High voltage CMOS transistor arrangement - has source zone of substrate-opposed type directly surrounded by substrate

摘要

A weakly doped semiconductor substrate of a first conductivity type has transistors with strongly-doped drain and source zones or the first conductivity type and at least one transistor with strongly-doped drain and source zone or a conductivity type opposite to that of the substrate. The drain zone on the substrate side is surrounded by a drift zone or the second conductivity type. The source zone or the transistor of the second conductivity type is directly surrounded by the substrate. Pref. the arrangement is made exclusively using standard CMos technology steps without additonal process steps. The transistors are pref. decoupled in the substrate by field implantation. The channel may be of first type, but stronger doped than the substrate.