Patent ID: 8049283

Claim:
A semiconductor device with a deep trench structure, comprising: a semiconductor substrate, comprising: a first conductivity type well; and a second conductivity type well, the second conductivity being a conductivity that is opposite to a conductivity of the first conductivity; a first gate oxide film and a second gate oxide film formed respectively on the first conductivity type well and the second conductivity type well; a first gate electrode and a second gate electrode formed respectively on the first gate oxide film and the second gate oxide film; second conductivity type drift regions formed on both sides of the first gate electrode; first conductivity type drift regions formed on both sides of the second gate electrode; a first isolation layer having a trench structure with a depth that is greater than depths of the first and second conductivity type wells, the first isolation layer isolating the first conductivity type well and the second conductivity type well from each other; and one or more second isolation layers having a trench structure with a depth that is less than the depth of the trench structure of the first isolation layer, each of the second isolation layers being formed between the first isolation layer and a respective one of the drift regions.