SEMICONDUCTOR DEVICE

A semiconductor device includes: a substrate; a drift region of a first conductivity type formed on a main surface of the substrate; a well region of a second conductivity type formed in a main surface of the drift region; a source region of the first conductivity type formed in the well region; a gate groove formed from the main surface of the drift region in a perpendicular direction while being in contact with the source region, the well region, and the drift region; a drain region of the first conductivity type formed in the main surface of the drift region; a gate electrode formed on a surface of the gate groove with a gate insulating film interposed therebetween; a protection region of the second conductivity type formed on a surface of the gate insulating film facing the drain region; and a connection region of the second conductivity type formed in contact with the well region and the protection region.