Morphological study of PLD grown carbon films

Carbon films have been deposited by ArF excimer laser ablation of a graphite target in argon ambient of pressures between 10(-4) and 200 Pa. Besides carbon, ex situ RBS and ERDA measurements reveal the presence of argon, hydrogen and oxygen in the films. Below 0.5 Pa the apparent growth rate, defined as the measured thickness per number of pulses, is almost constant at around 0.30 A per pulse. Between 0.5 and 5 Pa it drops to 0.15 A per pulse. The most salient feature of the pressure dependence is the unexpected increase in the apparent growth rate between 5 and 100 Pa. Above 100 Pa the growth rate further decreases below 0.07 A per pulse. Parallel AFM measurements reveal characteristic differences in the surface morphology in each domain. Comparative analysis of the dependence of parameters characteristic of film growth and the evolution of microstructure on argon pressure provides information on the growth mechanism up to 200 Pa. (C) 2002 Elsevier Science B.V. All rights reserved.