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:
Mar. 14, 1995
Filed:
Oct. 02, 1992
Applicant:
Inventors:
Katsuji Iguchi, Yamatokoriyama, JP;
Makoto Tanigawa, Kitakatsuragi, JP;
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 70 ; 437149 ; 437 52 ; 437952 ; 437924 ;
Abstract
A method of fabricating a semiconductor device having a p-type semiconductor substrate and a p-well for memory cells which is formed in the substrate is disclosed. N-type impurities are implanted into a region of the substrate in which the p-well for memory cells is to be formed. Then, the region is selectively and thermally oxidized to form an oxide film on the first region, and the n-type impurities are simultaneously diffused in the substrate. After the oxide film is removed, the p-well is formed within the region of the substrate in which the n-type impurities are diffused.