Correlation between surface oxygen content and microstructure of carbon nitride films

Carbon nitride films deposited by ArF excimer laser ablation of a graphite target in the 1-100-Pa N-2 pressure and 1.0-10-J cm(-2) fluence domains differ not only in their nitrogen but also in their oxygen content. The (surface) oxygen content correlates well with the compactness of the films. Oxygen contents below approximately 8 at.%, smooth surface, and mass densities above 2.2 g cm(-3) are typical of films deposited at low N-2 pressures (and high fluences) while deposition at/above 50 Pa results in films of oxygen contents exceeding 12 at.%, rough surface consisting of loosely connected cluster agglomerates, and density values at approximately 1.4 g cm(-3). At medium pressures high fluence processing is advantageous in terms of both nitrogen content and film morphology. (C) 2002 Elsevier Science B.V. All rights reserved.