Properties of amorphous WNx thin films prepared by RF magnetron sputtering

Amorphous WNx thin films were prepared as X-ray absorbers by using RF magnetron sputtering. The possibilities of anisotropic etching for the;films are studied as functions of the CHF3 concentration and other etching parameters by using ion etching equipment. Anisotropic etching profiles are achieved for the films prepared at a CHF3/SF6 ratio of similar or equal to 0.5/0.5 in Ar, a working pressure of similar or equal to 200 mTorr, an RF power density of 0.39 W/cm(2) and room temperature. From an analysis of X-ray Photoelectron Spectroscopy (XPS), it is concluded that the anisotropic etching profiles are caused by an inhibitor composed of carbon compounds on the side walls of WNx films.