The energy influx during plasma deposition of amorphous hydrogenated carbon films

Abstract

The integral energy influx from the plasma to the substrate was determined for amorphous hydrogenated carbon (a-C:H) film deposition by magnetron sputtering and in an electron cyclotron resonance (ECR) discharge. The measurements, for which a thermal probe was designed, are based on time evolution of the substrate temperature during the deposition process. The different contributions to the integral energy influx were estimated by model calculations on the basis of assumptions for the kinetic energy of the charge carriers, their recombination, and film condensation. The energy influx during deposition in the CH 4-ECR plasma, which is in the range of 0.5–2 J s −1, is predominantly determined by ions and chemical reactions, while the energy influx in magnetron sputtering, being in the range of 0.2–1.2 J s −1, is mainly determined by fast neutrals and target radiation. The present results emphasise that the energy influx is a key parameter in thin film deposition and is important for comparison and scaling-up of different plasma process systems.