Structural properties of amorphous carbon nitride films prepared by ion beam assisted deposition

Amorphous carbon nitride films (a-CNx) with nitrogen concentration ranging from 0 to 30 at.% were prepared by ion beam assisted deposition at different substrate temperatures, T = 150, 350 and 550 degreesC. In situ X-ray photoelectron spectroscopy, infrared spectroscopy, hardness and intrinsic stress measurements were applied to investigate the effects of the nitrogen incorporation and temperature in the structural properties of the films. For all T, N incorporation up to 20 at.% leads to increases in hardness and stress of the films. These changes are attributed to modifications of the bonding configurations of the disordered matrix that surrounds the small graphitic clusters in the films. On the other hand, increases in substrate temperature lead to increases in the size of ordered graphitic clusters in the films but have little effect in their overall mechanical properties. (C) 2004 Elsevier B.V. All rights reserved.