INFLUENCE OF THE POWER AND PRESSURE ON THE GROWTH-RATE AND REFRACTIVE-INDEX OF A-C-H THIN-FILMS DEPOSITED BY RF PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

Thin films of hydrogenated amorphous carbon (a-C:H) were prepared from a mixture of 10% methane and 90% hydrogen by the plasma-enhanced chem ical vapour deposition (PECVD) technique at an r.f. frequency of 13.56 MHz. Different conditions of pressure, power and gas how rate were em ployed. The films were characterized by a variety of surface analytica l techniques, and ellipsometry was used to characterize the optical pr operties of the films. The films obtained were uniform, soft, transpar ent, non-conducting and chemically inert, with good thermal conductivi ty and high stability. In this paper, we report and discuss some of th e parameters that influence the optical properties of the films and th e rate at which they are deposited.