A 700 V low specific on-resistance self-isolated DB-nLDMOS

Abstract

a 700 V self-ISO (isolated) DB-nLDMOS (dual P buried-layer nLDMOS) without epitaxy is proposed in this paper. By separately implanting deep junction NWELLs, drift region of low doping concentration in neck region is achieved.This alleviates the concentration of the electric field and avoids premature avalanche breakdown around the bird's beak.Furthermore, introduction of triple RESURF (reduce surface field) technology and optimal device sizes benefit for ultra-low Ron,s p (specific on-resistance). Finally, this ISO DB-nLDMOS is experimentally integrated in a 700 V BCD process platform.Testing results show that proposed device achieves 780-V BVd" 1 0.4-Q·mm 2 Ron,s p and 20-V floating voltage of source electrode.