Influence of Substrates on Conductivity of Thin Carbon Films Deposited by Methane Plasma and Subsequent Annealed

Abstract

Abstract The properties of thin carbon films obtained by the deposition of carbon in CH4 - plasma on the surface of various substrates (Si, SiO2 and quartz glass) and subsequent annealing at 650 to 800 °C were investigated. The sizes of graphene domains from 5 to 15 nm from Raman spectra were determined which increases with rising temperature on synthesis of carbon films. Also, sizes of graphene domains were estimated based on the electrical conductivities of obtained carbon films, and their values were equal ∼10.8 nm. The Efros-Shklovskii variable-range hopping (ES-VRH) conduction mechanism is replaced by percolation conductivity with increasing temperature from 650 to 800° C. When using Si substrates, the hopping mechanism was not observed at all temperatures.