Wing Choy Leung

US Patent:

7385851, Jun 10, 2008

Filed:

Dec 22, 2006

Appl. No.:

11/615710

Inventors:

Ming Kwan - San Leandro CA, US
Wing Leung - Palo Alto CA, US

Assignee:

Spansion LLC - Sunnyvale CA

International Classification:

G11C 16/06

US Classification:

36518522, 36518517, 36518521

Abstract:

Erase verify operations as described herein can be utilized for a flash memory device having an array of memory cells. The erase verify operations employ repetitive erase verify testing to double-check previously verified bits that might otherwise relax or settle into an under-erased state. Following an initial erase verify procedure, an erase verify operation may perform a secondary erase verify procedure and apply additional erase pulses to bits that have become under-erased.