Title:
METHOD FOR PULLING UP SINGLE CRYSTAL
Document Type and Number:
Japanese Patent JPS5957986
Kind Code:
A
Abstract:
PURPOSE:To reduce the dislocation density of a single crystal all over the length and to prevent the surface damage of the crystal by controlling the power of plural steps of heaters placed in a furnace for pulling up a single crystal by the Czochralski method as so to keep the temp. gradient of a part close to the interface between solid and liq. gentle during pulling. CONSTITUTION:A heater in a furnace for pulling up a single crystal by the Czochralski method is divided into plural steps of heaters. The upper heater 7 heats chiefly a pulled single crystal 6 on the interface between solid and liq., and the under heater 8 heats a molten starting material 3. While measuring the temp. of a seed holder 11 and the temp. of the bottom of a crucible 1, the power of the upper heater 7 for heating the pulled crystal 6 is controlled so as to provide a prescribed pattern using the distance from the melt 3 to the crystal 6 as a parameter to the difference in temp. between the crucible 1 and the holder 11. The dislocation density of the crystal 6 is reduced all over the length, and the surface damage of the crystal 6 due to the evaporation of a volatile component from the surface of the crystal 6 is prevented.
Inventors:
KOTANI TOSHIHIRO
Application Number:
JP16742382A
Publication Date:
April 03, 1984
Filing Date:
September 24, 1982
Export Citation:
Assignee:
SUMITOMO ELECTRIC INDUSTRIES
International Classes:
C30B15/14; C30B15/20; C30B15/22; C30B15/36; C30B27/02; C30B29/40; H01L21/02; H01L21/208; (IPC1-7): C30B15/20; C30B27/02; C30B29/40; H01L21/02
Attorney, Agent or Firm:
Hideki Aoki