Title:
PRODUCTION OF OXIDE SINGLE CRYSTAL
Document Type and Number:
Japanese Patent JPS6389487
Kind Code:
A
Abstract:
PURPOSE:To respectively or simultaneously automate the following two stages by carrying out operation based on the detection value from a load cell fixed to a freely liftable seed holding rod when a single crystal is produced by computer control except the seeding and detaching stages. CONSTITUTION:A crucible 2 is heated by a high-frequency coil 3 winding on the crucible, hence the raw material for a single crystal charged in the crucible is melted to form a melt 4. The temp. of the melt 4 is measured by an IR thermometer 13, the measured value is inputted to a microcomputer 16, and the temp. is controlled to a specified value. A seed 8 is held at the lower end of the holding rod 7 capable of being freely lifted up and down while rotating and provided with the load cell 9 capable of detecting an extremely light weight at the upper end. The weights before and after seeding and the weight of a single crystal 5 increasing as the crystal is pulled up are successively inputted to the microcomputer 6. The deviation between the weight variation during seeding and the set variation value, for example, is obtained by the microcomputer 6, and the lowering of the rod 7 is stopped when the deviation increases beyond the specified range.
Inventors:
KATAYAMA SHUJI
Application Number:
JP23126186A
Publication Date:
April 20, 1988
Filing Date:
October 01, 1986
Export Citation:
Assignee:
HITACHI METALS LTD
International Classes:
C30B15/00; C30B15/28; C30B29/30; (IPC1-7): C30B15/00; C30B15/28; C30B29/30
Attorney, Agent or Firm:
Takashi Honma