| US 7,403,424 B2 | ||
| Erasing non-volatile memory using individual verification and additional erasing of subsets of memory cells | ||
| Gerrit Jan Hemink, Yokohama (Japan); and Teruhiko Kamei, Yokohma (Japan) | ||
| Assigned to SanDisk Corporation, Milpitas, Calif. (US) | ||
| Filed on Dec. 06, 2005, as Appl. No. 11/296,055. | ||
| Claims priority of provisional application 60/667043, filed on Mar. 31, 2005. | ||
| Prior Publication US 2006/0221660 A1, Oct. 05, 2006 | ||
| Int. Cl. G11C 11/34 (2006.01) | ||
| U.S. Cl. 365—185.22 [365/185.29; 365/185.33] | 42 Claims |
| 1. A method of erasing non-volatile memory, comprising:
enabling erasing of a set of non-volatile storage elements, said enabling includes enabling erasing of a first and second
subset of said set of non-volatile storage elements;
applying one or more erase voltage pulses to said set while said first and second subset of non-volatile storage elements
are enabled for erasing until said first subset is verified as erased;
verifying, in between applying each of said one or more erase voltage pulses, whether said first subset of non-volatile storage
elements is erased, said verifying includes excluding said second subset of non-volatile storage elements from verification;
after said first subset is verified as erased, inhibiting said first subset from further erasing while enabling erasing of
said second subset; and
applying one or more additional erase voltage pulses to said set while said first subset is inhibited and said second subset
in enabled until said second subset is verified as erased.
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