of the base material, 0.25 ≤ Si / S ≤ 0.7.

[0014] In this way, by setting the ratio of Si to S to 0.7 for the area Si of the cavity viewed from above and the area S of the substrate mounting surface, it is possible to suppress isotropic heat transfer in the substrate and promote heat transfer in the upward direction of the substrate while maintaining the strength of the substrate.

[0015] (4) Furthermore, the electrode embedding member of the present invention is the electrode embedding member described in (2) above, and multiple Area of ​​the cavity viewed through the upper surface sum The material is characterized by the condition 0.25 ≤ Si / S ≤ 0.7, where Si is the surface area of ​​the substrate mounting surface of the base material.

[0016] This allows for maintaining the strength of the substrate while suppressing isotropic heat transfer within the substrate and promoting heat transfer upwards.

[0017] (5) Furthermore, the substrate holding member of the present invention is a substrate holding member characterized by comprising an electrode embedding member described in any of (1) to (4) above, and a support member joined to the lower surface of the substrate and supporting the electrode embedding member.

[0018] According to this, it is possible to design so that a temperature distribution occurs in the radial direction of the substrate surface, and a substrate holding member with an increased degree of freedom in designing the surface temperature distribution of the substrate can be configured.

Advantages of the Invention

[0019] According to the electrode embedding member and the substrate holding member of the present invention, a temperature distribution can be provided in the radial direction of the placed substrate.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic cross-sectional view showing an example of an electrode embedding member according to an embodiment of the present invention. [Figure 2] It is a schematic view showing an example of the upper surface of the electrode embedding member according to the embodiment. [Figure 3] (a) and (b) are schematic views showing the ranges of the area S of the substrate placement surface of the substrate and the area Si of the cavity as viewed from above in FIG. 2, respectively. [Figure 4] It is a schematic cross-sectional view showing a modified example of the electrode embedding member according to the embodiment. [Figure 5] It is a schematic view showing a modified example of the upper surface of the electrode embedding member according to the embodiment. [Figure 6] It is a schematic cross-sectional view showing a modified example of the electrode embedding member according to the embodiment. [Figure 7] It is a schematic view showing a modified example of the upper surface of the electrode embedding member according to the embodiment. [Figure 8] It is a schematic cross-sectional view showing a modified example of the electrode embedding member according to the embodiment. [Figure 9] It is a schematic cross-sectional view showing an example of the substrate holding member according to the embodiment. [Figure 10] (a) to (d) are schematic cross-sectional views showing one step of the manufacturing method of the electrode embedding member, respectively. [Figure 11] It is a schematic cross-sectional view showing one step of the manufacturing method of the electrode embedding member.

Modes for Carrying Out the Invention

[0021] Next, embodiments of the present invention will be described with reference to the drawings. To facilitate understanding of the explanation, the same reference numeral is used for identical components in each drawing, and redundant explanations are omitted. Note that the sizes of each component in the configuration diagrams are conceptual representations and do not necessarily represent actual dimensional ratios.

[0022] [Embodiment] (Configuration of electrode embedding components) An electrode embedding member according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view showing an example of an electrode embedding member according to an embodiment of the present invention. Figure 2 is a schematic diagram showing an example of the upper surface of an electrode embedding member according to an embodiment of the present invention. Figure 1 shows a cross-section along line AA in Figure 2. The electrode embedding member 100 according to an embodiment of the present invention comprises a base material 10 and a heater electrode 20.

[0023] The base material 10 is formed from a ceramic sintered body. The base material 10 may be in various shapes, such as a roughly circular disc, a polygonal plate, or an elliptical plate. The base material 10 is flat except for the cavity 30 and any protrusions formed on the upper surface 12. The base material 10 may also be convex or concave towards the center. If the pin-shaped protrusions 40 described later are not formed on the upper surface 12 of the base material 10, the upper surface 12 of the base material 10 forms a predetermined flat or curved surface (substrate mounting surface) on which the substrate is placed.

[0024] The base material 10 is preferably integrally formed from a ceramic sintered body. Integral formation of the base material 10 from a ceramic sintered body means that the ceramic sintered body forming the ceiling of the cavity 30 (described later) and the ceramic sintered body forming the bottom of the cavity 30 are joined together using or without a ceramic-containing bonding material. This increases the mechanical strength of the base material 10.

[0025] The heater electrode 20 is embedded in the substrate 10. The heater electrode 20 is used to heat the substrate (wafer). In Figure 2, the heater electrode 20 is embedded in a shape that corresponds to the design of the electrode embedding member 100.

[0026] The base material 10 has one or more tubular cavities 30 inside. In a vertical cross-section of the base material 10, the cavities 30 are located closer to the upper surface 12 of the base material 10 than the heater electrode layer 24 in which the heater electrodes 20 are embedded. The width of the cavities 30 is preferably 1 mm or more and 60 mm or less. The cross-sectional shape of the cavities 30 is not limited to a rectangle, but can be any shape that can be manufactured, such as a circle, ellipse, semicircle, or stepped shape.

[0027] The cavity 30, as seen through the substrate 10 from the top surface 12, includes an annular shape. By forming the cavity 30 in an annular shape, the heater electrode 20 can be divided into the inside and outside of the cavity 30. This allows for a design in which a temperature distribution occurs in the radial direction on the surface of the substrate 10, and the temperature distribution of the substrate can be set in the radial direction of the cavity 30. The dotted line in Figure 2 shows the shape of the cavity 30 as seen through the substrate 10 from the top surface 12. Other structures that can be seen through the cavity 30 are omitted.

[0028] When the area of ​​the cavity 30 viewed through the top surface 12 is Si and the area of ​​the substrate mounting surface of the base material 10 is S, it is preferable that 0.25 ≤ Si / S ≤ 0.7. This makes it possible to suppress isotropic heat transfer in the base material 10 and promote heat transfer upward in the base material 10 while maintaining the strength of the base material 10.

[0029] Figures 3(a) and 3(b) are schematic diagrams showing the area S of the substrate mounting surface of the base material 10 and the area Si of the cavity 30 viewed through the top surface 12, respectively, on the top surface of Figure 2. In the electrode embedding member 100 shown in the schematic diagrams of Figures 1 and 2, S and Si are measured as the areas shown in Figures 3(a) and 3(b). If the width of the cavity 30 differs in the depth direction of the cavity 30, Si shall be measured as the maximum width of each part viewed through the top surface 12 of the cavity 30. Furthermore, if the substrate mounting surface is curved, S and Si shall be measured as the area along that curved surface.

[0030] It is preferable that the heater electrode 20 is divided into multiple regions to which different power can be applied. This makes it possible to make the radial temperature distribution of the substrate placed on the electrode embedding member 100 sharper.

[0031] The ceiling of the cavity 30 is preferably located at a distance of 1 mm to 8 mm from the upper surface 12. This allows the strength of the upper surface 12 of the base material 10 to be maintained. In addition, other electrodes 70 can be embedded in the upper part of the cavity 30.

[0032] Figure 4 is a schematic cross-sectional view showing a modified example of the electrode embedding member according to an embodiment of the present invention. Figure 5 is a schematic diagram showing a modified example of the upper surface of the electrode embedding member according to an embodiment of the present invention. Figure 4 shows a cross-section along the line BB in Figure 5.

[0033] As shown in Figures 4 and 5, the substrate 10 preferably has a plurality of cavities 30 inside it, and the cavities 30 are preferably arranged concentrically in a shape that can be seen through the substrate 10 from the top surface 12. This allows the surface temperature of the substrate 10 to be finely distributed in the radial direction, making it easy to create a fine radial temperature distribution of the substrate. The plurality of cavities 30 arranged concentrically may be double-layered or triple-layered, as shown in Figures 4 and 5. The width of the gap between adjacent cavities 30 (the width of the substrate 10 in the gap between adjacent cavities 30) is preferably 2 mm or more. Furthermore, the width of the gap between adjacent cavities 30 is preferably 25% or more of the width of the cavity 30. This allows the strength of the substrate 10 to be maintained even when cavities 30 are formed inside the substrate 10.

[0034] Figure 6 is a schematic cross-sectional view showing a modified example of an electrode embedding member according to an embodiment of the present invention. Figure 7 is a schematic diagram showing a modified example of the upper surface of an electrode embedding member according to an embodiment of the present invention. Figure 6 shows a cross-section along the CC line in Figure 7.

[0035] As shown in Figures 6 and 7, the cavity 30 may include not only an annular cavity 30, but also a circular cavity 30 located at the center 16, as seen through the substrate 10 from the top surface 12. This allows for a finer radial distribution of the surface temperature of the substrate 10, making it easier to create a fine radial temperature distribution on the substrate.

[0036] The cavity 30 may include the shape of multiple arcs arranged in a ring. By forming the cavity 30 in an arc shape, a part of the base material 10 exists outside the ends of the arcs, thereby increasing the mechanical strength of the base material 10. The cavity 30 may also include a linear shape. By forming the cavity 30 in a linear shape, the heater electrode 20 can be partitioned on both sides of the line. This allows the temperature distribution of the substrate to be set perpendicular to the line. The annular cavity 30 and the arc-shaped cavity 30 may be combined to form two or more concentric circles. The arc-shaped cavity 30 and the linear cavity 30 may also be combined. The annular cavity 30, the arc-shaped cavity 30, and the circular cavity 30 and the linear cavity 30 may be in communication with each other.

[0037] As shown in Figures 6 and 7, the electrode embedding member 100 may be provided with pin-shaped protrusions 40. In that case, multiple pin-shaped protrusions 40 are formed, projecting upward from the upper surface 12 of the base material 10. The shape of the pin-shaped protrusions 40 can be appropriately selected from shapes such as cylindrical, prismatic, conical, pyramidal, or truncated cone or truncated pyramidal, with the upper part of the cone cut off.

[0038] The arrangement of the pin-shaped protrusions 40 is not particularly limited. It can be a known form or a similar form, for example, in addition to the concentric circle arrangement shown in Figure 7, it may be a regular arrangement such as a square grid or a triangular grid, or it may be an irregular arrangement where there are localized areas of density. Furthermore, annular protrusions may be arranged on the outer circumference of the upper surface 12 of the electrode embedding member 100 so as to surround the pin-shaped protrusions 40.

[0039] When pin-shaped protrusions 40 are formed on the base material 10, the upper ends of the multiple pin-shaped protrusions together form a predetermined flat or curved surface (substrate mounting surface) on which the substrate is placed. In this way, the multiple pin-shaped protrusions 40 support the substrate. That is, the substrate mounting surface formed by the upper ends of the multiple pin-shaped protrusions is determined. As a result, the upper ends of the multiple pin-shaped protrusions come into contact with the substrate, and the substrate is supported. It should be noted that some of the multiple pin-shaped protrusions 40 may not have their upper ends in contact with the substrate. This is because even if such protrusions exist, the substrate can still be supported depending on the arrangement of the surrounding pin-shaped protrusions 40. The upper ends of the pin-shaped protrusions may be in contact with the substrate over their entire surface, or only a portion of them may be in contact with the substrate.

[0040] The height of the pin-shaped protrusion 40 is preferably 10 μm or more and 500 μm or less. The height of the pin-shaped protrusion 40 refers to the distance from the upper surface 12 of the base material 10 to the upper end of the pin-shaped protrusion. The upper end of the pin-shaped protrusion is preferably a flat surface of a predetermined size. In that case, the maximum diameter of the flat surface at the upper end of the pin-shaped protrusion is preferably 100 μm or more and 5 mm or less. The surface roughness Ra of the flat surface at the upper end of the pin-shaped protrusion is preferably 0.01 μm or more and 1.6 μm or less.

[0041] Figure 8 is a schematic cross-sectional view showing a modified example of an electrode embedding member according to an embodiment of the present invention. As shown in Figure 8, it is preferable that the substrate 10 is further embedded with electrostatic adsorption electrodes or high-frequency electrodes (other electrodes 70). This makes the semiconductor manufacturing process more functional, such as the electrostatic adsorption function of the substrate and the application of bias by high-frequency power.

[0042] It is preferable that the other electrodes 70 are embedded in a position closer to the upper surface 12 of the base material 10 than to the ceiling of the cavity 30. This increases the design flexibility of the electrostatic adsorption electrodes or high-frequency electrodes. Figure 8 shows an example in which the other electrodes 70 are embedded in a position closer to the upper surface 12 of the base material 10 than to the ceiling of the cavity 30.

[0043] The electrode embedding member 100 may be provided with terminals 50, 51 and terminal holes 52 as needed. The electrode embedding member 100 may also be provided with lift pin holes (not shown) and ventilation holes for use as a vacuum chuck.

[0044] (Configuration of substrate holding member) Next, the configuration of the substrate holding member according to the embodiment will be described. Figure 9 is a schematic cross-sectional view showing an example of a substrate holding member according to an embodiment of the present invention. The substrate holding member 200 comprises an electrode embedding member 100 and a support member 110. The basic configuration of the electrode embedding member 100 is as described above. The substrate holding member 200 in Figure 9 shows an example using the electrode embedding member 100 of Figure 4.

[0045] The support member 110 is made of a ceramic sintered body and supports the electrode embedding member 100. This allows the substrate holding member 200 to be applied to a shaft heater or the like. The support member 110 is joined to a predetermined position on the lower surface 14 (the surface facing the upper surface 12 of the base material) of the electrode embedding member 100. The joining may be solid-phase joining or joining using a joining material. Preferably, the support member 110 is formed of a ceramic sintered body having the same main component as the base material 10 of the electrode embedding member 100.

[0046] [Manufacturing method for embedded electrode members] Next, a method for manufacturing an electrode embedding member according to an embodiment of the present invention will be described. An electrode embedding member according to an embodiment of the present invention is manufactured, for example, by stacking and joining electrode embedding member precursors produced by the molded body hot pressing method described below. Note that the method for manufacturing the electrode embedding member precursor is not limited to this method, and may be, for example, a powder hot pressing method or a conventional green sheet stacking method. The powder hot pressing method is a method in which ceramic raw material powder and predetermined heat-generating resistors or electrodes are alternately stacked to embed the heat-generating resistors or electrodes inside the ceramics, and then fired using a uniaxial hot pressing method.

[0047] The method for manufacturing an electrode embedded member according to an embodiment of the present invention by the molded body hot pressing method comprises a ceramic molded body formation step, a ceramic degreased body production step, a laminate formation step, a laminate firing step, a substrate precursor processing step, a substrate precursor bonding step, and a substrate processing step.

[0048] In the ceramic molded body formation process, for example, multiple ceramic molded bodies are formed from ceramic raw material powder mainly composed of AlN (aluminum nitride). Sintering aids may be added as needed. For example, AlN ceramic raw material powder is mixed with appropriate additives such as Y2O3 as the Y component of the sintering aid, a binder, a plasticizer, and a dispersant to prepare a slurry, and granules (ceramic raw material powder) are formed by a spray-drying method or the like. Subsequently, the granulated powder can be pressure-molded to form multiple ceramic molded bodies.

[0049] Besides AlN, other ceramic powders used as raw materials include, for example, SiC (silicon carbide), Al2O3 (aluminum oxide), and Si3N4 (silicon nitride). Among these, AlN, which has high thermal conductivity, is preferred. This is because the present invention allows for control of heat transfer in a set direction or area on the substrate mounting surface, even when using a material with high thermal conductivity.

[0050] The ceramic raw material powder is preferably of high purity, preferably 96% or higher, and more preferably 98% or higher. Furthermore, the average particle size of the ceramic raw material powder is preferably between 0.1 μm and 1.0 μm.

[0051] The mixing method may be either wet or dry, and mixers such as ball mills and vibratory mills can be used. As for the molding method, known methods such as uniaxial pressure molding or cold isostatic pressing (CIP) can be used. It should be noted that the method for forming the ceramic molded body is not limited to pressure molding; for example, green sheet lamination or casting can also be applied, and the ceramic molded body can be manufactured by appropriately degreasing or further calcining the materials.

[0052] The ceramic molded body may be shaped by machining after molding. Furthermore, grooves shaped to match the shape of heater electrodes, other electrodes, vias, wiring, etc., may be formed on one or both sides of the ceramic molded body (the bonding surface with other ceramic molded bodies). Machining may be performed after degreasing.

[0053] In the ceramic degreased body manufacturing process, multiple ceramic molded bodies are degreased at a predetermined temperature and for a predetermined time to produce multiple ceramic degreased bodies.

[0054] The ceramic molded body is heat-treated, for example, at a temperature of 500°C to 900°C to become a degreased ceramic body. The degreasing time is preferably 1 hour to 120 hours. An air furnace or a nitrogen atmosphere furnace can be used for degreasing, but an air furnace is preferred in order to remove organic components of the binder.

[0055] In the laminate formation process, heater electrodes and, if necessary, other electrodes, via materials, and wiring are prepared and combined with multiple degreased ceramic bodies to form multiple laminates in a flat plate shape. The multiple laminates may, for example, have a substrate mounting surface on their upper surface and include laminates with other electrodes embedded, laminates with heater electrodes embedded, and laminates with wiring embedded. A laminate may consist of a single degreased ceramic body. The other electrodes, via materials, and wiring are formed by foils, thin sheets, wires, meshes, or porous materials of molybdenum or tungsten, paste filling, or printing.

[0056] The heater electrodes are prepared in a shape that matches the design of the electrode embedding member. The shape of the heater electrodes can vary, including mesh and foil forms. Furthermore, the materials used can also vary, including molybdenum and tungsten.

[0057] In the laminate firing process, the formed laminates are fired under uniaxial pressure in the direction of the laminate to form base material precursors. Although the firing conditions vary depending on the material, when using ceramics mainly composed of AlN, the pressing force is preferably 1 MPa or more. The firing temperature is preferably between 1700°C and 2000°C. The firing time is preferably between 1 hour and 12 hours, and more preferably between 1 hour and 5 hours. The firing atmosphere is, for example, a nitrogen or inert gas atmosphere, but it may also be an atmosphere such as a vacuum. As a result, one or more degreased ceramic bodies are sintered in each laminate to form a ceramic sintered body, which is then integrated to obtain multiple base material precursors.

[0058] Multiple substrate precursors include, for example, a substrate precursor that serves as a lid for a cavity, a substrate precursor in which part of the cavity is formed, a substrate precursor in which other electrodes are embedded, a substrate precursor in which a heater electrode is embedded, and a substrate precursor in which wiring is embedded. Figures 10(a) to 10(d) and 11 are schematic cross-sectional views showing one stage of the manufacturing process for the electrode embedding member. Figure 10(a) shows cross-sections of a substrate precursor 101 that serves as a lid for a cavity, a substrate precursor 102 in which part of the cavity is formed, and a substrate precursor 103 in which a heater electrode is embedded. In Figure 10, a substrate is made using three substrate precursors, but the number of substrate precursors may be two or four or more depending on the design of the electrode embedding member.

[0059] In the substrate precursor processing step, each of the multiple substrate precursors is processed as needed. For example, grooves that will become cavities after joining are formed, or holes are made at the positions where vias will be placed and filled with via material. Figure 10(b) shows a cross-section of a substrate precursor 102 in which a groove 105 that will become a cavity after joining has been formed. In Figure 10, the cavity is formed when another substrate precursor covers the groove 105, but the cavity may also be formed when grooves formed in two separate substrate precursors are combined. Using this method, cavities of various shapes can be formed.

[0060] In the substrate precursor bonding process, multiple substrate precursors are bonded together to produce a substrate. Bonding can be performed using either a bonding material or a bonding method without a bonding material. Figure 10(c) shows the arrangement of multiple substrate precursors before bonding. Figure 10(d) shows the substrate after bonding. These bonding methods can be applied to the method of bonding electrode embedding members and support members to produce a substrate holding member.

[0061] First, a bonding method using a bonding material will be described. First, prepare the bonding material and apply it to at least one end face of the substrate precursor to be bonded. The end face of the substrate precursor to be bonded should preferably have a surface roughness Ra of 1.6 μm or less, and more preferably be polished to 0.4 μm or less. The thickness of the bonding material to be applied should preferably be between 5 μm and 30 μm.

[0062] Next, multiple substrate precursors are placed and heated while applying pressure perpendicular to the substrate mounting surface. The bonding conditions vary depending on the material, but when using ceramics mainly composed of AlN, the applied pressure is preferably 5 kPa or more. The heating temperature is preferably 1500°C to 1800°C. The heating time is preferably 0.5 hours to 5 hours. The heating atmosphere is, for example, a nitrogen or inert gas atmosphere, but it may also be an atmosphere such as a vacuum. This allows multiple substrate precursors to be bonded together.

[0063] The bonding material can be anything that can bond the substrate precursors together. For example, if the substrate precursors are formed from ceramics mainly composed of AlN, the bonding material may be a paste of mixed powder containing at least Y2O3 powder in addition to AlN powder, which has the same main component. Alternatively, the bonding material may be a paste containing 90 wt% to 95 wt% AlN and 5 wt% or more Y2O3, and may also contain CaO, MgO, ZrO2, or SiO2 to adjust the temperature at which it melts during bonding, as needed.

[0064] Next, a bonding method that does not use a bonding material will be described. First, multiple substrate precursors are arranged. It is preferable that the end faces of the substrate precursors to be bonded be polished to a surface roughness Ra of 0.1 μm or less. Next, the substrates are heated while applying pressure perpendicular to the substrate mounting surface. Bonding conditions vary depending on the material, but when using ceramics mainly composed of AlN, the applied pressure is preferably 1 MPa or more. The heating temperature is preferably 1600°C to 2000°C. The heating time is preferably 0.5 hours to 6 hours. The heating atmosphere is, for example, a nitrogen or inert gas atmosphere, but it may also be an atmosphere such as a vacuum. This allows multiple substrate precursors to be bonded.

[0065] In the base material processing process, the outer shape of the base material is processed. If necessary, pin-shaped protrusions are formed. Additionally, terminal holes for connecting terminals are drilled at predetermined positions on the underside.

[0066] Then, the terminals are connected to the terminal holes using brazing material or the like. The terminals can be made of nickel, etc. The brazing material can be made of gold, etc. Figure 11 shows a cross-section of the substrate to which the terminals have been connected.

[0067] Furthermore, a ceramic calcined body manufacturing step may be included between the ceramic degreased body manufacturing step and the laminate formation step. If a ceramic calcined body manufacturing step is included, the ceramic degreased body is calcined at a predetermined temperature to produce the ceramic calcined body. This allows for higher dimensional accuracy of the electrode embedded member. The calcination conditions vary depending on the material, but when using ceramics mainly composed of AlN, the calcination temperature is preferably 1200°C to 1700°C. The calcination time is preferably 0.5 hours to 12 hours. The calcination atmosphere is preferably a nitrogen or inert gas atmosphere, but an atmosphere such as vacuum may also be used. If a calcined body manufacturing step is included, machining may be performed after the calcined body manufacturing step.

[0068] Furthermore, in the method described above, the substrate precursor is formed from a ceramic sintered body and then joined together to form the substrate. However, the substrate precursor may also be formed from a ceramic calcined body and then joined together while sintering to produce the substrate. In addition, if the structure of the cavities or wiring is simple, the substrate can also be produced by processing a degreased ceramic body, laminating it, and sintering it. When the structure of the cavities or wiring is complex, when flow channels are provided, or when high dimensional accuracy of the cavities is required, the method of joining ceramic sintered bodies is preferable.

[0069] In this way, an electrode embedding member can be manufactured that provides a temperature distribution in the radial direction of the substrate on which it is placed.

[0070] [Manufacturing method for substrate holding member] Next, a method for manufacturing a substrate holding member according to an embodiment of the present invention will be described. The method for manufacturing a substrate holding member according to an embodiment of the present invention includes an electrode embedding member preparation step, a support member molded body formation step, a support member degreasing body manufacturing step, a support member firing step, and a joining step.

[0071] In the electrode embedding member preparation step, the electrode embedding member manufactured as described above is prepared. When manufacturing the substrate holding member, the drilling of the terminal holes in the electrode embedding member may be performed after the joining step with the support member. Furthermore, it is preferable to connect the terminals after the joining step with the support member.

[0072] In the support member molded body formation process, for example, a support member molded body is formed from ceramic raw material powder mainly composed of AlN. The method for producing the ceramic raw material powder and the method for forming the support member molded body may be the same as in the ceramic molded body formation process. It is preferable that the ceramic raw material powder does not contain sintering aids.

[0073] In the process of manufacturing the degreased support member, the molded support member is degreased at a predetermined temperature and for a predetermined time to produce the degreased support member. The numerical range of the degreasing conditions for the molded support member may be the same as in the process of manufacturing the degreased ceramic body in the method for manufacturing the electrode embedded member. The process of manufacturing the degreased support member may be performed simultaneously with the process of manufacturing the degreased ceramic body.

[0074] In the support member firing process, the degreased support member is fired to create the support member that supports the ceramic substrate. The firing conditions vary depending on the material, but when using ceramics mainly composed of AlN, it is preferable to fire the support member at atmospheric pressure. The firing temperature is preferably between 1800°C and 2000°C. The firing time is preferably between 1 hour and 12 hours. The firing atmosphere is, for example, a nitrogen or inert gas atmosphere, but it may also be an atmosphere such as a vacuum.

[0075] In the joining process, the electrode embedding member and the support member are joined together. The joining method described above can be used for this joining process.

[0076] If the electrode embedding member does not have terminal holes, terminal holes will be provided after joining it to the support member. If necessary, pin-shaped protrusions will be formed. Then, the terminals will be connected to the terminal holes using brazing material. The terminals can be made of materials such as Ni. The brazing material can be made of materials such as Au brazing material.

[0077] In this way, a substrate holding member can be manufactured that provides a temperature distribution in the radial direction of the placed substrate.

[0078] [Examples and Comparative Examples] (Example 1) Example 1 is a substrate holding member, as shown in Figure 9, in which annular cavities are formed in a double concentric pattern. The base material and support member are made of ceramic sintered bodies mainly composed of aluminum nitride (AlN). The heater electrode uses a Mo mesh (wire diameter 0.1 mm) processed into an arc-based shape. The heater electrode is shaped to have an outer diameter within a range of approximately 294 mm.

[0079] The annular cavities were formed with a 20 mm width cavity centered on a circumference with a radius of 40 mm, and another 20 mm width cavity centered on a circumference with a radius of 110 mm. The Si / S value was 0.267. The cavities were positioned such that the distance between the ceiling of the cavity and the top surface of the substrate was 3 mm, and the distance between the bottom of the cavity and the bottom surface of the substrate was 10 mm.

[0080] Three substrate precursors were joined together to form an electrode embedding member, which is roughly a disc-shaped structure with a diameter of φ300 mm and a thickness of 25 mm, in which the heater electrode described above is embedded in the substrate. A support member was also prepared. The electrode embedding member and the support member were then joined together. The joining of the three substrate precursors and the joining of the electrode embedding member and the support member were performed without the use of any bonding material.

[0081] The heater electrode was connected to the terminal by drilling a terminal hole in the substrate from the bottom side and inserting a nickel terminal.

[0082] Example 2 provided a substrate holding member with three concentric annular cavities. The annular cavities were 15 mm wide and centered on circles with radii of 37.5 mm, 77.5 mm, and 127.5 mm. Otherwise, the substrate holding member was manufactured under the same conditions as in Example 1. The Si / S value was 0.323.

[0083] Example 3 provided a substrate holding member in which six concentric annular cavities were formed. The annular cavities were 10 mm wide, with their centerlines at circumferences of radii of 35 mm, 55 mm, 75 mm, 95 mm, 115 mm, and 135 mm. Otherwise, the substrate holding member was manufactured under the same conditions as in Example 1. The Si / S value was 0.453.

[0084] Example 4 provided a substrate holding member in which twelve concentric annular cavities were formed. The annular cavities were 5 mm wide and centered on the circumferences of circles with radii of 22.5 mm, 32.5 mm, 42.5 mm, 52.5 mm, 62.5 mm, 72.5 mm, 82.5 mm, 92.5 mm, 102.5 mm, 112.5 mm, 122.5 mm, and 132.5 mm. Otherwise, the substrate holding member was manufactured under the same conditions as in Example 1. The Si / S value was 0.413.

[0085] Example 5 provided a substrate holding member in which twelve concentric annular cavities were formed. The annular cavities were formed with a width of 8 mm, centered on the circumferences of circles with radii of 24 mm, 34 mm, 44 mm, 54 mm, 64 mm, 74 mm, 84 mm, 94 mm, 104 mm, 114 mm, 124 mm, and 134 mm. Otherwise, the substrate holding member was manufactured under the same conditions as in Example 1. The Si / S value was 0.674.

[0086] (Comparative Example 1) Comparative Example 1 was manufactured under the same conditions as Example 1, except that no cavity was formed.

[0087] (Evaluation method for substrate holding members) In Example 1 and Comparative Example 1, a substrate (silicon wafer) was placed on the substrate holding member, and power was applied to the heater electrode to control the temperature, setting the temperature at a radius of 75 mm of the substrate to 400°C. That is, the area around the 75 mm radius was designated as the high-temperature region, and a temperature gradient was created towards the center and the outer edge. At this time, an infrared camera installed above the substrate was used to measure the temperature distribution of the substrate. In Comparative Example 1, the temperature difference obtained by subtracting the lowest temperature from the highest temperature in a φ290 mm region excluding 5 mm from the outer edge of the substrate was 2.7°C, with the highest value at the 75 mm radius and a monotonically decreasing temperature towards the center and the outer edge. In contrast, in Example 1, the temperature was measured near the center of a straight line aligned radially from the center, near the top surface of the center line of the inner cavity, near the midpoint between the inner and outer cavities, near the top surface of the center line of the outer cavity, and near the midpoint of the region outside the outer cavity. It was then confirmed whether a larger temperature gradient was created than the overall temperature difference in Comparative Example 1.

[0088] (Evaluation of substrate holding members) The temperatures of each part in Example 1 were 394.8°C, 398.2°C, 400.0°C, 397.8°C, and 395.0°C, respectively. This confirmed that a temperature gradient of 5.2°C, larger than the overall temperature difference in Comparative Example 1, could be created along a straight line aligned radially from the center, and that a temperature distribution with a high-temperature area in the radial direction (around a radius of 75 mm) of the substrate could be provided.

[0089] Furthermore, in Examples 2 to 5, when the temperature around a radius of 75 mm was measured and the temperature difference between the center or outer edge was measured, the temperature differences were 6.7°C, 8.0°C, 11.8°C, and 12.7°C, respectively. This confirmed that a larger temperature gradient could be created along a straight line aligned radially from the center than the temperature difference across the entire surface in Comparative Example 1, thus enabling a temperature distribution in the radial direction of the substrate. Comparing Examples 4 and 5, which had the same number of cavities, Example 5, which had a larger Si / S value, was able to create a larger temperature gradient. This is presumed to be because the larger Si / S value resulted in a greater effect of the cavities in suppressing heat transfer.

[0090] Furthermore, as shown in Example 5, it was found that manufacturing can be carried out without problems even if the wall between adjacent cavities is 2 mm thick. This confirmed that the Si / S value can be increased to approximately 0.7.

[0091] Based on the above, it has been confirmed that the electrode embedding member and substrate holding member of the present invention can provide a sharp temperature gradient to the substrate on which they are placed.

[0092] The present invention is not limited to the embodiments described above, and it goes without saying that it extends to various modifications and equivalents that fall within the spirit and scope of the present invention. Furthermore, the structure, shape, number, position, size, etc., of the components shown in each drawing are for illustrative purposes only and may be modified as appropriate. [Explanation of Symbols]

[0093] 10 Base material 12 Top side 14 Bottom side 16 center 20 Heater electrodes 24 Heater electrode layer 30 cavities 40 Pin-shaped protrusions Terminals 50 and 51 52 terminal holes 70 Other electrodes 100 Electrode embedding member 101, 102, 103 Base material precursor 105 Groove 110 Support member 200 Substrate holding member

Claims

1. An electrode embedding member, A substrate formed from a ceramic sintered body, The substrate comprises a heater electrode embedded in the substrate, The substrate has one or more cavities located inside the substrate that overlap with the heater electrode in the vertical direction. In the vertical cross-section of the substrate, the cavity is located closer to the upper surface of the substrate than the heater electrode layer in which the heater electrode is embedded. The electrode embedding member is characterized in that the cavity, when viewed through from the top surface, includes an annular shape.

2. The one or more cavities are a plurality of cavities located inside the substrate, in a position that overlaps with the heater electrode in the vertical direction, The electrode embedding member according to claim 1, characterized in that the plurality of cavities are arranged concentrically in the shape as viewed from the top surface.

3. The electrode embedding member according to claim 1, characterized in that when the sum of the areas of the one or more cavities viewed from the upper surface is Si and the area of ​​the substrate mounting surface of the base material is S, 0.25 ≤ Si / S ≤ 0.

7.

4. The electrode embedding member according to claim 2, characterized in that when the sum of the areas of the plurality of cavities viewed from the upper surface is Si and the area of ​​the substrate mounting surface of the base material is S, then 0.25 ≤ Si / S ≤ 0.

7.

5. A substrate holding member, An electrode embedding member according to any one of claims 1 to 4, A substrate holding member characterized by comprising a support member joined to the lower surface of the substrate and supporting the electrode embedding member.

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