| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor device capable of compatibly having a high breakdown voltage and lower on-state resistance. <P>SOLUTION: The semiconductor device includes a p-type base layer provided on an n-type drift layer, an n<SP>+</SP>-type source layer provided selectively on the base layer, a gate electrode provided in a trench penetrating the base layer to reach the drift layer, a source electrode coming into contact with the source layer and also coming into contact with the base layer through a contact groove provided penetrating the source layer between adjacent gate electrodes, and a p-type pillar layer provided in the drift layer at a corresponding part below the contact groove, wherein the uppermost portion of the p-type pillar layer comes into contact with the base layer, and the lowermost portion has higher impurity concentration than any other part of the p-type pillar layer and is positioned in the drift layer not to reach the drain layer, the p-type pillar layer being made thinner as it goes from the uppermost portion toward the lowermost portion. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
