Effect of Ti ion implanation, abrasion with particles, and thin film evaporation on the formation of CVD diamond on si substrates

摘要

In previosu studies it has been shown that diamond nucleation and growth on Si subsrates may be enhanced by subsrate abrasion with amxture of diamond and Ti metal pearticles. in this work, a gradual change in the surface compositon of Si was designed to enable a controled study of chemicla effects induced by Ti additives at teh initialstages of diamond CVD formatin. Diamond was deposited on Si substates pre-abraded with diamond or a mixure of diamond and titanium powders. Also, Si implanted with different energies and doses of Ti (50, 100, 134 KeV, and 10~14, 10~15 ions/cm~2) and abraded with diamond powder served as a substrate for diamond depostion. In order to ksudy the reacions of Ti additives during the depostion process, additoanl Si substrates were covered by thin Ti films (100 nm) and exposed to CVD conditiosn. AFM, SEM, FTIR, μ-Raman, AES, anjd SIMS were utilized in his study. The incorporation of Ti into the Si surface geion modifeid its reactivity towards the formation of CVD diamond. however, its exact locaation relative tothe gas phase was found to be of crucial imporatnce: the highest nucelaiton enhancement was obtianed with the Ti was placed on the Si surface,a nd was in direct interactionw with the gas phase. It is suggested that C is accumulated in the Ti rich zone, resutling in faster carbon saturation and enhancement in SiC formaion, which is believed to be a template for diamond growth on Si.