| abstract |
An operation method for stably operating a nonvolatile semiconductor memory device is provided. In a non-volatile semiconductor memory device having a split gate structure, when hot hole injection is performed, a hot hole injection operation is verified using an intersection that does not change over time. As a result, the erased state can be verified without considering the change with time. Further, writing or writing / erasing is performed by applying a plurality of pulse voltages or multi-step voltage to the gate portion. [Selection] Figure 8 |