Patent ID: 7005352
Filing Date: 2006-02-28
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device comprising the steps of: forming a drift region of a second conductivity type on a semiconductor substrate of a first conductivity type; removing selectively a part of the drift region and a part of the semiconductor substrate, whereby to form trenches; forming a gate insulation film with uniform thickness along the inner side walls and the bottom surface of each trench; forming a first electrical conductor on the gate insulation film; forming an oxide film on the first electrical conductor; removing selectively the region of the oxide film corresponding to an active region, whereby to expose the first electrical conductor in the region corresponding to the active region; etching back the first electrical conductor in the region corresponding to the active region such that the first electrical conductor is remaining along the side walls of the trench; forming a base region of the first conductivity type and a source region of the second conductivity type in the bottom portion of the trench; forming a first interlayer insulation film in the trench; removing the bottom portion of the first interlayer insulation film in the region corresponding to the active region and the portion of the gate insulation film below the removed bottom portion of the first interlayer insulation film, whereby to expose the source region; and forming a second electrical conductor in the trench, the second electrical conductor being connected electrically to the source region.