An analysis of the reverse characteristics of 4H-type diodes, in the pre-breakdown regime, was performed in order to clarify the effects which arose from the presence of dislocations and traps in the material. The results were found to compare favourably with recent data. The response was shown to be controlled mainly by the impact ionization process. A significant increase in the device current, a softer threshold and lower hold-off capabilities were predicted to occur in the presence of dislocation defects; in keeping with experimental measurements.

Dislocation Defect Based Model Analysis for the Pre-Breakdown Reverse Characteristics of 4H-SiC p+n Diodes. L.Zheng, R.P.Joshi, C.Fazi: Journal of Applied Physics, 1999, 85[11], 7935-8