Surface and Coatings Technology, 39/40 (1989) 397- 408 397 HIGH-TEMPERATURE X-RAY DIFFRACTION STUDIES ON PHYSICAL VAPOUR DEPOSITED TiN D. S. RICKERBY,S. J. BULL, A. M. JONES, F. L. CULLEN and B. A. BELLAMY Materials Engineering Centre, Harwell Laboratory, UKAEA, Oxfordshire 0 X l l ORA (U.K.) (Received March 23, 1989) Summary There is an increasing awareness of the importance of the interrelation- ship between coating microstructure and properties; however, most of the measurements in the literature relate to room temperature properties. High- temperature X-ray diffraction (XRD) studies confirm the importance of mi- crostructure in dictating the properties of physical vapour deposited (PVD) TiN thin films, but in addition illustrate that these changes in coating properties are not usually reversible. Evidence will be presented on the changes in the levels of residual stress and microstrain broadening which arise in PVD TiN films as a function of annealing temperature. These XRD results are discussed in the light of the structural models proposed for PVD TiN thin films. 1. Introduction In the field of surface engineering there is a growing awareness that the interrelationship between the properties of thin films and coating microstruc- ture, through variations in process-type and deposition conditions, is of crucial importance if 'optimum' coatings are to be selected for a whole range of applications which span the microelectronic and engineering industries [1-4]. To date, the criteria used for selection, such as hardness, level of coating-substrate adhesion and internal stress, resistivity etc., are based on measurements made at room temperature. However, there is evidence from the published literature which illustrates that many of the properties of physical vapour deposited (PVD) and chemical vapour deposited (CVD) coatings change with operating temperature. For example, in the case of PVD TiN tempering at elevated temperatures (up to 900 °C) results in a reduction in the levels of internal stress and hardness [5- 7] which are accompanied by changes in the colour of the nitride [8]. Similar reductions in stress and the coefficient of resistivity have also been reported by Ernsberger et al. [9] for sputtered TiN films annealed at temperatures as low as 300 °C. 0257-8972/89/$3.50 © Elsevier Sequoia/Printed in The Netherlands