Experimental study and simulations on two different avalanche modes in trench power MOSFETs

The avalanche behaviour of a new trench power MOSFET was investigated with the help of measurements and electro-thermal device simulation techniques. Two different destruction regimes were identified experimentally: energy-related destruction and current-related destruction. Possible simulation approaches to account for the different effects were proposed. The corresponding results agreed well with measurements. Furthermore, the simulations qualitatively predicted the experimental results´ dependence of avalanche behaviour on design parameters.