| 摘要 |
In order to further improve a driving performance without increasing an element area in a lateral MOS having a high driving performance, in which a gate width is increased per unit area by forming a plurality of trenches horizontally with respect to a gate length direction, the semiconductor device includes: a well region which is formed of a high resistance first conductivity type semiconductor at a predetermined depth from a surface of a semiconductor substrate; a plurality of trenches which extend from a surface to a midway depth in the well region; a gate insulating film which is formed on surfaces of concave and convex portions formed by the trenches; a gate electrode embedded inside the trenches; a gate electrode film which is formed on the surface of the substrate in contact with the gate electrode embedded inside the trenches in regions of the concave and convex portions, the regions excluding vicinities of both ends of the trenches; another gate electrode film which is embedded inside the trenches in the vicinities of the both ends of the trenches in contact with the gate electrode film so that a surface of the another gate electrode film is located at a position deeper than the surface of the semiconductor substrate; and a source region and a drain region which are formed as two low resistance second conductivity type semiconductor layers formed from a part of the semiconductor surface, the part being out of contact with the another gate electrode film, so as to be shallower than the depth of the well region. |
