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:
May. 08, 2001
Filed:
Feb. 16, 1999
Concetta Riccobene, Mountain View, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
High drain capacitance is reduced, thereby increasing device speed, by forming transistors with a gate oxide having a thickness which is smaller at the drain region than at the source region. Embodiments include selectively ion implanting neutral impurities, such as silicon, geranium or argon, into and/or roughening the substrate surface to increase its oxidation rate proximate the contemplated source region and/or selectively ion implanting nitrogen to reduce its oxidation rate proximate the contemplated drain region. Other embodiments include etching a gate oxide layer having a first thickness to form a portion having a reduced second thickness proximate the contemplated drain region and thermally oxidizing to form a transition zone having a thickness gradually decreasing from the first thickness to the second thickness.