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. 30, 2002
Filed:
Aug. 23, 2000
Kazuhiro Harada, Tokyo, JP;
Yoji Suzuki, Tokyo, JP;
Senlin Fu, Tokyo, JP;
Hisashi Furuya, Tokyo, JP;
Mitsubishi Materials Silicon Corporation, Tokyo, JP;
Abstract
A thermal shield device is equipped in a crystal-pulling apparatus for pulling a silicon monocrystal ingot from a silicon melt reserved in a quartz crucible having an outer peripheral surface encircled with a heater. The thermal shield device has a tubular part to be used for surrounding a silicon monocrystal ingot being pulled and grown in an upward direction to prevent radiant heat from the heater toward the silicon monocrystal ingot. The tubular part has a lower end positioned above a surface of the silicon melt with a predetermined spacing therebetween. A protruding part is formed on a lower portion of the tubular part and filled with a thermal-insulating member. The protruding part extends to the inside of the tubular part and has a bottom wall, a vertical wall, and a top wall. The bottom wall is shaped like a ring having an outer edge connected to a lower edge of the tubular part and extends to the proximity of an outer peripheral surface of the silicon monocrystal ingot. The vertical wall is positioned at a predetermined distance from the outer peripheral surface of the silicon monocrystal ingot and connected to an inner edge of the bottom wall. The top wall has a lower edge connected to an upper edge of the vertical wall and an upper edge attached to an inner peripheral surface of the tubular part and extends in an upward direction with a gradual increase in diameter.