Semiconductor manufacturing equipment parts

Abstract

The wafer mounting table 10 includes a ceramic plate 20 in which an electrostatic electrode 22 is embedded, a power supply member insertion hole 24 provided from the lower surface of the ceramic plate 20 to reach the front of the electrostatic electrode 22, a metallic power supply member 50 inserted into the power supply member insertion hole 24 with some play, a recessed hole 25 provided from the bottom surface of the power supply member insertion hole 24 to reach the electrostatic electrode 22 (electrode extraction portion 22a), a first brazing material layer 26 filled in the recessed hole 25, and a second brazing material layer 27 joining the entire tip surface 50a of the power supply member 50 to the first brazing material layer 26. A diameter D1 of the opening of the recessed hole 25 is smaller than a diameter D2 of the power supply member insertion hole 24 and is equal to or larger than a diameter D3 of the power supply member 50. The second brazing material layer 27 is provided so as not to reach a boundary portion 24a between the bottom surface and the side surface of the power supply member insertion hole 24.

Description

[Technical field]

[0001] The present invention relates to a member for a semiconductor manufacturing device. [Background technology]

[0002] In semiconductor manufacturing equipment, components for semiconductor manufacturing equipment such as a ceramic heater for heating a wafer and an electrostatic chuck for attracting and holding a wafer are adopted. Patent Document 1 discloses a structure for joining a power supply member to an electrode embedded in a ceramic plate in this type of semiconductor manufacturing equipment component. Specifically, a power supply member insertion hole is provided so as to reach the front of the electrode from the lower surface of the ceramic plate, and a concave housing part is provided so as to reach an electrode lead-out part added to the electrode from the bottom surface of the power supply member insertion hole. A first metal disk is housed in the housing part. The first metal disk is joined to the electrode lead-out part by a first brazing material layer. The power supply member is inserted into the power supply member insertion hole with play. A second brazing material layer containing a second metal disk is provided between the tip surface of the power supply member and the first metal disk. The second brazing material layer is provided so as to cover the entire bottom surface of the power supply member insertion hole (i.e., so as to reach the boundary part between the bottom surface and the side surface of the power supply member insertion hole). The second brazing material layer is provided so as to contact the entire tip surface of the power supply member and to extend up the side surface of the power supply member (FIG. 3 of Patent Document 1). Alternatively, the second brazing material layer is provided so as to contact the center of the tip surface of the power supply member but not to contact the outer periphery (FIGS. 4 and 5 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-203581 A (particularly, Figs. 3 to 5) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the second brazing material layer is provided so as to cover the entire bottom surface of the power supply member insertion hole (i.e., so as to reach the boundary between the bottom surface and the side surface of the power supply member insertion hole), so if the second brazing material layer is designed to contact the entire tip surface of the power supply member, the second brazing material is likely to creep up the side surface of the power supply member during manufacturing. In that case, the second brazing material may be insufficient between the tip surface of the power supply member and the second metal disk or between the second metal disk and the first metal disk, resulting in voids (pores) in those areas. Such voids may cause problems such as poor power supply. On the other hand, if the second brazing material layer is designed to contact only the center of the tip surface of the power supply member, the contact area between the two may not be sufficient, and problems such as poor power supply may occur.

[0005] The present invention has been made to solve the above-mentioned problems, and has as its main object to provide a method for effectively supplying power to an electrode embedded in a ceramic plate through a power supply member. [Means for solving the problem]

[0006] [1] The semiconductor manufacturing equipment member of the present invention is a ceramic plate having a wafer mounting surface on an upper surface thereof and an electrode embedded therein; a power supply member insertion hole provided from the lower surface of the ceramic plate to a position just in front of the electrode; a power supply member inserted into the power supply member insertion hole with some play; a recessed hole provided from a bottom surface of the power supply member insertion hole to reach the electrode or an electrode lead-out portion added to the electrode, the opening of which has a diameter smaller than the diameter of the power supply member insertion hole and equal to or larger than the diameter of the power supply member; A first brazing material layer filled in the recess; a second brazing layer that joins the entire end surface of the power supply member and the first brazing layer and does not reach a boundary between a bottom surface and a side surface of the power supply member insertion hole; It is equipped with the following:

[0007] In this semiconductor manufacturing device member, the diameter of the opening of the recess is smaller than the diameter of the power supply member insertion hole and is equal to or larger than the diameter of the power supply member. The first brazing material layer is filled in the recess. The second brazing material layer joins the entire end face of the power supply member to the first brazing material layer. This second brazing material layer is provided so as not to reach the boundary between the bottom surface and the side surface of the power supply member insertion hole. If the second brazing material layer reaches the boundary surface, the second brazing material is likely to creep up from the boundary surface to the side surface of the power supply member insertion hole or the side surface of the power supply member during manufacturing, and voids (air holes) are likely to occur in the second brazing material layer between the power supply member and the first brazing material layer. However, since the second brazing material layer does not reach the boundary surface here, it is possible to suppress the second brazing material from creeping up to the side surface of the power supply member insertion hole or the side surface of the power supply member during manufacturing, and it is possible to prevent voids from occurring in the second brazing material layer between the power supply member and the first brazing material layer. Therefore, power can be effectively supplied from the power supply member to the electrodes embedded in the ceramic plate.

[0008] The "border" is the portion where the bottom and side surfaces of the power supply member insertion hole intersect. If the "border" is not chamfered, the "border" is the edge where the bottom and side surfaces of the power supply member insertion hole intersect. If the edge is chamfered, the "border" is the portion after the edge has been chamfered (for example, the entire C-face in the case of C-chamfering, or the entire R-face in the case of R-chamfering).

[0009] [2] In the semiconductor manufacturing equipment member of the present invention (semiconductor manufacturing equipment member described in [1] above), the boundary portion may be chamfered, and the second brazing material layer may be provided so as not to reach the chamfered boundary portion. In this way, it is possible to prevent cracks from occurring starting from the boundary portion of the power supply member insertion hole. In addition, since the second brazing material layer does not reach the chamfered boundary portion, it is possible to further prevent the second brazing material from creeping up onto the side surface of the power supply member insertion hole or the side surface of the power supply member during manufacturing.

[0010] [3] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to the above [1] or [2]), the edge of the end face of the power supply member may be chamfered to C0.3 or less or R0.3 or less. This increases the area of ​​the end face of the power supply member, thereby increasing the contact area between the end face of the power supply member and the second brazing layer.

[0011] [4] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [3] above), the first brazing material layer may contain an active metal, and the second brazing material layer may contain no active metal or may have a lower content of active metal than the first brazing material layer. In this case, when the first brazing material layer is formed, the first brazing material contains an active metal and therefore tends to wet and spread over the surface of the recessed hole (ceramic plate). On the other hand, when the second brazing material layer is formed, the second brazing material does not contain an active metal or has a low content of active metal, so that it does not wet and spread over the surface of the ceramic plate and does not easily reach the boundary of the power supply member insertion hole.

[0012] [5] In the semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member described in [4] above), the interface between the first brazing material layer and the second brazing material layer may be a region where a component contained in the first brazing material layer and a component contained in the second brazing material layer are diffused. During production, a second brazing material layer that does not contain active metal or has a low content of active metal is formed on a first brazing material layer that contains active metal, but the components contained in both layers diffuse at the interface between the first brazing material layer and the second brazing material layer, and the region where both components are mixed is likely to be formed.

[0013] [6] The semiconductor manufacturing equipment member of the present invention (the semiconductor manufacturing equipment member according to any one of [1] to [5] above) may include a conductive cooling plate provided on the underside of the ceramic plate, and a cooling plate through-hole that vertically penetrates the cooling plate, communicates with the power supply member insertion hole, and through which the power supply member is inserted. In this case, the second brazing material layer does not reach the boundary between the bottom and side surfaces of the power supply member insertion hole, and therefore the distance (insulation distance) between the second brazing material layer and the cooling plate can be made longer than when the second brazing material layer is provided along the side surfaces of the power supply member insertion hole. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a cross-sectional view showing a schematic configuration of a wafer mounting table 10. [Diagram 2] A partially enlarged view of Figure 1. [Diagram 3] 5 is an explanatory diagram of a process for joining a power supply member 50 to an electrostatic electrode 22. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Fig. 1 is a cross-sectional view showing a schematic configuration of a wafer mounting table 10 of this embodiment (a cross-sectional view when the wafer mounting table 10 is cut along a plane including the central axis of the wafer mounting table 10), and Fig. 2 is an enlarged view (an enlarged view of a frame indicated by a two-dot chain line) of Fig. 1. Note that, although up / down, left / right, and front / rear are sometimes used in the following description, up / down, left / right, and front / rear merely refer to relative positional relationships.

[0016] The wafer mounting table 10 is an example of a semiconductor manufacturing equipment member used for processing a wafer W. As shown in FIG.

[0017] The ceramic plate 20 is a disk-shaped member having a wafer mounting surface 20a on its upper surface. The ceramic plate 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 whole is 50 mass% or more. Examples of ceramics include alumina and aluminum nitride.

[0018] An electrostatic electrode 22 is embedded in the ceramic plate 20. The electrostatic electrode 22 is formed of a material containing a metal such as W, Mo, WC, or MoC. The metal used for the electrostatic electrode 22 is preferably one having a thermal expansion coefficient close to that of the ceramic plate 20. In order to make the thermal expansion coefficient of the electrostatic electrode 22 close to that of the ceramic plate 20, the electrostatic electrode 22 may contain the ceramic contained in the ceramic plate 20. The electrostatic electrode 22 is a disk-shaped or mesh-shaped monopolar electrostatic electrode. The layer of the ceramic plate 20 above the electrostatic electrode 22 functions as a dielectric layer. A DC power source 62 for electrostatic adsorption is connected to the electrostatic electrode 22 via a power supply member 50.

[0019] The cooling plate 30 is a disk-shaped member having a refrigerant flow passage 32 inside 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 plate 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 plate 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. The conductive material used for the cooling plate 30 is preferably one whose thermal expansion coefficient is close to that of the ceramic plate 20 .

[0020] The bonding layer 40 bonds the lower surface of the ceramic plate 20 and the upper surface of the cooling plate 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 may be 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 pressurized and bonded while being heated to a temperature equal to or lower than the solidus temperature of the metal bonding material. As the bonding layer 40, an organic adhesive layer may be used instead of the metal bonding layer.

[0021] The power supply member 50 is a metal member that supplies power to the electrostatic electrode 22. The power supply member 50 is, for example, a metal rod. The metal used for the power supply member 50 is, for example, W, Mo, Ni, etc., and it is preferable that the thermal expansion coefficient of the metal is close to that of the ceramic plate 20. The power supply member 50 is inserted from the lower surface side of the cooling plate 30 through the cooling plate through hole 34 that penetrates the cooling plate 30 in the vertical direction and the bonding layer through hole 44 that penetrates the bonding layer 40 in the vertical direction into the power supply member insertion hole 24 provided in the ceramic plate 20. The diameter of the bonding layer through hole 44 is the same as the diameter of the cooling plate through hole 34. The power supply member 50 is electrically connected to the electrostatic electrode 22.

[0022] The joining structure between the power supply member 50 and the electrostatic electrode 22 will be described with reference to FIG. 2. The power supply member 50 passes through the inside of the insulating tube 36 arranged in the cooling plate through hole 34 and is inserted into the power supply member insertion hole 24 with some play. The outer circumferential surface of the insulating tube 36 is bonded to the inner circumferential surface of the cooling plate through hole 34 via an adhesive layer 35. The upper end surface of the insulating tube 36 is located higher than the upper surface of the cooling plate 30 and lower than the lower surface of the ceramic plate 20. The power supply member insertion hole 24 is a cylindrical hole and is provided so as to reach from the lower surface of the ceramic plate 20 to just before the electrostatic electrode 22. The boundary portion 24a (the portion surrounded by a dashed line frame in FIG. 2) between the bottom surface and the side surface of the power supply member insertion hole 24 is chamfered. The chamfering may be R chamfering or C chamfering. A recessed hole 25 is provided in the bottom surface of the power supply member insertion hole 24. The recessed hole 25 is provided so as to reach the electrode extraction portion 22a added to the electrostatic electrode 22. The diameter D1 of the opening of the recessed hole 25 is smaller than the diameter D2 of the power supply member insertion hole 24 and is equal to or larger than the diameter D3 of the power supply member 50. The opening of the recessed hole 25 does not reach the chamfered boundary portion 24a of the power supply member insertion hole 24.

[0023] The power supply member 50 is electrically connected to an electrode extraction portion 22a provided on the electrostatic electrode 22 via a first brazing material layer 26 and a second brazing material layer 27. The electrode extraction portion 22a is a circular plate member made of the same material as the electrostatic electrode 22. The lower surface of the electrode extraction portion 22a is exposed to the bottom surface of the recessed hole 25.

[0024] The first brazing material layer 26 is filled in the recessed hole 25. The first brazing material layer 26 is a layer formed by a first brazing material containing an active metal. The surface (lower surface) of the first brazing material layer 26 is flush with the bottom surface of the power supply member insertion hole 24. Examples of the first brazing material include silver brazing material, copper brazing material, nickel brazing material, gold brazing material, and palladium brazing material containing an active metal. Examples of the active metal include titanium, zirconium, hafnium, vanadium, niobium, and beryllium. Specific examples of the first brazing material include Ag-Cu-Ti brazing material and Ag-Cu-Ti-Sn brazing material. Since these first brazing materials are processed at 700° C. or higher, a chemical reaction may occur at the interface between the ceramic plate 20 and the first brazing material to form a reaction layer, and it is considered that such a reaction layer plays a role in increasing the bonding strength between the ceramic plate 20 and the first brazing material layer 26.

[0025] The second brazing material layer 27 joins the entire tip surface 50a of the power supply member 50 to the first brazing material layer 26. The second brazing material layer 27 is provided so as not to reach the boundary portion 24a of the power supply member insertion hole 24. The second brazing material layer 27 is a layer formed of a second brazing material that does not contain active metal. Examples of the second brazing material include Au-Ge brazing material, Au-Sn brazing material, and Au-Si brazing material. The first brazing material basically spreads on the surface of the first brazing material layer 26, but does not spread on the surface of the ceramic plate 20. Therefore, the second brazing material layer 27 is formed without protruding significantly from the surface of the first brazing material layer 26. The melting point of the second brazing material is lower than that of the first brazing material (for example, 200 to 500°C), so the processing temperature of the second brazing material is lower than that of the first brazing material.

[0026] Since the larger the area of ​​the tip surface 50a of the power supply member 50 is, the larger the bonding area with the second solder layer 27 is, the edge 50b of the tip surface 50a does not need to be chamfered, and if it is chamfered, it is preferable that it be C-chamfered to C0.3 or less, or R-chamfered to R0.3 or less.

[0027] Next, an example of use of the wafer mounting table 10 will be described. First, the wafer mounting table 10 is installed in a vacuum chamber (not shown), and the wafer W is mounted on the wafer mounting surface 20a of the wafer mounting table 10. Then, a voltage is applied to the electrostatic electrode 22 from the DC power source 62 via the power supply member 50. Then, the wafer W is attracted and fixed to the wafer mounting surface 20a. Then, the inside of the vacuum chamber is set to a vacuum atmosphere or a reduced pressure atmosphere, and the wafer W is processed in the vacuum chamber. For example, when processing the wafer W with plasma, an upper electrode equipped with a shower head is placed on the ceiling of the vacuum chamber, and a high frequency voltage is applied between the upper electrode and the cooling plate 30 while a reactive gas is supplied from the shower head to the space between the wafer W and the upper electrode to generate plasma. After the processing of the wafer W is completed, the application of the voltage to the electrostatic electrode 22 is released. Then, the wafer W is released from the attracted and fixed position on the wafer mounting surface 20a. Incidentally, a coolant is passed through the coolant flow passage 32 when it is necessary to lower the temperature of the wafer W.

[0028] Next, the manufacturing method of the wafer mounting table 10, particularly the step of joining the power supply member 50 to the electrostatic electrode 22, will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram of this step.

[0029] First, a ceramic plate 20 is prepared in which an electrostatic electrode 22 and an electrode extraction portion 22a that contacts the electrostatic electrode 22 are embedded (FIG. 3A). Such a ceramic plate 20 can be prepared by a known method. In addition, in FIGS. 3A to 3D, the surface of the ceramic plate 20 that becomes the wafer mounting surface 20a faces downward.

[0030] Next, a cylindrical first hole 125 is formed from one surface of the ceramic plate 20 toward the electrode lead-out portion 22a (FIG. 3B). At this time, the first hole 125 is formed so that the electrode lead-out portion 22a is exposed at the bottom surface of the first hole 125. The first hole 125 can be formed by, for example, countersinking. The diameter of the first hole 125 is the same as the diameter of the opening of the recessed hole 25. The boundary between the bottom surface and the side surface of the first hole 125 is formed into a chamfered shape.

[0031] Next, a first brazing material layer 126 is formed over the entire bottom surface of the first hole 125 (FIG. 3C). The first brazing material layer 126 can be formed, for example, by cutting a sheet of a first brazing material containing an active metal to fit the size of the bottom surface of the first hole 125, heating and melting the first brazing material while the sheet is laid on the bottom surface of the first hole 125, and then cooling and solidifying it. Alternatively, the first brazing material layer 26 may be formed by a gas phase method (CVD, sputtering) or a liquid phase method (electrolytic plating, electroless plating).

[0032] Next, a cylindrical second hole, a power supply member insertion hole 24, is formed from the surface of the ceramic plate 20 where the first hole 125 is formed toward the first brazing material layer 126 so as to be coaxial with the first hole 125 (FIG. 3D). The power supply member insertion hole 24 can be formed, for example, by countersinking. The power supply member insertion hole 24 is formed so that the bottom surface of the power supply member insertion hole 24 is above the bottom surface of the first hole 125 and below the surface of the first brazing material layer 126. A boundary portion 24a between the bottom surface and the side surface of the power supply member insertion hole 24 has a chamfered shape. When the power supply member insertion hole 24 is formed, the surface layer of the first brazing material layer 126 is scraped off to become the first brazing material layer 26 (FIG. 3D), and the surface of the first brazing material layer 26 becomes flush with the bottom surface of the power supply member insertion hole 24.

[0033] Next, a sheet of a second brazing material that does not contain active metal (or has a lower content of active metal than the first brazing material) is placed on the first brazing material layer 26, and the power supply member 50 is placed on the second brazing material. That is, the sheet of the second brazing material is sandwiched between the first brazing material layer 26 and the tip surface 50a of the power supply member 50. The melting point of the second brazing material is lower than that of the first brazing material. The size of the sheet of the second brazing material is adjusted so that the size of the sheet of the second brazing material is equal to the size of the first brazing material layer 26 when the sheet of the second brazing material melts and then solidifies. In this state, the sheet is treated at a temperature equal to or higher than the melting point of the second brazing material and lower than the melting point of the first brazing material. Then, the second brazing material melts. The second brazing material is easy to spread on the surface of the first brazing material layer 26, but is difficult to spread on the outer region (ceramic plate 20) of the first brazing material layer 26. Therefore, the second brazing material layer 27 after the second brazing material solidifies remains mostly in the region where the first brazing material layer 26 was formed. As a result, the diameter of the second brazing material layer 27 becomes equal to or larger than the diameter D2 of the power supply member 50 and does not reach the chamfered boundary portion 24a of the power supply member insertion hole 24.

[0034] When treated at a temperature equal to or higher than the melting point of the second brazing material and lower than the melting point of the first brazing material, the components contained in the first brazing material layer 26 and the components contained in the second brazing material diffuse. Therefore, the interface between the first brazing material layer 26 and the second brazing material layer 27 becomes a region where the components of both layers 26, 27 diffuse. Although the interface between the first brazing material layer 26 and the second brazing material layer 27 is clearly shown in Fig. 2, in reality, this interface becomes a region (gradation region) where the components of both layers 26, 27 diffuse.

[0035] The step of joining the power supply member 50 to the first brazing material layer 26 may be performed before joining the cooling plate 30 to the ceramic plate 20 or after joining the cooling plate 30 to the ceramic plate 20.

[0036] In the wafer mounting table 10 described above, the diameter D1 of the opening of the recessed hole 25 is smaller than the diameter D2 of the power supply member insertion hole 24 and is equal to or larger than the diameter D3 of the power supply member 50. The first brazing material layer 26 is filled in the recessed hole 25. Therefore, the first brazing material layer 26 does not exist or is almost not present outside the opening of the recessed hole 25. The second brazing material layer 27 joins the entire tip surface 50a of the power supply member 50 to the first brazing material layer 26. This second brazing material layer 27 is provided so as not to reach the boundary portion 24a of the power supply member insertion hole 24. If the second brazing material layer 27 reaches the boundary portion 24a, the second brazing material is likely to creep up from the boundary portion 24a to the side surface of the power supply member insertion hole 24 and the side surface of the power supply member 50 during manufacturing, and voids (pores) are likely to occur in the second brazing material layer 27 between the power supply member 50 and the first brazing material layer 26. However, since the second brazing material layer 27 does not reach the boundary portion 24a, the second brazing material is prevented from creeping up onto the side surface of the power supply member insertion hole 24 and the side surface of the power supply member 50 during manufacturing, and it is possible to prevent a gap from being generated in the second brazing material layer 27 between the power supply member 50 and the first brazing material layer 26. Therefore, power can be well supplied to the electrostatic electrode 22 by the power supply member 50.

[0037] In addition, the boundary portion 24a is chamfered. This makes it possible to prevent cracks from occurring starting from the boundary portion 24a of the power supply member insertion hole 24. In addition, the second brazing material layer 27 does not reach the chamfered boundary portion 24a. This makes it possible to further prevent the second brazing material from creeping up onto the side surface of the power supply member insertion hole 24 and the side surface of the power supply member 50 during manufacturing.

[0038] Furthermore, when the edge 50b of the tip surface 50a of the power supply member 50 is chamfered, it is preferable that the chamfering be performed to C0.3 or less or R0.3 or less. In this way, the area of ​​the tip surface 50a of the power supply member 50 is increased, and therefore the contact area between the tip surface 50a of the power supply member 50 and the second brazing material layer 27 is increased.

[0039] Furthermore, the first brazing material layer 26 contains an active metal, and the second brazing material layer 27 does not contain an active metal or has a lower content of the active metal than the first brazing material layer 26. When the first brazing material layer 26 is formed, the first brazing material contains an active metal and therefore easily spreads over the surface of the recessed hole 25 (ceramic plate 20). On the other hand, when the second brazing material layer 27 is formed, the second brazing material does not contain an active metal or has a low content of the active metal, so it does not easily spread over the surface of the ceramic plate 20 and is unlikely to reach the boundary portion 24a of the power supply member insertion hole 24.

[0040] Furthermore, the interface between the first brazing layer 26 and the second brazing layer 27 may be a region where the components contained in the first brazing layer 26 and the components contained in the second brazing layer 27 are diffused. During production, the second brazing layer 27, which does not contain active metal or has a low content of active metal, is formed on the first brazing layer 26, which contains active metal, but the components contained in both layers tend to diffuse at the interface between the first brazing layer 26 and the second brazing layer 27 to form a region where both components are mixed together.

[0041] Furthermore, since the second brazing material layer 27 does not reach the boundary portion 24a of the power supply member insertion hole 24, the distance (insulation distance) between the second brazing material layer 27 and the cooling plate 30 can be made longer than when the second brazing material layer 27 is provided along the side of the power supply member insertion hole 24, and insulation breakdown can be avoided.

[0042] 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.

[0043] In the above-described embodiment, the first brazing material layer 26 and the second brazing material layer 27 do not have a stress relaxation member therein (for example, a member formed of a material whose thermal expansion coefficient is lower than that of the power supply member 50 and higher than that of the ceramic plate 20), but this is not particularly limited. For example, the first brazing material layer 26 may have a stress relaxation member therein. The second brazing material layer 27 may have a stress relaxation member therein, but it is preferable that it does not have one. This is because if a stress relaxation member is provided inside the second brazing material layer 27, the volume of the second brazing material layer 27 tends to increase, making it difficult to prevent the second brazing material from creeping up to the side surface of the power supply member 50 and the side surface of the power supply member insertion hole 24.

[0044] In the above embodiment, a metal rod is used as the power supply member 50, but the power supply member 50 is not limited to this and may be, for example, a metal cable.

[0045] In the above-described embodiment, the wafer mounting table 10 may have at least one of a heater electrode and an RF electrode (electrode for generating plasma) embedded in the ceramic plate 20 instead of or in addition to the electrostatic electrode 22. In this case, the joining structure between the heater electrode and the power supply member for the heater electrode and the joining structure between the RF electrode and the power supply member for the RF electrode may be the same as the joining structure between the electrostatic electrode 22 and the power supply member 50 described above.

[0046] In the above-described embodiment, the electrode lead-out portion 22a is added to the electrostatic electrode 22. However, a part of the electrostatic electrode 22 may be directly exposed to the bottom surface of the recessed hole 25 without providing the electrode lead-out portion 22a.

[0047] In the above-described embodiment, when the power supply member 50 is made of a material that is difficult to wet and spread with the second brazing material, a metal coating that is easy to wet and spread with the second brazing material may be formed on the tip surface 50a of the power supply member 50. For example, when the power supply member 50 is made of Mo, a Ni coating may be formed on the tip surface 50a. The metal coating may be formed on the chamfered portion of the tip surface 50a and its edge 50b of the power supply member 50, and may be further provided to a height of 0.1 mm or less from the chamfered portion. If the height is about this level, it is possible to prevent the occurrence of a gap in the second brazing material layer 27 between the power supply member 50 and the first brazing material layer 26. [Industrial Applicability]

[0048] The present invention can be used in semiconductor manufacturing equipment used to process wafers. [Explanation of symbols]

[0049] 10 wafer mounting table, 20 ceramic plate, 20a wafer mounting surface, 22 electrostatic electrode, 22a electrode lead-out portion, 24 power supply member insertion hole, 24a boundary portion, 25 recessed hole, 26 first solder layer, 27 second solder layer, 30 cooling plate, 32 refrigerant flow path, 34 cooling plate through hole, 35 adhesive layer, 36 insulating tube, 40 bonding layer, 44 bonding layer through hole, 50 power supply member, 50a tip surface, 50b edge, 62 DC power source, 125 first hole, 126 first solder layer.

Claims

1. a ceramic plate having a wafer mounting surface on an upper surface thereof and an electrode embedded therein; a power supply member insertion hole provided from the lower surface of the ceramic plate to a position just in front of the electrode; a power supply member inserted into the power supply member insertion hole with some play; a recessed hole provided from a bottom surface of the power supply member insertion hole to reach the electrode or an electrode lead-out portion added to the electrode, the opening of which has a diameter smaller than the diameter of the power supply member insertion hole and equal to or larger than the diameter of the power supply member; A first brazing material layer filled in the recess; a second brazing layer that bonds the entire end surface of the power supply member to the first brazing layer and does not reach a boundary between a bottom surface and a side surface of the power supply member insertion hole; A semiconductor manufacturing equipment component comprising:

2. The boundary portion is chamfered, The second brazing material layer is provided so as not to reach the chamfered boundary portion. The semiconductor manufacturing equipment member according to claim 1 .

3. The edge of the end surface of the power supply member is chamfered to C0.3 or less or R0.3 or less. The semiconductor manufacturing equipment member according to claim 1 or 2.

4. The first brazing layer contains an active metal, The second brazing layer does not contain an active metal or has a lower content of the active metal than the first brazing layer. The semiconductor manufacturing equipment member according to claim 1 or 2.

5. The interface between the first brazing material layer and the second brazing material layer is a region where a component contained in the first brazing material layer and a component contained in the second brazing material layer are diffused. The semiconductor manufacturing equipment member according to claim 4.

6. 3. The semiconductor manufacturing equipment member according to claim 1 or 2, a conductive cooling plate provided on a lower surface of the ceramic plate; a cooling plate through hole penetrating the cooling plate in a vertical direction, communicating with the power supply member insertion hole, through which the power supply member is inserted; A semiconductor manufacturing equipment component comprising:

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