Patent ID: 7538396

Claim:
A complementary metal-oxide-semiconductor field effect transistor comprising: a substrate of a first type conductivity; an epitaxial layer of a second type conductivity and located on the substrate; a first sinker of the second type conductivity, the first sinker being located in the epitaxial layer, and extending from the substrate to an upper surface of the epitaxial layer, the first sinker partitioning a first region off from the epitaxial layer; a second sinker of the second type conductivity, the second sinker being located in the epitaxial layer, and extending from the substrate to the upper surface of the epitaxial layer, the second sinker partitioning a second region off from the epitaxial layer outside the first region; a well region of the first type conductivity, the well region being located in the first region; a first high voltage metal-oxide-semiconductor field effect transistor (HVMOSFET) located in the well region; a second high voltage metal-oxide-semiconductor field effect transistor (HVMOSFET) located in the second region; a first buried layer of the first type conductivity, the first buried layer being located between the first region and the substrate; and a second buried layer of the second type conductivity, the second buried layer being located between the first buried layer and the substrate, and between the second region and the substrate, the second buried layer between the first buried layer and the substrate connecting with the first sinker, and the second buried layer between the second region and the substrate connecting with the second sinker.