It was recalled that recent experiments on the deformation of semiconductors had revealed a sudden change in the variation of the critical resolved shear stress as a function of temperature. This was taken to imply a change in the deformation mechanism at a critical temperature. The latter appeared to coincide approximately with the brittle-to-ductile transition temperature. Here, new deformation experiments were performed on the wide-bandgap semiconductor 4H-SiC, over a range of temperatures, using 2 strain-rates. Transmission electron microscopy was used to characterize induced dislocations, below and above the critical temperature. On the basis of these and other results, a new model was proposed for the deformation of tetrahedrally coordinated materials at low and high temperatures, and the relationship between the transition in deformation mode and the transition in fracture mode (brittle to ductile) was explored.

On Transition Temperatures in the Plasticity and Fracture of Semiconductors. P.Pirouz, J.L.Demenet, M.H.Hong: Philosophical Magazine A, 2001, 81[5], 1207-27