Temperature dependence of avalanche breakdown in 4H-SiC devices

Abstract

We report new data on the temperature coefficient of the avalanche breakdown voltage (BV) in 4H-SiC devices. We compare avalanche in different device types (MOSFETs/Schottky diodes), different measurement types [Id(Vd)-sweeps and unclamped inductive switching stress], and avalanche directions (vertical and lateral) for a wide range of avalanche voltages. We fit the measured BV(T)-curves to the one-sided abrupt junction model and extract values for the temperature coefficients of impact ionization coefficients in their Chynoweth and Thornber forms for both holes and electrons.