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. 01, 1994
Filed:
Sep. 08, 1992
Kazunori Onozawa, Takasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor device has, in one embodiment, a p type insulated gate field effect transistor formed in an n type well formed on a semiconductor substrate and an n type insulated gate field effect transistor formed in a p type well formed on the semiconductor substrate. Each of the p type and n type insulated gate-field effect transistors has a composite impurity layer under its gate electrode in a surface portion of its associated well. The composite impurity layer includes a first doped layer of a p type and a second doped layer of an n type adjacent thereto to form a pn junction layer therebetween, while the composite impurity layer includes a first doped layer of a p type and a second doped layer of a p type adjacent thereto to form a junction layer therebetween having a p type impurity concentration lower than that of the p type well.