| 摘要 |
A semiconductor device has a well region formed of a first conductivity type semiconductor at a predetermined depth from a surface of a substrate, trenches formed in the well region, and a gate insulating film formed on surfaces of concave and convex portions of the trenches. A first gate electrode is embedded inside the trenches, and a second gate electrode is formed on the substrate in contact with the first gate electrode in regions of the concave and convex portions excluding vicinities of both ends of the trenches. Source and drain regions of a second conductivity type are formed from a part of a surface of the semiconductor so as to extend deeper in a side surface of the concave portion of each trench than in the surface of the convex portion of each trench and shallower than the depth of the well region. |
