Lateral semiconductor-on-insulator (SOI) semiconductor device having a buried diode

Claim 1

A lateral Semiconductor-on-Insulator (SOI) device comprising a substrate, a buried insulating layer on said substrate, and a lateral semiconductor device on said insulating layer, said semiconductor device comprising a source region of a first conductivity type, a channel region of a second conductivity type opposite to that of the first, an insulated gate electrode over said channel region, a lateral drift region of said first conductivity type at least partly on said buried insulating layer, and a drain contact region of said first conductivity type, laterally spaced apart from said channel region and connected thereto by said drift region, said substrate being of the second conductivity type, and a buried region of the first conductivity type in said substrate, adjacent a surface thereof, and beneath said drain contact region, said buried region forming a buried diode with said substrate, characterized in that said drift region comprises a continuous layer of substantially constantly and lightly-doped monocrystalline semiconductor material which also extends laterally into a region between said drain contact region and said buried region and electrically couples said buried region to said drain contact region.