Conjugate

Abstract

To provide a joint body with improved bonding strength at a joint.SOLUTION: A joint body 10 comprises: a power reception electrode 12; a via conductor 14 electrically connecting between the power reception electrode 12 and a resistance heating body; and a stress alleviation part 16 arranged between a ceramic member 11 and a second power feeding rod 15. An electrode opposing surface (first surface) 161F1 of the stress alleviation part 16 is bonded with the power reception electrode 12 via a first brazing filler material 17, and a rod opposing surface (second surface) 161F2 not connected with the electrode opposing surface 161F1 is bonded with the second power feeding rod 15 via a second brazing filler material 18.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a conjugate. [Background technology]

[0002] A ceramic substrate structure is known that is used in manufacturing semiconductors and includes a power supply pad for heating a supported semiconductor wafer (see, for example, Patent Document 1). The ceramic substrate structure described in Patent Document 1 includes a buffer member that is disposed between the power supply pad embedded in the ceramic base and a power supply terminal that is connected to a power source and supplies power, and electrically connects the power supply pad and the power supply terminal. The entire outer peripheral surface of the buffer member is coated with a metal, and this metal oxidizes before the power supply pad, thereby suppressing oxidation of the power supply pad. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-165126 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, since the joint surface and the side surface of the buffer member are made of the same material, the brazing material may wrap around to a side surface different from the joint surface. In such a case, the brazing material on the joint surface is insufficient, and the joint strength between the power supply pad and the buffer member is reduced. In addition, if the metal coating the buffer member is oxidized, the brazing material is joined to the buffer member via an oxide coating. In such a case, even though the joint is between the buffer member, which is a metal, and the brazing material, which is a metal, the joint strength between the buffer member and the brazing material is reduced due to the oxide coating between the buffer member and the brazing material. Therefore, in the ceramic substrate structure described in Patent Document 1, it has been desired to improve the joint strength at the joint between the power supply pad and the buffer member. The ceramic substrate structure is also called a joint body, the buffer member is also called a stress relaxation part, and the power supply pad is also called a power receiving electrode.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a joined body having improved joining strength at a joint. [Means for solving the problem]

[0006] The present invention has been made to solve the above-mentioned problems, and can be realized in the following form: A joint body, comprising: a ceramic member having a power receiving electrode, a conductive metal terminal, and a stress relaxation part disposed between the ceramic member and the metal terminal, the stress relaxation part being joined to the power receiving electrode via a brazing material on a first surface thereof, and being joined to the metal terminal via a brazing material on a second surface thereof that is not connected to the first surface. The main body is made of a tungsten-based sintered alloy containing W (tungsten) as a main component and at least one of Ni (nickel), Fe (iron), and Cu (copper) as a binder phase. and an oxide protective film covering a side surface of the main body portion connecting the first surface and the second surface, the oxide protective film having a thickness of 100 nm or more and 1000 nm or less.

[0007] (1) According to one aspect of the present invention, there is provided a joined body comprising: a ceramic member having a power receiving electrode, a conductive metal terminal, and a stress relaxation part disposed between the ceramic member and the metal terminal, the stress relaxation part having a main body part joined to the power receiving electrode via a brazing material at a first surface and joined to the metal terminal via a brazing material at a second surface not connected to the first surface, and an oxide protective film covering a side surface of the main body part connecting the first surface and the second surface.

[0008] According to this configuration, the stress relaxation portion is inserted between the power receiving electrode and the metal terminal, so that the thermal stress caused by the difference in thermal expansion coefficient resulting from the difference in the material between the power receiving electrode and the metal terminal can be attenuated. In addition, in the joint of this configuration, the side surface of the main body is covered with an oxide protective film. This prevents the brazing material from creeping up to the side surface of the stress relaxation portion, and as a result, the decrease in joint strength caused by the decrease in the brazing material at the joint surface due to the creeping up can be suppressed. Furthermore, the oxide protective film is not formed at the joint between the power receiving electrode and the main body, and at the joint between the main body and the metal terminal. In other words, since the main body and the brazing material are joined without the oxide protective film, there is no oxide protective film between the main body, which is a metal, and the brazing material, which may cause a decrease in joint strength. This ensures the joint strength between the main body and the brazing material. In other words, according to the joint of this configuration, the oxidation of the main body is suppressed, and the joint strength of the joint between the stress relaxation portion and the power receiving electrode, and the joint between the stress relaxation portion and the metal terminal can be improved.

[0009] (2) In the bonded body of the above aspect, the oxide protective film may contain one or more oxides of Cr, Ti, Zr, Hf, Nb, Al, V, and Ta. According to this configuration, the oxide protective film is relatively stable even in a high-temperature environment, and therefore the high-temperature durability of the bonded body is improved.

[0010] The present invention can be realized in various forms, for example, in the form of a bonded body, a substrate holding device, a semiconductor manufacturing apparatus, a ceramic heater, parts including these, and methods for manufacturing these. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view of a substrate holding member including a bonded body according to an embodiment of the present invention. [Diagram 2] 10 is an explanatory diagram of the joining between the power receiving electrode and the second power feed rod. FIG. [Diagram 3] FIG. 1 is an explanatory diagram showing the evaluation test results of Examples 1 to 8 and Comparative Examples 1 to 3 of joined bodies having different protective films in the stress relaxation portions. [Figure 4] 1 is a flowchart of a method for producing a bonded body. [Diagram 5] 4 is a flowchart of a method for manufacturing a ceramic member. [Figure 6] 4 is a flowchart of a method for manufacturing a stress relaxation portion. [Figure 7] 13A and 13B are explanatory views of a stress relaxation portion and a protective film according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Embodiment> 1 is a schematic cross-sectional view of a substrate holding member 100 including a bonded body 10 according to an embodiment of the present invention. The substrate holding member 100 is a part of a semiconductor manufacturing apparatus that performs plasma etching, ion implantation, electron beam exposure, etc. The substrate holding member 100 holds, corrects flatness, transports, etc. a semiconductor wafer W (hereinafter, also simply referred to as "wafer W"), and is used as a heating device that heats the wafer W to a predetermined temperature.

[0013] 1, the substrate holding member 100 includes a bonded body 10 that holds a wafer W on a mounting surface 10F, and a hollow shaft 20 that is connected to the opposite side of the mounting surface 10F of the bonded body 10. The bonded body 10 includes a ceramic member 11 having a power receiving electrode (not shown in FIG. 1) containing ceramics, a resistance heating element 13 disposed in the ceramic member 11, and a conductive second power supply rod (metal terminal) 15 for supplying power to the power receiving electrode 12.

[0014] The ceramic member 11 is formed of ceramics such as alumina, aluminum nitride, YAG, silicon nitride, silicon carbide, magnesium oxide, zirconium oxide, yttria, spinel, mullite, calcium titanate, and barium titanate. The power receiving electrode is formed of W (tungsten) and ceramics. The resistance heating element 13 is supplied with power through a via conductor (not shown in FIG. 1), the power receiving electrode, and a second power supply rod 15, and functions as a heater electrode for heating the wafer W held by the bonded body 10. The resistance heating elements 13, which are shown divided in FIG. 1, are electrically connected in series. Note that the rectangular resistance heating element 13 shown in FIG. 1 is shown in a simplified form.

[0015] The second power supply rod 15 is disposed in the shaft 20, one end of which is connected to the resistance heating element 13, and the other end of which is connected to a heater power source (not shown). Although the details of the connection between the second power supply rod 15 and the resistance heating element 13 are not shown in Fig. 1, the details of the connection will be described with reference to Fig. 2 together with the shapes of the power receiving electrode and the via conductor.

[0016] FIG. 2 is an explanatory diagram of the joining of the power receiving electrode 12 and the second power supply rod 15. FIG. 2 is a schematic cross-sectional view in which the X1 portion of FIG. 1 is enlarged. As shown in FIG. 2, the joined body 10 includes the power receiving electrode 12, a via conductor 14 electrically connecting the power receiving electrode 12 and the resistance heating element 13, and a stress relaxation portion 16 disposed between the ceramic member 11 and the second power supply rod 15. The stress relaxation portion 16 electrically connects the ceramic member 11 and the second power supply rod 15. As shown in FIG. 2, the stress relaxation portion 16 has an electrode facing surface (first surface) 161F1 joined to the power receiving electrode 12 via a first brazing material 17, and a rod facing surface (second surface) 161F2 not connected to the electrode facing surface 161F1 joined to the second power supply rod 15 via a second brazing material 18. In FIG. 2, the resistive heating element 13 is not shown, and some of the via conductors 14 on the resistive heating element 13 side are not shown.

[0017] 2, a part of the stress relaxation portion 16 is inserted into a recess 11M formed so as to be recessed in the ceramic member 11. The cross sections of the recess 11M and the stress relaxation portion 16 with respect to the central axis OL are substantially circular. Since the cross section of the stress relaxation portion 16 is smaller than the cross section of the recess 11M, a gap is formed between the stress relaxation portion 16 and the recess 11M.

[0018] As shown in FIG. 2, the stress relaxation portion 16 includes a main body portion 161 joined to the power receiving electrode 12 and the second power supply rod 15, and a protective film (oxide protective film) 162 covering the outer peripheral side surface 161S of the main body portion 161. The main body portion 161 of this embodiment is a metal material, and is a tungsten-based sintered alloy containing W as a main component and at least one of Ni (nickel), iron, and copper as a binder phase. The protective film 162 of this embodiment is an oxide protective film containing one or more oxides of Cr (chromium), Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Al (aluminum), V (vanadium), and Ta (tantalum). Note that the side surface 161S of the main body portion 161 in this embodiment can be said to be a surface that connects the electrode facing surface 161F1 and the rod facing surface 161F2. The thickness of the protective film 162 is preferably 100 nm to 1000 nm.

[0019] The power receiving electrode 12 is partially exposed in the recess 11M, and is joined to the stress relief portion 16 at an electrode opposing surface 161F1 by a first brazing material 17. On the other hand, the stress relief portion 16 is joined to the second power supply rod 15 by a second brazing material 18 at a rod opposing surface 161F2 on the opposite side of the first brazing material 17 along the central axis OL. The second power supply rod 15 in this embodiment is made of flexible pure nickel.

[0020] As the first brazing filler metal 17 and the brazing filler metal 2 in this embodiment, a Ni-based brazing filler metal foil (for example, amorphous Ni brazing filler metal foil from Hitachi Metals, Metglas (registered trademark)) or a gold-based brazing filler metal foil (for example, BAu-4 according to the JIS standard) is used.

[0021] Fig. 3 is an explanatory diagram showing the evaluation test results of Examples 1 to 8 and Comparative Examples 1 to 3 of the bonded body 10 having different protective films 162 of the stress relaxation portion 16. Fig. 3 shows the materials of the main body 161 and the protective film 162 in Examples 1 to 8 and Comparative Examples 1 to 3, and the three evaluation test results. Note that the materials constituting the bonded body 10 that are not shown in Fig. 3 are the same. For example, the material of the power receiving electrode 12 is a mixture of tungsten and aluminum nitride as a ceramic.

[0022] In the evaluation test shown in Fig. 3, three properties of the bonded body 10 were evaluated: the bond strength, the creeping of the brazing material, and the high temperature durability. In the evaluation test of the bond strength, a tensile strength test was performed on 10 samples of each of 11 types of bonded bodies, including 8 types of examples and 3 types of comparative examples. Among the 10 samples, the bonded bodies 10 in which none were broken at 20 MPa or more were evaluated as "○", and the bonded bodies 10 in which even one was broken were evaluated as "×".

[0023] In the evaluation test of the brazing filler metal creeping, the joined body 10 in which at least one of the first brazing filler metal 17 and the second brazing filler metal 18 did not creep up into the protective film 162 after the first brazing filler metal 17 and the second brazing filler metal 18 were joined was evaluated as "○", and the joined body 10 in which at least one of the first brazing filler metal 17 and the second brazing filler metal 18 had not creep up into the protective film 162 was evaluated as "×". In addition, in Comparative Example 2 in FIG. 3, in addition to the side surface 161S of the main body 161, the electrode opposing surface 161F1 and the rod opposing surface 161F2 are also coated with chromium oxide, that is, the entire surface of the main body 161 is coated. In Comparative Example 2, brazing with the first brazing filler metal 17 and the second brazing filler metal 18 was not possible, and the brazing fill up could not be evaluated, so the evaluation result is shown as "-".

[0024] In the evaluation test for high-temperature durability, the condition of the joined body 10 after being left in air at 600°C for 1000 hours (h) was evaluated. If there was a defect such as the second power feed rod 15 and the stress relaxation part 16 coming off, it was evaluated as "X", and if there was no defect, it was evaluated as "O". Note that, since there was a color change in the stress relaxation part of Comparative Example 3 after being left, it was determined that oxidation had progressed in the stress relaxation part, and it was evaluated as "X".

[0025] 3, when the protective film 162 covering the side surface 161S of the main body portion 161 was an oxide protective film, the results of the three evaluation tests were good. On the other hand, a bonded body without the protective film 162 as in Comparative Example 1, a bonded body in which the electrode facing surface 161F1 and the rod facing surface 161F2 in addition to the side surface 161S are covered with an oxide protective film as in Comparative Example 2, and a bonded body in which the side surface 161S is covered with a nitride protective film as in Comparative Example 3 showed a defect in at least one of the three evaluation tests.

[0026] Fig. 4 is a flowchart of a method for manufacturing the joined body 10. In the manufacturing flow of the joined body 10 shown in Fig. 4, first, the ceramic member 11 having the power receiving electrode 12 is fabricated (step S10). Next, the stress relaxation portion 16 to be bonded to the power receiving electrode 12 and the ceramic member 11 is created (step S20). The power receiving electrode 12 in the fabricated ceramic member 11, the stress relaxation portion 16, and the second power feed rod 15 are bonded to each other (step S30), and the joined body 10 is manufactured.

[0027] 5 is a flow chart of a method for manufacturing the ceramic member 11. As shown in FIG. 5, in the manufacturing flow of the ceramic member 11, first, a slurry for a green sheet that is the base of the ceramic member 11 is prepared (step S11). In this embodiment, an organic solvent (e.g., toluene) is added to a mixture of 100 parts by weight of aluminum nitride (AlN) powder, 0.5 parts by weight of yttrium oxide (Y2O3 (yttria)) powder, 20 parts by weight of an acrylic binder, and an appropriate amount of a dispersant and a plasticizer. This mixture is mixed in a ball mill for 20 hours to prepare a slurry for the green sheet.

[0028] The slurry is cast onto a sheet by a casting device and dried to produce a green sheet (step S12). An electrode paste is printed into through holes provided in the produced green sheet to form via conductors 14 in the green sheet (step S13).

[0029] On the green sheet on which the via conductors 14 are formed, a power receiving electrode 12 having an electrode pattern such as a heater or a distributor is formed (step S14). The power receiving electrode 12 is formed by printing a metallization layer and printing vias after providing through holes. The paste used for printing the metallization layer is, for example, a paste made by mixing powder of W or Mo, aluminum nitride powder, an acrylic binder, and an organic solvent such as terpineol. The amount of aluminum nitride powder mixed into the paste is adjusted according to the amount of W and Mo.

[0030] A green sheet laminate (e.g., 8 mm thick) is produced by stacking a plurality of (e.g., 20) green sheets on which the power-receiving electrode 12 is formed (step S15). The green sheet laminate is produced by pressing a plurality of green sheets together and cutting the periphery as necessary. The green sheet laminate is cut at the periphery by machining to produce a disk-shaped compact.

[0031] The produced laminate of green bodies is degreased at a temperature in the range of 450° C. to 600° C., and then fired (step S16). In this way, the ceramic member 11 having the power-receiving electrode 12 is produced, and the manufacturing flow of the ceramic member 11 is completed.

[0032] 6 is a flowchart of a method for manufacturing the stress relaxation portion 16. As shown in Fig. 6, in the manufacturing flow of the stress relaxation portion 16, a bar material for the main body portion 161 that is the base of the stress relaxation portion 16 is prepared (step S21). The bar material for the main body portion 161 prepared is a material processed to have the same cross section as that used for the joined body 10.

[0033] The surface of the prepared rod of the main body 161 is coated with an oxide that forms a protective film 162 (step S22). The rod of the main body 161 coated with the oxide is cut to a predetermined thickness as the stress relaxation part 16 (step S23), and the stress relaxation part 16 coated with the protective film 162 is created. For example, the stress relaxation part 16 of Example 1 shown in FIG. 3 is manufactured by coating a rod of tungsten alloy as the main body 161 with metal chromium, then performing oxidation heat treatment, and cutting it to a predetermined thickness. Also, the stress relaxation part 16 of Example 2 is manufactured by coating a rod of 42 alloy with metal titanium by PVD (physical vapor deposition) or the like, then performing oxidation heat treatment, and cutting it to a predetermined thickness. Also, the stress relaxation part 16 of Example 3 is manufactured by coating a rod of SUS430 with zirconium oxide by PVD or CVD (chemical vapor deposition), and cutting it to a predetermined thickness. The stress relaxation portions 16 of Examples 4 to 8 are manufactured using the same manufacturing method as in Example 3, but using different materials.

[0034] 4, a first brazing filler metal 17 (e.g., MBF-67) is sandwiched between the power receiving electrode 12 and the stress relaxation portion 16 of the fabricated ceramic member 11, and a second brazing filler metal 18 (e.g., BAu-4) is sandwiched between the stress relaxation portion 16 and the second power feed rod 15, and then the resulting members are heated to be joined by brazing (step S30). Heating conditions include, for example, heating in a vacuum at 950°C to 1150°C for 10 minutes to 30 minutes.

[0035] Instead of sandwiching a brazing filler metal between the power receiving electrode 12 and the stress relief portion 16, and between the stress relief portion 16 and the second power supply rod 15, a brazing filler metal paste may be applied. The first brazing filler metal 17 and the second brazing filler metal 18 do not have to be brazed under the same heating conditions. For example, the first brazing filler metal 17 may be brazed, and then the second brazing filler metal 18 may be brazed under different heating conditions.

[0036] As described above, the joined body 10 of the present embodiment includes the stress relaxation portion 16 disposed between the ceramic member 11 and the second power feed rod 15. The stress relaxation portion 16 includes the main body portion 161 and the protective film 16C covering the side surface 161S of the main body portion 161. The main body portion 161 is joined to the power receiving electrode 12 via the first brazing material 17 at the electrode facing surface 161F1, and is joined to the second power feed rod 15 via the second brazing material 18 at the rod facing surface 161F2. By loading the stress relaxation portion 16 between the power receiving electrode 12 and the second power feed rod 15, it is possible to attenuate thermal stress caused by the difference in thermal expansion coefficient resulting from the difference in material between the power receiving electrode 12 having low thermal expansion and the second power feed rod 15 having high thermal expansion. The side surface 161S of the main body portion 161 is covered with the protective film 162 which is an oxide protective film. The protective film 162 can suppress oxidation of the main body portion 161. Furthermore, the first brazing material 17 and the second brazing material 18 are prevented from creeping up the side surface of the stress mitigation portion 16. As a result, it is possible to prevent a decrease in the joint strength of the joint caused by a decrease in the brazing material due to the creeping up of the brazing materials 17 and 18. Furthermore, the protective film 162 is not formed on the joint between the power receiving electrode 12 and the main body 161 and the joint between the main body 161 and the second power supply rod 15. This ensures the joint strength between the main body 161 and the brazing material. That is, according to the joint body 10 of the present embodiment, it is possible to improve the joint strength of the joint between the stress mitigation portion 16 and the power receiving electrode 12 and the joint between the stress mitigation portion 16 and the second power supply rod 15 while preventing oxidation of the main body 161.

[0037] Moreover, the protective film 162 of the stress relaxation portion 16 of this embodiment contains one or more oxides of Cr, Ti, Zr, Hf, Nb, Al, V, and Ta. Therefore, as shown in the comparison between Examples 1 to 8 and Comparative Examples 1 to 3 shown in FIG. 3, the high temperature durability of the bonded body 10 is improved.

[0038] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0039] In the above embodiment, an example of the bonded body 10 has been described, but the bonded body 10 includes the stress relaxation portion 16 disposed between the ceramic member 11 and the second power supply rod 15, and can be deformed within a range in which the side surface 161S of the main body portion 161 is covered with the protective film 162 formed of an oxide. For example, the shapes and materials of the ceramic member 11, the second power supply rod 15, the stress relaxation portion 16, the first brazing material 17, and the second brazing material 18 can be deformed. The mounting surface 10F of the bonded body 10 may be processed so as to easily hold the wafer W. The material of the main body portion 161 and the material of the protective film 162 may be combined with those of Examples 1 to 8 shown in FIG. 3, and the main body portion 161 may be formed of a tungsten alloy, and the protective film 162 may be formed of titanium oxide.

[0040] Also, the protective film 162 covering the main body 161 can be modified in various ways. FIG. 7 is an explanatory diagram of the stress relaxation portion 16a of a modified example. FIG. 7 shows a schematic diagram of an enlarged cross section of the bonded body 10a of a modified example corresponding to the portion shown in FIG. 2 of the above embodiment. In the bonded body 10a of the modified example, the portion where the protective film 162a covers the stress relaxation portion 16 is different from that of the bonded body 10 of the above embodiment, and as a result, the bonding portion where the first brazing material 17a and the second brazing material 18a are bonded is different. Note that in the modified example, the shape and the like different from those of the above embodiment will be described, and the description of the same shape, material, and the like will be omitted.

[0041] 7, the protective film 162a of the modified example covers not only the side surface 161S of the main body 161a but also a part of the outer circumferential side of the electrode opposing surface 161F1 and a part of the outer circumferential side of the rod opposing surface 161F2. In this manner, the protective film 162a of the modified example does not have to be formed only on the side surface 161S of the main body 161a, and may be formed on a surface other than the side surface 161S. It is preferable that the protective film 162a covers the surface of the main body 161a to which the first brazing material 17a is not joined and the surface to which the second brazing material 18a is not joined.

[0042] The cross sections of the stress relaxation section 16 and the second power supply rod 15 do not necessarily have to be circular, and may be rectangular, or one of them may be rectangular and the other circular. The side surface of the main body covered by the protective film refers to a surface that connects the surface joined by the first brazing material 17 and the surface joined by the second brazing material 18, and may be a surface of a shape different from the side surface 161S of the circumferential surface in the above embodiment. For example, when the main body 161 has a polyhedral shape and is joined to the power receiving electrode 12 by a brazing material at one surface and joined to the second power supply rod 15 by a brazing material at the other surface, all other surfaces of the main body 161 that are not joined by the brazing material may be considered as side surfaces. The protective film 162 does not necessarily have to cover the entire side surface of the main body. For example, when cutting the stress relaxation section 16 in the above embodiment in the manufacturing flow (step S33 in FIG. 6), a part of the protective film 162 that covered the side surface 161S is scraped off, and the protective film 162 may cover the side surface other than the scraped part. Protective film 162 preferably covers 90% or more of side surface 161S of main body portion 161, and more preferably covers 95% or more of side surface 161S.

[0043] The substrate holding member 100 including the bonded body 10 can be modified in various ways as long as it includes the bonded body 10. For example, the substrate holding member 100 does not have to include the shaft 20.

[0044] Although the present aspect has been described above based on the embodiment and modified examples, the above-mentioned embodiment of the aspect is intended to facilitate understanding of the present aspect and does not limit the present aspect. The present aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in the present aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0045] 10, 10a...Conjugate 10F…Placement surface 11...Ceramics components 11M…Concave 12...Receiving electrode 13...Resistance heating element 14…Via conductor 15...Second power supply rod (metal terminal) 16, 16a…Stress relief section 161…Main body 161F1...electrode facing surface (first surface) 161F2...Rod facing surface (2nd surface) 161S…Side of main body 162,162a...Protective film (oxide protective film) 17, 17a…First brazing material 18, 18a…Second brazing material 20…Shaft 100...Substrate holding member OL…center axis W: Semiconductor wafer

Claims

1. A conjugate comprising: a ceramic member having a power receiving electrode; A metal terminal having electrical conductivity; a stress relaxation portion disposed between the ceramic member and the metal terminal; Equipped with The stress relaxation portion is a main body portion that is joined to the power receiving electrode via a brazing material at a first surface and is joined to the metal terminal via a brazing material at a second surface not connected to the first surface, the main body portion being made of a tungsten-based sintered alloy containing W (tungsten) as a main component and at least one of Ni (nickel), Fe (iron), and Cu (copper) as a binder phase; an oxide protective film covering a side surface of the main body portion connecting the first surface and the second surface; having The thickness of the oxide protective film is 100 nm or more and 1000 nm or less. A conjugate comprising:

2. The joint body according to claim 1 , 1. A joint body, wherein the oxide protective film contains one or more oxides of Cr, Ti, Zr, Hf, Nb, Al, V, and Ta.

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