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. 15, 2001
Filed:
Oct. 21, 2000
Janet Wang, San Francisco, CA (US);
Ravi Sunkavalli, Santa Clara, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A method of programming flash EEPROM devices that provides self-limiting multi-level programming states. Each cell in the flash EEPROM device can be programmed to have one of multiple threshold voltages. Each cell to be programmed has a programming voltage applied to the gate, a programming voltage applied to the drain and bias voltage applied to either the source (V,) or to the substrate (V,) or both. The bias voltages V,or V,are determined during a precharacterization procedure and each desired threshold voltage has a corresponding bias voltage V,or V,that provides the desired threshold voltage during the programming procedure. The bias voltages V,or V,are selected to provide self-limiting programming by the effective vertical field E,=V,−V,−(either V,or V,), where V,increases during programming until the programming stops. The lateral field E,=V,−(either V,and/or V,) is adjusted during programming to keep the lateral field E,equal to V,.