Preparation Of Hydrogenated Amorphous Silicon And Carbon Films By Plasma Enhanced Chemical Vapour Deposition Multifunction System

Plasma enhanced chemical vapour deposition system designed by our team were used to prepare amorphous silicon and carbon films (almost Diamond-like carbon films). ICP source (inductively coupled planar RF plasma) was used to get plasma during the preparation of amorphous silicon, and plused plasma source was used to get Diamond-like carbon films.ICP source (inductively coupled planar RF plasma) has attracted special interest in the potential deposition of various coatings. On one hand, ICP source can generate high plasma densities (>1011 cm-3) even at pressures below 10 Pa and owns the advantages of simple structure and low cost compared with RF capacitively coupled parallel plate plasma source. On the other hand, the substrate may be RF or DC biased independent from the RF induction power supply, the ion energy fluxed to the substrate can be therefore controlled to optimize the deposition parameters. Films of the anticipated properties can be prepared as a result. In the article, hydrogenated amorphous silicon films (a-Si:H) were produced by using an ICP source on polyimide substrates. Influence of RF power, gas flow rate and negative biased voltage on the films deposition rate was studied. The a-Si:H films deposition rate could reach as high as 3.5 nm/s under the optimizum growth condition.Diamond-like carbon (DLC) films were deposited on a-Ti substrates by pulsed plasma-enhanced chemical vapor deposition (PECVD) under various plused negative bias with the same device which was used to prepare a-Si:H films above. Effect of plused bias on the film microstructure was analyzed by Raman spectroscopy. Nano-hardness tester, scratch tester, friction and wear testing machine were used to measure the film hardness, adhesion strength between the films and substrates, tribological performance, respectively.The results confirmed that the plused bias could play an important role in DLC films deposition. DLC films containing the most sp3 carbon were deposited under the bias of-3000 V, and the film hardness was up to 36.451 GPa. It was not appropriate to deposite DLC films by further increasing the plused bias because the films will not only contain more graphite phase carbon, but also behave low film hardness and poor film-substrate adhesive strength.