The optically induced nucleation and expansion of stacking faults in hexagonal SiC structures was studied. The activation energy for partial dislocation glide under optical excitation was found to be reduced to 0.25eV. This was about 2eV lower than that for pure thermal activation. From measurements of the thermal activation and below-gap excitation spectroscopy of dislocation glide, it was concluded that the elementary process which controlled the expansion of stacking faults was kink-pair nucleation, assisted by the phonon-kick mechanism. It was proposed that solitons on 30° Si(g) partials with a Si core acted as deep 2.4eV+EV trap sites. This readily provided the electron-hole recombination energy required to enhance the motion of dislocations. The present results suggested that this was a general mechanism of structural degradation in hexagonal SiC.

Recombination-Induced Stacking Faults: Evidence for a General Mechanism in Hexagonal SiC. A.Galeckas, J.Linnros, P.Pirouz: Physical Review Letters, 2006, 96[2], 025502 (3pp)