Influence of process parameters on structure and optical properties of GeC thin films deposited by RF magnetron sputtering

Germanium carbide (Ge1 − xCx) films on silicon and quartz substrates have been prepared by the radio frequency (RF) reactive sputtering of a pure Ge target in a CH4/Ar discharge. Their structural and optical properties have been investigated as functions of the substrate temperature (TS) and the CH4 percentage to the gas mixture. The optical band gap of the films lies within the range 0.96–1.65 eV, varying proportionally with the carbon content and in inverse proportionality with TS.