ROLE OF THE PLASMA IN THE GROWTH OF AMORPHOUS-CARBON FILMS BY PULSED-LASER DEPOSITION

The plasma in the plume produced by the pulsed laser evaporation with a YAG laser (532 nm) of a graphite target, and its role in the growth of amorphous carbon films have been investigated. For a laser power of 10(10) W/cm(2), the mean velocity of particles in the plasma was abou t 8 cm/mu s. The plasma component of the plume was fully deflected usi ng a static magnetic field, allowing to deposit amorphous carbon films with and without plasma. Micro-Raman spectroscopy analysis showed tha t the amount of sp(3) hybridized carbon atoms of the nonplasma amorpho us carbon decreased to about half the amount found in the full plume d eposited films. Particles in the plasma constituted 23% of the total d eposited mass, as estimated from the difference in thickness and densi ty of both kinds of grown films. Langmuir probe measurements gave a si milar value for the plasma proportion of 25% if particles in the plasm a were singly ionized monatomic carbon. This result was consistent wit h the experimental ion velocity distribution, which was fitted to five Maxwell-Boltzmann distributions in which one of them carried most of the charge in the plasma. (C) 1998 American Institute of Physics.