We report on AlN and GaN film growth by laser ablation of Al or Ga targets, respectively, in N-2 reactive ambient atmosphere. The best experimental conditions are defined in relation with film. Due to the low chemical reactivity of N-2, it is necessary to increase N density to obtain pure nitride films to realise high quality films, Thus a radio frequency (RF) discharge device was added for N, dissociation. AIN and GaN hexagonal nitride phases and highly textured AIN films with epitaxial relationships with (0 0 0 1) Al2O3 substrates are grown without contamination. The plasma plume investigation by emission spectroscopy with and without RF discharge allows the reactive species kinetics study near the target, A secondary discharge device is mounted at the place of the substrate holder to study the dark zone near the substrate. The presence of N metastable species near the substrate has been evidenced as well as the increase of their concentration with RF discharge added. (C) 2002 Elsevier Science B.V. All rights reserved.