Effects of DC Bias on the Microstructure, Residual Stress and Hardness Properties of TiVCrZrTaN Films by Reactive RF Magnetron Sputtering

The TiVCrZrTaN thin film was prepared on Si substrate at 300 degrees C by reactive RF magnetron sputtering deposition. Effects of applied dc bias (from 0 V to 120 V) on the microstructure, residual stress, and hardness properties of TiVCrZrTaN films were investigated by field emission scanning electron microscopy, X-ray diffraction, Fizeau interferometer and nanoindentation system. The columnar structures are observed by field emission scanning electron microscopy. X-ray diffraction analysis reveals that TiVCrZrTaN films were polycrystalline and have preferred orientation along (111) when applied dc bias was below 100 V. The preferred orientation is changed from (111) to (200) as applied dc bias was 100V. The residual stress of all films was compressive stress. The average grain size and hardness of the films were investigated as a function of applied dc bias. The minimum average grain size and maximum hardness of TiVCrZrTaN film with applied dc bias 100 V were 6.1 nm and 30.9 GPa, respectively. In this work, the presented results illustrate that the optimum properties of TiVCrZrTaN films can be obtained at applied dc bias in the range of 50V to 120 V. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of MRS-Taiwan