Compositional and thickness distribution of carbon nitride films grown by PLD in the target plane

The peculiarities of a novel off-axis pulsed laser deposition configuration are reported in which the material is collected on substrates placed in the target plane. Carbon nitride films have been grown by KrF excimer laser ablation of a rotating graphite target in nitrogen atmosphere. The thickness distribution of films, recorded along the axes of symmetry of the laser spot, revealed that the increase of pressure from 1 to 40 Pa led to (i) thicker films, (ii) gradually more confined deposits and (iii) a transition from elliptical to circular distribution. X-ray photoelectron spectroscopy evidenced the reduced nitrogen content of the off-axis films as compared to their traditional on-axis counterparts. Nevertheless, the chemical structure of the deposits was identical in the two geometries. In the off-axis films the further away the deposition location is from the laser spot the more nitrogen can be incorporated into the film with concomitant increase in the oxygen content, the latter pointing to possible changes in the film microstructure. (C) 2003 Elsevier B.V. All rights reserved.