Ion-beam-induced amorphization of 6H-SiC

We have investigated the amorphization of GH-SiC during bombardment with Na ions of energy 100 and 155 keV, by means of Rutherford backscattering in channelling geometry, mechanical surface profiling and Raman spectroscopy. The material was found to amorphize at a critical damage rate of about 1/10 displacements per atom. An incubation fluence is needed to initiate the amorphization process. The observed density changes and the results of the Raman measurements also indicate that, at low fluences, an amorphous network is formed, which conserves the chemical short-range order of the crystalline material. Further application of higher fluences drives the system to form an atomically disordered structure without chemical short-range order.