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:
Apr. 15, 2014
Filed:
May. 25, 2010
Masanori Fukui, Akita, JP;
Hideki Watanabe, Tokyo, JP;
Nobumitsu Takase, Tokyo, JP;
Japan Super Quartz Corporation, Akita, JP;
Abstract
Leakage of silicon melt is monitored and touch of a seed crystal at the silicon melt is detected, and in addition, reinforcement of a vitreous silica crucible to be endurable during pulling for a long time and decrease of impurity concentration of a silicon single crystal can be expected. A method for manufacturing a silicon single crystal is provided. The method includes: detecting touching status of a seed crystal at silicon melt by supplying voltage Vusing a crucible side as a negative electrode and a wire side as a positive electrode and by monitoring change of the voltage, when the seed crystal provided at a front end of the wire touches the silicon melt inside a vitreous silica crucible; devitrifying an inner surface of the vitreous silica crucible as supplying voltage Vusing the crucible side as a positive electrode and the wire side as a negative electrode during a temperature control period; and growing a silicon single crystal by slowly pulling the seed crystal as supplying voltage Vusing the crucible side as a negative electrode and the wire side as a positive electrode after the temperature control period.