Influence of the energy of sputtered carbon atoms on the constitution of diamond-like carbon thin films

Abstract Diamond-like carbon thin films have been deposited by unbalanced radio frequency magnetron sputtering of a graphite target in a pure argon discharge. The formation of a dense sp 3 -coordinated structure is usually described by the subplantation model in which the role of two critical factors, i.e. the energy of bombarding argon ions E Ar+ and the flux ratio of ions to neutral carbon atoms, Φ Ar+ /Φ C , is well-known. The present study aimed, furthermore, at describing the influence of the energy of neutral carbon atoms E C on the constitution of resulting films. To this end, the ion energy dependence of the micro-density and the sp 3 content of the deposited films were examined by means of EELS for two different working pressures (0.2 Pa and 2 Pa) at a constant flux ratio Φ Ar+ /Φ C =5. Due to enhanced collisional processes in the plasma at 2 Pa, the effects of an energy reduction of carbon atoms are revealed. The results can be explained again according to subplantation processes.