Patent ID: 9356138
Filing Date: 2016-05-31
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a semiconductor substrate; a source region of a first conductivity type paired with a drain region of the first conductivity type, the source region and the drain region disposed over a principal plane of the semiconductor substrate; a separation insulating film embedded in an isolation trench formed over the principal plane of the semiconductor substrate between the source region and the drain region; a gate insulating film disposed over the semiconductor substrate between the separation insulating film and the source region; a gate electrode disposed in a manner extending immediately above the gate insulating film and immediately above the separation insulating film between the source region and the drain region; a drift region of the first conductivity type disposed in the semiconductor substrate under the separation insulating film, one edge of the drift region being located immediately under the gate insulating film; and a trench disposed over the upper surface of the separation insulating film, the trench having the gate electrode partially embedded therein, wherein the interval between the gate electrode and the drain region is longer than the interval between the gate electrode and the source region; wherein the trench is located away from an edge of the separation insulating film on the source region side of the separation insulating film, and the trench is disposed away from an edge of the gate electrode that is on the drain region side, wherein the bottom of the trench is positioned halfway through the depth of the separation insulating film, and wherein the separation insulating film has a structure made of a plurality of layered insulating films.