Reliability of NLDMOS transistors subjected to repetitive power pulses

The failure mechanisms for NLDMOS transistors subjected to rectangular power pulses are investigated. The study confirms by measurement and simulation that the transistors survive single power pulses up to an energy that causes snapback at a critical temperature. However, devices can fail due to large thermal-mechanical stress and metal migration when subjected to repetitive power pulses of significantly smaller energy. The failure mechanism is confirmed by physical analysis then a Coffin-Manson metal fatigue model is applied to predict transistor reliability.