Patent ID: 7629644
Filing Date: 2009-12-08
Classification: H01L

Abstract:
1. An insulated gate type semiconductor device comprising: a semiconductor substrate of a first conductivity type comprising a drain region; a channel layer of a second conductivity type formed on a surface of the drain region; a trench penetrating the channel layer to reach the drain region; a gate insulating film formed on an inner wall of the trench; a source region of the first conductivity type provided adjacent the trench; a gate electrode disposed in the trench; an interlayer dielectric film disposed in the trench so as to be on top of the gate electrode, the interlayer dielectric film being thinner at a center portion thereof than at a peripheral portion thereof so as to have a dent portion; a source electrode disposed over the trench so as to fill the dent portion of the interlayer dielectric film; and a body region of the second conductivity type that is in contact with the source electrode and is positioned lower than a surface of the channel layer, wherein the gate insulating film and the interlayer dielectric film do not extend beyond the trench, and the source region comprises an undercut dent portion, and part of the body region is disposed in the undercut dent portion.