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:
Feb. 19, 2019
Filed:
Apr. 21, 2016
Sumco Corporation, Tokyo, JP;
Tomokazu Katano, Tokyo, JP;
SUMCO CORPORATION, Tokyo, JP;
Abstract
A silicon single crystal is pulled up such that nitrogen concentration of the crystal is 1×10to 2×10atoms/cm, the crystal cooling rate is about 4.2° C./min at a temperature of a silicon melting point to 1350° C. and is about 3.1° C./min at a temperature of 1200° C. to 1000° C., and oxygen concentration of a wafer is 9.5×10to 13.5×10atoms/cm. After a heat treatment is performed on the wafer sliced from the silicon single crystal in a treatment condition of 875° C. for about 30 min, growth of an epitaxial layer is caused. Thus, an epitaxial wafer in which the number of epitaxial defects is not increased while maintaining predetermined oxygen concentration and slips do not occur is produced.