Properties of Reactively Sputtered WNx Films

摘要

Tungsten nitride (WNX) films were prepared by reactive rf sputtering of a tungsten target in N2/Ar plasma. The resistivity, intrinsic stress and atomic composition of the films were studied as functions of various sputtering parameters: sputtering power, gas pressure, gas composition and substrate bias. The atomic percentage of nitrogen (x) of the WNX films was found to decrease with sputtering power and to increase with the partial pressure of nitrogen. The intrinsic stress if WNX is compressive. The dependence of film properties upon sputtering parameters for WNX differs significantly from that of reactively sputtered TiN films, and may be attributed to the difference in the formation mechanisms of TiN and WNX.