High figure-of-merit vertical double diffused MOSFET with the charge trenches on partial SOI

Abstract

A novel silicon-on-insulator (SOI) high figure-of-merit vertical double diffused MOSFET (VDMOS) structure and its breakdown mechanism are presented in this paper. The structure is characterized by oxide trenches on the top interface of the buried oxide layer on partial SOI (TPSOI). The accumulation charges located in the trenches enhance the electric field in the buried oxide layer and uniform the electric field in the drift region, therefore the breakdown voltage (V br ) is enhanced. Simulation shows that the V br and the figure-of-merit of the TPSOI VDMOS increase by 66.8% and 148.1% in comparison with the conventional VDMOS, respectively.