Biaxially aligned titanium nitride thin films deposited by reactive unbalanced magnetron sputtering

Texture control of sputter-deposited nitride films has provoked a great deal of interest due to its technological importance. However, to our knowledge, studies on the influence of the crystallographic texture of nitride films on the thin film properties have only investigated the influence of the preferred out-of-plane orientation. In this study, we investigated the mechanism responsible for the biaxial alignment in TiN layers. These biaxially aligned TiN layers were deposited by reactive unbalanced (type II) magnetron sputtering on a polycrystalline substrate (stainless steel). The preferred out-of-plane orientation was investigated by carrying out depositions on a nontilted substrate. It was observed that this preferred out-of-plane orientation changed from a (111) to a (002) out-of-plane orientation by increasing the N-2 partial pressure and was unaffected by the variation in substrate bias (0 or +10 V). It was also noticed that biaxially aligned layers can be obtained by tilting the substrate with respect to the incoming material flux. A model for the development of the preferred out-of-plane and in-plane orientation (biaxial alignment) is proposed. (c) 2004 Elsevier B.V. All rights reserved.