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. 21, 1988
Filed:
Feb. 19, 1987
Applicant:
Inventor:
Yoshihisa Koyama, Mitaka, JP;
Assignees:
Hitachi Ltd., Tokyo, JP;
Hitachi Microcomputer Eng., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; G11C / ;
U.S. Cl.
CPC ...
357 41 ; 357 236 ; 357 55 ; 365149 ;
Abstract
Herein disclosed is a DRAM which has such a carrier trapping region around a memory cell array as can trap minority carriers deep in a semiconductor substrate so that the minority carriers to be generated in the semiconductor substrate by alpha rays may be sufficiently trapped. The memory cell of the DRAM has a capacitor which is partially formed of the semiconductor substrate. The carrier trapping region is formed by making use of trenches or a well region.