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. 29, 2000
Filed:
Mar. 03, 1998
Kathleen R Early, Santa Clara, CA (US);
Michael K Templeton, Atherton, CA (US);
Nicholas H Tripsas, San Jose, CA (US);
Maria C Chan, San Jose, CA (US);
Mark T Ramsbey, Sunnyvale, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A method for fabricating a first memory cell and a second memory cell having floating gates electrically isolated from each other. A first polysilicon (poly I) layer is formed on an oxide coated substrate, portions of the poly I layer to serve as future floating gates for the first and second memory cells. An interpoly dielectric layer is formed over the poly I layer. At least a portion of the interpoly dielectric layer is etched to expose at least a portion of the poly I layer so as to pattern the floating gates on either side of the exposed portion of the poly I layer. The exposed portion of the poly I layer is transformed into an insulator via thermal oxidation such that the insulator electrically isolates a floating gate of the first memory cell from a floating gate of the second memory cell. A second polysilicon (poly II) layer is formed substantially free of abrupt changes in step height.