Method of fabricating a semiconductor device of high-voltage CMOS structure

摘要

A transistor of a second conductivity type is of an LMOS structure, and a transistor of a first conductivity type is of an LDMOS structure. The transistor of the first conductivity type has a drain base layer which functions in the same manner as a drain offset diffusion layer and is formed in a substrate separately from a source base diffusion layer. The transistor of the first conductivity type has a stably high breakdown voltage and a low on-state resistance as with the transistor of the second conductivity type.