LOW-TEMPERATURE SYNTHESIS OF DIAMOND-LIKE CARBON-FILMS ON STEEL SUBSTRATES BY ELECTRON-CYCLOTRON-RESONANCE PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

Using microwave electron-cyclotron-resonance plasma-enhanced chemical vapor deposition, diamond-like carbon films were directly grown at low temperatures (less than or equal to 400 degrees C) on Fe-based alloy substrates without diamond seeding or use of a template layer. A singl e, broad line in the Raman spectra was observed in the region of 1328- 1335 cm(-1) for films grown in gas mixtures with a ratio of CH4:H-2 gr eater than or equal to 2%. In contrast, disordered carbon and graphite phases appeared in the spectra for film grown with a concentration of 20% CH4 in hydrogen. Diamond nucleation with an amorphous carbon laye r was observed in the initial growth stage, while many diamond particl es with irregular morphological features were observed on the surface of thicker films. These growth features are a consequence of the catal ytic nature of the Fe-based substrate.