Influence of Shockley stacking fault propagation and contraction on electrical behavior of 4H-SiC pin diodes and DMOSFETs

Abstract

Silicon carbide is a desirable material for high power and temperature bipolar and unipolar electronic devices, such as high blocking voltage pin and Schottky diodes, respectively. However, the presence of electron-hole pair (ehp) recombination at basal plane dislocations (BPDs) in the drift layer of bipolar devices has been observed to create Shockley stacking faults (SSFs). Continued ehp injection causes the SSFs to propagate further, which in turn induces an increase in the forward voltage drop (Vf) [1]. Furthermore, while the effect of SSFs upon SiC-based devices is well known, the driving force for SSF propagation and contraction are still in question. The results presented here provide significant insight into the origin of the SSF driving force, illustrate that both SSF propagation and contraction can be favorable under current injection conditions and that the drift in the specific on-state resistance of DMOSFETS may be recovered via annealing, providing further evidence that SSFs are to blame.