A new back-gate SOI high voltage device with a compound layer

A back-gate silicon on insulator (SOI) high voltage device with a compound layer (BG CL SOI-LDMOS) is proposed to enhance breakdown voltage of SOI device. Introducing of compound layer(CL) can effectively suppress gain of surface electric field at source side, and increase electric field in the buried oxide layer. Thus breakdown voltage of device is increased remarkably with invariable specific on-resistance. The breakdown voltage and electric field profile are researched for the new structure by using 2D MEDICI software. Simulation result shows that BG CL SOI-LDMOS can reach 557 V, 165.8 % higher than conventional SOI, at 1 mum-thick buried oxide layer, 40 mum-length drift region and 240 V back-gate voltage.