Analysis of high current breakdown and UIS behavior of resurf LDMOS (RLDMOS) devices

Abstract

This work analyzes unclamped inductive switching (UIS) behavior of two types of 40 V resurf (reduced surface field) lateral diffused MOSFETs (RLDMOSFETs). It is shown that the addition of a deep buffer implant region on the drain side of the device increases the snap-back current limit as well as UIS robustness. It is also shown, using 2D simulation, that the failure current limit under UIS conditions is not the same as the current at which the parasitic BJT turns on.