Deposition conditions and composition and structure relationships for nitride carbon films obtained by ECR plasma-assisted CVD and reactive rf magnetron sputtering

Hydrogenated carbon nitride and carbon nitride films were deposited by ECR plasma-assisted CVD (PACVD) and rf reactive magnetron sputtering. Film comp osition (N/C ratio), growth rate (V-g) and microhardness H were investigate d depending on the type (de or rf) and the level of substrate bias in the r ange 0 to -200 V. As was revealed, the ion bombardment influences the compo sition and growth rate of carbon nitride films during their deposition. An increase in rf bias voltage up to --200 V results in a decrease in V,up to zero, while the dependence of N/C on rf bias value reveals a peak at about -130 to -150 V. Analysis of Raman spectra for both film types indicates a d ecrease in size of the film-forming clusters and simultaneous arrangement o f atoms towards :graphite-like structure with increasing ion bombardment in tensity. From the resemblance of V,, N/C and Raman spectra behavior to the variation in ion bombardment characteristics, it can be,concluded that the ion bombardment effect reveals common features for two essentially differen t deposition methods, whereas the film growth mechanisms are strongly diffe rent for these deposition techniques and substantially influence the compos ition and growth rate of the films. The microhardness of CN,H, films increa sed with increasing ion bombardment intensity, but did not exceed 7000 N/mm (2). These effects are related to the film microstructure evolution under t he ion bombardment and sp(2) nature of the chemical bonds in the film-formi ng clusters. (C) 2000 Elsevier Science S.A. All rights reserved.