JPS5940446Y2 - Diffusion jig - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a diffusion jig used in a process of diffusing impurities into a semiconductor material such as silicon wafer, and particularly provides an assembly type and sturdy jig.

Generally, in the diffusion process, a bond is created by gasifying the impurity metal in a high-temperature furnace and diffusing it into the semiconductor wafer in the furnace. Because it affects the characteristics of the wafer, high purity is required.

This means that all the jigs used in the furnace in this diffusion process must be made of the same material as the material to be diffused, or be made of a material that does not react with them, and must be able to withstand the high temperature inside the furnace. It is required that it does not deteriorate.

Quartz glass is a material for jigs that meets the above conditions.
Silicon and the like are known, and quartz glass in particular has been widely used as a material for diffusion jigs because it can be fused by welding.

However, since the quartz glass and silicon mentioned above are also hard and brittle, there are difficulties in processing them.

In addition, quartz glass deteriorates more easily due to heat than silicon, while silicon has excellent heat resistance, but it is impossible to fuse by welding, and it is expensive. This was one of the major difficulties.

Therefore, the inventor of the present application has separately developed an assembly type diffusion jig made of silicon as shown in FIG. ,
2 and 2' are suspended horizontally in parallel, with two on top and one on the bottom.

Each of the wafer supports 2 has a wafer support groove 3 formed on one surface (upper surface in the figure) of a prismatic shape.

Each of the supports 1, 1 has a substantially rectangular plate shape, and has Ueno-support fitting portions 1a, 1a, . In addition, a wafer support fitting part 1a' is formed in the center of the wide side of the plate in the widthwise direction in the figure by a deep notch extending from the top to the bottom.

Reference numeral 4 in the figure is a fixing plate.

This diffusion jig is placed on a mother boat 6 to be accommodated in the furnace 5 as shown in FIG. Both lower sides are connected to each wafer support 2, 2 on both upper sides.
The supporting grooves 3... are fitted and supported and housed in the furnace 5 for diffusion.

However, as can be seen in Fig. 2, in order to improve the thermal efficiency within the circular furnace 5, it is preferable that the diameter of the wafer P be closer to the diameter of the furnace 5, and for this purpose the lower end of the wafer P should move downward. It is better to lower the wafer support τ downward as shown in FIG. In that case, there is a drawback that the notch becomes deep, making it more likely to break.

The purpose of the present invention is to provide a diffusion jig that eliminates these difficulties.In the jig, the wide surfaces of two support plates face each other and three wafer supports are horizontally suspended between them. Each support plate has a wafer support fitting portion formed by a notch at both ends of its wide surface, and a wafer support fitting portion formed by a notch extending upward from the lower end at the center of the width of the wide surface. , a pedestal part is formed on one side of the lower part of each of the support plates when assembled, and each of the wafer supports has wafer support grooves carved in parallel in the longitudinal direction in the prismatic ridge corner part, and the top edge of the image. A diffusion jig characterized in that a supporting plate fitting part is formed in a peripheral edge of the part, and each supporting plate fitting part is fitted into the wafer support fitting part to form an integral assembly. .

According to the present invention configured as described above, the wafer support fitting portion is formed by cutting upward from the lower end of the wide central portion of the support plate, so that the wafer support at the center can be placed at a low position. In addition to this, the wafer support is made into a prismatic shape with wafer support grooves carved into its ridges, making it suitable for supporting the circumferential edge of a wafer.

Embodiments of the present invention will be described below based on the drawings.

Fig. 3 and subsequent figures relate to the present invention; Fig. 3 is a side view, Fig. 4 is a plan view, and Fig. 5 is a front view.

The wide surfaces of the two support plates 7, 7 are made to face each other, and three wafer supports 9, 9, 9' are placed horizontally on the respective wafer support fitting parts 8, 8, 8'... There is.

Each of the supporting plates 7, 7 is a substantially rectangular silicon plate, and the upper ridge corners of both ends thereof are cut out as shown in FIG. Wafer support fitting portions 8, 8 are formed by penetrating both wide surfaces of the plate and are formed by rectangular notches extending diagonally downward in the figure from the tapered surface.

Also, a wafer support fitting portion 8 formed by a rectangular notch shown upward in the figure from the lower end of the center of each support plate 7.70 width.
' is formed.

A pedestal part 7a is formed on the lower outer surface of both the support plates 7, 70 in the figure from approximately the middle of the height of the wafer support fitting part 8' at the lower center.

Each of the wafer supports 9, 9, 9' is made of silicon and has a substantially prismatic shape, and support fitting portions 10, 10, 10 are formed at both end peripheries thereof by cutting edge portions.

Further, wafer support grooves 11 are formed in parallel at appropriate intervals in the longitudinal direction in one ridge corner of each wafer support body 9, 9, 9'.

The wafer support groove 11... has a ■-shaped cross section or a Y-shaped cross section.
Character shape etc. can be selected arbitrarily.

The wafer supports 9, 9°γ are attached to the respective wafer support fitting portions 8, 8' of the support plate 7 configured as described above.
The respective support fitting portions 10... are fitted.

In this case, the upper two ways...supports 9, 9 can be simply pushed in from above downwards, but before that, the lower ways...supports 9' have their support fitting portions 10 aligned in the longitudinal direction. The pedestal part 7a of the support plate 7 is fitted in a position where it does not get in the way, and then the wafer support 9 is fitted.
Push the supports 7, 7 toward the front end of the wafer support 9' as shown in FIG.
... is fitted onto the protrusion 7a.

Therefore, when assembling the central lower wafer support 9', the support plate fitting portions 10, 1 are located inwardly from the support plates 7, 7.
A fixing member 12 shown in phantom lines in FIGS. 4 and 5 and shown in front in FIG. 7 is fitted into the gap 0 to fix the wafer support and the support.

Since it is constructed as described above, it can be made of silicon, which cannot be welded, and can be easily assembled.

In addition, in the structure shown in FIG. 1, the support plate was prone to break from the center, but this defect has been improved in the structure of the present invention.

Furthermore, even though the wafer supports in Figure 1 and Figure 3 have the same thickness, the one in Figure 1 has a deep wafer support groove cut into the plane, so it is easy to break. In the device of the present invention shown in FIG. 3, the wafer support groove is carved in the ridge corner, so it has the feature that it is strong and hard to break even if it is made of the same material and has the same thickness.

Note that the present invention is not limited to the above structure.

For example, the wafer support shown in FIG. 1 can be used in two upper and horizontal sections.

Further, the design of the pedestal part formed on one side of the lower part of the support plate is not limited to one side, but can be changed so that it is formed on one side of the vertical wall of the cutout of the support fitting part.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional diffusion jig, Fig. 2 is a front view showing the conventional diffusion jig housed in a furnace, Fig. 3 and the following are related to the present invention, and Fig. 3 is a side view; 4 is a plan view, FIG. 5 is a front view, and FIG. 6 is a front view of the tip of each wafer support in FIG. 5 taken longitudinally. FIG. 1 is a front view of the fixing member. 7...Base plate, 7a...
・Case part, 8, 8'... Ueno/support fitting part, 9
, 9'... Ueno support, 9'a = -edge corner,
DESCRIPTION OF SYMBOLS 10... Bearing part fitting part, 11... Waeno/support groove, 12... Fixing member.

Claims (2)

[Scope of utility model registration request] (1) In a jig for horizontally suspending three wafer supports between two support plates with their respective wide surfaces facing each other, each support plate has wafer support fitting portions at both ends of the wide surfaces. In addition to forming a notch, a wafer support fitting part is formed at the lower end of the center of the wide surface width by a notch directed upward from the lower end, and each support plate forms a pedestal part on one side of the lower part when assembled. Each of the wafer supports has a prismatic shape, and wafer support grooves are arranged in parallel at appropriate intervals in the longitudinal direction, and support fitting portions are formed on the peripheral edges of both ends, so that each of the support plates can be fitted. 1. A diffusion jig characterized in that a joint part is fitted into each Ueno-support fitting part to form an integral assembly. (2) Among the wafer supports, the one that fits into the wafer support fitting part at the lower center of the wide side of the support plate has a wafer support groove carved in its ridge corner, and the leading edge of the image. 2. The diffusion jig according to claim 1, wherein the horizontal ridge corner of the diffusion jig is configured to be placed on the pedestal portion of the support plate.