| 摘要 |
In a memory system, a programming waveform reduces program noise by using sets of multiple adjacent sub-pulses which have a saw-tooth shape. In a set, an initial sub-pulse steps up from an initial level such as 0 V to a peak level, then steps down to an intermediate level, which is above the initial level. One or more subsequent sub-pulses of the set can step up from an intermediate level to a peak level, and then step back down to an intermediate level. A last sub-pulse of the set can step up from an intermediate level to a peak level, and then step back down to the initial level. A verify operation is performed after the set of sub-pulses. The number of sub-pulses per set can decrease in successive sets until a solitary pulse is applied toward the end of a programming operation.
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