| 摘要 |
PURPOSE:To improve the accumulation efficiency of electric charges by a method wherein a charge accumulation region of the same conductive type as a semiconductor layer and of low density is formed directly under the gate electrode of the semiconductor layer. CONSTITUTION:The p type charge accumulation region 8 is formed separately from a source region 5 and a drain region 6, directly under the gate electrode 4, that is, in a channel region, and surrounded with the semiconducter layer 2 of p type. In such a constitution, most of the injected electrons are trapped in the region 8 to become the accumulated charges. |
