Patent ID: 8860172

Claim:
A high voltage semiconductor device, comprising: a second conductivity type semiconductor region provided on a first conductivity type semiconductor substrate; a logic circuit provided in the surface layer of the semiconductor region; an insulated gate field effect transistor having a second conductivity type source region provided on the outer peripheral side of the semiconductor region, a gate electrode provided on the semiconductor region via an insulating film, and a second conductivity type drain region provided in the surface layer of the semiconductor region so as to be spaced a predetermined distance from the outer peripheral edge of the semiconductor region; a second conductivity type pick-up region provided in the surface layer of the semiconductor region, away from the drain region, so as to be spaced the predetermined distance from the outer peripheral edge of the semiconductor region; a first conductivity type opening portion, reaching the semiconductor substrate from the surface of the semiconductor region, provided away from the drain region, second conductivity type pick-up region, and logic circuit, between the logic circuit and a region from the drain region to a portion of the semiconductor region extending to one drain region side portion of the second conductivity type pick-up region via a portion of the semiconductor region sandwiched between the drain region and second conductivity type pick-up region, and a load resistance formed of a portion of the semiconductor region sandwiched between the drain region and second conductivity type pick-up region.