SUPPRESSION OF CVD DIAMOND GROWTH BY ION-BEAM-INDUCED ANNIHILATION OFNUCLEATION AND GROWTH-CENTERS

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 irradiati on on deposited diamond particles density (DPD) is studied. For all sl urries used, ion irradiation at a fixed ion dose of 2 x 10(15)cm(-2) a nd different energies results in a monotonic decrease in DPD with incr easing ion energy (40-300 keV). In the case of ion irradiation at a fi xed ion energy of 300 keV and different doses (8 x 10(12)-2 x 10(15)cm (-2)) it is found that DPD is not affected by the lowest irradiation d ose. However, a significant decrease is observed following an irradiat ion dose of 3 x 10(14)cm(-2), and a nearly total suppression of the di amond deposition takes place after irradiation at a dose of 2 x 10(15) cm(-2). In all cases studied, whether implanted or unimplanted, CVD di amond nucleation on non-abraded substrates are found to be similar and very low. These results suggest that for all three slurries used, dia mond CVD nucleation and growth takes place on the debris left on the s urface during the abrasion process which, when damaged by ion irradiat ion at appropriate energies and doses, results in the suppression of d iamond growth. The contribution of substrate surface defects created b y ion implantation to DPD is negligible. Based on the dependence of DP D on both ion energy and ion dose, the debris size distribution in the case of diamond abrasion is estimated to be predominantly smaller tha n 100 A.