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

In this study the effect of surface roughness and damage, as well as chemical modification with Ti additives, in different dispersion states, on the dc glow discharge enhanced diamond nucleation on silicon were investigated. It was established that the relative sp3 content in the carbon film produced by the dc-glow discharge process is enhanced as a result of surface damage. 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 films have a deleterious effect on nucleation, while particles catalyze precursor film generation. This phenomenon was explained as a balance between Ti aided accumulation of carbon on the one hand, and Ti induced dissolution of diamond nucleation centers in the hydrogen rich atmosphere. As a result of surface abrasion the optimal temperature for nano-diamond formation during the dc glow discharge stage is shifted to lower temperatures relative to that observed for virgin silicon.