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:
Jan. 03, 1995
Filed:
Oct. 18, 1993
Chen-chi P Chang, Newport Beach, CA (US);
Mei F Li, Mission Viejo, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A flash or block erase electrically erasable programmable read-only memory (EEPROM) cell (10) includes a substrate (12) having a channel region (22), and a source (28) and a drain (32) formed in the substrate (12) on opposite sides of the channel region (22). A first oxide layer (19), a floating gate (20), a second oxide layer (24) and a control gate (26) are formed over the channel region (22). The cell (10) is programmed by hot electron injection from the drain (32) into the floating gate (20), and erased by Fowler-Nordheim tunneling from the floating gate (20) to the source (28). A gap (36) is provided between a sidewall (20a) of the floating gate (20) and the drain (32) to increase the electric field in the drain depletion region. An oxide sidewall spacer (38) is formed on the first oxide layer (19) in the gap (36) which traps electrons. The gap (36) and sidewall spacer (38) increase the hot electron injection efficiency, and enable programming to be accomplished at high speed, with low applied voltages and at high temperatures.