Reliability analysis of power MOSFET's with the help of compact models and circuit simulation

This paper shows that circuit simulation with accurate physical device models is an effective tool in investigating stress conditions and detecting possible failure mechanisms which can threaten the reliable device operation. As an example the analysis of power MOSFETs used as synchronous rectifiers in half-bridge topologies switching an inductive load is presented. The detected effects, which cannot be observed directly by measurements are: avalanche breakdown at supply voltages clearly below breakdown voltage and unintended turn-on of the MdSFET when its body diode is used as a freewheeling element.