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, 1994
Filed:
Sep. 18, 1992
Paolo Cappelletti, Seveso, IT;
Giuseppe Corda, Saronno, IT;
Paolo Ghezzi, Rivolta D'Adda, IT;
Carlo Riva, Monza, IT;
Bruno Vajana, Bergamo, IT;
SGS-Thomson Microelelctronics s.r.l., Agrate Brianza, IT;
Abstract
The manufacturing process comprises a first step of formation of an N type sink on a single-crystal silicon substrate, a second step of formation of an active area on the surface of said sink, a third step of implantation of N- dopant in a surface region of the sink inside said active area, a fourth step of growth of a layer of gate oxide over said region with N- dopant, a fifth step of N+ implantation inside said N- region, a sixth step of P+ implantation in a laterally displaced position with respect to said N+ region and a seventh step of formation of external contacts for said N+ and P+ regions. There is thus obtained a zener diode limiter, having a cut-off voltage which is stable over time and not much dependent on temperature and which does not require the addition of process steps with respect to those usually necessary for the accomplishment of EEPROM memory cells.