JP2777791B2 - Quartz glass wafer boat transfer jig - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a quartz glass wafer boat transport jig used when a wafer boat on which semiconductor wafers are mounted is taken in and out of a furnace tube. 2. Description of the Related Art When a wafer boat on which semiconductor wafers are mounted is taken in and out of a furnace core tube, a notch is provided at one end of a tubular or rod-shaped heat-resistant material to form a wafer boat holding portion. A transport jig is used. Conventionally, this type of wafer boat transfer jig is mainly made of quartz glass from the viewpoint of purity. However, in the case of a quartz glass carrying jig, the wafer boat holding portion at one end is inserted into a high-temperature furnace and the other end is fixedly supported at room temperature during use. When a temperature gradient is generated in the jig, a thermal stress is generated in the transport jig due to the temperature gradient, and this reduces the mechanical strength of the material as residual stress. For this reason, the conventional quartz glass wafer boat transfer jig has a drawback that it breaks or bends. This bending or bending is likely to occur particularly at a portion where the bending moment is greatest. In order to solve such a drawback, it is conceivable to increase the thickness of the quartz glass wafer boat transfer jig as a whole. However, in this case, thermal deformation easily occurs due to the weight of the transfer jig. The present invention has been made in view of the above circumstances, and has as its object to provide a quartz glass wafer boat transport jig having high mechanical strength. SUMMARY OF THE INVENTION A quartz glass wafer boat transport jig of the present invention is a quartz glass wafer boat transport jig used when a wafer boat on which semiconductor wafers are mounted is taken in and out of a furnace core tube. In the tool, a notch is formed at one end of a tubular quartz glass with a vertical cross-sectional shape of an arc shape and a straight line to form a wafer boat holding portion, and a portion where the bending moment of the wafer boat holding portion becomes the largest and the portion thereof. The vicinity is made thicker than other portions over 1/4 to 1/2 of the entire length of the wafer boat holding portion, and the wafer boat holding portion is made substantially the same thickness except for the thick portion. This is a quartz glass wafer boat transfer jig. According to such a quartz glass wafer boat transport jig, it is possible to prevent the wafer boat holder from being bent or bent, and to reduce the deflection of the tip of the wafer boat holder. Can be. In the present invention, the length of the thick portion is set to １ ／ to の of the entire length of the wafer boat holding portion for the following reason. That is, when the length of the thick portion is less than 1/4 of the entire length of the wafer boat holding portion, the bending stress is remarkably large, and the deflection amount is also large. On the other hand, if the length of the thick portion exceeds half of the entire length of the wafer boat holding portion, the amount of deflection increases due to the weight of the thick portion. The reason why the thickness except for the thick portion is substantially the same is to reduce the weight of the entire wafer boat transport jig as much as possible and to enhance the operability. An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a side view partially showing a vicinity of a wafer boat holding portion of a quartz glass wafer boat transfer jig according to the present invention, and FIG. 2 is a plan view. In FIG. 1 and FIG. 2, the transfer jig body 1 has a tubular shape as a whole, and a notch portion having a vertical cross-sectional shape of an arc and a straight line is provided at a tip portion thereof, and a wafer boat holding portion 2 is formed. Is formed. A thick portion 3 is formed in a portion A of the wafer boat holding portion 2 where the bending moment is the largest (a boundary between a circular arc and a straight line of a notch having a vertical cross-sectional shape of an arc and a straight line) and in the vicinity thereof. . The thickness of each part of the wafer boat transport jig is, for example, 4.5 mm for the main body 1 part and 4.5 mm for the tip part of the wafer boat holding part 2.
mm, and the thickness 3 is 7.5 mm. Note that the thick portion 3 can be formed by, for example, overlaying, filling, welding, or the like. The length of the thick portion 3 is the same as that of the wafer boat holding portion 2.
The length is set to about ４ to 全長 of the entire length of the wire, and is provided from the vicinity of the portion A where the maximum bending moment occurs to the tip side. Except for the thick portion 3, the entire transport jig body 1 has substantially the same thickness, and the thickness of both ends 4 and 5 of the thick portion 3 in the length direction of the transport jig body 1 is reduced. The shape is inclined. The base end of the transport jig body 1 of the quartz glass wafer boat transport jig is the same as the conventional one, and is fixed to a predetermined position of a transport device (not shown). Further, the semiconductor wafer boat is placed on the wafer boat holding section 2 and transported, and is put in and out of the furnace core tube. According to the quartz glass wafer boat transfer jig, the portion of the wafer boat holding portion 2 where the bending moment is greatest and its vicinity are made thicker than the other portions. 2 can be prevented from being bent or bent.
The deflection at the tip of the can be reduced. Referring to FIGS. 3 and 4, the relationship between the length of the thick portion 3 and the deformation of the wafer boat holding portion 2 will be described in detail. FIG. 3 is a diagram showing the relationship between the length of the thick portion and the bending stress of the wafer boat holding portion with respect to the entire length of the wafer boat holding portion. As is apparent from FIG. 3, the ratio of the length of the thick portion to the entire length of the wafer boat holding portion is 1 /
In the range of 4 to 1, the bending stress is small. In particular, when the length of the thick portion 3 is in the range of about 1/4 to 1/2 of the entire length of the wafer boat holding section, the bending stress is very small. However, when the length of the thick portion 3 becomes less than about 1/4 of the entire length of the wafer boat holding portion, the bending stress gradually increases. FIG. 4 shows the length of the thick portion with respect to the entire length of the wafer boat holding portion and 6 mm at the tip of the wafer boat holding portion.
FIG. 4 is a diagram showing a relationship between the deflection amount when a load of kg is lacked. As is apparent from FIG. 4, the amount of deflection gradually decreases until the length of the thick portion with respect to the entire length of the wafer boat holding portion decreases to about ４ to 、, but the amount of deflection decreases with respect to the entire length of the wafer boat holding portion. When the length of the thick portion exceeds about 1/2, the amount of deflection increases again due to the weight of the thick portion 3. Accordingly, the ratio of the length of the thick portion to the entire length of the wafer boat holding portion is reduced to 1 / from FIG. 3 and FIG.
When it is set to 4 to 1/2, it is considered that the bending phenomenon of the wafer boat holder 2 can be most effectively dealt with. In fact, when the length of the thick portion 3 is short, the strength of the portion of the wafer boat holding portion 2 provided with the thick portion 3 increases, but the strength on the tip side of the thick portion 3 does not change. It was inevitable that the wafer boat holding part 2 would be bent or bent near the tip of the thick part 3. In the case where the thick portion 3 is provided over the entire length of the wafer holding portion 2, the weight of the thick portion 3 acts to increase the amount of deflection at the tip of the wafer boat holding portion 2, and the wafer boat There was a problem with transportation. On the other hand, when the ratio of the length of the thick portion 3 to the entire length of the wafer boat holding portion 2 is set to １ ／ to ２, the strength of 1.5 times or more is obtained, and The amount of deflection at the tip of the boat holding section 2 was also small. As described above in detail, according to the quartz glass wafer boat carrying jig of the present invention, the wafer boat holding portion can be prevented from being bent or bent, and the wafer boat holding portion can be prevented from being bent. It has a remarkable effect, such as being able to reduce the deflection at the tip.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing, in partial cross section, the vicinity of a wafer boat holding portion of a quartz glass wafer boat transport jig according to the present invention. FIG. 2 is a plan view of the quartz glass wafer boat transfer jig of FIG. 1; FIG. 3 is a diagram showing a relationship between the length of a thick portion and the bending stress of the wafer boat holding portion with respect to the entire length of the wafer boat holding portion. FIG. 4 is a diagram showing the relationship between the length of a thick portion relative to the entire length of a wafer boat holding portion and the amount of deflection when a load of 6 kg is applied to the tip of the wafer boat holding portion. [Description of Signs] 1 Transport jig main body 2 Wafer boat holding section 3 Thick section

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Makoto Kumakura               No. 378, Ogunimachi, Ogunicho, Nishiokitama-gun, Yamagata Prefecture               Toshiba Ceramics Co., Ltd.               Inside the factory

Claims (1)

(57) [Claims] In a quartz glass wafer boat transport jig used when a wafer boat on which semiconductor wafers are mounted is taken in and out of a furnace tube, a notch having a circular cross section and a linear cross section is formed at one end of a tubular quartz glass. Forming a wafer boat holding portion, and making the portion of the wafer boat holding portion where the bending moment is largest and its vicinity thicker than other portions over 1/4 to 1/2 of the entire length of the wafer boat holding portion, its other portion wall thickness in the longitudinal direction of the conveying jig to and thicker portion to substantially the same thickness across the transfer jig
A quartz glass wafer boat transport jig , wherein both ends are inclined so as to reduce the thickness .