| 摘要 |
A MOSFET formed on an SOI substrate secures a high withstand voltage and a reduced element area. The SOI substrate includes an insulator layer and an n--type semiconductor layer formed on the insulator layer. The MOSFET consists of a p-type impurity diffusion region formed on the semiconductor layer, an n+-type source region formed in a surface area in the p-type impurity diffusion region, a gate insulating layer formed on the p-type impurity diffusion region and covering a region between the source region and the semiconductor layer, a gate electrode formed on the gate insulating layer, an n+-type drain region formed on the semiconductor layer at a predetermined position separated from the p-type impurity diffusion region, and an n-type well formed around the drain region. The impurity concentration of the n-type well is lower than that of the drain region and higher than that of the semiconductor layer.
|
