Diamond growth on CoSi₂/Si by bias-enhanced microwave plasma chemical vapor deposition method

Diamond was grown on polycrystalline CoSi₂/Si substrates by bias-enhanced microwave plasma chemical vapor deposition. Both of the positive and negative biasing effects were investigated by microstructural characterization. It has been found that nucleation density can reach ∼10⁹ cm^-2 with positive biasing, much higher than with negative biasing. Cross-sectional transmission electron microscopy shows that diamond deposited by positive biasing grows on a relatively smooth CoSi₂ surface, while the etching effect of ion bombardment during negative biasing results in a rough CoSi₂ surface. The diamond morphology obtained with negative bias has a flat surface with a strong (1 0 0) texture.