| US 7,474,565 B2 | ||
| Programming scheme for non-volatile flash memory | ||
| Chun-Jen Huang, Tainan (Taiwan); Chia-Jung Chen, Chiayi County (Taiwan); and Hsin-Yi Ho, Hsinchu (Taiwan) | ||
| Assigned to MACRONIX International Co., Ltd., Hsinchu (Taiwan) | ||
| Filed on Dec. 11, 2006, as Appl. No. 11/636,920. | ||
| Prior Publication US 2008/0137427 A1, Jun. 12, 2008 | ||
| Int. Cl. G11C 11/34 (2006.01); G11C 16/04 (2006.01) | ||
| U.S. Cl. 365—185.19 [365/185.28] | 4 Claims |
| 1. A method of programming a memory cell in a first state having a maximum initial threshold voltage to one of a plurality
of states having a higher target threshold voltage relative to the maximum initial threshold voltage, wherein there is a cue
threshold voltage between the maximum initial threshold voltage and the target threshold voltage, the memory cell having a
drain, the method comprising:
(a) applying a drain voltage in a form of a programming pulse having a first width to the drain of the cell;
(b) determining whether the cell has reached the cue threshold voltage;
(c) if the cell has reached the cue threshold voltage, changing the programming pulse width from the first pulse width to
a second pulse width, the second pulse width being smaller than the first pulse width; and
(d) after step (b), if the cell has not reached the cue threshold voltage, increasing the drain voltage and repeating from
step (a) with the increased drain voltage.
|