The influence of surface roughness and chemical modification of silicon surfaces on dc-glow discharge enhanced diamond nucleation

In this study the effect of surface roughness and damage, as well as chemic al modification with Ti additives, in different dispersion states, on the d e glow discharge enhanced diamond nucleation on silicon were investigated. It was established that the relative sp(3) content in the carbon film produ ced by the de-glow discharge process is enhanced as a result of surface dam age. Consequently, diamond DPD (deposited particle density) obtained in the subsequent deposition is substantially enhanced. Also it was found that Ti surface coverage influences the efficiency of nucleation. Continuous Ti fi lms have a deleterious effect on nucleation, while particles catalyze precu rsor film generation. This phenomenon was explained as a balance between Ti aided accumulation of carbon on the one hand, and Ti induced dissolution o f diamond nucleation centers in the hydrogen rich atmosphere. As a result o f surface abrasion the optimal temperature for nano-diamond formation durin g the dc glow discharge stage is shifted to lower temperatures relative to that observed fur virgin silicon. (C) 2001 Elsevier Science Ltd. All rights reserved.