Patent ID: 9331194
Filing Date: 2016-05-03
CPC Classification: H01L

Claim Text:
1. A semiconductor device having an insulated gate structure, the device comprising: a first conductivity-type semiconductor substrate constituting a first conductivity-type drift layer; a second conductivity-type well region that is provided selectively on a surface layer of one of main surfaces of the first conductivity-type semiconductor substrate; a first conductivity-type source region that is provided selectively near the main surface inside the second conductivity-type well region; a second conductivity-type low-concentration region that is provided selectively near the main surface inside the second conductivity-type well region and has a net doping concentration lower than a concentration of a second conductivity-type impurity contained in the second conductivity-type well region, and the second conductivity-type low-concentration region is surrounded by the second conductivity-type well region; and a gate insulator that is provided on surfaces of the main surface, and a gate electrode that is provided on surfaces of the gate insulator, and the gate electrode is provided over the first conductivity-type source region, the second conductivity-type low-concentration region, the second conductivity-type well region, and the first conductivity-type drift layer.