Patent ID: 8389969
Filing Date: 2013-03-05
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate of a first conductivity type including a trench having a bottom surface and an inner wall; a gate insulating film that is formed on the bottom surface and a part of the inner wall of the trench; a first gate electrode that is embedded in a lower portion of the trench so as to cover the gate insulating film; a first cap insulating film that is embedded in an upper portion of the trench so as to cover the first gate electrode; a first diffusion region that is formed in the semiconductor substrate and located on a first side surface of the first cap insulating film; a second diffusion region that is formed in the semiconductor substrate and located on a second side surface of the first cap insulating film opposite to the first side surface; and a third diffusion region that is formed in the semiconductor substrate located on the second side surface of the first cap insulating film and located between an upper surface of the semiconductor substrate and an upper surface of the second diffusion region, wherein the first and second diffusion regions and the first gate electrode constitute a first field-effect transistor, the second and third diffusion regions and the semiconductor substrate constitute a first bipolar transistor, the first field-effect transistor and the first bipolar transistor constitute a first selective element, the first and second diffusion regions have a second conductivity type opposite to the first conductivity type, and the third diffusion region has the first conductivity type.