JP6875805B2 - Substrate support member with shaft and its manufacturing method - Google Patents

Description

The present invention relates to a substrate support member with a shaft used in a semiconductor manufacturing apparatus and the like, and a method for manufacturing the same.

As a ceramic heater as a heat source used in semiconductor manufacturing equipment such as CVD and sputtering, a disk-shaped substrate support member in which a resistance heating element is embedded and a hollow shaft attached to the center of the lower surface of the substrate support member are provided. A ceramic heater with a shaft is known (see, for example, Patent Document 1). Such a ceramic heater with a shaft is integrated by diffusion bonding in which the shaft is heated in a pressed state at the center of the lower surface of the substrate support member during manufacturing. Then, the pressing of the shaft against the substrate support member is performed by applying a force toward the substrate support member on the end surface (non-contact side with the substrate support member) of the shaft.

Japanese Unexamined Patent Publication No. 11-339939

However, the heated shaft is in a softened state, and when pressed as described above, there is a problem that the heated shaft is bent or greatly deformed depending on the shape of the shaft.

The present invention has been made in view of the above conventional problems, and an object of the present invention is a method for manufacturing a substrate support member with a shaft capable of preventing deformation when the shaft is diffusion-bonded to the substrate support member, and a method for manufacturing the same. To provide a substrate support member with a shaft obtained by the above.

The method for manufacturing a substrate support member with a shaft of the present invention includes a step of diffusing joining the flange side of a hollow shaft having a flange at least one end at the center of the lower surface of the disk-shaped substrate support member. It ’s a manufacturing method,
When the outer diameter of the shaft is D, the length of the shaft in the longitudinal direction is L, and the cross-sectional area along the plane whose longitudinal direction is the normal direction is S, L / D ≧ 2 or L / In ^{the case of S 0.5} ≥ 3, the flange is pressed in a state where the flange of the shaft is in contact with the substrate support member at the time of diffusion joining between the substrate support member and the shaft.

In the method for manufacturing a substrate support member with a shaft of the present invention, when the flange side of the flanged shaft is diffusion-bonded to the substrate support member, in the case of a predetermined shape that is easily deformed during heating, the upper end of the shaft is diffusion-bonded. Instead, since the flange portion is pressed toward the substrate support member, no external force is applied to the upper portion of the shaft, and bending and deformation can be prevented.

The substrate support member with a shaft of the present invention is a substrate support member with a shaft in which the flange side of a hollow shaft having a flange is joined to the center of the lower surface of the disk-shaped substrate support member.
A diffusion bonding layer is provided at an interface between the substrate support member and the flange, and the thickness of the diffusion bonding layer is 50 μm or less. The substrate support member with a shaft of the present invention is manufactured by the above-mentioned manufacturing method of the present invention, the thickness of the diffusion bonding layer is 50 μm or less, and there is no bending or deformation of the shaft, if any.

A cross-sectional view of the (A) shaft portion of the ceramic heater with a shaft according to the embodiment of the present invention along the line AA of (B) and a cross-sectional view of the portion (B) along the line BB of (A). The conceptual diagram which shows the state which the split sleeve-shaped push jig presses the lower flange of a shaft. The conceptual diagram which shows the state which a pushing jig presses the upper flange of a shaft. A drawing substitute photograph showing a joint portion between the substrate support member and the shaft of the substrate support member with a shaft according to the embodiment of the present invention. A drawing substitute photograph showing a joint portion between the substrate support member and the shaft of the substrate support member with a shaft according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

<Manufacturing method of substrate support member with shaft>
1A and 1B are views showing a ceramic heater 10 with a shaft according to an embodiment of the present invention, in which FIG. 1A is a cross-sectional view taken along the line AA of FIG. It is sectional drawing along line B. The ceramic heater 10 with a shaft shown in FIG. 1 has a shaft 14 bonded to a disk-shaped substrate support member 12, and FIG. 1 shows a state when the substrate support member 12 and the shaft 14 are diffusion-bonded. Is shown.

The substrate support member 12 is a member made of disk-shaped ceramics, and is made of, for example, aluminum nitride. A resistance heating element that heats the heating surface 12A, which is the support surface (surface) of the wafer, is embedded in the substrate support member 12, and the shaft 14 is joined to the other surface.

An upper flange 16 is formed at the upper end of the shaft 14, and a lower flange 18 is formed at the lower end of the shaft 14 so as to project outward in the radial direction.

In the above configuration, the process of diffusion bonding of the shaft 14 to the substrate support member 12 differs depending on the shape of the shaft 14. That is, when the outer diameter of the shaft 14 is D, the length of the shaft 14 in the longitudinal direction is L, and the cross-sectional area along the plane whose longitudinal direction of the shaft 14 is the normal direction is S, L / D ≧ 2 or When L / S ^0.5 ≥ 3, the lower flange 18 is pressed during diffusion bonding. When the shaft 14 has L / D ≧ 2 or L / S ^0.5 ≧ 3, the shaft 14 in a softened state at the time of heating is easily deformed by an external force, and when pressed from the upper flange 16, the external force is transmitted to the shaft 14 and bends. And deformation becomes large. In order to prevent such bending and deformation, the lower flange 18 is pressed. On the contrary, when the shaft 14 has L / D <2 and L / S ^0.5 <3, it is difficult to be deformed by an external force even in a softened state at the time of heating, and even if it is pressed from the upper flange 16, the bending and deformation become large. There is no such thing.

The outer diameter D of the shaft 14 is an outer diameter other than the portions of the upper flange 16 and the lower flange 18 of the shaft 14. The length L of the shaft 14 in the longitudinal direction is the length from the upper end to the lower end of the shaft 14. Further, the cross-sectional area S along the plane whose normal direction is the longitudinal direction of the shaft 14 is the area of the cross section other than the portions of the flanges 16 and 18 of the shaft 14 (the hatched region of FIG. 1A). is there.

When the lower flange 18 is pressed when the shaft 14 is diffusion-bonded to the substrate support member 12, the split sleeve is used by using a split sleeve-shaped push jig or the like in which the substantially cylindrical cylinder is divided into a plurality of parts around the central axis thereof. One end of the shaped push jig can be placed on the lower flange 18 of the shaft 14 and pressed so that the press pressure is directly applied to the split sleeve-shaped push jig.

FIG. 2 conceptually shows a state in which the split sleeve-shaped pushing jig 20 presses the lower flange 18 of the shaft 14. The lower flange 18 is a substrate support member by pressing the upper end 24 of the split sleeve-shaped pushing jig 20 downward while the pressing portion at the lower end of the split sleeve-shaped pushing jig 20 is placed on the lower flange 18. It can be pressed toward 12.

On the other hand, in the present invention, ^{when neither L / D ≧ 2 nor L / S 0.5} ≧ 3 is satisfied, the pushing jig 30 is placed on the upper flange 16 and the pushing jig 30 is placed on the upper flange 16 as shown in FIG. By pressing the upper surface of the lower flange 18, the lower flange 18 can be pressed toward the substrate support member 12.

In the present embodiment, the temperature at the time of diffusion bonding is preferably 1400 to 1900 ° C. The pressing force at the time of diffusion bonding is preferably 0.01 to 40 MPa. More preferably, the temperature at the time of diffusion bonding is preferably 1500 to 1800 ° C. The pressing force at the time of diffusion bonding is 0.02 to 8 MPa. Here, the pressing force means a value obtained by dividing the total load at the time of joining by the joining area between the shaft and the substrate support member.

In the above embodiments, only the diffusion bonding between the substrate support member and the shaft in the method for manufacturing the substrate support member with a shaft is shown, but the resistance heating element is embedded in the substrate support member and a current is applied to the resistance heating element. The power supply terminals to be supplied can be arranged according to a standard method.

Although FIG. 1 shows a form in which the upper flange 16 is provided on the shaft 14, the upper flange 16 may not be provided if it is unnecessary.

On the other hand, when a shaft having no flange is to be diffusely joined to the substrate support member, when the shaft satisfies L / D ≧ 2 or L / S ^0.5 ≧ 3, one end of the shaft (diffuse to the substrate support member). By intentionally providing a flange on the joining side) and pressing the flange during diffusion joining, it is possible to prevent the shaft from bending or deforming.

<Board support member with shaft>
The substrate support member with a shaft of the present embodiment obtained by the above manufacturing method has a diffusion bonding layer at the interface between the substrate support member 12 and the flange 18, and the thickness of the diffusion bonding layer is 50 μm or less. That is, the thickness of the diffusion bonding layer when the lower flange 18 of the shaft 14 is pressed for diffusion bonding is 50 μm or less. Here, the diffusion bonding layer is a layer formed at the boundary portion after the flange and the substrate support member are diffusion bonded, but the "thickness of the diffusion bonding layer" in the case where the flange and the substrate support member are not layered is defined at the bonding interface. The thickness of the part where the grain boundary component has moved. The following will be described with reference to the drawing substitute photograph.

4 and 5 are electron micrographs showing the interface between the substrate support member and the flange. In FIG. 4, a tissue that point appears white like comprises a sintering aid (Y ₂ O ₃ component), a region where the tissue containing the sintering aid is dotted, the dotted region not The interface is the joint surface. In the example shown in FIG. 4, the grain boundary component does not move at the bonding interface. In FIG. 5, a region in which the sintering aid component is linearly diffused above the joint surface is seen, and this region is recognized to be within 50 μm from the joint surface.

In the above embodiments, the substrate support member is a ceramic heater, and examples of the substrate support member include a vacuum chuck, an electrostatic chuck, a susceptor with a built-in electrode, and the like, in addition to the ceramic heater.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Examples 1 to 4, Reference Example 1]
(Disc-shaped substrate support member)
As disc-shaped substrate supporting member, the material is ALN _(Y including 2 _{O 3} 3%), size diameter: 350 mm, thickness: were prepared as the 25 mm.

(Hollow shaft)
As hollow shafts, shafts (1) to (5) (upper flange shape omitted) having different dimensions and made of ALN as a material were prepared. The dimensions of each shaft are shown in Table 1. The shafts (1) to (4) ^{satisfy both L / D ≧ 2 and L / S 0.5} ≧ 3, whereas the shaft (5) does not satisfy any of the inequalities.

(Diffusion bonding of the shaft to the substrate support member)
In each of Examples 1 to 4, the shafts (1) to (4) were diffusion-bonded to the substrate support member. Here, since the shafts (1) to (4) ^{satisfy both L / D ≧ 2 and L / S 0.5} ≧ 3, the split sleeve as shown in FIG. 2 is used with respect to the prepared substrate support member. The flange of the shaft was diffusively bonded under the conditions of a temperature of 1600 ° C., a pressing pressure of 6 MPa, and a bonding time of 4 hours using a conventional pressing jig. Here, the pressing force means a value obtained by dividing the total load at the time of joining by the joining area between the shaft and the substrate support member.
Further, in Reference Example 1, the shaft (5) was diffusion-bonded to the substrate support member. The shaft (5) does not satisfy either L / D ≧ 2 and L / S ^0.5 ≧ 3, but is diffusion-bonded in the same manner as the shafts (1) to (4).

[Comparative Examples 1 to 4]
In each of Comparative Examples 1 to 4, the shafts (1) to (4) were diffusion-bonded to the substrate support member. Here, the shafts (1) to (4) ^{satisfy both L / D ≧ 2 and L / S 0.5} ≧ 3, but the prepared substrate support member is pressed against the prepared substrate support member as shown in FIG. Using a jig, the upper part of the shaft was diffusively bonded under the conditions of a temperature of 1600 ° C., a pressing force of 6 MPa, and a bonding time of 4 hours.

[Reference example 2]
In Reference Example 2, the shaft (5) was diffusion-bonded to the substrate support member. Here, the shaft (5) does not satisfy either L / D ≧ 2 and L / S ^0.5 ≧ 3, but a pushing jig as shown in FIG. 3 is used for the prepared substrate support member. , The upper part of the shaft was diffusively bonded under the conditions of a temperature of 1600 ° C., a pressing force of 6 MPa, and a bonding time of 4 hours.

[Evaluation]
1. 1. Shaft flexion After diffusion bonding, the shaft swells like a drum near the center of the shaft height. The rate of change of the outer diameter of the shaft at that time before and after joining was measured. The results are shown in Tables 2 and 3.

From Tables 2 and 3, it can be seen that in Examples 1 to 4, the deflection was small and the shapes before and after the diffusion bonding could be sufficiently maintained.
On the other hand, in all of Comparative Examples 1 to 4, the deflection of the shaft became large after joining, and the shape could not be maintained. Reference examples 1 and 2 are examples in which a shaft (5) that does not satisfy either L / D ≧ 2 and L / S ^0.5 ≧ 3 is used, and the lower flange or the upper flange of the shaft is pressed. The deflection was small.

10 Ceramic heater with shaft 12 Substrate support member 14 Shaft 16 Upper flange 18 Lower flange 20 split sleeve-shaped pushing jig 22 Pressing part 24 Upper end

Claims (1)

A method for manufacturing a substrate support member with a shaft, which comprises a step of diffusing and joining the flange side of a hollow shaft having flanges at both ends at the center of the lower surface of the disk-shaped substrate support member.
When the outer diameter of the shaft is D, the length of the shaft in the longitudinal direction is L, and the cross-sectional area along the plane whose longitudinal direction is the normal direction is S, 6.21 ≧ L / D ≧ In the case of 2 or 13.64 ≧ L / S0.5 ≧ 3, the flange of the shaft on the board support member side was brought into contact with the board support member at the time of diffusion bonding between the board support member and the shaft. A method for manufacturing a substrate support member with a shaft, which comprises pressing the flange with a pressing force of 6 MPa or more and 40 MPa or less using a split sleeve-shaped pressing jig in this state.

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