Holding device

Abstract

To inhibit a crack from occurring at a first brazed portion joining a terminal member to a buffer member disposed between an electrode and the terminal member.SOLUTION: A supporting device comprises a supporter having a first surface and a second surface, an electrode, and a terminal member, and supports an object on the first surface of the supporter. The electrode is disposed so that at least part of the electrode is exposed on the second surface of the supporter. The supporting device further comprises a buffer member disposed between the electrode and the terminal member, a first brazed portion joining the terminal member to the buffer member, and a second brazed portion joining the electrode to the buffer member. A thermal expansion coefficient of the buffer member is smaller than a thermal expansion coefficient of the terminal member. In at least one specific cross section approximately perpendicular to the first surface and in a second direction, a terminal member side end face of the buffer member is positioned within a range of an electrode side end face of the buffer member and the terminal member side end face of the buffer member is positioned inside a range of a buffer member side end face of the terminal member.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a holding device that holds an object. [Background technology]

[0002] There is known a heating device (also called a "susceptor") that holds an object (e.g., a semiconductor wafer) and heats it to a predetermined temperature (e.g., about 400 to 800°C). The heating device is used as a part of semiconductor manufacturing equipment such as a film formation device (a CVD film formation device, a sputtering film formation device, etc.) or an etching device (a plasma etching device, etc.). In general, a heating device includes a holder having a surface (hereinafter referred to as the "holding surface") substantially perpendicular to a predetermined direction, and a surface (hereinafter referred to as the "rear surface") opposite to the holding surface. A heater electrode is disposed inside the holder. An electrode (also referred to as an "electrode pad") is electrically connected to the heater electrode via a via conductor or the like. The electrode is disposed so that at least a portion of the electrode is exposed on the rear surface of the holder. A terminal member is joined to the electrode, for example, by brazing (hereinafter also referred to as the "brazing portion"). When a voltage is applied to the heater electrode via the terminal member and the electrode, the heater electrode generates heat, and an object held on the holding surface of the holder is heated.

[0003] If the electrode and the terminal member are made of different materials, stress caused by the difference in thermal expansion between them may cause cracks in the holder near the joint between them. A technique for arranging a buffer member between the electrode and the terminal member to suppress the occurrence of such cracks has been known (see, for example, Patent Document 1). By forming the buffer member from a material having a thermal expansion coefficient between the thermal expansion coefficient of the material forming the electrode and the thermal expansion coefficient of the material forming the terminal member, or a material having the same thermal expansion coefficient as the material forming the electrode, the buffer member can be made to have the function of mitigating the thermal expansion difference between the electrode and the terminal member.

[0004] A typical brazing process is as follows: First, a brazing material is placed between the terminal member and the buffer member, and then the brazing material is heated. The brazing material is melted by heating and allowed to penetrate into the surface of the terminal member facing the buffer member and the surface of the buffer member facing the terminal member, and then the brazing material is solidified by, for example, returning to room temperature. This allows the terminal member and the buffer member to be brazed and joined by the brazing portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-123601 A Summary of the Invention [Problem to be solved by the invention]

[0006] Simply placing a buffer member as in the above-described conventional technology may result in cracks occurring in the brazed portion joining the buffer member and the terminal member due to stress resulting from the difference in thermal expansion between the buffer member and the terminal member.

[0007] Note that this problem is not limited to the above-mentioned heating device, but is a common problem with holding devices in general that include a holder, an electrode (e.g., a heater electrode, an RF electrode, an electrode (electrode pad) electrically connected to the RF electrode) arranged so that at least a portion of it is exposed on the back surface of the holder, a terminal member, a buffer member arranged between the electrode and the terminal member, and brazing portions that join the electrode and the buffer member and between the buffer member and the terminal member, and that hold an object on the surface of the holder.

[0008] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0009] The technology disclosed in this specification can be realized, for example, in the following forms.

[0010] (1) A holding device disclosed in the present specification includes a holder having a first surface substantially perpendicular to a first direction and a second surface opposite to the first surface, an electrode arranged such that at least a portion of the electrode is exposed on the second surface of the holder, a terminal member, a buffer member arranged between the electrode and the terminal member in the first direction, a first brazing portion joining the buffer member and the terminal member, and a second brazing portion joining the electrode and the buffer member. In the holding device that holds an object on the first surface of the holder, The expansion coefficient is smaller than the thermal expansion coefficient of the terminal member, and in at least one specific cross section substantially perpendicular to the first surface, in a second direction substantially perpendicular to the first direction, among the end faces of the buffer member in the first direction, the terminal member side end face facing the terminal member is located within the range of the electrode side end face of the buffer member facing the electrode, and in the second direction, the terminal member side end face of the buffer member is located inside the range of the buffer member side end face facing the terminal member side end face among the end faces of the terminal member in the first direction.

[0011] In the present holding device, in the second direction in the specific cross section, the terminal member side end face of the buffer member is located inside the range of the buffer member side end face of the terminal member. Therefore, during brazing, the brazing material forming the first brazing portion is more likely to creep up onto the outer peripheral surface of the buffer member than onto the outer peripheral surface of the terminal member. In other words, the first brazing portion is less likely to be positioned on the outer peripheral surface of the terminal member.

[0012] Here, when the terminal member side end face of the buffer member is located outside the range of the buffer member side end face of the terminal member, the brazing material forming the first brazing portion is likely to creep up onto the outer peripheral surface of the terminal member during brazing. In a configuration in which the brazing material forming the brazing portion is arranged on the outer peripheral surface of the terminal member, the thermal expansion coefficient of the terminal member is greater than that of the buffer member, and therefore, when the brazing material solidifies during the brazing, tensile stress tends to be applied to the brazing material due to the contraction of the terminal member. As a result, cracks tend to occur on the surface of the brazing portion. On the other hand, in a configuration in which the terminal member side end face of the buffer member is located inside the range of the buffer member side end face of the terminal member in the second direction in the specific cross section, as in the present holding device, the first brazing portion is more likely to be arranged on the buffer member side end face of the terminal member than on the outer peripheral surface of the terminal member. Therefore, when the brazing material solidifies, the generation of tensile stress on the brazing material due to the contraction of the terminal member is suppressed.

[0013] In addition, in the present holding device, the generation of tensile stress during solidification of the brazing material in the brazing joint is suppressed, which in turn suppresses the generation of tensile residual stress remaining in the first brazing part, and therefore, even during the thermal cycle after the brazing joint, the generation of cracks in the first brazing part due to tensile residual stress and the propagation of the cracks can be suppressed.

[0014] Therefore, according to the present holding device, it is possible to prevent tensile stress from being applied to the first brazing portion that joins the buffer member and the terminal member, and ultimately to prevent cracks from occurring in the first brazing portion.

[0015] (2) In the above-mentioned holding device, in the second direction in the specific cross section, the terminal member side end face of the buffer member may be located inside the range of the electrode side end face of the buffer member, and in the specific cross section, the buffer member may be configured to be composed of a substantially rectangular terminal member side portion having the terminal member side end face as one side and a substantially rectangular electrode side portion having the electrode side end face as one side. In other words, in the present holding device, in the above-mentioned specific cross section, the electrode side end face of the buffer member may be configured to be larger than the terminal member side end face. By adopting this configuration, the bonding strength between the buffer member and the electrode can be improved, and the tensile strength at the second brazed portion can be improved, compared to a configuration in which the electrode side end face of the buffer member has an area equivalent to that of the terminal member side end face. Therefore, according to the present holding device, it is possible to suppress detachment of the buffer member and therefore the terminal member from the electrode.

[0016] (3) In the holding device, the exposed surface exposed on the second surface of the electrode in the second direction in the specific cross section may be located inside the range of the electrode side end surface of the buffer member. In other words, the entire surface of the exposed surface may be covered by the electrode side end surface in the specific cross section. If a portion of the exposed surface is not covered by the second brazing portion, the portion, and thus the electrode itself, may be oxidized or deteriorated in the air. By adopting this configuration, the entire surface of the exposed surface is more likely to be covered by the brazing material (second brazing portion) in the second direction in the specific cross section, compared to a configuration in which the exposed surface of the electrode is located outside the range of the electrode side end surface of the buffer member. Therefore, according to this holding device, it is possible to suppress oxidation and deterioration of the electrode in the air atmosphere, and thus to suppress detachment of the buffer member and thus the terminal member from the electrode.

[0017] (4) In the above-mentioned holding device, when viewed in the first direction, an outer edge of the buffer member side end face of the terminal member may surround an outer edge of the terminal member side end face of the buffer member. By adopting this configuration, it is possible to suppress the generation of tensile stress in the brazing material during the brazing joint in any of the specific cross sections, and to suppress the generation of the tensile residual stress in the first brazing portion. Therefore, according to this holding device, it is possible to more effectively suppress the application of tensile stress to the first brazing portion that joins the buffer member and the terminal member, and thus to more effectively suppress the generation of cracks in the first brazing portion.

[0018] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a heating device, an electrostatic chuck, a holding device, a manufacturing method thereof, etc. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing a schematic external configuration of a heating device 100 according to the present embodiment. [Diagram 2] 1 is an explanatory diagram illustrating a schematic XZ cross-sectional configuration of a heating device 100 according to the present embodiment. [Diagram 3] 2. FIG. 2 is an explanatory diagram showing an enlarged XZ cross-sectional configuration of a portion (X1 portion in FIG. 2) of the heating device 100 in the present embodiment. [Figure 4] 2. FIG. 2 is an explanatory diagram showing an enlarged XY cross-sectional configuration of a portion (X1 portion in FIG. 2) of the heating device 100 in this embodiment. [Diagram 5] 10A to 10D are explanatory views each showing a schematic XZ cross-sectional configuration of a heating device in each modified example. [Figure 6] 10 is an explanatory diagram illustrating a schematic XZ cross-sectional configuration of a heating device according to a modified example and a comparative example. FIG. [Figure 7] FIG. 11 is an explanatory diagram showing the performance evaluation results. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A. Embodiment: A-1. Configuration of heating device 100: FIG. 1 is a perspective view showing the external configuration of the heating device 100 in this embodiment, and FIG. 2 is an explanatory diagram showing the XZ cross-sectional configuration of the heating device 100 in this embodiment. FIG. 3 is an explanatory diagram showing an enlarged XZ cross-sectional configuration of a part (X1 part in FIG. 2) of the heating device 100 in this embodiment. FIG. 4 is an explanatory diagram showing an enlarged XY cross-sectional configuration of a part (X1 part in FIG. 2) of the heating device 100 in this embodiment. Each figure shows mutually orthogonal XYZ axes for specifying a direction. In this specification, for convenience, the positive direction of the Z axis is referred to as the upward direction, and the negative direction of the Z axis is referred to as the downward direction, but the heating device 100 may actually be installed in a direction different from such directions.

[0021] The heating apparatus 100 is an apparatus that holds an object (e.g., a semiconductor wafer W) and heats it to a predetermined processing temperature (e.g., about 400 to 800° C.), and is also called a susceptor. The heating apparatus 100 is used as a part of a semiconductor manufacturing apparatus such as a film forming apparatus (a CVD film forming apparatus, a sputtering film forming apparatus, etc.) or an etching apparatus (a plasma etching apparatus, etc.).

[0022] As shown in FIGS. 1 and 2, the heating device 100 includes a holder 10 and a columnar support 20. The holder 10 and columnar support 20 are made of a material such as aluminum.

[0023] The holder 10 is a substantially disk-shaped member having a surface (hereinafter referred to as the "holding surface S1") that is substantially perpendicular to a predetermined direction (the Z-axis direction in this embodiment) and a surface (hereinafter referred to as the "rear surface S2") opposite to the holding surface S1. The holder 10 is formed of ceramics containing aluminum nitride (AlN) and alumina (Al2O3) as main components. The main component here means the component with the highest content ratio (weight ratio). The diameter of the holder 10 is, for example, about 100 mm or more and 500 mm or less, and the thickness of the holder 10 (length in the vertical direction) is, for example, about 3 mm or more and 20 mm or less. The holder 10 corresponds to the ceramic member in the claims, the holding surface S1 corresponds to the first surface in the claims, the rear surface S2 corresponds to the second surface in the claims, and the Z-axis direction corresponds to the first direction in the claims.

[0024] As shown in FIG. 2, a heater electrode 50, which is a heating resistor, is disposed inside the holder 10. The heater electrode 50 is formed of a material containing a metal such as tungsten or molybdenum. In this embodiment, the heater electrode 50 forms a linear pattern extending in a substantially concentric manner when viewed in the Z-axis direction. Both ends of the linear pattern of the heater electrode 50 are disposed near the center of the holder 10, and the upper ends of the via conductors 52 are connected to the respective ends. In addition, as shown in FIG. 2 and FIG. 3, a pair of recesses 12 are formed on the rear surface S2 of the holder 10, and a conductive power supply electrode (electrode pad) 54 is provided at the position of each recess 12. In this embodiment, the power supply electrode 54 is substantially circular when viewed in the Z-axis direction, and is formed of a material containing tungsten (for example, a mixed material of tungsten and aluminum nitride). In this embodiment, the entire surface of the power supply electrode 54 on the side of the buffer member 60 is exposed to the rear surface S2 of the holder 10 (hereinafter, the surface of the power supply electrode 54 exposed to the rear surface S2 is also referred to as the "exposed surface Se"). However, as long as at least a part of the power supply electrode 54 is exposed to the rear surface S2 of the holder 10, a part of the power supply electrode 54 (for example, an end) may be embedded inside the holder 10. The lower end of the via conductor 52 is connected to the power supply electrode 54. As a result, the heater electrode 50 and the power supply electrode 54 are electrically connected to each other through the via conductor 52. The power supply electrode 54 corresponds to an electrode in the claims.

[0025] The columnar support 20 is a substantially cylindrical member extending in the above-mentioned predetermined direction (vertical direction). Like the holder 10, the columnar support 20 is formed of ceramics containing aluminum nitride or alumina as a main component. The outer diameter of the columnar support 20 is, for example, about 30 mm or more and 90 mm or less, and the height of the columnar support 20 (length in the vertical direction) is, for example, about 100 mm or more and 300 mm or less.

[0026] The holder 10 and the columnar support 20 are arranged so that the back surface S2 of the holder 10 and the top surface S3 of the columnar support 20 face each other in the vertical direction. The columnar support 20 is joined to the center of the back surface S2 of the holder 10 via a joint 30 formed from a known joining material.

[0027] 2, the columnar support 20 is formed with a through hole 22 that opens to the rear surface S2 side of the holder 10. A plurality of (two in this embodiment) terminal members 70 are housed in the through hole 22. The terminal members 70 are, for example, columnar members that are substantially circular when viewed in the Z-axis direction, and are made of a material containing nickel (Ni) (for example, pure nickel or an alloy containing nickel (for example, Kovar)). Here, the thermal expansion coefficient of the material forming the terminal members 70 is, for example, 5K -1 More than 13K -1 The dimensions of the buffer member side end surface St (see FIG. 3) of the terminal member 70 will be described later.

[0028] In addition, buffer members 60 are disposed between the upper end of each terminal member 70 and each power supply electrode 54 in the Z-axis direction. The buffer members 60 are, for example, plate-shaped members that are substantially circular when viewed in the Z-axis direction, and are made of a material containing tungsten (for example, pure tungsten or an alloy containing tungsten). The buffer members 60 are members that serve to reduce the thermal expansion difference between the terminal members 70 and the power supply electrodes 54. For this reason, the thermal expansion coefficient of the material forming the buffer members 60 is the same as the thermal expansion coefficient of the material forming the power supply electrodes 54, or the thermal expansion coefficient of the material forming the buffer members 60 is smaller than the thermal expansion coefficient of the material forming the terminal members 70. The thermal expansion coefficient of the material forming the buffer members 60 is, for example, 6K -1 The difference between the thermal expansion coefficient of the material forming the buffer member 60 and the thermal expansion coefficient of the material forming the terminal member 70 is, for example, 9K. -1 The following applies. The diameter of the buffer member 60 is, for example, 4.5 mm to 10.0 mm. The thickness ta of the buffer member 60 is, for example, 2 mm or more. The configuration of the buffer member 60 will be described in detail later.

[0029] 3, the lower surface (terminal member side end surface Sbt) of the buffer member 60 is joined to the terminal member 70 (specifically, the buffer member side end surface St) by a terminal side brazing portion 81. The upper surface (electrode side end surface Sbe) of the buffer member 60 is joined (brazed) to the lower surface (exposed surface Se) of the power supply electrode 54 by an electrode side brazing portion 82. The terminal side brazing portion 81 and the electrode side brazing portion 82 are, for example, Ni-based (Ni-Cr-based alloy, etc.), Au-based (pure Au, Au-Ni-based alloy, etc.), or Ag-based (pure Ag, etc.) brazing material. The terminal side brazing portion 81 corresponds to a first brazing portion in the claims, and the electrode side brazing portion 82 corresponds to a second brazing portion in the claims.

[0030] When a voltage is applied to the heater electrode 50 from a power source not shown through each terminal member 70, each buffer member 60, each power supply electrode 54, and each via conductor 52, the heater electrode 50 generates heat, and an object (e.g., a semiconductor wafer W) held on the holding surface S1 of the holder 10 is heated to a predetermined temperature (e.g., about 400 to 800°C).

[0031] In the heating device 100 of this embodiment, the following configuration is adopted in a cross section (cross section shown in FIG. 3) that is parallel to the Z-axis direction (i.e., substantially perpendicular to the holding surface S1) and passes through the center of the buffer member 60 as viewed in the Z-axis direction, and in a cross section (cross section shown in FIG. 4) at the position IV-IV in FIG. 3 (the position of the buffer member side end face St of the terminal member 70). The dotted line shown in FIG. 4 is a dotted line illustrated for convenience in the following explanation. Also, as described below, in this embodiment, the following configuration is adopted in any cross section that is parallel to the Z-axis direction and passes through the center of the buffer member 60 as viewed in the Z-axis direction. Therefore, the heating device 100 of this embodiment has the same configuration as the following configuration in any cross section parallel to the Z-axis direction.

[0032] <Configuration 1> In the X-axis direction, the terminal member side end face Sbt of the buffer member 60 is located inside the range of the electrode side end face Sbe of the buffer member 60. Specifically, in the cross section, both end points of the line segment corresponding to the terminal member side end face Sbt are located inside both end points of the line segment corresponding to the electrode side end face Sbe. Here, the length of the line segment corresponding to the terminal member side end face Sbt (the diameter Dbt of the terminal member side end face Sbt) is preferably, for example, 4.5 mm or less. In addition, the length of the line segment corresponding to the electrode side end face Sbe (the diameter Dbe of the electrode side end face Sbe) is preferably, for example, 5 mm or more. In addition, the distance twice the distance Lb between one end point of the line segment corresponding to the terminal member side end face Sbt and one end point of the line segment corresponding to the electrode side end face Sbe (i.e., the difference between the diameter Dbt of the terminal member side end face Sbt and the diameter Dbe of the electrode side end face Sbe) is preferably, for example, 1 mm or less from the viewpoint of ensuring the brazing area of ​​the terminal member side end face Sbt. In this embodiment, as viewed in the Z-axis direction, the outer edge Ebe of the electrode side end face Sbe of the buffer member 60 surrounds the outer edge Ebt of the terminal member side end face Sbt of the buffer member 60. The X-axis direction corresponds to the second direction in the claims.

[0033] <Configuration 2> In this embodiment, in the X-axis direction, the terminal member side end surface Sbt of the buffer member 60 is located inside the range of the buffer member side end surface St of the terminal member 70. Specifically, in the cross section, both end points of the line segment corresponding to the terminal member side end surface Sbt are located inside both end points of the line segment corresponding to the buffer member side end surface St. Here, the length of the line segment corresponding to the buffer member side end surface St (the diameter Dt of the buffer member side end surface St) is preferably, for example, 4.5 mm or less. In addition, the distance twice the distance Lt between one end point of the line segment corresponding to the buffer member side end surface St and one end point of the line segment corresponding to the terminal member side end surface Sbt (i.e., the difference between the diameter Dt of the buffer member side end surface St and the diameter Dbt of the terminal member side end surface Sbt) is preferably, for example, 1 mm or less from the viewpoint of ensuring the brazing area of ​​the terminal member side end surface Sbt. In this embodiment, the outer edge Et of the buffer member side end face St of the terminal member 70 surrounds the outer edge Ebt of the terminal member side end face Sbt of the buffer member 60 when viewed in the Z axis direction.

[0034] <Configuration 3> In this embodiment, the buffer member 60 is composed of a substantially rectangular terminal member side portion 61 having a terminal member side end face Sbt as one side, and a substantially rectangular electrode side portion 62 having an electrode side end face Sbe as one side. In other words, the buffer member 60 is composed of a substantially cylindrical terminal member side portion 61 having a terminal member side end face Sbt, and a substantially cylindrical electrode side portion 62 having an electrode side end face Sbe. Here, in the Z-axis direction, the thickness t1 of the terminal member side portion 61 is, for example, 1 mm or more, and the thickness t2 of the electrode side portion 62 is, for example, 1 mm or more.

[0035] <Configuration 4> In this embodiment, in the X-axis direction, the exposed surface Se of the power supply electrode 54 is located inside the range of the electrode side end surface Sbe of the buffer member 60. Specifically, in the cross section, both end points of the line segment corresponding to the exposed surface Se are located inside both end points of the electrode side end surface Sbe. Here, the length of the line segment corresponding to the exposed surface Se (the diameter De of the exposed surface Se) is preferably, for example, 5 mm or more. In addition, the distance twice the distance Le between one end point of the line segment corresponding to the electrode side end surface Sbe and one end point of the line segment corresponding to the exposed surface Se (i.e., the difference between the diameter Dbe of the electrode side end surface Sbe and the diameter De of the exposed surface Se) is preferably, for example, 2 mm or less from the viewpoint that the entire surface of the exposed surface Se is easily covered by the electrode side brazing portion 82 interposed between the power supply electrode 54 and the buffer member 60. In addition, in this embodiment, the outer edge Ebe of the electrode side end surface Sbe of the buffer member 60 surrounds the outer edge Ee of the exposed surface Se of the power supply electrode 54 when viewed in the Z-axis direction.

[0036] A-2. First modified example of this embodiment: Fig. 5(A) is an explanatory diagram that shows a schematic configuration of a heating device 100a in a first modified example of this embodiment. Fig. 5(A) shows an XZ cross-sectional configuration of the heating device 100a in the first modified example, which corresponds to the cross-section in Fig. 3 described above. In the following, among the configurations of the heating device 100a in the first modified example, the same configurations as those of the heating device 100 in the present embodiment described above are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0037] As shown in FIG. 5(A), the configuration of the heating device 100a of the first modification is different from the configuration of the heating device 100 of the present embodiment described above in that the shape of the buffer member 60a is different. That is, the buffer member 60a of the first modification is different from the buffer member 60 of the present embodiment in the above configuration 3. Specifically, in the cross section, the buffer member 60a is substantially trapezoidal with the terminal member side end face Sbt and the electrode side end face Sbe as one side. In other words, the buffer member 60a is substantially truncated cone with the terminal member side end face Sbt as one side and the electrode side end face Sbe as the other side. Here, the included angle θa formed by the buffer member side end face St of the terminal member 70 and the side face Sa of the buffer member 60a is, for example, 50° or more and 90° or less from the viewpoint of the stability of the structure (e.g., shape) of the fillet of the terminal side brazing portion 81 to be formed.

[0038] A-3. Second modification of this embodiment: Fig. 5(B) is an explanatory diagram that shows a schematic configuration of a heating device 100b in a second modified example of this embodiment. Fig. 5(B) shows an XZ cross-sectional configuration of the heating device 100b in the second modified example, which corresponds to the cross-section in Fig. 3 described above. In the following, among the configurations of the heating device 100b in the second modified example, the same configurations as those of the heating device 100 in the present embodiment described above are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0039] As shown in FIG. 5(B), the configuration of the heating device 100b of the second modified example is different from the configuration of the heating device 100 of the present embodiment described above in that the shape of the buffer member 60b is different. That is, the buffer member 60b of the second modified example is different from the buffer member 60 of the present embodiment in the above configuration 3. Specifically, in the cross section, the buffer member 60b is composed of a terminal member side portion 61b having a substantially trapezoidal shape with the terminal member side end face Sbt as one side, and a substantially rectangular electrode side portion 62b having the electrode side end face Sbe as one side. In other words, the buffer member 60b is composed of a terminal member side portion 61b having a substantially truncated cone shape with the terminal member side end face Sbt, and a substantially cylindrical electrode side portion 62b having the electrode side end face Sbe. Here, the included angle θb formed between the buffer member side end face St of the terminal member 70 and the side face Sb of the terminal member side portion 61b of the buffer member 60b is, for example, 10° or more and 45° or less from the viewpoint of stability of the structure (e.g., shape) of the fillet of the terminal side brazing portion 81 to be formed. In addition, in the Z-axis direction, the thickness t1 of the terminal member side portion 61b is, for example, 1 mm or more, and the thickness t2 of the electrode side portion 62b is, for example, 1 mm or more.

[0040] A-4. Third Modification of the Present Embodiment: Fig. 5(C) is an explanatory diagram that shows a schematic configuration of a heating device 100c in a third modified example of this embodiment. Fig. 5(C) shows an XZ cross-sectional configuration of the heating device 100c in the third modified example, which corresponds to the cross-section in Fig. 3 described above. In the following, among the configurations of the heating device 100c in the third modified example, the same configurations as those of the heating device 100 in the present embodiment described above are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0041] As shown in FIG. 5(C), the configuration of the heating device 100c of the third modification is different from the configuration of the heating device 100 of the present embodiment described above in that the shape of the buffer member 60c is different. That is, the buffer member 60c of the third modification is different from the buffer member 60 of the present embodiment in the above configuration 4. Specifically, in the cross section, the exposed surface Se of the power supply electrode 54 is located outside the range of the electrode side end surface Sbe of the buffer member 60c in the X-axis direction. Specifically, in the cross section, both end points of the line segment corresponding to the exposed surface Se are located outside both end points of the electrode side end surface Sbe. Here, the length of the line segment corresponding to the electrode side end surface Sbe (the diameter Dbe of the electrode side end surface Sbe) is, for example, 4 mm or more. In addition, the distance twice the distance Le between one end point of the line segment corresponding to the electrode side end surface Sbe and one end point of the line segment corresponding to the exposed surface Se (i.e., the difference between the diameter Dbe of the electrode side end surface Sbe and the diameter De of the exposed surface Se) is 1 mm or less. In the third modified example, as viewed in the Z-axis direction, the outer edge Ee of the exposed surface Se of the power supply electrode 54 surrounds the outer edge Ebe of the electrode side end face Sbe of the buffer member 60. Like the heating device 100 of the first embodiment, the heating device 100c also includes a substantially rectangular terminal member side portion 61c having one side defined by the terminal member side end face Sbt, and a substantially rectangular electrode side portion 62c having one side defined by the electrode side end face Sbe.

[0042] A-5. Fourth Modification of the Present Embodiment: Fig. 6(A) is an explanatory diagram that shows a schematic configuration of a heating device 100d in a fourth modified example of this embodiment. Fig. 6(A) shows an XZ cross-sectional configuration of the heating device 100d in the fourth modified example, which corresponds to the cross-section in Fig. 3 described above. In the following, among the configurations of the heating device 100d in the fourth modified example, the same configurations as those of the heating device 100 in the present embodiment described above are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[0043] As shown in FIG. 6(A), the configuration of the heating device 100d of the fourth modification is different from the configuration of the heating device 100 of the present embodiment described above in that the shape of the buffer member 60d is different. That is, the buffer member 60d of the fourth modification is different from the buffer member 60 of the present embodiment in the above configurations 1 and 3. Specifically, in the cross section, the terminal member side end face Sbt of the buffer member 60d is located at the same position as the electrode side end face Sbe of the buffer member 60d in the X-axis direction. In other words, in the cross section, both end points of the line segment corresponding to the terminal member side end face Sbt are located at the same positions as both end points of the line segment corresponding to the electrode side end face Sbe. That is, in the cross section, the buffer member 60d is substantially rectangular with the terminal member side end face Sbt and the electrode side end face Sbe as one side. Also, the buffer member 60d is substantially cylindrical extending in the Z-axis direction with the terminal member side end face Sbt as one side and the electrode side end face Sbe as the other side. In the fourth modification, the length of the line segment corresponding to the terminal member side end face Sbt (the diameter Dbt of the terminal member side end face Sbt) and the length of the line segment corresponding to the electrode side end face Sbe (the diameter Dbe of the electrode side end face Sbe) of the buffer member 60d are, for example, 6 mm or less. Also, in the fourth modification, the length of the line segment corresponding to the exposed surface Se of the power supply electrode 54 (the diameter De of the exposed surface Se) is, for example, 6 mm or less.

[0044] A-6. Comparative example: Fig. 6(B) is an explanatory diagram that shows a schematic configuration of a heating device 100x in a comparative example. Fig. 6(B) shows an XZ cross-sectional configuration of the heating device 100x in the comparative example, which corresponds to the cross-section in Fig. 3 described above. In the following, among the configurations of the heating device 100x in the comparative example, the same configurations as those of the heating device 100 in the present embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0045] As shown in FIG. 6B, the configuration of the heating device 100x of the comparative example is different from the configuration of the heating device 100 of the present embodiment described above in that the shape of the buffer member 60x is different. That is, the buffer member 60x of the comparative example is different from the buffer member 60 of the present embodiment in the above-mentioned configuration 2. Specifically, in the comparative example, the terminal member side end face Sbt of the buffer member 60x is located outside the range of the buffer member side end face St of the terminal member 70 in the X-axis direction. Specifically, in the cross section, both end points of the line segment corresponding to the terminal member side end face Sbt are located outside both end points of the line segment corresponding to the buffer member side end face St. Here, the length of the line segment corresponding to the terminal member side end face Sbt (the diameter Dbt of the terminal member side end face Sbt) is, for example, 4 mm or more. In addition, the distance twice the distance Lt between one end point of the line segment corresponding to the buffer member side end face St and one end point of the line segment corresponding to the terminal member side end face Sbt (i.e., the difference between the diameter Dt of the buffer member side end face St and the diameter Dbt of the terminal member side end face Sbt) is, for example, 1 mm or more.

[0046] A-7. Manufacturing method of heating device 100: A method for manufacturing the heating device 100 of this embodiment is, for example, as follows: First, the holder 10 and the columnar supports 20 are fabricated.

[0047] The method for producing the holder 10 is, for example, as follows. First, an organic solvent such as toluene is added to a mixture of 100 parts by weight of aluminum nitride powder, 1 part by weight of yttrium oxide (Y2O3) powder, 20 parts by weight of an acrylic binder, and an appropriate amount of dispersant and plasticizer, and the mixture is mixed in a ball mill for 20 hours to produce a slurry for the green sheet. This slurry for the green sheet is formed into a sheet shape using a casting device and then dried to produce multiple green sheets.

[0048] Also, a metallization paste is prepared by adding metal powder such as tungsten to a mixture of aluminum nitride powder, an acrylic binder, and an organic solvent such as terpineol, and kneading the mixture. This metallization paste is printed, for example, using a screen printing device, to form unsintered conductor layers that will later become heater electrodes 50, power supply electrodes 54, etc., on specific green sheets. Also, by printing on green sheets with via holes already provided therein, unsintered conductor parts that will later become via conductors 52 are formed.

[0049] Next, a plurality of these green sheets (e.g., 20 sheets) are thermocompression bonded, and the outer periphery is cut as necessary to produce a green sheet laminate (e.g., 8 mm thick). This green sheet laminate is cut by machining to produce a disk-shaped compact, which is degreased, and the degreased body is fired to produce a fired body. The surface of this fired body is polished. Through the above steps, the holder 10 is produced.

[0050] The columnar support 20 can be produced, for example, as follows. First, an organic solvent such as methanol is added to a mixture of 100 parts by weight of aluminum nitride powder, 1 part by weight of yttrium oxide powder, 3 parts by weight of PVA binder, and an appropriate amount of dispersant and plasticizer, and mixed in a ball mill to obtain a slurry. This slurry is granulated in a spray dryer to produce a raw material powder. Next, the raw material powder is filled into a rubber mold in which a core corresponding to the through hole 22 is placed, and a molded body is obtained by cold isostatic pressing. The obtained molded body is degreased, and the degreased body is further fired. Through the above steps, the columnar support 20 is produced.

[0051] Next, the support 10 and the columnar supports 20 are bonded together. After performing a wrapping process on the back surface S2 of the support 10 and the top surface S3 of the columnar supports 20 as necessary, a known bonding agent made into a paste form by mixing, for example, rare earth elements and an organic solvent is uniformly applied to at least one of the back surface S2 of the support 10 and the top surface S3 of the columnar supports 20, and then a degreasing process is performed. Next, the back surface S2 of the support 10 and the top surface S3 of the columnar supports 20 are overlapped, and hot press sintering is performed to bond the support 10 and the columnar supports 20 together.

[0052] After the holder 10 and the columnar support 20 are joined, each buffer member 60 is inserted into the through hole 22, and the electrode side end face Sbe of each buffer member 60 is brazed to the exposed face Se of each power supply electrode 54 using a brazing material (for example, Ni-based, Au-based, Ag-based brazing material), thereby forming an electrode side brazed portion 82. Also, each terminal member 70 is inserted into the through hole 22, and the buffer member side end face St of each terminal member 70 is brazed to the terminal member side end face Sbt of each buffer member 60 using a brazing material (for example, Ni-based, Au-based, Ag-based brazing material), thereby forming a terminal side brazed portion 81. Each brazing can be performed using a vacuum furnace under predetermined brazing conditions (in a vacuum, at a temperature of about 950°C to 1150°C, for a time of about 10 minutes to 30 minutes). The heating device 100 having the above-mentioned configuration is manufactured mainly by the above manufacturing method.

[0053] The method of producing the buffer member 60 is, for example, as follows. A substantially cylindrical columnar body made of the material forming the buffer member 60 and having substantially the same diameter as the diameter Dbe of the electrode side end face Sbe of the buffer member 60 is prepared. The columnar body is cut in the longitudinal direction so as to have substantially the same thickness as the thickness ta of the buffer member 60. The cut columnar body is processed by lathe machining so as to have the above-mentioned shape (diameter Dbt, thickness t1 of the terminal member side portion 61, diameter Dbe, thickness t2 of the electrode side portion 62), thereby producing the buffer member 60.

[0054] A-8.Performance evaluation: A performance evaluation was carried out to confirm the effects of the heating device 100 of the present embodiment, the heating devices of the modifications, and the heating device of the comparative example described above. Fig. 7 is an explanatory diagram showing the performance evaluation results.

[0055] As shown in Fig. 7, six heating device samples (SA1 to SA6) were used for the performance evaluation. Each sample was produced by a manufacturing method based on the manufacturing method of the heating device of the above-mentioned embodiment. Each sample has a different configuration of the buffer member.

[0056] Specifically, sample SA1 used a buffer member having a configuration similar to that of buffer member 60 in heating device 100 of the present embodiment. Samples SA2 to SA6 used buffer members having a configuration similar to that of buffer member 60a in heating device 100a of the first modified example, buffer member 60b in heating device 100b of the second modified example, buffer member 60c in heating device 100c of the third modified example, buffer member 60d in heating device 100d of the fourth modified example, and buffer member 60x in heating device 100x of the comparative example.

[0057] A-8-1. Evaluation method: The above samples SA1 to SA6 were subjected to evaluation of the occurrence of cracks in the terminal side brazed portion 81 during bonding (i.e., brazing) of the terminal member 70 to the power supply electrode 54. The brazing conditions during brazing were based on the manufacturing method of the heating device 100 of the above embodiment. The evaluation of the occurrence of cracks during brazing was performed on each sample after brazing and cooling to room temperature. A plurality of samples were prepared (e.g., n samples. Specifically, for example, two samples each of the samples SA1 to SA6). First, a part of each sample (e.g., m samples) was polished to expose a cross section that is substantially parallel to the Z-axis direction and includes the terminal side brazed portion 81 (e.g., the cross section shown in FIG. 3). The obtained cross section was observed under a microscope to determine whether or not there was a crack. When no cracks were present, it was judged as "◎", when there were one or two cracks, it was judged as "◯", and when there were three or more cracks, it was judged as "×". For samples in which cracks were present, the length of the cracks was measured.

[0058] In addition, the occurrence of cracks in the terminal-side brazed portion 81 during the thermal cycle and the propagation of the cracks were evaluated for the samples SA1 to SA6. The thermal cycle conditions were that each sample was heated to 700°C and then cooled to room temperature, with 300 cycles of the cycle being performed. The occurrence of cracks during the thermal cycle was evaluated for the samples that were judged as having cracks occurring during brazing after cooling to room temperature. First, the remaining samples (for example, nm pieces) were cross-sectioned in the same manner as above. The presence or absence of cracks was determined for the obtained cross sections by microscopic observation. The results were judged as follows: no cracks occurred, "◎", one or two cracks occurred, "○", and three or more cracks occurred. The propagation of cracks during the thermal cycle was evaluated for the samples that were judged as having cracks occurring during brazing after cooling to room temperature, with "○" and "×". First, the remaining pieces (e.g., nm pieces) of each sample were cross-sectioned in the same manner as described above. The lengths of the cracks in the obtained cross sections were measured by microscopic observation. If the length of the crack was 20% or more longer than the length of the crack generated during brazing, it was judged as "x", and if it was less than 20%, it was judged as "◎".

[0059] Additionally, samples SA1 to SA6 were evaluated for the tensile strength of the electrode-side brazed portion 82. Specifically, the load required for vertical tension breakage of the terminal member 70 was measured. As a result, a tensile strength of 20 kgf or more was judged as "◎", and a tensile strength of less than 20 kgf was judged as "×".

[0060] The oxidation resistance of the power supply electrode 54 was evaluated for the samples SA1 to SA6. Specifically, each sample was exposed to a predetermined condition (temperature: 600°C, time: 1000 hours). As a result, when the terminal member 70 was detached from the power supply electrode 54, it was judged as "X", and when it was not detached, it was judged as "◎".

[0061] A-8-2. Evaluation results: As shown in FIG. 7, sample SA1 was rated as "◎" in the occurrence of cracks during brazing, the occurrence of cracks during thermal cycles, the tensile strength, and the oxidation resistance, and thus good results were obtained. In sample SA1, like the heating device 100 of the embodiment, in the above cross section, in the X-axis direction, the terminal member side end face Sbt of the buffer member 60 is located inside the range of the buffer member side end face St of the terminal member 70 (see FIG. 3). For this reason, during brazing, the brazing material forming the terminal side brazing portion 81 is more likely to creep up onto the outer peripheral surface of the buffer member 60 than onto the outer peripheral surface of the terminal member 70, in other words, the terminal side brazing portion 81 is less likely to be disposed on the outer peripheral surface of the terminal member 70. It is believed that this is why good results were obtained in the occurrence of cracks during brazing and the occurrence of cracks during thermal cycles. In addition, in the sample SA1, the diameter Dbe (area of ​​the electrode side end face Sbe) of the electrode side end face Sbe that is joined to the power supply electrode 54 in the buffer member 60 is larger than the diameter Dbt (area of ​​the terminal member side end face Sbt) of the terminal member side end face Sbt. This improves the joining strength between the buffer member 60 and the power supply electrode 54, and it is considered that a good result was obtained in the tensile strength of the electrode side brazing part 82. In addition, in the sample SA1, the exposed surface Se of the power supply electrode 54 is covered by the electrode side end face Sbe of the buffer member 60. This makes it easy for the entire exposed surface Se to be covered by the electrode side brazing part 82 interposed between the power supply electrode 54 and the buffer member 60, and oxidation and deterioration of the power supply electrode 54 in the air atmosphere are suppressed, and it is considered that a good result was obtained in the detachment of the terminal member 70 from the power supply electrode 54.

[0062] Also, in the sample SA2, as in the sample SA1, the occurrence of cracks during brazing, the occurrence of cracks during thermal cycles, the tensile strength, and the oxidation resistance were all rated as "◎", and good results were obtained. This is considered to be because, in the sample SA2, as in the sample SA1, in the above cross section, in the X-axis direction, the terminal member side end face Sbt of the buffer member 60a is located inside the range of the buffer member side end face St of the terminal member 70, the diameter Dbe (area of ​​the electrode side end face Sbe) of the electrode side end face Sbe that joins with the power supply electrode 54 is larger than the diameter Dbt (area of ​​the terminal member side end face Sbt) of the terminal member side end face Sbt, and the exposed surface Se of the power supply electrode 54 is covered by the electrode side end face Sbe of the buffer member 60a.

[0063] In addition, in sample SA3, except for the occurrence of cracks during brazing being marked with "○", the extension of cracks during thermal cycles, the tensile strength, and the oxidation resistance were all marked with "◎", and good results were obtained. This is considered to be because, in the sample SA3, as in the sample SA1, in the cross section, in the X-axis direction, the terminal member side end face Sbt of the buffer member 60b is located inside the range of the buffer member side end face St of the terminal member 70, the diameter Dbe (area of ​​the electrode side end face Sbe) of the electrode side end face Sbe that joins with the power supply electrode 54 is larger than the diameter Dbt (area of ​​the terminal member side end face Sbt) of the terminal member side end face Sbt, and the exposed surface Se of the power supply electrode 54 is covered by the electrode side end face Sbe of the buffer member 60b. Regarding the result that the occurrence of cracks during brazing was "○", it is considered that the reason is that if the included angle θb formed between the buffer member side end face St of the terminal member 70 and the side face Sb of the terminal member side portion 61b of the buffer member 60b is too small, the terminal member is easily affected by thermal stress.

[0064] In addition, in sample SA4, except for the oxidation resistance being "x", the occurrence of cracks during brazing, the occurrence of cracks during thermal cycles, and the tensile strength were all "◎", and good results were obtained. This is considered to be because, in the above cross section, in the X-axis direction, in sample SA4 as in sample SA1, the terminal member side end face Sbt of the buffer member 60c is located inside the range of the buffer member side end face St of the terminal member 70, and the diameter Dbe (area of ​​the electrode side end face Sbe) of the electrode side end face Sbe that joins with the power supply electrode 54 is larger than the diameter Dbt (area of ​​the terminal member side end face Sbt) of the terminal member side end face Sbt. In addition, the result of the oxidation resistance being "x" is considered to be due to the fact that a part of the exposed face Se of the power supply electrode 54 is not covered by the electrode side end face Sbe of the buffer member 60c.

[0065] In addition, in sample SA5, except for the tensile strength being "x", the brazing crack occurrence, the thermal cycle crack occurrence, and the oxidation resistance were all "◎", and good results were obtained. This is considered to be because, in the sample SA5, as in the sample SA1, in the above cross section, in the X-axis direction, the terminal member side end face Sbt of the buffer member 60d is located inside the range of the buffer member side end face St of the terminal member 70, and the exposed face Se of the power supply electrode 54 is covered by the electrode side end face Sbe of the buffer member 60b. In addition, the result of the tensile strength being "x" is considered to be because, in the above cross section, in the X-axis direction, the diameter Dbe (area of ​​the electrode side end face Sbe) of the electrode side end face Sbe that is joined to the power supply electrode 54 is equivalent to the diameter Dbt (area of ​​the terminal member side end face Sbt) of the terminal member side end face Sbt.

[0066] In addition, in sample SA6, the tensile strength and oxidation resistance were rated as "◎", while the occurrence of cracks during brazing and the propagation of cracks during thermal cycles were rated as "×". As with sample SA1, the tensile strength and oxidation resistance of sample SA6 are considered to be due to the fact that the diameter Dbe (area of ​​electrode side end face Sbe) of the electrode side end face Sbe joining with the power supply electrode 54 in the X-axis direction in the cross section is larger than the diameter Dbt (area of ​​terminal member side end face Sbt) of the terminal member side end face Sbt, and the exposed surface Se of the power supply electrode 54 is covered by the electrode side end face Sbe of the buffer member 60x. On the other hand, the occurrence of cracks during brazing and the propagation of cracks during thermal cycles are considered to be due to the fact that the terminal member side end face Sbt of the buffer member 60x is located outside the range of the buffer member side end face St of the terminal member 70 in the X-axis direction in the cross section.

[0067] A-9. Advantages of this embodiment: As described above, the heating device 100 of this embodiment includes the holder 10 and the terminal member 70, and is a device that holds an object such as a semiconductor wafer W on the holding surface S1 of the holder 10. The holder 10 is a member having a holding surface S1 that is substantially perpendicular to the Z-axis direction and a back surface S2 on the opposite side to the holding surface S1. The power supply electrode 54 is disposed so as to be exposed on the back surface S2 of the holder 10. Between the power supply electrode 54 and the terminal member 70 in the Z-axis direction, a buffer member 60 having a thermal expansion coefficient smaller than that of the terminal member 70 is disposed. The heating device 100 of this embodiment also includes a terminal-side brazing portion 81 that joins the buffer member 60 and the terminal member 70, and an electrode-side brazing portion 82 that joins the power supply electrode 54 and the buffer member 60. In the heating device 100 of this embodiment, in the above cross section, the terminal member-side end surface Sbt of the buffer member 60 is located within the range of the electrode-side end surface Sbe in the X-axis direction. Furthermore, in the X-axis direction, the terminal member side end surface Sbt of the buffer member 60 is located inside the range of the buffer member side end surface St of the terminal member 70.

[0068] In the heating device 100 of this embodiment, in the X-axis direction in the above cross section, the terminal member side end face Sbt of the buffer member 60 is located inside the range of the buffer member side end face St of the terminal member 70. For this reason, during brazing, the brazing material forming the terminal side brazing portion 81 is more likely to creep up onto the outer circumferential surface of the buffer member 60 than onto the outer circumferential surface of the terminal member 70. In other words, the terminal side brazing portion 81 is less likely to be positioned on the outer circumferential surface of the terminal member 70.

[0069] Here, when the terminal member side end surface Sbt of the buffer member 60 is located outside the range of the buffer member side end surface St of the terminal member 70, the brazing material forming the terminal side brazing portion 81 is likely to creep up onto the outer peripheral surface of the terminal member 70 during brazing. In a configuration in which the brazing material forming the brazing portion is disposed on the outer peripheral surface of the terminal member 70, the thermal expansion coefficient of the terminal member 70 is greater than that of the buffer member 60, and therefore, when the brazing material solidifies during the brazing, tensile stress tends to be applied to the brazing material due to the contraction of the terminal member 70. As a result, cracks tend to occur on the surface of the brazing portion. On the other hand, in a configuration in which the terminal member side end surface Sbt of the buffer member 60 is located inside the range of the buffer member side end surface St of the terminal member 70 in the X-axis direction in the above cross section, as in the heating device 100 of this embodiment, the terminal side brazing portion 81 is more likely to be disposed on the buffer member side end surface St of the terminal member 70 than on the outer peripheral surface of the terminal member 70. Therefore, when the brazing material solidifies, the generation of tensile stress in the brazing material due to the contraction of the terminal member 70 is suppressed.

[0070] Furthermore, in the heating device 100 of the present embodiment, the generation of tensile stress during solidification of the brazing material in the brazing joint is suppressed, which in turn suppresses the generation of tensile residual stress remaining in the terminal-side brazing portion 81. As a result, even during the thermal cycle after the brazing joint, the generation of cracks in the terminal-side brazing portion 81 due to tensile residual stress and the propagation of the cracks can be suppressed.

[0071] Therefore, according to the heating device 100 of this embodiment, it is possible to prevent tensile stress from being applied to the terminal side brazing portion 81 that joins the buffer member 60 and the terminal member 70, and ultimately to prevent cracks from occurring in the terminal side brazing portion 81.

[0072] In the heating device 100 of the present embodiment, the terminal member side end face Sbt of the buffer member 60 is located inside the range of the electrode side end face Sbe of the buffer member 60 in the X-axis direction in the cross section. In addition, in the cross section, the buffer member 60 is composed of a substantially rectangular terminal member side portion 61 having the terminal member side end face Sbt as one side, and a substantially rectangular electrode side portion 62 having the electrode side end face Sbe as one side. In other words, in the heating device 100 of the present embodiment, the electrode side end face Sbe of the buffer member 60 is larger than the terminal member side end face Sbt in the cross section. Therefore, compared with a configuration in which the electrode side end face Sbe of the buffer member 60 has an area equivalent to that of the terminal member side end face Sbt, the joint strength between the buffer member 60 and the power supply electrode 54 can be improved, and the tensile strength of the electrode side brazed portion 82 can be improved. Therefore, according to the heating device 100 of the present embodiment, detachment of the buffer member 60 and the terminal member 70 from the power supply electrode 54 can be suppressed.

[0073] In the heating device 100 of the present embodiment, the exposed surface Se of the power supply electrode 54 exposed on the rear surface S2 of the holder 10 is located inside the range of the electrode side end surface Sbe of the buffer member 60 in the X-axis direction in the cross section. In other words, in the cross section, the entire surface of the exposed surface Se is covered by the electrode side end surface Sbe. If any part of the exposed surface Se is not covered by the electrode side brazing portion 82, this part, and in turn, the power supply electrode 54 itself, may be oxidized or deteriorated in the air atmosphere. In the heating device 100 of the present embodiment, the entire surface of the exposed surface Se is more likely to be covered by the brazing material (electrode side brazing portion 82) in the X-axis direction in the cross section, compared to a configuration in which the exposed surface Se of the power supply electrode 54 is located outside the range of the electrode side end surface Sbe of the buffer member 60. Therefore, according to the heating device 100 of the present embodiment, it is possible to suppress oxidation and deterioration of the power supply electrode 54 in the air atmosphere, and therefore to suppress detachment of the buffer member 60 and therefore the terminal member 70 from the power supply electrode 54.

[0074] In addition, in the heating device 100 of this embodiment, as viewed in the Z-axis direction, the outer edge Et of the buffer member side end face St of the terminal member 70 surrounds the outer edge Ebt of the terminal member side end face Sbt of the buffer member 60. Therefore, in any of the cross sections, the generation of tensile stress in the brazing material during the brazing joint can be suppressed, and the generation of the tensile residual stress in the terminal side brazing portion 81 can be suppressed. Therefore, according to the heating device 100 of this embodiment, the application of tensile stress to the terminal side brazing portion 81 that joins the buffer member 60 and the terminal member 70 can be more effectively suppressed, and thus the generation of cracks in the terminal side brazing portion 81 can be more effectively suppressed.

[0075] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0076] The configuration of the heating device 100 in the above embodiment is merely an example and can be modified in various ways. For example, in this embodiment, the above configuration may be adopted in at least one cross section that is parallel to the Z-axis direction and passes through the center of the buffer member 60 when viewed in the Z-axis direction. Also, in this embodiment, the above configuration may be adopted in at least one cross section that is parallel to the Z-axis direction and does not pass through the center of the buffer member 60 when viewed in the Z-axis direction.

[0077] The heating device 100 of the present embodiment may have a configuration in which a part of the surface of the power supply electrode 54, which faces the electrode side end surface Sbe of the buffer member 60 (hereinafter also referred to as the "lower surface of the power supply electrode 54"), is exposed on the rear surface S2 of the holder 10. In such a configuration, the exposed surface Se corresponds to the part of the lower surface of the power supply electrode 54 that is exposed on the rear surface S2 of the holder 10.

[0078] The shapes of the members in the above embodiment are merely examples and can be modified in various ways. For example, in the above embodiment, the power supply electrode 54 is substantially circular when viewed in the Z-axis direction, but the shape of the power supply electrode 54 when viewed in the Z-axis direction may be a shape other than substantially circular. The same applies to the buffer member 60 and the terminal member 70.

[0079] Moreover, the materials forming each member in the heating device 100 of the above embodiment are merely examples, and each member may be formed of other materials. Moreover, the manufacturing method of the heating device 100 of the above embodiment is merely an example, and various modifications are possible.

[0080] In the above embodiment, the heating device 100 is described in detail, which includes the power supply electrode 54 electrically connected to the heater electrode 50, the terminal member 70, the buffer member 60 arranged between the power supply electrode 54 and the terminal member 70, the terminal-side brazing portion 81 joining the buffer member 60 and the terminal member 70, and the electrode-side brazing portion 82 joining the buffer member 60 and the power supply electrode 54. However, the technology disclosed in this specification is similarly applicable to other holding devices (e.g., electrostatic chucks, etc.) that hold an object on the surface of a holder and include an electrode such as a heater electrode, an RF electrode, or a power supply electrode electrically connected to an RF electrode, which is arranged so that at least a portion of the electrode is exposed on the back surface of the holder, a terminal member, a buffer member arranged between the electrode and the terminal member, a terminal-side brazing portion joining the buffer member and the terminal member, and an electrode-side brazing portion joining the buffer member and the electrode. [Explanation of symbols]

[0081] 10: Holding body 12: Recess 20: Columnar support 22: Through hole 30: Joint 50: Heater electrode 52: Via conductor 54: Power supply electrode 60: Cushioning member 60a: Cushioning member 60b: Cushioning member 60c: Cushioning member 60d: Cushioning member 60x: Cushioning member 61: Terminal member side portion 61b: Terminal member side portion 61c: Terminal member side portion 62: Electrode side portion 62b: Electrode side portion 62c: Electrode side portion 70: Terminal member 81: Terminal side brazing portion 82: Electrode side brazing portion 100: Heating device 100a: Heating device 100b: Heating device 100c: Heating device 100d: Heating device 100x: Heating device S1: Holding surface S2: Back surface S3: Top surface Sa: Side surface Sb: Side surface Sbe: Electrode side end surface Sbt: Terminal member side end face Se: Exposed surface St: Buffer member side end face W: Semiconductor wafer

Claims

1. a holder having a first surface substantially perpendicular to a first direction and a second surface opposite the first surface; an electrode disposed so as to be at least partially exposed on the second surface of the holder; A terminal member; a buffer member disposed between the electrode and the terminal member in the first direction; a first brazing portion that joins the buffer member and the terminal member; a second brazing portion that joins the electrode and the buffer member; A holding device for holding an object on the first surface of the holder, the buffer member has a thermal expansion coefficient smaller than that of the terminal member; In at least one specific cross section substantially perpendicular to the first surface, in a second direction substantially perpendicular to the first direction, a terminal member side end face of the buffer member facing the terminal member is located within a range of an electrode side end face of the buffer member facing the electrode, In the second direction, the terminal member side end face of the buffer member is located inside a range of a buffer member side end face that faces the terminal member side end face among end faces of the terminal member in the first direction, an exposed surface of the electrode that is exposed on the second surface in the specific cross section in the second direction is located inside a range of the electrode side end surface of the buffer member, In the second direction in the specific cross section, the terminal member side end surface of the buffer member is located inside a range of the electrode side end surface of the buffer member, In the specific cross section, the buffer member is a terminal member side portion having a substantially rectangular shape with the terminal member side end surface as one side; and a substantially rectangular electrode side portion having the electrode side end surface as one side. A holding device characterized in that

2. 2. The holding device according to claim 1, When viewed in the first direction, an outer edge of the end surface of the terminal member on the buffer member side surrounds an outer edge of the end surface of the buffer member on the terminal member side. A holding device characterized in that

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