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:
Aug. 23, 1977
Filed:
Nov. 21, 1975
Seiichi Iwamatsu, Tokyo, JA;
Hitachi, Ltd., , JA;
Abstract
A method of manufacturing a semiconductor storage device comprises the steps of forming a source region and a drain region in a surface of a semiconductor substrate of a first conductivity type in a manner to be spaced from each other, said source and drain regions having a second conductivity type; forming an insulating film on said semiconductor substrate between said source and drain regions; implanting ions of an electrically conductive element into said insulating film, to thus form a floating gate; and leading out source and drain electrodes from said source and drain regions, respectively. By varying the implantation energy and the implantation dose rate in the implanting step, the amount of charges to be accumulated in the floating gate can be controlled.