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:
Jul. 01, 1997
Filed:
Sep. 28, 1995
Applicant:
Inventor:
Hisamitsu Suzuki, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437 26 ; 437 27 ; 437149 ; 437154 ;
Abstract
A method of manufacturing wherein an NPN bipolar transistor, an N-type impurity region is formed in an N-type epitaxial region or an N-type well region between an N.sup.+ -buried layer region and a P-type intrinsic base region. The N-type impurity region is formed only just below the P-type intrinsic base region. The impurity concentration of the N-type impurity region is either uniform or is higher at a central portion of the region located just below an emitter diffused region than the impurity concentration at the surrounding the central portion.