Effect of substrate temperature on structural and physical properties of carbon thin films prepared by ion beam sputtering deposition method

In this study the effect of substrate temperature (from room temperature (RT) to 400°C) on the sructural and physical properties of cabon thin films were investigated. The films were prepared by ion beam sputtering deposition technique on glass substrate. Optical and structural properties were studied by UV-visible spectroscopy, Raman spectroscopy and atomic force microscopy, respectively. The results showed that optical transparency decreased with the increase in the substrate temperature. Raman spectra indicated a structural transition from amorphous to graphite-like phase by increasing temperatures since in the spectra; D peak disappeared in the layer at the substrate temperature of 400°C. The result of sheet resistance and the optical band gap showed the reduction trend by the increase in the substrate temperature from 100 to 400°C. However the enhancement of the surface roughness with the substrate temperature was observed. In the layer prepered with the substrate temperature equal to 100 °C , a minimum size of the graphite crystallites (with sp2 bands (La)) was equal to 0.36 nm and a maximum optical band gap was equal to 3 eV.