Effect of the N-2/(Ar+N-2) Flow Ratio on the Synthesis of Zirconium Nitride Thin Films by DC Reactive Sputtering

Abstract

We investigate the effect of the N-2/(Ar+N-2) flow ratio (F(N-2)) On the structural and the electrical properties of ZrNx thin films deposited on Si(111) substrates by DC reactive sputtering at room temperature (R.T.), by using glancing-angle X-ray diffraction (GA-XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The films show stoichiometric ZrN structures for F(N-2) from 4.3% to 10% and changed into non-stoichiometric Zr3N4 structures with increasing F(N-2) from 11.8% to 25%. On the other hand, the electrical resistivity rapidly increase from 40.8 mu Omega.cm to 1291.87 mu Omega.cm with increasing F(N-2), which may be related to compositional changes from ZrN to Zr3N4. We also observed that the stoichiometric ZrN film had larger and denser granular-type grains because of it had a higher growth rate of grains than the non-stoichiometric Zr3N4 film.