Amorphous silicon-carbon films prepared by reactive evaporation

Abstract

An ion-beam-assisted deposition (IBAD) technique, based on reactive evaporation using hydrogen/ methane gas mixture, has been used for the preparation ofa-Si1−x C x : H films. Measurements are reported on the composition, optical gap, infra-red vibrational absorption bands and on the electrical dark-conductivity temperature dependence to verify the reliability of this deposition method. On increasing the compositional parameterx up to 0.35, the IR results show an increasing hydrogenation and the presence of Si-CH3 units in addition to the ones with the carbon fully coordinated with the silicon, while the optical-gap and the dark-conductivity activation energies reached the values of 2.44 eV and 0.77 eV, respectively.