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:
Sep. 01, 1998
Filed:
Aug. 16, 1995
Ryuichi Okamura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The invention provides a diffusion region structure in a semiconductor device wherein the diffusion region is applied with alternating voltages in an operation of the semiconductor device. The structure comprises at least one diffusion region being doped with an impurity of a first conductivity type at a first impurity concentration and also being provided in a semiconductor bulk region doped with an impurity of a second conductivity type at a second impurity concentration lower than the first impurity concentration, and at least a diffusion capacitance reduction layer provided under the diffusion region so as to be in contact with a bottom of the diffusion region. The diffusion capacitance reduction layer may be doped with an impurity of the second conductivity type at a third impurity concentration which is at least lower than the second impurity concentration of the semiconductor bulk region and not lower than zero or may be mode of an insulating material to thereby reduce a capacitance of the diffusion region.