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:
Jul. 11, 1995
Filed:
Dec. 23, 1992
Applicant:
Inventor:
William E Miller, Los Gatos, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 29 ; 437 44 ; 437 45 ; 437 52 ; 437 57 ;
Abstract
ROM cell programmed ON has N+ source implant spaced a given distance from the gate with LDD bridging the gap between the N+ source and the N channel. ROM cell programmed OFF has P+ implanted into this gap so as to completely override the LDD in this gap. The P+ prevents the N channel from forming ohmic connection to the N+ source.