High-voltage SOI lateral MOSFET with a dual vertical field plate

A new silicon-on-insulator (SOI) power lateral MOSFET with a dual vertical field plate (VFP) in the oxide trench is proposed. The dual VFP modulates the distribution of the electric field in the drift region, which enhances the internal field of the drift region and increases the drift doping concentration of the drift region, resulting in remarkable improvements in breakdown voltage (BV) and specific on-resistance (Ron,sp). The mechanism of the VFP is analyzed and the characteristics of BV and Ron,sp are discussed. It is shown that the BV of the proposed device increases from 389 V of the conventional device to 589 V, and the Ron,sp decreases from 366 mΩcm2 to 110 mΩcm2.