JPS5812730B2 - wafer jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer jig, and more particularly to a wafer jig used during diffusion of semiconductor wafers.

As is well known, in the semiconductor industry, impurities are diffused onto the surface of a silicon wafer by passing impurity vapor such as boron B through a heating furnace and heating it at a temperature of about 1200 degrees Celsius. There is.

During such wafer diffusion, a wafer jig is used which has a plurality of grooves formed therein to allow a large number of silicon wafers to stand in parallel.

In the conventional wafer jig, the shape of the groove on which the wafer is placed is formed into a U-shaped cross section with a width commensurate with the thickness of the wafer 1, as shown in FIG. The wafer 1 dropped into the groove 2 is supported while being in surface contact with the inner surface 2a of the groove 2.

Therefore, when the wafer is diffused using the conventional wafer jig having the grooves 2, the impurity vapor 3 does not spread around the wafer 1 in contact with the jig, and the impurity vapor 3 does not spread to the wafer 10 surface. Unevenness occurred and the desired spread wafer could not be obtained.

Therefore, the yield of the diffusion wafer 1 is reduced, and furthermore, the electrical characteristics of the wafer are deteriorated.

In addition, in conventional wafer jigs, the contact area between the wafer and the groove is large, so if there is dirt on the jig side, for example, that dirt will adhere to the wafer side. This causes inconveniences such as contaminating the surface of the wafer.

The present invention is intended to solve the above-mentioned conventional disadvantages, and its purpose is to provide a wafer jig having a structure that allows diffusion to be performed evenly over the entire surface of the wafer.

Another object of the present invention is to provide a wafer jig having a structure in which dirt on the jig side is not transferred to the wafer.

The basic structure of the present invention to achieve such an object is that the inner surface of the groove on the side of the jig that supports the wafer is in contact with the ridge line of the wafer, as shown in the drawings below. The present invention will be explained in detail by means of examples shown.

FIG. 2 is a perspective view showing the entire wafer jig according to the present invention.

In the figure, a wafer jig 10 according to the present invention has three quartz glass rods 11, 12.13 arranged in a chevron shape, and a connecting member 14 is interposed between each quartz glass rod 11, 12.13. By this connecting member 14, the quartz glass rod 11
, 12.13 are integrated.

Further, the quartz glass rods 11 and 13 are the quartz glass rod 12.
The quartz glass rod 1
2 is located one step lower than the quartz glass rods 11 and 13.

On the side of the recess 14 formed by the combination of the three quartz glass rods 11, 12.13, a plurality of grooves 11a are formed in the radial direction toward the extension direction of each quartz glass rod 11, 12.13. 12a, 13a are provided, and the grooves 11a, 12a, 13a are provided with respective quartz glass rods 11, 12,
13, respectively, are provided at corresponding positions.

Furthermore, the shape of the grooves 11a, 12a, 13a is
As shown in the figure, it is formed into a "V-shaped" cross section, and its opening angle is, for example, 60 degrees, and the depths of the grooves 11a, 12a, 13a are the outer edges 11b of the quartz glass rods 11, 12, 13, respectively. It has a depth that is 211 degrees deeper than 12bν13b.

Further, the width of the open side of the grooves 11a, 12a, and 13a is about three times the thickness of the wafer 15, and each groove 1
The distance between adjacent grooves 1a, 12a, and 13a is wafer 1.
The distance is four times the thickness of 5.

In the above embodiment, the grooves 11a, 12a, 13& are formed in a -V shape, but the grooves 1
The shape of 1at12ap13a is “U” as shown in FIG.
It goes without saying that the groove 16 may have a ``letter'' shape, or the groove 17 may have a ``trapezoid'' shape as shown in FIG.

Even in this case, the width of the groove shown in FIGS. 4 and 5 is formed to be sufficiently wider than the thickness of the wafer 15, and the ridge angle of the wafer 15 and the slope of the groove are and are in point or line contact.

As described above, according to the present invention, the shapes of the grooves 11a, 12a, and 13a for dropping and supporting the wafer 15 are formed so as to be in point or line contact with the ridges of the wafer 15. For example, since the surface of wafer 15 is not covered with the groove surface,
When performing diffusion, impurity vapor such as boron B sufficiently spreads over the surface of the wafer 15 through the gaps formed between the surfaces of the grooves 11a, 12a, 13a and the wafer 15.

Therefore, highly accurate diffusion (surface treatment) is possible without causing variations in impurity diffusion to the surface of the wafer 15, and there is no appearance or characteristic defect of the wafer 15.

In addition, since the wafer 15 and the surface of the groove are not in surface contact with each other, even if the wafer 15 is placed in a heating furnace together with the jig and heated, the wafer 15 may not be tightly sandwiched in the groove due to the difference in thermal expansion coefficient. Many effects can be obtained such that the wafer 15 is not damaged when the wafer 15 is found.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the structure of a conventional wafer jig;
The figure is a perspective view showing the whole wafer jig according to the present invention, FIG. 3 is an enlarged sectional view of the main part of the wafer jig according to the present invention, and FIGS. 4 and 5 are the shapes of grooves of the wafer jig according to the present invention. It is another example figure which shows. 1...Wafer, 2...Groove, 2a...
...Inner surface, 3...Impurity vapor, 10...
...Wafer jig, 11...Glass rod, 1
2...Glass rod, 13...Glass rod,
11a...Groove, 12a...Groove, 13a
...Groove, 1lb...Outer edge, 12b...
... Outer edge, 13b... Outer edge, 14...
...Concavity, 15...Wafer, 16...
・Groove having a “U-shaped” shape, 17.・Groove having a “trapezoid” shape.

Claims (1)

[Claims] 1. A wafer jig having a groove for supporting a wafer in an upright position, wherein the groove has opposed slopes for supporting the wafer in contact with a ridge of the wafer.