Effects of electric field on the properties of carbon-based thin films deposited by electron cyclotron resonance microwave plasma (ECR-MP) system

In this study, carbon-based semiconductor thin films were deposited on glass and silicon substrates by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MP CVD) system. Methane (CH4) gas was used as a carbon plasma source. Hydrogenated silicon- carbide thin-films (SixCy: H) (taking substrate as Si source) obtained for the first time. The optical and structural properties of the produced films were measured by spectrophotometer, Raman spectroscopies, X-ray diffractometer and atomic force microscopy (AFM). An external electric field was applied to the plasma during deposition some of the films that will help in optimizing the deposition. The influences of the applied bias voltage on the film properties were investigated. The effects of the deposition pressure on optical properties were also discussed. The results indicate that the band gap energy increases with increasing the deposition pressure while it decreases as the applied voltage increases. The optical transmission ratio decreases in the presence of the electric field. C and H ions with different q/m ratios result in different C/H film regions. The biased deposited films were more crystalline and more ordered structure as compared to unbiased films. Keywords: Carbon thin films, CH4, ECR-MP CVD, Band gap energy