Semiconductor device, method of manufacturing same and method of designing same

摘要

A partial oxide film ( 31 ) with well regions formed therebeneath isolates transistor formation regions in an SOI layer ( 3 ) from each other. A p-type well region ( 11 ) is formed beneath part of the partial oxide film ( 31 ) which isolates NMOS transistors from each other, and an n-type well region ( 12 ) is formed beneath part of the partial oxide film ( 31 ) which isolates PMOS transistors from each other. The p-type well region ( 11 ) and the n-type well region ( 12 ) are formed in side-by-side relation beneath part of the partial oxide film ( 31 ) which provides isolation between the NMOS and PMOS transistors. A body region is in contact with the well region ( 11 ) adjacent thereto. An interconnect layer formed on an interlayer insulation film ( 4 ) is electrically connected to the body region through a body contact provided in the interlayer insulation film ( 4 ). A semiconductor device having an SOI structure reduces a floating-substrate effect.