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:
Nov. 13, 2001
Filed:
Jun. 22, 2000
Satoru Muramatsu, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Disclosed are a structure of a semiconductor substrate and a method of manufacturing the semiconductor substrate preventing a reduction of gettering capability due to a high-temperature heat treatment. In a semiconductor substrate containing a highly concentrated impurity having a polysilicon layer to be a gettering site on a rear surface side and an epitaxial layer,on a front surface side, an impurity concentration is lower near the rear and front surfaces and higher at the center in a cross section of the semiconductor substrate. The method of manufacturing the semiconductor substrate comprises the steps of: performing the heat treatment of a silicon substrate at a temperature of 1100° C. or more and a melting temperature or less of the silicon substrate before forming the polysilicon layer,and the epitaxial layer,; forming the polysilicon layer,on the rear surface side of the silicon substrate; and forming the epitaxial layer,on the front surface side of the silicon substrate.