Analysis of electro-thermal-stress failure of the LDMOS FET under HPM pulses

This article discusses a laterally diffused MOS (LDMOS) FET's thermal-stress failure test experiment under high-power microwave (HPM) pulses with different pulse widths and describes the 2-D transient coupled electro-thermal-stress (E-T-S) simulation of its structure model via finite-element method (FEM). The test experiment system mainly consists of an HPM generator, an oscilloscope, some attenuators and couplers. The thermal-stress failure is explained by some experimental phenomenon and the failure temperature is calculated via the FEM code with the measured HPM pulses. Furthermore, the transient thermal and stress distributions of the high power device are achieved and the temperature profile is verified by the commercial software of COMSOL.