Patent ID: 7582946

Claim:
A semiconductor device in which a high withstand voltage semiconductor device and logic circuits are integrated on a single chip, comprising: said high-withstand voltage semiconductor device having an oxide film and an epitaxial layer on a support substrate, a high-potential-side logic circuit connected to the high-potential-side electrode of said high-withstand voltage semiconductor device, a low-potential-side logic circuit that outputs control signals for controlling the driving of said high-withstand voltage semiconductor device, and a multi-trench separation region that separates a high-potential island including said high-potential-side logic circuit, that is formed of multiply overlaid trench separation regions biased by using capacitance couplings and that has a level shift region for connecting said high-potential-side logic circuit to the high-potential-side electrode of said high-withstand voltage semiconductor device and wherein a part of said multiply overlaid trench separation regions is arranged to overlap with a part of said high-withstand voltage semiconductor device, and said level shift region is biased by the capacitance coupling to have high-potential in said multiply overlaid trench separation regions, and is arranged in an area overlapping with the part of said high-potential-side logic circuit, so as to connect said high-potential-side logic circuit to the high-potential-side electrode of said high-withstand voltage semiconductor device.