High voltage (>1100V) SOI LDMOS with an accumulated charges layer for double enhanced dielectric electric field

Abstract

A high voltage silicon-on-insulator (SOI) LDMOS with an accumulated charges layer (ACL) for double enhanced dielectric electric field (DEDF) is proposed. The electrons and holes can be accumulated in the ACL with a back-gate bias in off-state. These charges can enhance the dielectric field in the buried oxide (BOX) layer under the source and drain for improving breakdown voltage (BV). Moreover, the ACL can also enhance the reduced surface field (RESURF) effect. Compared with the conventional SOI and Shield-Trench SOI, BV of the DEDF SOI can achieve 1163V at 1µm BOX and 550V back-gate voltage.