Suppression of CVD diamond growth by ion beam induced annihilation of nucleation and growth centers

Abstract

Silicon surfaces both untreated and treated with Diamond, c-BN and SiC slurries are subjected to Xe + ion-beam irradiation at different doses and energies prior to diamond deposition. The effect of the irradiation on deposited diamond particles density (DPD) is studied. For all slurries used, ion irradiation at a fixed ion dose of 2 × 10 15cm −2 and different energies results in a monotonic decrease in DPD with increasing ion energy (40–300 keV). In the case of ion irradiation at a fixed ion energy of 300 keV and different doses (8 × 10 12−2 × 10 15cm −2) it is found that DPD is not affected by the lowest irradiation dose. However, a significant decrease is observed following an irradiation dose of 3 × 10 14cm −2, and a nearly total suppression of the diamond deposition takes place after irradiation at a dose of 2 × 10 15cm −2. In all cases studied, whether implanted or unimplanted, CVD diamond nucleation on non-abraded substrates are found to be similar and very low. These results suggest that for all three slurries used, diamond CVD nucleation and growth takes place on the debris left on the surface during the abrasion process which, when damaged by ion irradiation at appropriate energies and doses, results in the suppression of diamond growth. The contribution of substrate surface defects created by ion implantation to DPD is negligible. Based on the dependence of DPD on both ion energy and ion dose, the debris size distribution in the case of diamond abrasion is estimated to be predominantly smaller than 100 A.