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:
Jan. 16, 1990
Filed:
Sep. 01, 1987
Youji Yamashita, Yokohama, JP;
Masakatu Kojima, Yokosuka, JP;
Yoshiaki Matsushita, Kawasaki, JP;
Masanobu Ogino, Yokosuka, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
The present invention discloses a crystal pulling apparatus having a double-crucible structure, wherein an inner crucible is located in an outer crucible. An end of a pipe-like passage is located in a through hole formed in a side wall of an inner crucible located in an outer crucible, and a melt is supplied from the outer crucible to the inner crucible through the pipe-like passage, during crystal pulling. During melting or neckdown, prior to crystal pulling, diffusion of an impurity between the melts in the outer crucible and the inner crucible, and exchange of the melts between the outer crucible and the inner crucible are prevented by the pipe-like passage.