Patent ID: 8546889

Claim:
A semiconductor device, comprising: a second conductivity type breakdown voltage region situated on a first conductivity type semiconductor substrate, a second conductivity type drain diffusion region formed in a surface layer of a part of the breakdown voltage region, a first conductivity type base region formed in contact with the breakdown voltage region in such a manner as to be apart from the drain diffusion region and to surround the drain diffusion region, a first conductivity type pickup region formed in a surface layer of the base region, a first main electrode connected to the pickup region, a second main electrode connected to the drain diffusion region, and to be applied with a higher voltage than a voltage to be applied to the first main electrode, and an isolation region in contact with the semiconductor substrate and surrounding the breakdown voltage region, the breakdown voltage region including a drift region having the drain diffusion region, and another region not having the drain diffusion region and electrically connected to the drain diffusion region or the second main electrode via a high resistance element, the semiconductor device further comprising: a first conductivity type semiconductor region formed between the drift region and the other region so as to be in contact with the isolation region and the semiconductor substrate and to isolate the drift region and the other region from each other; a second conductivity type source diffusion region situated in a surface layer of the base region in the drift region, and connected to the first main electrode; and a gate electrode formed on a surface of the base region between the drift region and the source diffusion region via an insulation film, wherein a resistance value R (Ω) of the high resistance element satisfies the following expression (1): R≧ 1/(2π· C·fc ) (1) where R: resistance value (Ω) of the high resistance element, C: output capacitance (F) of the high breakdown voltage semiconductor device, and fc: switching operation frequency (Hz) of the high breakdown voltage semiconductor device.