Overall energy model for preferred growth of TiN films during filtered arc deposition

Abstract

TiN films with different preferred crystalline orientations have been prepared by a new cathodic arc evaporation technique - filtered arc deposition (FAD). The evolution of the preferred orientation in the TiN films was investigated systematically. Three kinds of preferred orientation, i.e. the (200), (111), and (220) preferred orientation, were achieved continuously in one deposition procedure by varying the film thickness and substrate bias which determines the bombarding energy of the deposited energetic particles. At the initial stage of film growth, the (200) orientation is dominant at a lower substrate bias. When the film becomes thicker and/or substrate bias increases, the preferred orientation will be (111) instead of (200). If the substrate bias increases further, then the preferred (220) growth occurs at any film thickness. The evolution of the preferred orientation from (200) to (111) and then to (220) is discussed on the basis of a new concept, the so-called overall energy which consists of the surface energy, the strain energy, and the stopping energy. The preferred orientation of TiN films is determined by the competition between the surface energy, the strain energy and the stopping energy.