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:
Jun. 30, 1987
Filed:
Jun. 05, 1985
Applicant:
Inventor:
Keijiro Uehara, Sagamihara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
2957 / ; 29578 ; 148-15 ; 148187 ; 156643 ; 357 34 ;
Abstract
An impurity-doped region that serves as an intrinsic base region of a bipolar transistor is formed in a very early stage, and an electrode for taking out the base and a graft base region are formed in a late stage. This makes it possible to reliably connect the intrinsic base region and the graft base region together without permitting them to separate away from each other even when the base region has a very small depth.