| 摘要 |
PURPOSE:To perform a normal writing operation and to prevent a breakdown due to a punch through by separating a source electrode from a substrate and applying a voltage of a special intermediate potential to the source electrode at the time of writing. CONSTITUTION:A voltage of a data writing application source electrode 2 of first nonvolatile memories 10, 20 of a semiconductor device is VS, a voltage of a first bit line B1 is VB1, and a voltage of a second bit line B2 is VB2. One of low voltage side of the voltages VB1, VB2 is set to minimum (VB1, VB2), and the other of the high voltage side is set to maximum (VB1, VB2). A voltage VS represented by the following formula different from a substrate applying voltage to the electrode 2 is applied at the time of writing. A formula min (VB1, VB2)<VS<max (VB1, VB2). Thus, only a low voltage is applied between a drain and a source, writing is normally conducted, and hence a breakdown due to a punch through is prevented. |
