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:
Jun. 04, 1991
Filed:
Feb. 21, 1989
Youji Yamashita, Yokohama, JP;
Masakatu Kojima, Yokosuka, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a crystal pulling process using an integral type double crucible, a cylindrical separation wall is mounted in and is coaxial with a crucible, for receiving semiconductor material melt to divide the crucible into inner and outer chambers. A coupling tube fixed at the side wall of the separation wall and having a pipe-like passage with a small hole is provided to make a pass between the inner and outer chambers. While material melt in the outer chamber is being supplied to the inner chamber via the coupling tube, crystal is pulled from the melt received in the inner chamber and having an impurity composition different from that of the melt in the outer chamber.