Behaviour of 1.2 kV SiC JBS diodes under repetitive high power stress

Abstract

A methodology and a dedicated test-bench to evaluate the behaviour of SiC JBS diodes under repetitive high power stresses and surge currents have been developed and illustrated with JBS and Schottky 1.2 kV SiC diodes. The concept of dissipated energy versus the number of cycles is introduced to characterize the degradation evolution of the tested device. The sweeping current pulse technique offers the possibility to evaluate the effect of the self-heating on the I (V). This is especially relevant for JBS SiC diodes whose series resistance highly depends on the junction temperature. JBS diodes show a ×2.66 (×4.16) higher surge current capability at 25 °C (225 °C) than the pure Schottky diodes. The fabricated SiC JBS and Schottky diodes have been submitted to more than 300,000 power cycles at a dissipated energy of 0.7 J, showing no relevant degradation.