PREPARATION OF SINGLE CRYSTAL

Japanese Patent JPS56164098

A

PURPOSE:To prepare a single cystal accurately in high productivity, by determining automatically the fittest seeding temperature of a melt from the relation between the contact times of a seed crystal and the melt and the change in weight of the seed crystal, and by starting automatically the growth of crystal from the seeding process. CONSTITUTION:A raw material of crystal is melted, the time when the seed crystal 5 is brought into contact with the melt 2 by the lifting device 8 for pulling up a shaft is detected by the weight sensor 7, and the outputs of the counting circuit 9 of contact times and the detecting circuit 10 of contact weight are input to the memory circuit 11. After a fixed time, the seed crystal 5 is cut from the melt once, it is brought into contact with the melt 2 again, and the outputs of the circuit 9 and 10 are memorized in the circuit 11. In this manner the relation between the contact times and the change in weight are memorized in the memory 11, and the content of the memory is compared and judged by the comparing and judging circuit 12, to determine automatically the fittest seeding temperature of the melt 2. The seed crystal 5 is then pulled up, the diameter is controlled by the diameter regulating device 14, and the temperature of the melt 2 is kept at the fittest temperature by the high-frequency oscillator 15.

WASHITSUKA SHIYOUICHI

JP6647280A

December 16, 1981

May 21, 1980

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TOKYO SHIBAURA ELECTRIC CO

C30B15/00; C30B15/28; H01L21/02; H01L21/208; (IPC1-7): C30B15/28; H01L21/02; H01L21/208

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