Inffluence of the silicon surface treatment by plasma etching and scratching on the nucleation of diamond grown in HFCVD - a comparative study

A comparative study for the nucleation of diamond was carried out using surface treatment like (i) surface scratching with I pin diamond paste and (ii) surface etching using chlorine plasma at different RF powers (50, 100 and 150 W). Atomic force microscopic study shows variation in roughness from 31 rim to I 10 rim. Scratching results in random scratches, whereas plasma etches a surface uniformly. Scanning. electron microscopic observations show well faceted crystallites with a predominance of angular shaped grains corresponding to < 100 > and < 110 > crystallite surfaces for the scratched as well as plasma etched substrate. Surface etching at 150 W plasma power results in a better growth in comparison with 50 and 100 W plasma powers. Chlorine-radical is found responsible for the changes in the growth morphology. Raman spectroscopy shows a sharp peak at 1,332 cm(-1) and a peak at similar to 1,580 cm(-1) for both samples.