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. 14, 2005
Filed:
Jan. 30, 2004
Masayuki Nakamura, Nagoya, JP;
Kazuyuki Miyazawa, Hidaka, JP;
Hidetoshi Iwai, Ohme, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor IC device includes, in a substrate, a P-type well region having a dynamic memory array section and applied with a reduced back bias voltage suitable for refreshing. Also included is a P-well region where N-channel MOSFETs of a peripheral circuit are formed. This P-well region is applied with a back bias voltage of an absolute value smaller than that applied to the P-type well of the memory array section. A P-type well section, where there are formed N-channel MOSFETs of an input circuit or an output circuit connected with external terminals, is applied with a back bias voltage of an absolute value large enough to provide a measure of protection against undershoot, while the refresh characteristics are improved by reducing the leakage current between the source/drain region connected with a capacitor and the P-type well, to thereby raise the operation speed of the peripheral circuit.