Investigation of stress and adhesion of cubic boron nitride films

Cubic boron nitride (c-BN) films can be deposited by PVD and CVD methods. Massive ion bombardment of the growing film is required, leading to compressive stress and therefore poor adhesion. In a simple approach, stress is modelled by the balance of defect formation, due to ion bombardment, and thermal as well as ion-induced recombination processes. The model predicts stress to be reducible using high ion energies and high substrate temperatures, whereas the ion to atom flux ratio is of minor importance only. New results concerning c-BN nucleation show an orientational relationship between an initial textured h-BN layer and the first c-BN crystals. The influence of interlayers prior to c-BN deposition on the nucleation sequence and him adhesion is discussed.