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:
Oct. 22, 2002
Filed:
Jul. 18, 2000
Takayuki Kubo, Hyogo, JP;
Masanori Kuwahara, Osaka, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A single crystal silicon is produced using a Czocharalski (CZ) method. Silicon nitride powder is put in the bottom of a quartz crucible to provide a nitrogen concentration in the single crystal silicon of not less than about 1×10 atoms/cm . A poly-silicon raw material is then charged in the crucible. A pulling rate for the single crystal silicon is low so that an oxidation induced stacking faults ring exists or disappears at the center. Maintaining the nitrogen concentration of the single crystal silicon to not less than 1×10 atoms/cm decrease the vacancy cluster and existinguish the dislocation cluster. Wafers prepared from the single crystal silicon have very high quality with minimal defects.