Thin Solid Films 402 (2002) 195–202 0040-6090/02/$ - see front matter  2002 Elsevier Science B.V. All rights reserved. PII: S0040-6090 Ž 01 . 01672-8 Residual stress states in sputtered Ti Si N films 1yx x y F. Vaz *, L. Rebouta , Ph. Goudeau , J.P. Riviere , E. Schaffer , G. Kleer , M. Bodmann a, a b b c c d ` ¨ Universidade do Minho, Departamento de Fısica, Azurem, 4810 Guimaraes, Portugal a ´ ´ ˜ Laboratoire de Metallurgie Physique, Universite de Poitiers, 86960 Futuroscope, France b ´ ´ Fraunhofer-Institut fur Werkstoffmechanik, 79108 Freiburg, Germany c ¨ Formerly at Fraunhofer-Institut fur Werkstoffmechanik, 79108 Freiburg, Germany d ¨ Received 23 September 2000; received in revised form 29 June 2001; accepted 9 October 2001 Abstract The present paper reports on the influence of Si addition on the properties, namely stresses and thermoelastic behaviour, of r.f. reactive magnetron sputtered TiN coatings, in order to reach a further increase of coating performance in industrial application. Residual stresses were determined by two distinct methods, one of them being the so-called mechanical method. In this method, the deflection of the substrates, before and after deposition, is measured using a high precision co-ordinate measuring unit as well as an interference optical microscope (deflection method). The second method used is X-ray diffraction using the sin c method. 2 By heating the samples and in situ observation of substrate deflection evolution with temperature, the analysis of thermally- induced stresses was also carried out. Regarding the results, compressive residual stresses up to approximately 11 GPa were observed. The stress magnitude was found to depend on the total amount of Si addition to TiN matrix; for large Si additions ()12 at.%) a significant reduction was observed. Furthermore, the analysis of thermally-induced stress allowed the determination of the real effective deposition temperature, which led to a value of approximately 200 8C for the conditions employed within this work.  2002 Elsevier Science B.V. All rights reserved. Keywords: Nanostructures; Stress; Titanium nitride; X-Ray diffraction 1. Introduction Tailoring of the surface properties of a bulk material can be accomplished, for example by the application of thin hard coatings. However, if the maximum benefits, in engineering applications, are to be obtained for a given coating–substrate composite, the hardness, fracture toughness, Young’s modulus, and other mechanical properties of the coating must be optimised. Moreover, it is well-known that the mechanical and tribological properties of coated components are strongly influenced by the magnitude and the in-depth distribution of the residual stresses w1,2x. This fact attracted the attention of several research teams, revealing the residual stresses * Corresponding author. Tel.: q351-253510151; fax: q351- 253510153. E-mail address: fvaz@fisica.uminho.pt (F. Vaz). as an increasingly important technological issue from a reliability and performance point of view. For example, a high compressive stress state within the coating has been claimed to increase its fracture toughness w2x, which is an extremely important property in PVD coatings w1x. Anyhow, excessive amounts of these stress- es either compressive or tensile will eventually end up in severe failure problems. Film and substrate cracking in the case of tensile stresses, and film decohesion by buckling caused by compressive ones, are included in these problems w3x, concerning not only the integrity and performance of films applied as protective coatings w4x, but also coatings used in active and passive elec- tronics as well as in optical devices, electronic packaging w5x, layered composite structures, and in adhesive joints w6x. Particularly important are the applications that need to operate at high temperatures (normally up to 800