Reduction of intrinsic stress in cubic boron nitride films

Several techniques reported to be effective for the preparation of thin films of cubic phase boron nitride (c-BN) are reviewed. In order to maintain integrity and adhesion for such films at a useful thickness, it is critical to minimize their intrinsic stress. A method is detailed for stress reduction by MeV ion radiation following the deposition of c-BN films. Based on these successful processes, a new method is proposed, in which the production of stress-reducing atom displacements is achieved during ion-assisted c-BN deposition, by concurrent bombardment of the growing film with energetic ions, typically at keV energies.