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:
Feb. 25, 1992
Filed:
Mar. 13, 1989
Roland Q Bekkering, Varese, IT;
Manlio S Cereda, Lomagna, IT;
SGS-Thomson Microelectronics S.r.l., Agrate Brianza, IT;
Abstract
A method for programming ROM memories at an advanced memory manufacture stage. The method, after defining the active regions, possibly implanting threshold-correction boron, performing gate oxidation and providing the gate regions, comprises at least partially masking the regions adjacent to the gate regions of the memory cells which must be made permanently non-conductive. During the subsequent implanting of the source and drain regions, the regions thus shielded are not implanted, so that in the programmed cells at least one region of the source and drain regions is completely missing so as to prevent switching on of the memory cell when reading in the memory.