Patent ID: 7208375

Claim:
A method of manufacturing a semiconductor device including: a processed substrate including a drain layer of a first conductivity type provided on one face thereof, a gate insulating film, gate electrode plugs in contact with one face of the gate insulating film, a base region of a second conductivity type in contact with an opposite face of the gate insulating film, and a source region of a first conductivity type provided at inner surface of the base region to be contact with the gate insulating film, wherein, when a voltage is applied to the gate electrode plugs to invert a conductivity type of a portion of the base region in contact with the gate insulating film into the first conductivity type so as to form an inversion layer, the source region and the drain layer are connected to each other through the inversion layer, the method of manufacturing a semiconductor device, comprising the steps of: forming an insulating film on the processed substrate surface, where the drain layer is provided; patterning the insulating film to form a plurality of first shallow holes and second shallow holes surrounding the first shallow holes; etching the processed substrate being positioned at bottom faces of the first and second shallow holes so as to form first and second deep holes situated below the first and second shallow holes; growing fillers made of a semiconductor of the second conductivity type in the first and second deep holes and the first and second shallow holes; and removing the fillers in the first shallow holes and the fillers in upper parts of the first deep holes so as to form buried regions including remaining parts of the fillers respectively in the first deep holes.