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Patent Searching and Data


Title:
PRODUCTION OF SINGLE CRYSTAL
Document Type and Number:
Japanese Patent JPS63291891
Kind Code:
A
Abstract:
PURPOSE:To obtain inexpensive single crystal having good quality, by feeding back minimum diameter of melt of melt zone measured by an optical detection method to temperature and height of the melt and controlling the diameter of a grown crystal. CONSTITUTION:A minimum diameter d of solution of melt zone 23 linking a raw material rod 21 with a grown crystal 22 in deposition of single crystal by floating zone method is obtained by comparing two images A and B extracted by time sharing and being different in time, distinguishing a stationary part with motion part, leading the boundary by processing treatment and scanning into the length in the horizontal direction of the boundary. Then the signal of the minimum diameter d is compared with a minimum diameter d0 before definite time and reference value in a control part 35 to judge way of transition in melt state and converted to various kind of control signals, which is then sent through a DA converter 36 to lamp power control part 40, where lamp power is adjusted to control melt temperature or gap adjustment is carried out by a gap adjust 41 to adjust height H of the melt and diameter DS of the grown crystal is controlled.

Inventors:
TAKEDA SHIGERU
MAKIO SATOSHI
SATO MASAZUMI
FURUKAWA YASUNORI
Application Number:
JP12577987A
Publication Date:
November 29, 1988
Filing Date:
May 25, 1987
Export Citation:
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Assignee:
HITACHI METALS LTD
International Classes:
C30B13/30; (IPC1-7): C30B13/30