ON THE RESIDUAL-STRESS AND PICO-STRUCTURE OF TITANIUM NITRIDE FILMS .2. A PICO-STRUCTURAL MODEL

A model is presented in which the texture adopted by TiN films made by plasma-enhanced physical vapor deposition (PVD) methods is affected by the lattice defects formed during growth. It is proposed that the defects formed are those whose formation absorbs a maximum amount of the energy accompanying the deposition process. Specifically, in sub- and stoichiometric films, extrinsic dislocation loops are formed on (111) planes by migration (diffusion or channeling) which then cause the [111] growth texture to be preferred by the film. In super-stoichiometric films, the additional nitrogen is incorporated as dumb-bell pairs in second nearest neighbor tetrahedral sites oriented in the [200] or [220] directions which cause these to be the favored growth textures. It is considered that the trapped argon is associated with the extrinsic loops in the former case.