Electronic driving force for stacking fault expansion in 4H-SiC

Trapping of electrons in stacking fault SF interface states may lower the energy of a SF more than it costs to form the SF. This “electronic stress” driving force for SF expansion is evaluated for single and double stacking faults in 4H-SiC in terms of a two-dimensional free-electron density of states model based on first-principles calculations. In contrast with previous work, which claimed that the number of electrons that can be trapped in the SF is severely limited by the potential barrier arising from the space-charge region adjacent to the SF, we find that the potential barrier is strongly reduced by screening and its effect is negligible.