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:
Dec. 06, 1994
Filed:
Apr. 01, 1994
Kuang-Yeh Chang, Los Gatos, CA (US);
Subhash R Nariani, San Jose, CA (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
The present invention is directed to a semiconductor memory device and a method for fabricating a semiconductor memory device, in particular a E.sup.2 PROM, having an improved tunnel area wherein electrons travel to and from a floating gate. The tunnel area is characterized by properties which lend to a relatively large number of programming and erasure cycles over the life of the E.sup.2 PROM. The tunnel area includes a tunneling gate which is fabricated via two implant stages. Because these two stages are separate from one another, each of the implant stages can be independently optimized to improve the properties of the tunnel area. Further, the windows used to define the implant regions are easily fabricated and are designed to facilitate formation of the implant regions. The method of defining the window lends to easy scaling of the process for advancing generations of technology.