| 摘要 |
When data is programmed into nonvolatile memory cells, a programming voltage is applied, with increasing, to the memory cells a plurality of times. During this data programming, the increment of the programming voltage is set to a first voltage, which is maintained until the threshold voltages of all the memory cells to be programmed reach an initial value. Thereafter, the increment is set to a second voltage, which is maintained until the threshold voltages reach a target value. Increasing the programming voltage without varying the increment thereof allows the threshold voltages of the memory cells to approach the target value in a smaller number of times programmed. Additionally, setting the increment of the programming voltage to the second voltage after the threshold voltages exceed the initial value can minimize the deviation of the threshold voltages from the target value. Consequently, the programming time of the memory cells can be reduced.
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