Shin-etsu Handotai Co., Ltd.

Katsuyuki Kitagawa

Masahiko Urano

Katsuhiro Yoshida

The present invention is a method for producing a single crystal, the method in which, after a charging process, a crucible position setting process including a step of placing a lower end of a conical valve below a lower end of a purge tube, a step of performing a movement in such a way that the conical valve and the crucible get relatively closer to each other while measuring changes in the weight of the conical valve, a step of detecting contact between the lower end of the conical valve and an upper end of a raw material based on the rate of change in the weight of the conical valve, a step of measuring the position of the upper end of the raw material based on the position of the lower end of the conical valve at which the contact was detected, and a step of setting the position of the crucible so that the spacing between the lower end of the purge tube and the upper end of the raw material charged in the crucible becomes a predetermined distance and a melting process including a crucible position adjusting step of adjusting the position of the crucible so that the spacing between the lower end of the purge tube and the upper end of the raw material maintains a predetermined distance in accordance with the progress of melting of the raw material are performed. As a result, it is possible to perform control so that the spacing between the lower end of the purge tube and the upper end of the raw material charged in the crucible becomes a predetermined distance.

Method for producing single crystal

A method of charging raw material, includes: storing the material in a recharge tube including a quartz cylinder for storing the material and a conical valve for opening or closing an opening at a lower end of the cylinder; installing the recharge tube storing the raw material in a chamber; and feeding the raw material stored in the recharge tube into the crucible by locating the recharge tube and crucible such that a distance between the lower end of the recharge tube and raw material or melt in the crucible ranges from 200 to 250 mm, and lowering the conical valve to open the opening while simultaneously lowering the crucible such that a ratio CL/SL of the lowering speed of the crucible to the lowering speed of the conical valve ranges from 1.3 to 1.45. The method can inhibit damage of the quartz crucible and recharge tube.

Growing community of inventors

Nishigo-mura, Japan

Katsuyuki Kitagawa