Power supply member and wafer placement table

Abstract

To provide a power supply member having a sufficient strength.SOLUTION: A power supply member 50 comprises: an electrode side terminal 51; an insert 52; a connector 53; and a cable 56. The electrode side terminal 51 is formed by a high-melting point metal containing material, and is bonded to an electrode embedded into a ceramic base material. The insert 52 is formed by a Cu containing material, and includes a bonding part 52a directly bonded without being through the electrode side terminal 51 and a solder material and a hole part 52b provided to the side opposite to the bonding part 52a. The connector 53 is formed by a Cu containing material, and includes a socket part 53a to which a conductive member which is another from the power supply member 50 is electrically connected, and a concave part 53b provided to the side opposite to the socket part 53a. The cable 56 is formed by a Cu containing material, is bonded to the insert 52 in a state where one end is inserted into the hole part 52b of the insert 52, and is bonded to the connector 53 in a state where the other end is inserted into the concave part 53b of the connector 53.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a power supply member and a wafer mounting table. [Background technology]

[0002] Semiconductor manufacturing equipment is used for adsorbing wafers and heating / cooling wafers in etching equipment, ion implantation equipment, electron beam exposure equipment, etc. Such semiconductor manufacturing equipment includes a ceramic electrostatic chuck having a wafer mounting surface and incorporating an electrostatic electrode and a heater electrode, and a metal base member bonded to the surface of the electrostatic chuck opposite to the wafer mounting surface. Patent Document 1 discloses a power supply member used to supply power to the electrodes (electrostatic electrodes and heater electrodes) embedded in the electrostatic chuck of such semiconductor manufacturing equipment. The power supply member includes an electrode side terminal joined to the electrode, a flexible cable having an upper end connected to the electrode side terminal, and a female connector connected to the lower end of the cable. A male connector of an external device is connected to the female connector. According to this power supply member, even if a force acts on the female connector to press against the electrode, the cable bends to absorb the force, so that the electrostatic chuck can be prevented from being damaged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-191626 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when producing the above-mentioned power supply member, a hole for inserting a cable is provided in the electrode terminal made of Mo, and the upper end of the cable made of Cu is inserted into the hole and joined by electron beam welding or laser beam welding. However, in such a welding method, since the temperature does not rise to the vicinity of the melting point of Mo, it is difficult to form an alloy between Mo and Cu, and the molten Cu of the cable is not joined to the inner surface of the hole of the electrode terminal, but is only in contact with it. In addition, when the molten Cu solidifies, pores may be generated at the interface between Cu and Mo. As a result, the joining strength between the electrode terminal made of Mo and the cable made of Cu may not be sufficient.

[0005] The present invention has been made to solve the above problems, and has as its main object to provide a power supply member having sufficient strength. [Means for solving the problem]

[0006] The power supply member of the present invention is A power supply member used to supply power to an electrode embedded in a ceramic substrate, comprising: an electrode side terminal formed of a high melting point metal-containing material and joined to the electrode; an insert formed of a Cu-containing material, the insert having a joint portion directly joined to the electrode-side terminal without a brazing material and a hole portion provided on an opposite side to the joint portion; a connector formed of a Cu-containing material, the connector having a joint portion electrically connected to a conductive member other than the power supply member and a recess portion provided on an opposite side to the joint portion; a cable formed of a Cu-containing material, one end of which is joined to the insert in a state where it is inserted into the hole of the insert, and the other end of which is joined to the connector in a state where it is inserted into the recess of the connector; It is equipped with the following:

[0007] In this power supply member, the electrode side terminal made of a high melting point metal-containing material is directly joined to the joint of the insert made of a Cu-containing material without using a brazing material. Therefore, the electrode side terminal and the insert are joined with sufficient strength. In addition, one end of the cable made of a Cu-containing material is joined while being inserted into the hole of the insert, and the other end of the cable is joined while being inserted into the recess of the connector made of a Cu-containing material. These joints are between members made of a Cu-containing material, so sufficient strength is obtained. Therefore, this power supply member has sufficient strength.

[0008] In the power supply member of the present invention, the electrode side terminal is preferably made of a material containing Mo. This can prevent cracks from occurring between the electrode side terminal and the ceramic base material when the ceramic base material is made of an alumina-containing material. This is because alumina and Mo have similar thermal expansion coefficients, so that the stress generated by the difference in thermal expansion is small.

[0009] The wafer mounting table of the present invention comprises: a ceramic substrate having a wafer mounting surface on a surface thereof; an electrode embedded in the ceramic substrate; a power supply member that is inserted into a surface of the ceramic base opposite to the wafer mounting surface and is joined to the electrode; A wafer mounting table comprising: The power supply member is the power supply member of the present invention described above, and the electrode side terminal is joined to the electrode. It is something.

[0010] In this wafer mounting table, the electrode side terminal made of a high melting point metal-containing material is directly joined to the joint of the insert made of a Cu-containing material without using a brazing material. Therefore, the electrode side terminal and the insert are joined with sufficient strength. In addition, one end of the cable made of a Cu-containing material is joined while being inserted into the hole of the insert, and the other end of the cable is joined while being inserted into the recess of the connector made of a Cu-containing material. These joints are between members made of a Cu-containing material, so sufficient strength is obtained. Therefore, this power supply member has sufficient strength.

[0011] In the wafer mounting table of the present invention, it is preferable that the ceramic base is made of an alumina-containing material, and the electrode terminal is made of a Mo-containing material. This can prevent cracks from occurring between the electrode terminal and the ceramic base. This is because alumina and Mo have similar thermal expansion coefficients, so that stress caused by the difference in thermal expansion is reduced. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view showing an outline of the wafer mounting table 10. [Diagram 2] FIG. 2 is a vertical cross-sectional view showing a schematic configuration of a power supply member 50. [Diagram 3] 5A to 5C are diagrams showing the manufacturing process of the power supply member 50. [Figure 4] FIG. 2 is a vertical cross-sectional view showing a schematic configuration of a power supply member 150. [Diagram 5] 1 is a graph showing breaking strength of an embodiment and a comparative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Fig. 1 is a cross-sectional view showing a schematic configuration of a wafer mounting table 10 of this embodiment (a cross-sectional view of the wafer mounting table 10 cut along a plane including the central axis of the wafer mounting table 10), and Fig. 2 is a vertical cross-sectional view showing a schematic configuration of a power supply member 50 (a cross-sectional view of the power supply member 50 cut along a plane including the central axis of the power supply member 50). Note that in the following description, up / down, left / right, and front / rear are sometimes used, but these terms merely refer to relative positional relationships.

[0014] The wafer mounting table 10 is used for processing a wafer W. As shown in Fig. 1, the wafer mounting table 10 includes a ceramic base 20, an electrostatic electrode 22, a heater electrode 24, a cooling base 30, a bonding layer 40, and power supply members 50A and 50B.

[0015] The ceramic substrate 20 is a disk-shaped member having a wafer mounting surface 20a on its surface. The ceramic substrate 20 is made of a ceramic-containing material. The ceramic-containing material is a material whose main component is ceramic, and may contain components derived from sintering aids (e.g., rare earth elements, etc.) and unavoidable components in addition to ceramic. The main component means that the proportion of the total is 50 mass% or more (the same applies below). Examples of ceramics include alumina and aluminum nitride.

[0016] The electrostatic electrode 22 and the heater electrode 24 are embedded in the ceramic base material 20. The electrostatic electrode 22 is embedded closer to the wafer mounting surface 20a than the heater electrode 24. These electrodes 22 and 24 are formed of a material containing, for example, W, Mo, WC, MoC, etc. The electrostatic electrode 22 is a disk-shaped or mesh-shaped monopolar electrostatic electrode. The layer of the ceramic base material 20 above the electrostatic electrode 22 functions as a dielectric layer. A DC power source 62 for electrostatic attraction is connected to the electrostatic electrode 22 via a power supply member 50A. The heater electrode 24 is wired in a single stroke from one end to the other end so as to cover the entire surface of the wafer mounting surface 20a in a plan view. A heater power source 64 is connected to one end of the heater electrode 24 via a power supply member 50B. Although not shown, the other end of the heater electrode 24 is also connected to the heater power source 64 via the power supply member 50B in the same manner as the one end of the heater electrode 24.

[0017] The cooling substrate 30 is a disk-shaped member having a refrigerant flow passage 32 through which a refrigerant can circulate. The refrigerant flow passage 32 is formed in a single stroke from one end to the other end so as to cover the entire surface of the ceramic substrate 20 in a plan view. One end and the other end of the refrigerant flow passage 32 are connected to a refrigerant circulation pump (not shown) that has a function of adjusting the temperature of the refrigerant. The cooling substrate 30 is made of a conductive material containing, for example, a metal. Examples of the conductive material include composite materials and metals. Examples of the composite material include metal composite materials (also called metal matrix composites (MMCs)), and examples of the MMC include materials containing Si, SiC, and Ti, and materials in which a porous SiC body is impregnated with Al and / or Si. A material containing Si, SiC, and Ti is called SiSiCTi, a material in which a porous SiC body is impregnated with Al is called AlSiC, and a material in which a porous SiC body is impregnated with Si is called SiSiC. Examples of the metal include Al, Ti, Mo, and alloys thereof.

[0018] The bonding layer 40 bonds the lower surface of the ceramic base material 20 and the upper surface of the cooling base material 30. The bonding layer 40 may be, for example, a metal bonding layer formed of solder or a metal brazing material. The metal bonding layer is formed, for example, by TCB (thermal compression bonding). TCB refers to a known method in which a metal bonding material is sandwiched between two members to be bonded, and the two members are pressure-bonded while being heated to a temperature equal to or lower than the solidus temperature of the metal bonding material.

[0019] The power supply member 50A is inserted into a through hole 22a extending from the lower surface of the ceramic base material 20 to the electrostatic electrode 22 via a through hole that vertically penetrates the cooling base material 30 and a through hole that vertically penetrates the bonding layer 40, and has an upper end joined to the electrostatic electrode 22. An insulating tube 42 is inserted into the through hole that vertically penetrates the cooling base material 30 and the through hole that vertically penetrates the bonding layer 40. The power supply member 50A passes through the inside of this insulating tube 42.

[0020] The power supply member 50B is inserted into a through hole 24a extending from the lower surface of the ceramic base material 20 to the heater electrode 24 via a through hole that vertically penetrates the cooling base material 30 and a through hole that vertically penetrates the bonding layer 40, and has an upper end joined to the heater electrode 24. An insulating tube 44 is inserted into the through hole that vertically penetrates the cooling base material 30 and the through hole that vertically penetrates the bonding layer 40. The power supply member 50B passes through the inside of this insulating tube 44.

[0021] The power supply members 50A and 50B have the same structure except for the length of the cables, and therefore will be hereinafter described as the power supply member 50 without distinguishing between the power supply members 50A and 50B.

[0022] As shown in FIG. 2, the power supply member 50 includes an electrode side terminal 51, an insert 52, a connector 53, and a cable 56.

[0023] The electrode side terminal 51 is a disk-shaped member made of a high-melting-point metal-containing material. The high-melting-point metal-containing material is a material whose main component is a high-melting-point metal, and may contain inevitable components and components contained in the ceramic substrate 20 in addition to the high-melting-point metal. Examples of high-melting-point metals include Mo and W. When the ceramic substrate 20 is made of an alumina-containing material, it is preferable that the electrode side terminal 51 is made of a Mo-containing material. The electrode side terminal 51 is brazed to the electrode (the electrostatic electrode 22 or the heater electrode 24) and the ceramic substrate 20 around the electrode. Examples of brazing materials include Au-containing alloys. Examples of Au-containing alloys include Au Examples of the brazing material include a Ge alloy, an AuSn alloy, an AuSi alloy, etc. When the electrode terminal 51 is formed of a material containing Mo, it is preferable to use an AuGe alloy as the brazing material.

[0024] The insert 52 is a cylindrical member formed of a Cu-containing material. The Cu-containing material is a material mainly composed of Cu, and may contain inevitable components other than Cu. The insert 52 has a joint 52a to be joined to the electrode side terminal 51, and a hole 52b provided on the opposite side to the joint 52a. In this embodiment, the joint 52a is the upper surface of the cylinder, and is directly joined to the electrode side terminal 51 without using a brazing material. Therefore, the strength of the joint between the joint 52a and the electrode side terminal 51 is sufficiently high. When the joint between the joint 52a and the electrode side terminal 51 is viewed in a SEM photograph, it is preferable that no gap is seen at the joint interface.

[0025] The connector 53 is made of a Cu-containing material and has a socket portion 53a (corresponding to a joint portion of the present invention) and a recess 53b. The socket portion 53a is provided on the lower side of the connector 53 and is electrically connected to a conductive member of an external device (for example, a DC power source 62 or a heater power source 64). In this embodiment, the socket portion 53a is a banana jack, and the conductive member of the external device is a banana plug inserted into the banana jack. The recess 53b is a hole provided on the upper side of the connector 53. The connector 53 is formed by joining a lower member 54 having a socket portion 53a and an upper member 55 having a recess 53b. The lower member 54 and the upper member 55 can be joined by soldering, electron beam welding, laser beam welding, or the like. Since both the lower member 54 and the upper member 55 are made of a Cu-containing material, the strength of the welded portion of both members 54 and 55 is sufficiently high.

[0026] The cable 56 is a flexible cable made of a Cu-containing material. In this embodiment, the cable 56 is a strand of thin metal wires made of a Cu-containing material. An upper end 56a of the cable 56 is joined to the insert 52 in a state where it is inserted into a hole 52b of the insert 52. A lower end 56b of the cable 56 is joined to the connector 53 in a state where it is inserted into a recess 53b of the connector 53. The joining of the cable 56 to the insert 52 and the joining of the cable 56 to the connector 53 can be performed by electron beam welding, laser beam welding, or the like. Since the cable 56, the insert 52, and the connector 53 are all made of a Cu-containing material, the strength of the welded portion is sufficiently high.

[0027] Next, a manufacturing example of the power supply member 50 (including an example of attachment to an electrode) will be described with reference to Fig. 3. Fig. 3 is a manufacturing process diagram of the power supply member 50. Here, the electrode side terminal 51 is formed of a Mo-containing material, and the insert 52, connector 53 (lower member 54 and upper member 55), and cable 56 are formed of a Cu-containing material.

[0028] First, the electrode side terminal 51 and the insert 52 are prepared, and the lower surface of the electrode side terminal 51 and the upper surface of the insert 52, which is the joint portion 52a, are directly joined together (see FIG. 3A). . It is also possible to prepare a cylindrical body (without the hole 52b) instead of the insert 52, directly bond the cylindrical body to the electrode side terminal 51, and then form the hole 52b in the cylindrical body to serve as the insert 52.

[0029] Next, the upper end 56a of the cable 56 is inserted into the hole 52b provided in the lower surface of the insert 52 and welded, and the lower end 56b of the cable 56 is inserted into the recess 53b of the upper member 55 and welded (see FIG. 3B). The welding at this time can be performed by electron beam welding, laser beam welding, or the like.

[0030] Next, the electrode side terminal 51 is bonded to the electrode (electrostatic electrode 22 or heater electrode 24) embedded in the ceramic base material 20 and to the ceramic base material 20 around the electrode (see FIG. 3C). The bonding at this time can be performed using an Au-containing alloy (e.g., AuGe alloy). As a result, the electrode side terminal 51 is bonded to the electrode and the ceramic base material 20 around the electrode via the brazing layer 23.

[0031] Finally, the lower surface of the upper member 55 and the upper surface of the lower member 54 are joined (see FIG. 3D) to obtain the power supply member 50. The joining at this time can be performed by soldering, electron beam welding, laser beam welding, or the like. Alternatively, a small projection for alignment may be provided on the lower surface of the upper member 55, and a small hole that fits with the small projection may be provided on the upper surface of the lower member 54, so that the small projection fits into the small hole. In this way, the upper member 55 and the lower member 54 can be easily aligned.

[0032] Next, a power supply connected to the electrode of the wafer mounting table 10 Materials The breaking strength of 50 is explained. Materials The electrode side terminal 51 of the electrode 50 is made of Mo, and the insert 52, the connector 53 (the lower member 54 and the upper member 55) and the cable 56 are made of Cu. MaterialsThe insert 52 was manufactured according to the above-mentioned manufacturing example and attached to the electrode. When the joint portion 52a of the insert 52 and the electrode side terminal 51 were observed in a SEM photograph, no gap was observed at the joint interface. Materials The fracture strength of the electrode 150 attached to the wafer stage 10 was also measured. Materials The electrode terminal 150 is made of Mo and is fabricated by integrating the electrode terminal 51 and the insert 52 described above. The upper end 56a of the cable 56 is inserted into the hole 151a of the electrode terminal 151 and joined by electron beam welding. Materials 50 and attached to the electrode of the wafer mounting table 10. The breaking strength of this embodiment and the comparative embodiment were measured under the same conditions in accordance with "JIS Z 2241: Metallic material tensile test method". The results are shown in FIG. 5. As can be seen from FIG. 5, the breaking strength of this embodiment was improved by about four times compared to the breaking strength of the comparative embodiment. In the comparative embodiment, the connection between the holed electrode side terminal 151 and the cable 56 came off and broke, whereas in this embodiment, the cable 56 itself broke. Also, in the comparative embodiment, gaps (pores) were found at the joint interface between the holed electrode side terminal 151 and the cable 56.

[0033] In the power supply member 50 described above, the electrode side terminal 51 made of a high melting point metal-containing material is directly joined to the joint portion 52a of the insert 52 made of a Cu-containing material without using a brazing material. Therefore, the electrode side terminal 51 and the insert 52 are joined with sufficient strength. In addition, the upper end 56a of the cable 56 made of a Cu-containing material is joined in a state where it is inserted into the hole portion 52b of the insert 52, and the lower end 56b of the cable 56 is joined in a state where it is inserted into the recess 53b of the connector 53 made of a Cu-containing material. These joints are joined between members made of a Cu-containing material, so sufficient strength is obtained. Therefore, the power supply member 50 has sufficient strength. As a result, the wafer stage 10 can be used without any problem even if the upper limit of the operating temperature is set to a high temperature (for example, 300°C).

[0034] Moreover, the electrode side terminal 51 is preferably made of a material containing Mo. This can prevent cracks and the like from occurring between the electrode side terminal 51 and the ceramic substrate 20 when the ceramic substrate 20 is made of a material containing alumina. This is because alumina and Mo have similar thermal expansion coefficients, and therefore the stress generated by the difference in thermal expansion is reduced.

[0035] It goes without saying that the present invention is not limited to the above-described embodiment, and can be embodied in various forms within the technical scope of the present invention.

[0036] For example, in the above embodiment, the connector 53 is produced by soldering or welding the lower member 54 and the upper member 55, but instead of forming the connector 53 by joining a plurality of members, the connector 53 may be formed as an integrated unit. In this way, the manufacturing process of the power supply member 50 does not require a step of soldering or welding the lower member 54 and the upper member 55.

[0037] In the above-described embodiment, the connector 53 of the power supply member 50A may be fixed to the insulating tube 42, and the connector 53 of the power supply member 50B may be fixed to the insulating tube 44.

[0038] In the above-described embodiment, the electrostatic electrode 22 and the heater electrode 24 are embedded in the ceramic substrate 20, but it is also possible to embed only one of them. Also, it is also possible to embed a plasma generation electrode in the ceramic substrate 20 and attach the power supply member 50 to the electrode in the same manner as in the above-described embodiment.

[0039] In the above-described embodiment, the connector 53 has the socket portion 53a which is a banana jack, but a banana plug may be provided instead of the socket portion 53a. In this case, the banana plug of the connector 53 is inserted into a banana jack serving as a conductive member of an external device (for example, the DC power supply 62 or the heater power supply 64) and electrically connected to the external device.

[0040] In the above-described embodiment, the bonding layer 40 is a metal bonding layer, but it may be a resin adhesive layer. [Explanation of symbols]

[0041] 10 wafer mounting table, 20 ceramic substrate, 20a wafer mounting surface, 22 electrostatic electrode, 22a through hole, 23 solder bonding layer, 24 heater electrode, 24a through hole, 30 cooling substrate, 32 coolant flow path, 40 bonding layer, 42, 44 insulating tube, 50, 50A, 50B power supply member, 51 electrode side terminal, 52 insert, 52a bonding portion, 52b hole portion, 53 connector, 53a socket portion, 53b recess, 54 lower member, 55 upper member, 56 cable, 56a upper end, 56b lower end, 62 DC power source, 64 heater power source, 150 power supply Materials , 151 electrode side terminal, 151a hole, W wafer.

Claims

1. A power supply member used to supply power to an electrode embedded in a ceramic substrate, comprising: an electrode side terminal formed of a high melting point metal-containing material and joined to the electrode; an insert formed of a Cu-containing material, the insert having a joint portion directly joined to the electrode-side terminal without using a brazing material and a hole portion provided on an opposite side to the joint portion; a connector formed of a Cu-containing material, the connector having a joint portion electrically connected to a conductive member other than the power supply member and a recess portion provided on an opposite side to the joint portion; a cable made of a Cu-containing material, one end of which is joined to the insert in a state where it is inserted into the hole of the insert, and the other end of which is joined to the connector in a state where it is inserted into the recess of the connector; A power supply member comprising:

2. The electrode side terminal is made of a Mo-containing material. The power supply member according to claim 1 .

3. a ceramic substrate having a wafer mounting surface on a surface thereof; an electrode embedded in the ceramic substrate; a power supply member that is inserted into a surface of the ceramic base opposite to the wafer mounting surface and is joined to the electrode; A wafer mounting table comprising: The power supply member is the power supply member according to claim 1 or 2, and the electrode side terminal is joined to the electrode. Wafer placement stage.

4. the ceramic substrate is formed of an alumina-containing material; The electrode side terminal is formed of a Mo-containing material. The wafer stage according to claim 3 .

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