Temperature-Dependent Stability of Polytypes and Stacking Faults in Si C : Reconciling Theory and Experiments

Ubiquitous stacking faults in SiC are a major problem in power electronics, since they are predicted to cause the deterioration, and eventually failure, of devices. Understanding the thermodynamic stabilities of the different crystal polytypes in these faults is crucial to improving the quality of epitaxial SiC, and thus devices. This sophisticated density-functional study resolves the paradox of SiC polytype stability, predicting the correct free-energy hierarchy with varying temperature. The physical insight gained here should extend to other classes of semiconductors as well.