Cubic-boron nitride (c-BN) films with low stress have been produced by simultaneous 35 keV N+ ion implantation during growth by ion assisted sputtering. The stress release is achieved at the lost of a decrease in the C-BN content. Despite this fact, films with a high c-BN content and relatively large thickness (similar to0.4 mum) have been produced. The decrease on the c-BN content is discussed in terms of the damage induced by the medium-energy ion implantation. (C) 2003 American Vacuum Society.