Influence of substrate temperature and microwave power on the properties of a-C:H films prepared using the ECR-CVD method

Abstract

Abstract The deposition of hydrogenated amorphous carbon (a-C:H) films from a mixture of hydrogen and methane, using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) method is reported. The effects of the substrate temperature and microwave power on the deposition rate, optical band gap, infrared (IR) absorption, photoluminescence (PL) and Raman scattering characteristics were investigated. We found that the deposition rate decreases with increasing substrate temperature and exhibits a peak value at 1000 W, for microwave power ranging from 200 to 1300 W. The optical bandgap and PL peak energy decrease with increasing substrate temperature, but the decrease was much smaller in the case of the PL peak energy. The optical band gap variation with substrate temperature and microwave power correlates well with the IR absorption for CH bondings. The E 04 optical band gap reaches a maximum value of 3.3 eV in the films deposited at room temperature.