| 摘要 |
Provided is a semiconductor device having an insulating gate field effect transistor equipped with a metal oxide film in a portion, on the side of a source region, between a gate insulating film and a gate electrode. The metal oxide film is provided above a p+ type semiconductor region for punch-through stopper so as to cover the entire region thereof. Such a metal oxide film contributes to a decrease in the impurity concentration of the p+ type semiconductor region, making it possible to reduce variations in the threshold voltage of the transistor. On the side of a drain region, the gate insulating film is formed as a single film without stacking the metal oxide film thereon. As a result, the resulting transistor can escape deterioration in reliability which will otherwise occur due to hot carriers on the side of the end of the drain region. |
