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:
Oct. 10, 2000
Filed:
Dec. 18, 1997
Basab Bandyopadhyay, Austin, TX (US);
Nick Kepler, Saratoga, CA (US);
Olov Karlsson, San Jose, CA (US);
Larry Wang, San Jose, CA (US);
Effiong Ibok, Sunnyvale, CA (US);
Christopher F Lyons, Fremont, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
An insulated trench isolation structure is formed in a semiconductor substrate with an oxide or nitride spacer overlying and protecting a portion of a pad oxide layer at the trench edge such that the pad oxide layer acts as part of the gate oxide layer. Embodiments include providing a step between the trench fill and the pad oxide layer and forming the protective spacer thereon. The protective spacer protects the underlying portion of the pad oxide layer at the trench edge during pad oxide removal prior to forming a gate oxide. Therefore, it is only necessary to grow the gate oxide on the main surface of the substrate, not at the trench edges. The gate oxide can then be formed uniformly thin, while the remaining pad oxide at the trench edges is relatively thick.