Self-irradiation of thin SiC nanowires with low-energy ions : A molecular dynamics study

Irradiation of ultra-thin silicon carbide nanowires (SiC NWs) with low-energy ions was investigated with the molecular dynamics (MD) method. The energies of the incident Si and C ions varied from 0.2 to 5.0keV. Simulation results show that the ion range predicted by the SRIM code is a little shorter than that obtained from the MD simulation when the incident energy is low and the implanted ions can form a peak-like distribution inside the NW. Compared with bulk material, the sputtering yield of the SiC NW is much higher as a result of the NW's larger surface-to-volume ratio, and for a high ion energy, the sputtering yields show a different dependence to the nuclear stopping power because the NW's limited volume stops the collision cascade from fully evolving. Moreover, the calculated short-range order values indicate that the amorphous degree for most irradiated samples is acceptable and repairable. For a high ion energy range, the SiC NW is more difficult to amorphize compared with bulk SiC. By carefully optimizing the implantation parameters, a desirable distribution of dopants can be achieved in the thin SiC NW while the irradiation damage is kept at an acceptable level.