Diamondlike carbon films sputter deposited with an electron cyclotron resonance reactor

Abstract

Amorphous carbon thin films were sputter deposited using a microwave electron cyclotron resonance reactor with a graphite target. Films were deposited at a temperature range of −50–50 °C, at reactor pressures ranging between 0.1 and 0.4 Pa, and with the substrate rf biased, floating, and grounded. The films were shown to be hard, to have optical band gaps of 0.9–1.4 eV, refractive indices ranging between 2.0 and 3.0, and Raman spectra characteristic of diamondlike carbon material. The effect of process conditions on the physical properties of the deposited films is investigated. The refractive index showed a dependence on pressure, increasing slightly with decreasing pressure. Electrical resistivity decreased with rf substrate bias.