Title:
METHOD FOR CONTROLLING DIAMETER OF SINGLE CRYSTAL
Document Type and Number:
Japanese Patent JPS5945991
Kind Code:
A
Abstract:
PURPOSE:To control the diameter of a single crystal at a definite value, in the pulling of the single crystal using the Czochralski method, by heating the molten liquid around the single crystal locally with infrared heating. CONSTITUTION:In the pulling of a single crystal by the Czochralski method, a pair of condenser-type infrared heaters 7 are placed at the symmetrical positions slantly above the crucible 5, and the infrared ray reflected by the condenser mirror 9 is focused to a part 10 of the molten raw material liquid 1 around the single crystal. The lowering of the height of the molten liquid according to the growth of the crystal is calculated by the computer 12 from the change in the weight of the crystal, and the angle and the position of the infrared heater 7 are controlled by the computer so as to keep the focus of the infrared ray and the distance of the part 10 heated by the infrared heater 7 from the center of the crucible to the preset levels. The symmetrical parts 10, 10 at the circumference of the single crystal 3 are concentratedly irradiated with infrared ray, and the surface of the molten liquid is locally heated at a high temperature, however, the ring 11 can be heated uniformly by the rotation of the crucible 5.
Inventors:
MIYAZAWA SHINTAROU
NAKAI RIYUUSUKE
NAKAI RIYUUSUKE
Application Number:
JP15135482A
Publication Date:
March 15, 1984
Filing Date:
August 31, 1982
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
SUMITOMO ELECTRIC INDUSTRIES
SUMITOMO ELECTRIC INDUSTRIES
International Classes:
C30B15/18; C30B15/16; C30B15/22; H01L21/208; (IPC1-7): C30B15/18; H01L21/02
Attorney, Agent or Firm:
Hideki Aoki