Super junction LDMOS with P-trench and stepped buried oxide layer for high performance

Abstract

In this paper, a new silicon-on-insulator superjunction lateral double-diffused MOSFET (SOI SJLDMOS) with a p-trench layer and stepped buried oxide, is investigated using 3D numerical simulation. The p-trench layer and stepped buried oxide distinguish it from a conventional SOI SJLDMOS. The etched buried oxide layer, with its stepped buried -oxide structure, which facilitates a more even electric field distribution via the electric field modulation effect, increases the breakdown-voltage (BV). Furthermore, the p-trench layer improves the doping concentration through compensation depletion, which further decreases the specific on-resistance (Ron,sp). The simulation indicates that the new device has a higher BV (increased by 29%) than the conventional SOI SJLDMOS. At the same time, Ron,sp decreases by 20% for the on-state for a given drift-region length.