Electron-beam-induced amorphization in SiC

We performed electron irradiation into silicon carbide (SiC) using a transmission electron microscope equipped with a field-emission gun. It was found that a crystalline-to-amorphous phase transformation takes place with 200-keV electrons at room temperature. The incident electron energies are much larger than the threshold displacement energy of carbon atoms, while it is almost the same as or smaller than that of silicon atoms. An amorphized area undergoes a transformation from amorphous SiC to amorphous silicon because of the exclusive displacements of carbon atoms rather than silicon atoms by the low incident electron energy of <300 keV. We also discuss amorphization mechanisms in electron-irradiated SiC within the context of our results as well as previous observations.