Substrate holding member and method for manufacturing the substrate holding member

Abstract

To provide a substrate holding member capable of reducing the number of terminals for supplying a power to each electrode, in a substrate holding member with a plurality of buried electrodes.SOLUTION: A substrate holding member 100 comprises a ceramic base material 110. In the ceramic base material 110, three electrodes 121 to 123, three conductive members 131 to 133, five connection portions 141 to 145, four terminals 151 to 154, and two lands 171 and 172 are buried.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a substrate holding member for holding a substrate such as a silicon wafer and a method for manufacturing the substrate holding member.

Background Art

[0002] Patent Document 1 discloses a ceramic heater in which two heating resistors corresponding to two different heating areas are embedded as an example of a substrate holding member for holding a substrate such as a wafer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ceramic heater described in Patent Document 1, two terminals are connected to each of the two heating resistors to supply power to the two heating resistors. Therefore, a number of terminals twice the number of heating resistors is required.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a technique capable of reducing the number of terminals for supplying power to each electrode in a substrate holding member in which a plurality of electrodes are embedded.

Means for Solving the Problems

[0006] According to an aspect of the present invention, a ceramic base material having an upper surface and a lower surface facing the upper surface in the vertical direction, a plurality of electrodes embedded in the ceramic base material, at least one conductive member embedded in the ceramic base material, Multiple connection parts, each of which one end is electrically connected to one of the multiple electrodes, A land electrically connected to at least one conductive member, Multiple terminals, At least one terminal is electrically connected to the land, and the remaining terminals are One of the aforementioned multiple electrodes, or The at least one conductive member and It comprises multiple electrically connected terminals, Of the aforementioned multiple connection parts, The connection portion connected to the at least one conductive member and , among the plurality of terminals, connected to at least one conductive member terminals and The resistance value between them 、 The resistance value between the ends of the plurality of electrodes Which of the resistance values Smaller than, The number of the aforementioned multiple terminals is less than twice the number of the aforementioned multiple electrodes. The land is at a first position on a horizontal plane perpendicular to the vertical direction, at least one terminals and The aforementioned overlapping in the vertical direction, The land is at a second position different from the first position on the horizontal plane, A substrate holding member is provided, characterized in that it overlaps one of the connection portions and one of the electrodes in the vertical direction, or overlaps with at least one conductive member in the vertical direction. [Effects of the Invention]

[0007] In the above embodiment, the number of terminals is less than twice the number of electrodes. This reduces the space required to arrange the terminals. Furthermore, the resistance between the portion of at least one conductive member connected to the terminal and the connection portion is equal to the resistance between the terminals. The resistance value is smaller than that of the conductive material. As a result, even when the electrode and terminal are connected via a conductive material and a connecting part, heat generation in the conductive material can be minimized. In addition, by providing a land, the resistance of the part where the land is provided can be reduced, so heat generation can be suppressed especially in the part where the land is provided and between the land and the connecting part.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a perspective view of a substrate holding member 100. [Figure 2] FIG. 2 is a diagram schematically showing a longitudinal section of a ceramic substrate 110. [Figure 3] FIG. 3(a) is a diagram schematically showing a cross-section of the ceramic substrate 110 on a virtual plane A, and FIG. 3(b) is a diagram schematically showing a cross-section of the ceramic substrate 110 on a virtual plane B. [Figure 4] FIG. 4 is an explanatory diagram showing a case where a bonding convex portion 114 is provided on the lower surface 113 of the ceramic substrate 110. [Figure 5] FIGS. 5(a) to 5(e) are diagrams showing the process flow of a method for manufacturing the ceramic substrate 110. [Figure 6] FIGS. 6(a) to 6(e) are diagrams showing the process flow of another method for manufacturing the ceramic substrate 110. [Figure 7] FIG. 7 is a diagram corresponding to FIG. 2 of a ceramic substrate 210 in which four electrodes 221 to 224 are embedded. [Figure 8] FIG. 8(a) is a diagram corresponding to FIG. 3(a) of a ceramic substrate 210 in which four electrodes 221 to 224 are embedded, and FIG. 8(b) is a diagram corresponding to FIG. 3(b) of a ceramic substrate 210 in which four electrodes 221 to 224 are embedded. [Figure 9] FIG. 9 is a flowchart showing a method for manufacturing the substrate holding member 100. [Figure 10] FIG. 10(a) is a diagram corresponding to FIG. 6(c) of the ceramic substrate 110, and FIG. 10(b) is a diagram corresponding to FIG. 6(e) of the ceramic substrate 110.

Embodiments for Carrying Out the Invention

[0009] The substrate holding member 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The substrate holding member 100 according to the present embodiment is a ceramic heater used for heating a semiconductor wafer such as a silicon wafer (hereinafter simply referred to as wafer 10). In the following description, the vertical direction 5 is defined based on the state in which the substrate holding member 100 is installed so as to be usable (the state in FIG. 1). As shown in FIG. 1, the substrate holding member 100 according to the present embodiment includes a ceramic base material 110 and a shaft 160. Further, as shown in FIGS. 2, 3(a), and 3(b), electrodes 121 to 123, conductive members 131 to 133, connection portions 141 to 145, terminals 151 to 154, and lands 171 and 172 are embedded in the ceramic base material 110. Further, as shown in FIG. 3(b), in the vicinity of the terminals 151 to 153, passages TC1 to TC3 for arranging temperature sensors such as thermocouples at various locations of the substrate holding member are provided.

[0010] <Ceramic base material 110> The ceramic base material 110 is a member having a circular plate shape with a diameter of 12 inches (about 300 mm) and a thickness of 25 mm. As shown in FIG. 1, the wafer 10 to be heated is placed on the upper surface 111 of the ceramic base material 110. In FIG. 1, the wafer 10 and the ceramic base material 110 are shown separated from each other for easy viewing of the drawing. The ceramic base material 110 can be formed of, for example, a ceramic sintered body such as aluminum nitride, silicon carbide, alumina, or silicon nitride.

[0011] FIG. 2 is a diagram schematically showing a longitudinal section of the ceramic base material 110. The virtual planes A and B shown by dotted lines in FIG. 2 are both horizontal planes orthogonal to the vertical direction 5. Virtual plane A In the vertical direction 5, B is located between the upper surface 111 and the lower surface 113 of the ceramic substrate 110, and virtual surface A is located above virtual surface B. Figure 3(a) is a schematic representation of the cross-section of the ceramic substrate 110 at virtual surface A, and Figure 3(b) is a schematic representation of the cross-section of the ceramic substrate 110 at virtual surface B. As shown in Figures 2, 3(a) and 3(b), three electrodes 121-123, three conductive members 131-133, five connection parts 141-145, four terminals 151-154, and two lands 171 and 172 are embedded inside the ceramic substrate 110.

[0012] <Electrodes 121~123> Electrodes 121 to 123 will be described with reference to Figures 2, 3(a), and 3(b). Electrodes 121 to 123 are formed by cutting a heat-resistant metal (a high melting point metal with a melting point of 2000°C or higher) such as a mesh or foil woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten into strips. When electrodes 121 to 123 are used as heater electrodes, it is preferable to use a mesh to ensure sufficient resistance. The resistance of electrodes 121 to 123 is preferably about 2Ω to 20Ω. Electrodes 121 to 123 can be formed, for example, by cutting a Mo mesh (wire diameter 0.1 mm, plain weave #50 mesh) material into a predetermined pattern. The purity of the tungsten and molybdenum is preferably 99% or higher. The thickness of electrodes 121 to 123 is preferably 0.03 mm to 0.2 mm, excluding the wire intersections. Furthermore, the width of the strip-shaped electrodes 121 to 123 is preferably 2.5 mm to 20 mm, and more preferably 5 mm to 15 mm. In this embodiment, electrodes 121 to 123 are cut into the shapes shown in Figures 3(a) and 3(b), respectively, but the shapes of electrodes 121 to 123 are not limited to these and can be changed as appropriate. In addition to electrodes 121 to 123, at least one of the following may be embedded inside the ceramic substrate 110: an electrostatic chuck electrode for attracting the wafer 10 to the upper surface 111 by Coulomb force, and a plasma electrode for generating plasma above the ceramic substrate 110.

[0013] As shown in Figure 3(a), electrode 121 is positioned approximately in the center of the virtual surface A of the ceramic substrate 110, and electrode 122 is positioned to surround the outside of electrode 121. Electrode 121 includes a substantially annular ring portion 121a and two linear portions 121b extending in a straight line. The ring portion 121a has an open annular shape at the top of Figure 3(a), and the two linear portions 121b extend downward from both ends of the open annular ring portion 121 in Figure 3(a). The electrode 122 includes two semicircular annular inner ring portions 122a arranged to surround the outside of the ring portion 121a of the electrode 121, a substantially annular outer ring portion 122b arranged to surround the outside of the two inner ring portions 122a, and two linear portions 122c extending linearly to connect the two inner ring portions 122a and the outer ring portion 122b. The outer ring portion 122b has an annular shape that is open on the left side in Figure 3(a). The two linear portions 122c extend in the left-right direction in Figure 3(a) to connect both ends of the outer ring portion 122b and the two inner ring portions 122a, respectively.

[0014] As shown in Figure 3(b), the electrode 123 is positioned on the outer periphery of the virtual surface B of the ceramic substrate 110. The electrode 123 includes a roughly annular ring portion 123a with an open top, as shown in Figure 3(b). When virtual surfaces A and B are superimposed, the electrode 123 is positioned outside the electrodes 121 and 122, and electrodes 121, 122, and 123 are arranged concentrically so as not to overlap each other. In other words, the outer diameter of electrode 123 is larger than the outer diameters of electrodes 121 and 122. As a result, the upper surface 111 of the ceramic substrate 110 is divided into three zones corresponding to electrodes 121, 122, and 123, respectively (a zone overlapping with electrode 121 in the vertical direction, a zone overlapping with electrode 122, and a zone overlapping with electrode 123).

[0015] <Conductive members 131-133> Next, conductive members 131 to 133 will be described with reference to Figures 2, 3(a), and 3(b). As shown in Figure 3(b), conductive members 131 to 133 are arranged on the same virtual plane B. Conductive members 131 to 133 are arranged so as not to overlap each other, occupying a roughly circular area inside electrode 123. Conductive member 131 is roughly semicircular in shape and occupies approximately the left half of the area inside electrode 123 in Figure 3(b). A rectangular notch 131C is formed in the approximate center of the right side of conductive member 131. Conductive member 132 has a sector shape with a central angle of approximately 90° and is positioned to the right of conductive member 131, facing the lower half of conductive member 131. A rectangular notch 132C is formed in the approximate center of the upper side of conductive member 132. The conductive member 133 has a sector shape with a central angle of approximately 90° and is positioned to the right of the conductive member 131, facing the upper half of the conductive member 131.

[0016] The total area of ​​conductive members 131 to 133 is preferably 40% or more, and more preferably 55% or more, of the area of ​​the virtual circle defined by the outer diameter of electrode 123, which has the largest outer diameter among electrodes 121 to 123. Furthermore, the areas of conductive member 131, conductive member 132, and conductive member 133 are each preferably 40% or more, and more preferably 55% or more, of the area obtained by dividing the area of ​​the virtual circle by the number of electrodes 121 to 123 (3).

[0017] The conductive members 131 to 133 are formed, like the electrodes 121 to 123, by cutting a heat-resistant metal (high melting point metal), such as a mesh or foil woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten, into a predetermined shape. It is preferable that the conductive members 131 to 133 are formed from the same metal material as the electrodes 121 to 123. In this case, manufacturing becomes easier and distortion caused by differences in shrinkage rates during firing can be suppressed. As described later, the conductive member 131 is connected to the connection portion 144 (see Figure 3(b)). The conductive member 131 is also connected to the terminal 152 via the land 171. The resistance between the portion of the conductive member 131 connected to the land 171 and the connection portion 144 is approximately 0.001Ω to 1Ω, which is smaller than the resistance of either of the electrodes 121 to 123. The conductive member 132 is connected to terminal 153 and connection portion 143 (see Figure 3(b)). The resistance between the portion of the conductive member 132 connected to terminal 153 and connection portion 143 is approximately 0.001Ω to 1Ω, which is smaller than the resistance of any of the electrodes 121 to 123. However, in this embodiment, a notch 132C is formed in the conductive member 132 to secure space for installing the temperature sensor TC3. As a result, the resistance between the portion of the conductive member 132 connected to terminal 153 and connection portion 143 is slightly higher than when the notch 132C is not present. The conductive member 133 is connected to terminal 154 and connection portions 141, 142, and 145 (see Figure 3(b)). The resistance between the portion of the conductive member 133 connected to terminal 154 and the connection portion 141, the resistance between the portion of the conductive member 133 connected to terminal 154 and the connection portion 142, and the resistance between the portion of the conductive member 133 connected to terminal 154 and the connection portion 145 are all approximately 0.001Ω to 1Ω, which is smaller than the resistance of electrodes 121 to 123.

[0018] <Connection section 141~145> Next, the connection portions 141 to 145 will be explained with reference to Figures 2, 3(a), and 3(b). As shown in Figure 2, connection portions 141 and 142 are positioned between virtual plane A and virtual plane B. The lower ends of connection portions 141 and 142 are electrically connected to the conductive member 133. In the following explanation, electrically connected will simply be referred to as connected. The upper end of connection portion 141 is connected to the straight portion 121b of electrode 121, and the upper end of connection portion 142 is connected to the ring portion 122a of electrode 122. Connection portion 143 is also connected Similar to parts 141 and 142, it is positioned between virtual plane A and virtual plane B (see Figures 3(a) and 3(b)). The lower end of connecting part 143 is connected to the conductive member 132, and the upper end of connecting part 143 is connected to the ring portion 122a of electrode 122. These connecting parts 141 to 143 are via structures that connect virtual plane A and virtual plane B. Also, as shown in Figure 3(b), connecting parts 144 and 145 are positioned on virtual plane B. One end of connecting parts 144 and 145 (the upper end in Figure 3(b)) is connected to electrode 123. The other end of connecting part 144 (the lower end in Figure 3(b)) is connected to the conductive member 131, and the other end of connecting part 145 (the lower end in Figure 3(b)) is connected to the conductive member 133. The connecting portions 144 and 145 are formed from the same material as the multiple electrodes 121-123 and conductive members 131-133 (a mesh or foil woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten). As a result, the connecting portion 144 is integrated with the conductive member 131 and electrode 123, and the connecting portion 145 is integrated with the conductive member 133 and electrode 123.

[0019] <Terminals 151-154> Next, terminals 151 to 154 will be described with reference to Figures 2, 3(a), and 3(b). As shown in Figure 2, the upper end of terminal 151 is connected to the straight portion 121b of electrode 121 (see Figure 3(a)). The upper end of terminal 151 may be in contact with the straight portion 121b of electrode 121. Alternatively, the upper end of terminal 151 and the straight portion 121b of electrode 121 may be in contact via a pellet formed of tungsten, molybdenum, or an alloy containing at least one of these. The same applies to terminals 152 to 154, which will be described later. Terminal 151 extends downward from the straight portion 121b of electrode 121 and further extends downward through the hollow portion of the hollow cylindrical portion 161 of shaft 160, which will be described later. As shown in Figure 3(b), a rectangular notch 131C is formed in the approximate center of the right side of the conductive member 131 located on the virtual plane B. Since terminal 151 extends downward through the portion of the virtual surface B where the notch 131C is formed, terminal 151 and the conductive member 131 are not electrically connected.

[0020] As shown in Figure 2, the upper end of terminal 154 is connected to the conductive member 133 located on virtual plane B. Terminal 154 extends downward from the conductive member 133 and, like terminal 151, extends downward through the hollow portion of the cylindrical part 161 of shaft 160. The upper end of terminal 152 is connected to the land 171 located on virtual plane B (see Figure 3(b)). Terminal 152 extends downward from the land 171 and, like terminal 151, extends downward through the hollow portion of the cylindrical part 161 of shaft 160. Also, similar to terminal 151, terminal 152 extends downward through the portion of virtual plane B where the notch 131C is formed. Therefore, terminal 152 does not directly contact the conductive member 131. Furthermore, the upper end of terminal 153 is connected to the conductive member 132 located on virtual plane B (see Figure 3(b)). Terminal 153 extends downward from the conductive member 132 and, like terminal 151, extends downward through the hollow portion of the cylindrical part 161 of the shaft 160. In this way, four terminals 151 to 154 are arranged in the hollow portion of the cylindrical part 161 of the shaft 160. In the region where the notch 131C is formed, passages TC1 and TC2 are provided near terminals 151 and 152, respectively, and temperature sensors such as thermocouples are arranged through passages TC1 and TC2. Similarly, in the region where the notch 132C is formed, passage TC3 is provided near terminal 153, and a temperature sensor is arranged through passage TC3.

[0021] <Land 171, 172> As shown in Figures 2 and 3(b), the land 171 has a roughly rectangular, plate-like outer shape. The land 171 extends in the left-right direction in Figure 3(b) so as to cover the upper end of the terminal 152 and the conductive member 131 on the virtual plane B. In Figure 3(b), the left end of the land 171 is conductive. The land 171 is connected to member 131, and its right end is connected to the upper surface of terminal 152. As will be described later, the land 171 and terminal 152 may be connected via a pellet made of tungsten, molybdenum, or an alloy containing at least one of these. The land 172 has a roughly L-shaped plate-like outer shape. In the virtual plane B, the land 172 extends downward in Figure 3(b) from a position covering the upper end of terminal 153, avoiding the notch 132C, and then extends to the right. In Figure 3(b), the left-right position of the right end of the land 172 is approximately the same as the left-right position of the connection portion 143.

[0022] Land 171 is provided to electrically connect terminal 152 and conductive member 131. As described later, land 172 is provided to reduce the resistance between terminal 153 and connection portion 143. Lands 171 and 172 are preferably made of a high melting point metal with a melting point of 2000°C or higher. In particular, they are preferably made of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten. The width of lands 171 and 172 is preferably about 1 mm to 10 mm, and the thickness is preferably about 0.1 mm to 4 mm. Land 171 has a linear shape and land 172 has a polygonal linear shape, but they do not necessarily have to be such shapes; for example, they may be curved.

[0023] <Shaft 160> Next, the shaft 160 will be described with reference to Figures 1, 2, and 4. As shown in Figures 1 and 2, the shaft 160 is connected to the lower surface 113 of the ceramic substrate 110. The shaft 160 has a hollow, substantially cylindrical cylindrical portion 161 and a large-diameter portion 162 (see Figure 1) provided below the cylindrical portion 161. The large-diameter portion 162 has a larger diameter than the diameter of the cylindrical portion 161. In the following description, the longitudinal direction of the cylindrical portion 161 is defined as the longitudinal direction 6 of the shaft 160. As shown in Figure 1, in the usage state of the substrate holding member 100, the longitudinal direction 6 of the shaft 160 is parallel to the vertical direction 5.

[0024] As shown in Figure 2, a through hole extending in the longitudinal direction 6 (see Figure 1) is formed inside the cylindrical portion 161 of the shaft 160 (the region inside the inner diameter), and as described above, terminals 151 to 154 for supplying power to electrodes 121 to 123 are arranged therein. As a result, power is supplied to electrodes 121 to 123 via terminals 151 to 154.

[0025] Furthermore, a projection 114 (hereinafter referred to as the joining projection 114) for joining with the shaft 130 can be provided on the lower surface 113 of the ceramic substrate 110 (see Figure 4). The shape of the joining projection 114 is preferably the same as the shape of the upper surface of the shaft 160 to be joined, and the diameter of the joining projection 114 is preferably 100 mm or less. The height of the joining projection 114 (height from the lower surface 113) should be 0.2 mm or more, and preferably 1 mm or more. There is no particular upper limit on the height, but considering the ease of manufacturing, the height of the joining projection 114 is preferably 20 mm or less. Also, the lower surface of the joining projection 114 is preferably parallel to the lower surface 113 of the ceramic substrate 100. The surface roughness Ra of the lower surface of the joining projection 114 should be 1.6 μm or less. Furthermore, the surface roughness Ra of the lower surface of the joining projection 114 is preferably 0.4 μm or less, and more preferably 0.2 μm or less.

[0026] The upper surface of the cylindrical portion 161 is fixed to the lower surface 113 of the ceramic base material 110 (or the lower surface of the joining projection 114 if one is provided). The shaft 160 may be formed from a ceramic sintered body such as aluminum nitride, silicon carbide, alumina, or silicon nitride, similar to the ceramic base material 110. Alternatively, to improve heat insulation, it may be formed from a material with lower thermal conductivity than the ceramic base material 110. Furthermore, the upper surface of the cylindrical portion 161 has an enlarged diameter portion similar to the large diameter portion 162 provided below the cylindrical portion 161. 163 may be provided.

[0027] <Method for manufacturing the substrate holding member 100> Next, the manufacturing method of the substrate holding member 100 will be described. In the following description, the case in which the ceramic substrate 110 and the shaft 160 are formed of aluminum nitride will be used as an example. However, for the sake of clarity, it will be assumed that the ceramic substrate 110 has a conductive member 132, a connecting member 143, an electrode 122, and a land 172 embedded within it.

[0028] First, the method for manufacturing the ceramic substrate 110 will be described. As shown in Figure 5(a), granulated powder P, mainly composed of aluminum nitride (AlN) powder, is placed in a carbon bed mold 501 and pre-pressed with a punch 502. Preferably, the granulated powder P contains 5 wt% or less of a sintering aid (e.g., Y2O3). Next, as shown in Figure 5(b), conductive members 132 cut to a predetermined shape are placed on top of the pre-pressed granulated powder P. The conductive members 132 are placed parallel to the surface perpendicular to the pressing direction (the bottom surface of the bed mold 501). At this time, pellets made of tungsten, molybdenum, or an alloy containing at least one of these may be embedded in a position that overlaps with the terminal 153 (see Figure 3(b)).

[0029] Furthermore, as shown in Figure 5(b), a preform 143P is placed on the conductive member 132. The preform 143P is a porous material formed from tungsten, molybdenum, or an alloy containing at least one of these. Also, as shown in Figure 5(b), a land 172 is placed on the conductive member 132.

[0030] As shown in Figure 5(c), granulated powder P is further added to the bed mold 501 so as to cover the conductive member 132, land 172 and preform 143P, and after temporary pressing with the punch 502 in the same manner as described above, the electrode 122 is placed on the preform 143P. At this time, pellets made of tungsten, molybdenum, or an alloy containing at least one of these may be embedded in a position overlapping with the terminal 153 (see Figure 3(b)). If pellets are embedded, a paste of high-melting-point metal powder such as tungsten or molybdenum may be applied between the conductive member 132 and the pellets, and between the electrode 122 and the pellets, if necessary. This can improve the adhesion between the conductive member 132 and the pellets, and between the electrode 122 and the pellets.

[0031] Next, as shown in Figure 5(d), more granulated material P is added to the bed-type mold 501 so as to cover the electrode 122, and the granulated powder P with the conductive member 132, land 172, preform 143P and electrode 122 embedded in it is fired while being pressed. The pressure applied during firing is preferably 1 MPa or more. It is also preferable to fire at a temperature of 1800°C or higher. At this time, by firing under a predetermined pressure applied to the preform 143P, the porous preform 143P becomes a dense via structure, forming the connection portion 143. Note that it is not always necessary to use a porous preform 143P. A via structure can also be formed by creating a predetermined hole at the position where the preform 143P will be placed, filling the hole with a paste containing tungsten or molybdenum, and firing it. Next, as shown in Figure 5(e), blind holes are machined up to the conductive member 132 in order to form the terminal 153. If pellets are to be buried, it is sufficient to drill blind holes leading up to the pellets.

[0032] The ceramic substrate 110 can also be manufactured by the following method. As shown in Figure 6(a), a binder is added to granulated aluminum nitride powder P and CIP molding is performed, and the resulting discs are processed to produce multiple molded bodies 510 of aluminum nitride (see Figure 9: process S1). Next, as shown in Figure 6(b), the molded bodies 510 are degreased, and the binder is removed. Remove.

[0033] Prepare the conductive member 132, the land 172, and the electrode 122 (see Figure 9: step S2). As shown in Figure 6(c), recesses 511 for embedding the conductive member 132, the land 172, and the electrode 122, and through holes for inserting the preform 143P are formed in the degreased molded body 510 (see Figure 9: step S3). The recesses 511 and through holes may be formed in the molded body 510 in advance.

[0034] A conductive member 132 is placed in a recess 511 of a molded body 510 (see Figure 9: step S4). A land 172 and an electrode 122 are placed in a recess 511 of another molded body 510 (see Figure 9: step S5). A preform 143P is placed in a through hole (see Figure 9: step S6). Then, multiple molded bodies 510 are stacked (see Figure 9: step S7). The land 172 is positioned so as to contact the conductive member 132 when the multiple stacked bodies 510 are stacked. In addition, pellets made of tungsten, molybdenum, or an alloy containing at least one of these may be embedded in a position that overlaps with the terminal 153 (see Figure 3(b)). If pellets are embedded, a paste of high-melting-point metal powder such as tungsten or molybdenum may be applied between the conductive member 132 and the pellet, and between the electrode 122 and the pellet, if necessary. This improves the adhesion between the conductive member 132 and the pellet, and between the electrode 122 and the pellet. Next, as shown in Figure 6(d), the stacked molded bodies 510 are fired in a pressed state (uniaxial hot press firing) to produce a fired body (see Figure 9: step S8). The pressure applied during firing is preferably 1 MPa or more. It is also preferable to fire at a temperature of 1800°C or higher. At this time, as in the above-described step, the preform 143P is fired under a predetermined pressure, causing the porous preform 143P to form a dense via structure and the connection portion 143 to be formed. After producing the fired body, blind holes are drilled up to the conductive member 132 to form the terminal 153, as in the above-described step (see Figure 9: step S9). This exposes the portion of the conductive member 132 that overlaps with the land 172. If pellets are embedded, blind holes should only be drilled up to the pellets.

[0035] The upper surface 111 of the ceramic substrate 110 formed in this manner is then subjected to external shaping. The lower surface 113 of the ceramic substrate 110 may be provided with a joining projection 114 (see Figure 4) that protrudes from the lower surface 113. Then, the shaft 160 is joined to the ceramic substrate 110 as described later (see Figure 9: process S10).

[0036] Next, the manufacturing method of the shaft 160 and the method of joining the shaft 160 to the ceramic substrate 110 will be described. First, granulated aluminum nitride powder P with several wt% binder added is molded under hydrostatic pressure (approximately 1 MPa) to process the molded body into a predetermined shape. The outer diameter of the shaft 160 is approximately 30 mm to 100 mm. A flange portion 163 having a diameter larger than the outer diameter of the cylindrical portion 161 may be provided at the end face of the cylindrical portion 161 of the shaft 160 (see Figure 4). The length of the cylindrical portion 161 can be, for example, 50 mm to 500 mm. After processing the molded body into a predetermined shape, the molded body is fired in a nitrogen atmosphere. For example, it is fired at a temperature of 1900°C for 2 hours. Then, the shaft 160 is formed by processing the sintered body into a predetermined shape after firing. The upper surface of the cylindrical portion 161 and the lower surface 113 of the ceramic substrate 110 can be fixed by diffusion bonding under a uniaxial pressure of 1 MPa or higher at a temperature of 1600°C or higher. In this case, the surface roughness Ra of the lower surface 113 of the ceramic substrate 110 is preferably 0.4 μm or less, and more preferably 0.2 μm or less. Alternatively, the upper surface of the cylindrical portion 161 and the lower surface 113 of the ceramic substrate 110 can be joined using a bonding agent. As a bonding agent, for example, an AlN bonding paste containing 10 wt% Y2O3 can be used. For example, the above AlN bonding paste can be applied to the interface between the upper surface of the cylindrical portion 161 and the lower surface 113 of the ceramic substrate 110 to a thickness of 15 μm, and then applied to the upper surface 111. The two parts can be joined by applying a force of 5 kPa in the perpendicular direction (longitudinal direction 6 of the shaft 130) while heating at a temperature of 1700°C for 1 hour. Alternatively, the upper surface of the cylindrical part 161 and the lower surface 113 of the ceramic base material 110 can be fixed together by screwing, brazing, or the like.

[0037] <Power supply path for electrodes 121-123> As shown in Figures 2 and 3(a), terminal 151 is connected to one end of electrode 121 (the straight section 121b on the left in Figure 3(a)). The other end of electrode 121 (the straight section 121b on the right in Figure 3(a)) is connected to connection portion 141. As shown in Figure 3(b), connection portion 141 is connected to conductive member 133, and conductive member 133 is further connected to terminal 154. This forms an electrical circuit from terminal 151 through electrode 121, connection portion 141, conductive member 133, to terminal 154. By connecting an external power supply to terminals 151 and 154, with terminal 154 as the ground terminal, current can be supplied to electrode 121. In other words, conductive member 133 is connected to ground.

[0038] As shown in Figure 3(b), terminal 153 is connected to conductive member 132, and conductive member 132 is connected to connection portion 143. As shown in Figure 3(a), connection portion 143 is connected to one end of electrode 122, and the other end of electrode 122 is connected to connection portion 142. As shown in Figure 3(b), connection portion 142 is connected to conductive member 133, and conductive member 133 is further connected to terminal 154. This forms an electrical circuit from terminal 153 through conductive member 132, connection portion 143, electrode 122, connection portion 142, conductive member 133 to terminal 154. As a result, by connecting an external power supply to terminals 153 and 154 with terminal 154 as the ground terminal, current can be supplied to electrode 122. In other words, conductive member 133 is connected to ground. Also, conductive member 132, which is arranged in the same plane as conductive member 133, is connected to an external power supply.

[0039] Furthermore, a rectangular notch 132C extending downward in Figure 3(b) is formed between the portion of the conductive member 132 connected to terminal 153 and the portion connected to connection portion 143. As described above, by providing the notch 132C, space for placing the temperature sensor TC3 near terminal 153 can be easily secured. On the other hand, the current cannot flow linearly along the shortest distance between the portion of the conductive member 132 connected to terminal 153 and the portion connected to connection portion 143, and will flow to avoid the notch 132C. Therefore, in this embodiment, the resistance value between the portion of the conductive member 132 connected to terminal 153 and the portion connected to connection portion 143 is higher than in the case where the notch 132C is not provided. For this reason, in this embodiment, a land 172 is placed on the conductive member 132 so as to avoid the notch 132C. As described above, current can flow through the land 172 between the portion of the conductive member 132 connected to terminal 153 and the portion connected to connection portion 143. This makes it possible to reduce the resistance between the portion connected to terminal 153 and the portion connected to connection portion 143 compared to the case where the land 172 is not provided.

[0040] As shown in Figure 3(b), terminal 152 is connected to one end of land 171, and the other end of land 171 is connected to conductive member 131. Conductive member 131 is connected to connection portion 144. Furthermore, connection portion 144 is connected to one end of electrode 123, and the other end of electrode 123 is connected to connection portion 145. Connection portion 145 is connected to conductive member 133, and conductive member 133 is further connected to terminal 154. Thus, an electrical circuit is formed from terminal 152 through land 171, conductive member 131, connection portion 144, electrode 123, connection portion 145, conductive member 133 to terminal 154. By connecting an external power supply to terminals 153 and 154, with terminal 154 as the ground terminal, current can be supplied to electrode 123. In other words, conductive member 133 is connected to ground. Conductive member 131, which is arranged in the same plane as conductive member 133, is connected to an external power supply.

[0041] <Effects of the Embodiment> In the above embodiment, the substrate holding member 100 comprises a ceramic substrate 110, electrodes 121-123, conductive members 131-133, connection portions 141-145, terminals 151-154, and lands 171 and 172. The electrodes 121-123, conductive members 131-133, connection portions 141-145, and lands 171 and 172 are embedded in the ceramic substrate 110. Connection portion 141 connects electrode 121 and conductive member 133, connection portion 142 connects electrode 122 and conductive member 133, connection portion 145 connects electrode 123 and conductive member 133, connection portion 143 connects electrode 122 and conductive member 132, and connection portion 144 connects electrode 123 and conductive member 131. Terminal 151 is connected to electrode 121, terminal 152 is connected to land 171, terminal 153 is connected to conductive member 132, and terminal 154 is connected to conductive member 133. Land 171 overlaps terminal 152 in the vertical direction at a first position (the right end of land 171 in this embodiment), and overlaps conductive member 131 in the vertical direction at a second position different from the first position (the left end of land 171 in this embodiment). At this time, land 171 can electrically connect terminal 152 and conductive member 131.

[0042] By connecting terminals to both ends of each electrode, power can be supplied to the electrodes from an external power source through the two terminals. However, in this case, twice the number of terminals as the number of electrodes are required. In contrast, in the above embodiment, the conductive member 133 has a connection portion 141 connected to electrode 121, a connection portion 142 connected to electrode 122, and a connection portion 145 connected to electrode 123. Furthermore, a terminal 154 is connected to the conductive member 133. Therefore, multiple electrodes 121 to 123 are connected to one terminal 154 via one conductive member 133. With this configuration, the number of terminals 151 to 154 (4) can be less than twice the number of electrodes 121 to 123 (3). This reduces the space required to arrange multiple terminals. Also, since electrodes and terminals can be connected via conductive members, lands, and connection portions, the degree of freedom in terminal placement can be increased compared to the case where electrodes and terminals are connected without conductive members, lands, and / or connection portions. For example, as in this embodiment, the terminals 151 to 154 can be gathered near the center of the lower surface 113 of the ceramic substrate 110 so that all of the terminals 151 to 154 pass through the through-hole of the shaft 160.

[0043] In the above embodiment, the resistance between the portion of land 171 connected to terminal 152 and the connection portion 144 is smaller than the resistance of any of the electrodes 121 to 123. The resistance between the portion of conductive member 132 connected to terminal 153 and the connection portion 143 is smaller than the resistance of any of the electrodes 121 to 123. The resistance between the portion of conductive member 133 connected to terminal 154 and the connection portion 141 is smaller than the resistance of the electrodes 121 to 123. Similarly, the resistance between the portion of conductive member 133 connected to terminal 154 and the connection portion 142, and the resistance between the portion connected to terminal 154 and the connection portion 145 are smaller than the resistance of the electrodes 121 to 123. As a result, even when the electrodes and terminals are not directly connected, heat generation between the electrodes and terminals can be minimized.

[0044] The land 172 extends in an L-shape from a first position (the upper end of the land 172 in this embodiment) to a second position different from the first position (the right end of the land 172 in this embodiment). At the first position, the land 172 overlaps the terminal 153 in the vertical direction. As described above, the land 172 can form a bypass for the current flowing from the first position to the second position in the conductive member 132. In other words, if the land 172 is not formed, the current can flow from the first position to the second position through the conductive member 132. When the land 172 is formed on the conductive member 132, the current can flow from the first position to the second position through the conductive member 132 and also through the land 172. Therefore, the resistance value between the first position and the second position can be reduced. Furthermore, the thickness of the land 172 is greater than the thickness of the conductive member 132. This also contributes to lowering the resistance value between the first position and the second position. Thus, in this embodiment, by providing lands 171 and 172, the resistance in the area where the lands are provided can be reduced, and therefore, heat generation can be suppressed particularly in the area where the lands 171 and 172 are provided.

[0045] In the above embodiment, the ceramic substrate 110 contains aluminum nitride. The lands 171 and 172 are formed from a high-melting-point metal having a melting point of 2000°C or higher. The difference in average linear thermal expansion coefficients between aluminum nitride and high-melting-point metals such as tungsten and molybdenum is small. Therefore, when the lands 171 and 172 are embedded in the aluminum nitride ceramic substrate 110 and fired, the occurrence of cracks and the like can be suppressed.

[0046] In the above embodiment, the conductive member 131 is provided with a notch 131C, and the terminal 151 extends upward through the region where the notch 131C is provided so as not to come into contact with the conductive member 131. This allows the terminal to be positioned in a location that overlaps with a conductive member that is not electrically connected to the terminal, thereby increasing the flexibility of terminal placement. Furthermore, when connecting the terminal and the electrode without using a connecting member embedded inside the ceramic substrate 110, the risk of connection failure inside the ceramic substrate 110 can be reduced. Temperature sensors TC1 and TC2, such as thermocouples, are provided near terminals 151 and 152 in the region where the notch 131C is provided. The conductive member 132 is provided with a notch 132C, and a similar temperature sensor TC3 is provided near terminal 153 in the region where the notch 132C is provided. In this way, by forming a notch in the conductive member, space for placing temperature sensors can be easily secured. However, as mentioned above, providing a notch in the conductive member may increase the resistance between the terminal and the connection point. In this embodiment, as mentioned above, the land is arranged to bypass the notch, so it is possible to suppress the increase in resistance between the terminal and the connection point.

[0047] In the above embodiment, a cylindrical shaft 160 is provided on the lower surface 113 of the ceramic substrate 110. The terminals 151 to 154 are positioned inside the outer diameter of the shaft 160. In this case, the terminals 151 to 154 can be protected from the external environment of the shaft 160 by hermetically sealing the inside and outside of the cylindrical shaft 160. Furthermore, by providing the cylindrical shaft 160, direct contact between the ceramic substrate 110 and external devices can be avoided. This allows the ceramic substrate 110 to be insulated from its surroundings, thereby improving the uniformity of the heat distribution of the ceramic substrate 110.

[0048] In the above embodiment, the conductive members 131-133 and the electrodes 121-123 are formed from the same material (a mesh or foil woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten). This facilitates the manufacturing of the substrate holding member 100. In the above embodiment, the connecting portions 141-143 are via structures connecting virtual surface A and virtual surface B. The connecting portions 144 and 145 are also formed from the same material as the electrodes 121-123 and the conductive members 131-133 (a mesh or foil woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum and / or tungsten). Furthermore, the connecting portion 144 is integrated with the conductive member 131 and electrode 123, and the connecting portion 145 is integrated with the conductive member 133 and electrode 123. This ensures that the connecting portions are reliably connected to the electrodes and / or conductive members, reducing the risk of connection failure. Furthermore, the materials of electrodes 121 to 123 may differ from those of conductive members 131 to 133. In that case, the degree of freedom in selecting the materials for electrodes 121 to 123 and conductive members 131 to 133 can be increased. For example, electrodes 121-123 can be formed from a mesh woven from wires of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum, in order to increase the resistance value and thus the amount of heat generated by using a material with high sheet resistance and volume resistivity and reducing its surface area. Conductive members 131-133 can be formed from foils of tungsten (W), molybdenum (Mo), or an alloy containing molybdenum, in order to reduce the resistance value and thus the amount of heat generated by using a material with low sheet resistance and volume resistivity and increasing its surface area.

[0049] <Change form> The embodiments described above are merely illustrative and can be modified as appropriate. For example, the shape and dimensions of the ceramic substrate 110 and the shaft 160 are not limited to those of the embodiments described above and can be modified as appropriate. Also, the shape, dimensions, and number of electrodes, conductive members, joints, terminals, and lands embedded in the ceramic substrate 110 can be modified as appropriate. Furthermore, the shape and dimensions of the notches formed in the conductive members can also be modified as appropriate. Alternatively, openings can be formed in the conductive members instead of notches.

[0050] In the above embodiments, molybdenum, tungsten, and an alloy containing molybdenum and / or tungsten were used as electrodes 121 to 123, but the present invention is not limited to such embodiments. For example, metals or alloys other than molybdenum and tungsten can also be used.

[0051] In the above embodiment, the substrate holding member 100 was provided with three electrodes 121 to 123 embedded in the ceramic substrate 110. However, the present invention is not limited to such embodiments, and the number of electrodes embedded in the ceramic substrate 110 of the substrate holding member 100 may be two or four or more. For example, as shown in Figures 7, 8(a) and 8(b), four electrodes 221 to 224 may be embedded in the ceramic substrate 210.

[0052] As shown in Figures 7, 8(a), and 8(b), four electrodes 221-224 are arranged on virtual surface A of the ceramic substrate 210, and four conductive members 231-234 and three lands 271-273 are arranged on virtual surface B. In addition, five terminals 251-255 are provided on the ceramic substrate 210, and passages TC1-TC4 for placing temperature sensors and the like are provided near terminals 251-254, respectively. The materials of electrodes 221-224 are the same as those of electrodes 121-123 described above, the materials of conductive members 231-234 are the same as those of conductive members 151-153 described above, the materials of lands 271-273 are the same as those of lands 171 and 172 described above, and the materials of terminals 251-255 are the same as those of terminals 151-154 described above, so their explanation is omitted.

[0053] As shown in Figures 7 and 8(a), terminal 251 is connected to one end of electrode 221. The other end of electrode 221 is connected to connection portion 241. As shown in Figure 8(b), connection portion 241 is connected to conductive member 234, and conductive member 234 is further connected to terminal 254. This forms an electrical circuit from terminal 251 through electrode 221, connection portion 241, conductive member 234, to terminal 254. By connecting an external power supply to terminals 251 and 254, with terminal 254 as the ground terminal, current can be supplied to electrode 221.

[0054] As shown in Figure 8(b), terminal 253 is connected to conductive member 233, and conductive member 233 is further connected to connection portion 243. Conductive member 233 is provided with a notch 233C, and an L-shaped land 272 similar to land 172 is provided to avoid the notch 233C. Connection portion 243 is connected to one end of electrode 222. The other end of electrode 222 is connected to connection portion 242. As described above, the connection portion 242 is connected to the conductive member 234, and the conductive member 234 is further connected to the terminal 254. This forms an electrical circuit from terminal 253 through the conductive member 233, connection portion 243, electrode 222, connection portion 242, conductive member 234, to terminal 254. As a result, by connecting an external power supply to terminals 253 and 254 with terminal 254 as the ground terminal, current can be supplied to electrode 222. A land 272 is provided on the conductive member 233. Therefore, current can flow through the land 272 between the portion of the conductive member 233 connected to terminal 253 and the portion connected to connection portion 243. This reduces the resistance between the portion connected to terminal 253 and the portion connected to connection portion 243 compared to the case where the land 272 is not provided, and thus suppresses heat generation in this portion.

[0055] As shown in Figure 8(b), terminal 255 is connected to conductive member 231, and conductive member 231 is further connected to connection portion 246. Connection portion 246 is connected to one end of electrode 223. The other end of electrode 223 is connected to connection portion 247. As shown in Figure 8(b), connection portion 247 is connected to conductive member 234, and conductive member 234 is further connected to terminal 254. This forms an electrical circuit from terminal 255 through conductive member 231, connection portion 246, electrode 223, connection portion 247, conductive member 234, to terminal 254. By connecting an external power supply to terminals 255 and 254, with terminal 254 as the ground terminal, current can be supplied to electrode 223.

[0056] As shown in Figure 8(b), terminal 252 is connected to land 271, land 271 is connected to conductive member 232, and conductive member 232 is further connected to connection portion 245. Connection portion 245 is connected to one end of electrode 224. The other end of electrode 224 is connected to connection portion 244. As shown in Figure 8(b), connection portion 244 is connected to conductive member 234, and conductive member 234 is further connected to terminal 254. This forms an electrical circuit from terminal 252 through conductive member 232, connection portion 245, electrode 224, connection portion 244, conductive member 234, to terminal 254. By connecting an external power supply to terminals 252 and 254 with terminal 254 as the ground terminal, current can be supplied to electrode 224. Note that, as shown in Figure 8(b), land 271 extends on conductive member 232 to the vicinity of connection portion 245. This makes it possible to reduce the resistance between terminal 252 and connection portion 245 compared to the case where land 272 does not extend to the vicinity of connection portion 245, thereby suppressing heat generation between terminal 252 and connection portion 245.

[0057] Thus, even when four electrodes 221 to 224 are embedded in the ceramic substrate 110, the same effects and advantages as those of the substrate holding member 100 described above can be achieved.

[0058] In the above embodiment, the substrate holding member 100 was equipped with a shaft 160, but the present invention is not limited to such an embodiment, and the substrate holding member 100 does not necessarily have to be equipped with a shaft 160.

[0059] In the above embodiment, the land was placed on the conductive member, but the present invention is not limited to such an embodiment, and the land may be placed below the conductive member. A substrate holding member 100 in which the land is placed below the conductive member can be manufactured, for example, as follows. Note that the same steps as those for the manufacturing method of the substrate holding member 100 in the above embodiment will be omitted, and different steps will be described. In the manufacturing method of the substrate holding member 100 in the above embodiment, in Figure 6(c), the conductive member 132 was placed in the recess 511 of the lower molded body 510, and the land 172 was placed in the recess 511 on the lower surface of the central molded body 510. Alternatively, as shown in Figure 10(a), the land 172 is placed in the recess 511 of the lower molded body 510 The conductive member 132 is placed in the recess 511 on the lower surface of the central molded body 510. Then, after uniaxial hot press firing in the same manner as described above, blind holes are machined up to the land 172 in order to form the terminal 153 (see Figure 10(b)). This allows the land 172 to be exposed. Alternatively, the land 172 and the conductive member 132 may be placed on top of each other in the lower molded body 510. In that case, a two-tiered recess should be provided in the lower molded body 510 at the position where both are placed. In addition, in the process shown in Figure 10(a), a pellet made of tungsten, molybdenum, or an alloy containing at least one of these may be embedded below the land 172, at a position overlapping with the terminal 153 (see Figure 3(b)). If a pellet is embedded, blind holes should be machined up to the pellet.

[0060] Although embodiments and modified versions of the invention have been described above, the technical scope of the present invention is not limited to the scope described above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is also clear from the claims that such modified or improved forms may be included in the technical scope of the present invention.

[0061] The order in which each process in the manufacturing method shown in the specification and drawings is executed is not specifically defined, and unless the output of a previous process is used in a later process, the processes can be executed in any order. Even if phrases such as "first," and "next," are used for convenience, this does not mean that the processes must be performed in that order.

[0062] This disclosure can also be implemented in the following forms: [Application Example 1] A ceramic substrate having an upper surface and a lower surface that is opposite to the upper surface in the vertical direction, Multiple electrodes embedded in the aforementioned ceramic substrate, At least one conductive member embedded in the ceramic substrate, Multiple connection parts, each of which one end is electrically connected to one of the multiple electrodes, A land electrically connected to at least one conductive member, A plurality of terminals, each having one end connected to one of the plurality of electrodes, the at least one conductive member, or the land, The resistance value between the connection portion and the terminal connected to the at least one conductive member is smaller than the resistance value between both ends of the plurality of electrodes. The number of the aforementioned multiple terminals is less than twice the number of the aforementioned multiple electrodes. The land, at a first position on a horizontal plane perpendicular to the vertical direction, overlaps with one of the terminals in the vertical direction. The land is at a second position different from the first position on the horizontal plane, A substrate holding member characterized in that it overlaps one of the connection portions and one of the electrodes in the vertical direction, or overlaps with at least one conductive member in the vertical direction. [Application Example 2] The substrate holding member according to Application Example 1, characterized in that at least a portion of the plurality of electrodes and at least one conductive member is a mesh woven from wires of at least one metal selected from tungsten, molybdenum, and an alloy containing molybdenum and / or tungsten. [Application Example 3] The substrate holding member according to Application Example 1 or Application Example 2, characterized in that the thickness of the plurality of electrodes and the conductive member is 0.03 mm to 0.2 mm, except for the intersection of the wires. [Application Example 4] The substrate holding member according to any one of the three application examples, wherein the ceramic substrate contains aluminum nitride, and the land contains a metal having a melting point of 2000°C or higher. [Application Example 5] Furthermore, the ceramic substrate is provided with a cylindrical shaft joined to the lower surface, The substrate holding member according to any one of the four application examples 1 to 4, wherein the plurality of terminals are arranged inside the outer diameter of the shaft. [Application Example 6] A process of preparing multiple flat ceramic molded bodies containing aluminum nitride as a component, A step of preparing multiple electrodes, at least one conductive member and a land, The process involves arranging the plurality of electrodes on one surface of one of the ceramic molded bodies, and arranging one of the at least one conductive member on the other surface or on one surface of another ceramic molded body. A step of arranging a connection portion between the plurality of electrodes and the at least one conductive member, A step of arranging the land so as to be in contact with the conductive member, A step of forming a laminate by stacking one of the ceramic molded bodies, the other ceramic molded body, and the yet another ceramic molded body so as to embed the plurality of electrodes, the at least one conductive member, and the lands in another ceramic molded body and yet another ceramic molded body, The process of firing the laminated body using a uniaxial hot press, A method for manufacturing a substrate holding member, comprising the steps of exposing the lands from the fired laminate, or exposing a portion of at least one conductive member that overlaps with the lands in the vertical direction. [Application Example 7] Furthermore, the method for manufacturing a substrate holding member according to Application Example 6, further comprising the step of joining a cylindrical ceramic shaft containing aluminum nitride to the lower surface of the laminate, in which portions of the plurality of terminals, the lands, or at least one conductive member that overlap vertically with the lands are exposed. [Explanation of Symbols]

[0063] 100 Substrate holding member 110 Ceramic substrate 121~123, 221~224 electrode 131-133, 231-234 Conductive members Connection sections 141-145, 241-247 Terminals 151-154, 251-255 160 shaft 171, 172, 271-273 Land

Claims

1. A ceramic substrate having an upper surface and a lower surface that is opposite to the upper surface in the vertical direction, Multiple electrodes embedded in the aforementioned ceramic substrate, At least one conductive member embedded in the ceramic substrate, Multiple connection parts, each of which one end is electrically connected to one of the multiple electrodes, A land electrically connected to at least one conductive member, Multiple terminals, At least one terminal is electrically connected to the land, and the remaining terminals are electrically connected to one of the plurality of electrodes or to the at least one conductive member, The resistance value between the connection portion connected to the at least one conductive member among the plurality of connection portions and the terminal connected to the at least one conductive member among the plurality of terminals is smaller than any of the resistance values ​​between the ends of the plurality of electrodes. The number of the aforementioned multiple terminals is less than twice the number of the aforementioned multiple electrodes. The land, at a first position on a horizontal plane perpendicular to the vertical direction, overlaps with the at least one terminal in the vertical direction. The land is at a second position different from the first position on the horizontal plane, A substrate holding member characterized in that it overlaps one of the connection portions and one of the electrodes in the vertical direction, or overlaps with at least one conductive member in the vertical direction.

2. The substrate holding member according to claim 1, characterized in that at least a portion of the plurality of electrodes and at least one conductive member is a mesh woven from wires of at least one metal selected from tungsten, molybdenum, and an alloy containing molybdenum and / or tungsten.

3. The substrate holding member according to claim 2, characterized in that the thickness of the plurality of electrodes and the conductive member is 0.03 mm to 0.2 mm, except for the intersection of the wires.

4. The substrate holding member according to any one of claims 1 to 3, wherein the ceramic substrate comprises aluminum nitride, and the land comprises a metal having a melting point of 2000°C or higher.

5. Furthermore, the ceramic substrate is provided with a cylindrical shaft joined to the lower surface, The substrate holding member according to any one of claims 1 to 3, wherein the plurality of terminals are arranged inside the outer diameter of the shaft.

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