Title:
CONTROL OF DIAMETER OF SINGLE CRYSTAL
Document Type and Number:
Japanese Patent JP3769807
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a method for controlling the diameter of a single crystal suitable for controlling a dimensional accuracy especially of a seed part in pulling a single crystal.
SOLUTION: This method for controlling the diameter of a single crystal is used for an apparatus for pulling a single crystal by a Czochralski method. A single crystal is pulled up in excellent dimensional accuracy by successively carrying out the following steps. (1) A standard pulling speed is predetermined so as to make the diameter of the single crystal coincident with the target diameter after the temperature of a melt is made coincident with the target temperature. (2) The single crystal is pulled up at a pulling speed of N (0.7-0.8) as much as the standard pulling speed for a fixed time and then pulled up at the standard pulling speed. (3) After the single crystal is pulled up at the standard pulling speed for a fixed time, the pulling speed is changed so as to make the deviation of the diameter of the single crystal zero and the pulling speed is changed by assuming a lag time when there is difference in temperature between the measured temperature on the surface of the melt and the target temperature.
Inventors:
Haruo Yamamura
Kirio Yamamoto
Kirio Yamamoto
Application Number:
JP6418396A
Publication Date:
April 26, 2006
Filing Date:
March 21, 1996
Export Citation:
Assignee:
Sumco inc.
International Classes:
C30B15/22; C30B29/06; H01L21/208; (IPC1-7): C30B15/22; //C30B29/06; H01L21/208
Domestic Patent References:
| JP62083395A |
Attorney, Agent or Firm:
Michio Mori
Terutada Hogami
Terutada Hogami