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. 10, 1999
Filed:
Nov. 28, 1997
Applicant:
Inventors:
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
438149 ; 438439 ; 438525 ;
Abstract
Generation of parasitic transistor in active layer edge is prevented. In an NMOS region of a semiconductor layer (21) on an insulating film (20), boron ions are implanted by rotary oblique injection, using a nitride film (23) and a resist (253a) as mask. In the vicinity of a region for separating element by LOCOS method, that is, only in the edge region of the semiconductor layer (21) as the active layer of NMOS transistor, boron ions are implanted by about 3.times.10.sup.13 /cm.sup.2. After LOCOS oxidation, the impurity concentration is heightened to such a level as the boron ions may not be sucked up into the oxide film.