| 摘要 |
<p>PURPOSE:To provide the nonvolatile semiconductor device capable of reducing the dispersion of the threshold potential of a memory transistor after deletion by giving the memory transistor the deletion operation of selection and non- selection even in a deletion operation. CONSTITUTION:In memory transistors 1-4, word lines WL1, 2 are set at GND level, source lines SL1, 2 are set at high-voltage level, and bit lines BL1, 2 are set at an open level to perform deletion when the deletion is selected. When the deletion is not selected, the word lines WL1, 2 are set at the high-voltage level, source lines SL, 1 is set at the open level, and bit lines BL1, 2 are set at the open level and no deletion is performed. The selection of deletion and non-deletion is performed by switching a word line signal.</p> |
