Patent ID: 7012301
Filing Date: 2006-03-14
Classification: H01L

Abstract:
1. A semiconductor device comprising: a trench provided in a semiconductor substrate of a first conductivity type; a source region of a second conductivity type which is formed in the substrate surface region, outside said trench; a base region of the first conductivity type formed below said source region, outside said trench; a drift region of the second conductivity type formed below said base region along the side portions of said trench, outside said trench; a drain region of the second conductivity type formed in the bottom portion of said trench; a gate insulating film formed inside said trench along the side portions and bottom portion of said trench; a first conductor formed on the inside of said gate insulating film; and a second conductor formed on the inside of said first conductor via an interlayer insulating film, and electrically connected to said drain region, wherein, in an active region of said device, the gate insulating film on the bottom surface of said trench extends from the side wall of said trench to said second conductor and contacts said second conductor, and wherein the gate insulating on the bottom surface of said trench becomes thicker, as measured in the direction of the depth of the trench, from the side wall of said trench or said first conductor toward said second conductor.