Growth of cubic boron nitride films by ibad and triode sputtering: development of intrinsic stress
Two methods are employed to evidenced the stress behavior in c-BN films. On the one hand, in depth stress profile of c-BN film, deposited by ion beam assisted evaporation, was performed by recording infrared spectra and substrate curvature after reactive ion etching (RIE) steps. It shows a peak of stress up to - 17 GPa in the h-BN basal layer and a stress relaxation when the cubic phase appears. On the other hand, dynamic stress profiles of c-BN films deposited by a triode sputtering system, are obtained by recording infrared spectra and substrate curvature after various c-BN deposition times, with the same experimental conditions. Likewise, a peak of stress of - 12 GPa is unmistakably observed in the h-BN basal layer followed by a stress release during c-BN nucleation, where an average value of - 12 GPa is observed in the c-BN film volume. These results provide a support for the stress model proposed by McKenzie even if along with a minimum stress a high level of densification of the layer is needed. (C) 2001 Elsevier Science B.V. All rights reserved.