The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
Feb. 18, 1992
Sumio Kobayashi, Yamatokohriyama, JP;
Shunji Miyahara, Itami, JP;
Toshiyuki Fujiwara, Nishinomiya, JP;
Takayuki Kubo, Amagasaki, JP;
Hideki Fujiwara, Amagasaki, JP;
Shuichi Inami, Nishinomiya, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
An apparatus for growing a single crystal having a crucible, two heaters arranged at the outside of the crucible and along the vertical direction, a heat shield placed at the outside of the heaters, a radiation shield for shielding the single crystal from the radiation heat, and an upper heat shield for preventing the upward heat, transfer of the heaters. In the apparatus, a melted layer and solid layer of raw material are formed in the upper and lower portions of the crucible, respectively. While melting the solid layer, the single crystal is pulled up. The lower portion of the heat shield is thinner than the upper portion. The ratio of the height to the diameter of the crucible is 0.85 or more. The melting amount of the solid layer is controlled in the pulling process according to the non-segregation condition in the variable-thickness melted layer method. The oxygen concentration of the pulled single crystal is controlled in the pulling process by adjusting the rotation speed and rotation direction of the crucible.