| 摘要 |
PURPOSE: To provide a semiconductor memory in which the number of rewritable times can be increased. CONSTITUTION: First and second impurity diffusion regions are arranged, at an interval, in a part of the surface layer part of a semiconductor substrate. A gate electrode is formed on a channel region defined between them. A gate insulation film is provided between the channel region and the gate electrode. A part of the gate insulation film on at least a partial region in the lengthwise direction of a route connecting the first and second impurity diffusion regions has a multilayer structure of a first insulation film, a charge trap film, and a second insulation film laid in this order. The charge trap film is formed of an insulation material which can trap charges more easily than the first and second insulation films. A control circuit applies a positive hole removing voltage higher than the voltages being applied to the first and second impurity diffusion regions to the gate electrode, and discharges holes trapped in each layer between the gate electrode and the channel region or on the interface of adjacent layers.
|
