JPH053244A - Wafer jig - Google Patents

Abstract

(57) [Abstract] [Purpose] A wafer heat treatment jig can hold multiple wafers in parallel and stably support them without damaging or contaminating the wafers when supporting the wafers in a groove, and for wafer attachment / detachment. Also make sure that there is no problem. [Configuration] A groove having a V-shaped cross section is made to have one surface vertical and the other surface is inclined at an appropriate angle so that at least one main surface around the wafer is vertically aligned without scratches or dirt. The condition can be kept stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer jig having a V-shaped groove for vertically supporting a semiconductor wafer during the heat treatment of the semiconductor wafer in the course of manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In manufacturing a semiconductor device, a disc-shaped semiconductor wafer is subjected to heat treatment such as impurity diffusion oxidation. For the purpose of performing this heat treatment, a wafer heat treatment jig 5 having support grooves 4 at a plurality of positions for arranging a plurality of wafers 3 in a vertical direction as shown in FIG. 1 is used and installed in a reaction tube 6. To be done. The wafer heat treatment jig is formed by assembling a plurality of rods 1 made of a stable and highly heat-resistant material such as quartz with a holding plate 2 in a frame shape. Depending on the cross-sectional shape, the wafer support grooves 4 provided at predetermined intervals on the rod 1 have a concave groove as shown in FIG. 2, a U groove as shown in FIG. 3, and a V-shaped groove as shown in FIG. 4 (Japanese Patent Laid-Open No. 50-37355). Alternatively, a Y groove as shown in FIG. 5 is adopted.

The wafer supporting grooves in the conventional wafer jig described above are formed such that the surfaces of the facing grooves are symmetrical with respect to the vertical surface. This causes various problems as described below when the wafer is vertically supported in these grooves.

For example, when the wafer 3 is supported by the concave groove shown in FIG. 2, the surfaces on both sides of the wafer to be supported are likely to come into direct contact with the corners of the concave groove 4, so that the surface near the peripheral edge of the wafer is contacted. The formed semiconductor element is often scratched or attached with dirt. Further, in the impurity deposition process, it is difficult to sufficiently supply the impurities for forming elements in the peripheral portion where the wafer enters the groove. Further, in order to facilitate the attachment / detachment work of the wafer, it is necessary to allow a slight margin in the width of the groove with respect to the thickness of the wafer, which allows the wafer to be supported in the concave groove with some inclination.
If a plurality of wafers are arranged, the parallelism between the wafers is easily damaged.
Therefore, the amount of the impurity gas supplied to the wafer surface becomes uneven between the wafers. As a result of these, especially in the case of a small-signal semiconductor product, the yield is lowered, or a product with low reliability is produced.

In the case of the V groove shown in FIG. 4, since the opposing side surfaces of the groove portion 4 are not parallel to each other, there are few defects that occur at the peripheral edge of the wafer as in the case of supporting the wafer in the concave groove shown in FIG. There is a problem in how to select the groove angle. For example, if the angle of the V groove is large, it is difficult to stably support the wafer, and it is necessary to increase the number of supporting points on the wafer, and the structure of the entire jig is complicated. It is not desirable to have a large heat capacity. Further, if the angle of the V groove is made small, there is a problem that it becomes difficult to insert the wafer into the groove and the workability of setting the wafer is deteriorated.

[0006]

The problem to be solved is to maintain parallelism between a plurality of aligned wafers without causing scratches or stains on the peripheral portion of the wafer by a jig during wafer heat treatment. It is to have a groove that can be stably supported, and to prevent the trouble of the wafer from occurring.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a plurality of V
In a wafer jig having a groove having a V-shaped cross section, one surface of the V-shaped cross section of the groove has a vertical direction, and the other surface facing the V-shaped cross section is inclined at an appropriate angle to form an asymmetric groove. It is characterized by The opening of the groove is in the range of 30 ° to 60 °. Further, a small groove having the same width as the thickness of the wafer is formed at the bottom of the groove having the V-shaped cross section. As a result, scratches and stains are less likely to occur when the wafer is supported, the parallelism among the plurality of wafers is maintained, the wafers are stably supported, and the setting of the wafers is facilitated.

[0008]

EXAMPLE FIG. 6 is a sectional view of a wafer supporting groove in an example of a semiconductor wafer heat treatment jig according to the present invention.
Is a bar, 2 is a holding frame, 4 is a V groove, and 3 is a wafer. In the figure, one surface of the V-shaped groove is almost vertical (vertical surface 7 of the groove), and the other surface facing it is inclined with respect to the former, and the angle (opening) θ between them is 30 ° to 60 °. Within the range of °. In the setting of the wafer 3, the main surface of the wafer on which the impurity diffusion region is formed faces the inclined surface side (the inclined surface 8 of the groove). At this time, the edge portion of the other main surface of the wafer in which the diffusion region is not formed is in a state of being parallel to the vertical surface 7.

FIG. 7 is a sectional view of a wafer supporting groove in another embodiment of the semiconductor wafer heat treatment jig according to the present invention. In this embodiment, a small groove 9 is formed at the bottom of the V groove which is vertical to one side shown in FIG. 6, and the width a of the small groove 9 is
The width is approximately equal to or slightly larger than the thickness of the supported wafer. The wafer is more stably supported in the V groove by inserting the end portion of the wafer into the small groove.

As shown in the embodiments of FIGS. 6 and 7, in the wafer heat treatment jig, the wafer can be vertically supported by the vertical surface 7 of the wafer supporting groove having the V-shaped cross section. Since the other main surface is directed to the inclined surface 8, it is possible to diffuse impurities into this main surface without any hindrance, and at least this main surface can be protected from scratches and contamination by the corners of the groove. By setting the angle V of the V groove in the range of 30 ° to 60 °, the setting of the wafer is facilitated,
Moreover, it can be stably supported in the groove. By making one of the V-grooves a vertical surface, the angle at which the wafer is leaned can be regulated, and the intervals between the arranged wafers can be kept uniform. Further, in the embodiment shown in FIG. 7, by providing the small groove 9 at the bottom of the V groove, the leaning angle of the wafer can be regulated, and the stable holding of the wafer can be further ensured.

FIGS. 8 to 11 are sectional views showing a state in which the wafer heat treatment jig of the present invention is viewed from the side and the wafer is supported. As described above, FIG. 8 shows a jig for supporting the wafer by the rectangular rods arranged at two positions. FIG. 9 shows a jig in which the rectangular rod bodies 12 are similarly arranged at three positions. 8 and 9 show a jig for supporting a wafer by surface support,
FIG. 10 shows a trapezoidal jig 13 having a structure for supporting a wafer by line support. Further, FIG. 11 shows an example in which the groove structure of the present invention is applied to a jig 14 having an arcuate cross section obtained by dividing a cylindrical body into three or four parts.

In the examples shown in FIGS. 8 to 11, the case where the rectangular cross-section rod body is used is shown. However, as shown in FIG. The structure can be adopted. Although a quartz (Si) material is generally used as the material of the jig, a similar structure can be adopted by using a silicon carbide (SiC) material depending on the application.

[0013]

As described above, according to the present invention,
Due to the structure in which the main surface of the wafer on which the device is formed does not contact the side surfaces and corners of the groove of the jig that supports the wafer, deterioration of the device does not occur without damaging the periphery of the wafer or attaching dirt. Can be prevented. Further, since the jig of the present invention is the V groove having an appropriate angle, the wafer can be easily attached and detached, and moreover, the wafer stands upright and the parallelism between adjacent wafers can be maintained. As a result, the impurity gas easily circulates between the wafers, the deposition is not concentrated in the vicinity of the groove portion around the wafer, the variation in the impurity deposition is small, and a homogeneous semiconductor product can be obtained. Diffusion can be performed over the entire main surface of the wafer, and the semiconductor material can be used without waste.

[Brief description of drawings]

FIG. 1 is an overall side sectional view of a wafer jig during heat treatment of a semiconductor wafer.

FIG. 2 is an enlarged view of an example of the wafer jig in FIG.
It is a front cross-sectional view taken along line A.

FIG. 3 is a partially enlarged cross-sectional view of a rod body in an example of a wafer jig.

FIG. 4 is a partially enlarged cross-sectional view of a rod body in an example of a wafer jig.

FIG. 5 is a partially enlarged cross-sectional view of a rod body in an example of a wafer jig.

FIG. 6 is a partially enlarged sectional view of a rod body of an embodiment of a wafer jig according to the present invention.

FIG. 7 is a partially enlarged cross-sectional view of a rod body according to another embodiment of the wafer jig of the present invention.

FIG. 8 is a side view of an example of a wafer jig during wafer heat treatment.

FIG. 9 is a side view of another example of the wafer jig during the wafer heat treatment.

FIG. 10 is a side view of another example of a wafer jig during wafer heat treatment.

FIG. 11 is a side view of another example of the wafer jig during the wafer heat treatment.

FIG. 12 is a side view of another example of a wafer jig during wafer heat treatment.

[Explanation of symbols]

1 Wafer jig rod 2 Wafer jig holding plate 3 wafers 4 Wafer support groove 5 Wafer jig 6 Reaction vessels (tubes) 7 Vertical surface of groove 8 Groove slope 9 small groove 10 arc jig 11 round bar 12 Square rod 13 Stand jig 14 Arc jig

Claims (3)

[Claims] 1. A wafer jig having a plurality of V-shaped grooves for vertically supporting a thin disc-shaped wafer, wherein one surface of the V-shaped section has a vertical direction. A wafer jig characterized in that the other surface is formed asymmetrically with a proper angle. 2. The wafer jig according to claim 1, wherein the opening of the groove having the V-shaped cross section is in the range of 30 ° to 60 °. 3. The wafer jig according to claim 1 or 2, wherein a small groove having the same width as the thickness of the wafer is formed at the bottom of the groove having an asymmetric V-shaped cross section.