Patent ID: 8716794
Filing Date: 2014-05-06
Classification: H01L

Abstract:
1. An SOI lateral MOSFET device comprising a semiconductor substrate layer, a dielectric buried layer, on said semiconductor substrate layer, an active layer on said dielectric buried layer, a trench gate in said active layer, consisting of gate dielectric and conductive material surrounded by the gate dielectric, wherein the terminal of said conductive material is trench gate electrode, wherein, the trench gate going through the active layer to said dielectric buried layer, a drain region and a body region separating from each other on said active layer surface on a side of said trench gate, and drain electrode acting as the drain region terminal, source region a, body contact region and source region b on the surface of said body region in sequence, with a source electrode as their common terminal, said body region and source region a is in contact with said trench gate, a dielectric trench located between said source region b and said drain region, being in contact with said body region and source region b, wherein the permittivity of the dielectric in said dielectric trench is lower than that of the material of said active layer, the depth of the said dielectric trench is larger than that of the body region and less than the thickness of the active layer, a buried gate of conductive material inset in said dielectric trench in the vicinity of the source region b and surrounded by the dielectric in said dielectric trench, with a depth no less than that of said body region and less than that of dielectric trench, the terminal of said buried gate is the buried gate electrode, said trench gate electrode and buried gate electrode are connected electrically, and the common terminal of said trench gate electrode and buried gate electrode is a gate electrode.