Boron nitride films deposited by ion beam assisted deposition (IBAD) and triode sputtering system are studied. The presence of the cubic phase was checked by transmission infrared spectroscopy. The adhesion of the films was very poor, the films delaminated just after deposition. In an attempt to improve the adhesion, the deposition conditions (ion energy and flux) were changed after the c-BN nucleation. The results were, on one hand, a broadening of the window of deposition conditions for obtaining the cubic phase. On the other hand, a significant improvement of the adhesion was obtained. Scratch tests showed critical loads up to 5 N. Nevertheless, in contrast to the expected results, even after lowering the ion bombardment no stress relief was observed. It appears that the compressive stress within the cubic layer is related to the mechanical properties of the material rather than to the synthesis conditions.