摘要 |
Programming a semiconductor memory device includes: performing a program loop using a blind program operation until the selected cell threshold voltages reach a first verification level; upon detecting a cell having the threshold voltage reaching the first verification level, verifying whether a cell having the threshold voltage reached a second verification level higher than the first verification level; upon verifying a cell having the threshold voltage reaching the second verification level, continuously performing program loops on cells having the first verification level as a target level and on cells having the second verification level as a target level; and upon verifying no cell having the threshold voltage reaching the second verification level, performing a program loop on memory cells having a target level higher than the first verification level, after programming the memory cells having the first verification level as the target level. |