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:
Aug. 14, 2001
Filed:
Apr. 06, 2000
Applicant:
Inventors:
Assignee:
Komatsu Electronic Metals Co., Ltd., Kanagawa, JP;
Primary Examiner:
Int. Cl.
CPC ...
C30B 1/520 ;
U.S. Cl.
CPC ...
C30B 1/520 ;
Abstract
In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080° C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0° C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0×10,/cm,or a FPD density of larger than 6.0×10,/cm,. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 &mgr;m from the wafer surface.