Structural and mechanical study of thermally annealed tungsten nitride thin films

Abstract

Summary Tungsten nitride films were deposited by RF reactive magnetron sputtering using Tungsten target. The films were subsequently annealed under high vacuum at different temperatures (700–850 °C) for 2 h each. The phase of the films were obtained using X-ray diffraction. EDAX and Nano-indentation tests were carried out to obtain the elemental composition and hardness respectively. XRD results of the as prepared film show the formation of pure fcc W2N phase and it is stable up to 700 °C. Beyond 700 °C mixed phase of W and W2N were observed. Mechanical study shows almost stable hardness value up to 700 °C temperature and beyond that temperature, hardness value reduce drastically, due to transformation of W2N phase to pure W phase. Our preliminary study shows that these films were stable up to