| 摘要 |
For programming data "0", a reference voltage Vss (e.g., 0 V) is applied to a drain and a source of a memory cell to be programmed via a corresponding main bit line, a corresponding select transistor, and a corresponding local bit line, while a second voltage Vpp (e.g., 15 V) is applied to a control gate of the memory cell via a word line connected with the memory cell. As a result, electrons are injected from the drain, source and channel region to a floating gate of the memory cell via its tunnel oxide. For erasing the memory cell, a third voltage Vds (e.g., 0-6 V) is applied to a semiconductor substrate of the memory cell and a fourth voltage Vneg (e.g., -10 V) is applied to the control gate via the word line. At this time, the third voltage is also applied to the source and drain. Alternatively, the source and drain of the memory cell are placed in a floating state. Consequently, electrons are ejected from the floating gate to the channel region via the tunnel oxide.
|
