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. 01, 2003
Filed:
Aug. 16, 2001
Peter J. Hopper, San Jose, CA (US);
Yuri Mirgorodski, San Jose, CA (US);
Chin Miin Shyu, San Jose, CA (US);
David Tsuei, Sunnyvale, CA (US);
Peter Johnson, Sunnyvale, CA (US);
Alexander H. Owens, Los Gatos, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method for making an electrically programmable and erasable memory cell is disclosed. Specifically, a method for creating a floating gate using shallow trench isolation-type techniques is utilized to provide a floating gate having sharply defined tip characteristics. A first insulating layer is formed over a substrate. A conductive material is formed over the first insulating layer. A trench is defined in the conductive layer. This trench is filled with an oxide which is used as a mask to define tips of the floating gate during an etching process which defines the edges of the floating gate. After the floating gate has been etched, a tunneling oxide deposited over the floating gate. A conductive material is then formed over the tunneling oxide.