Influence of Nitrogen Vacancy Concentration on Mechanical and Electrical Properties of Rocksalt Zirconium Nitride Films

摘要

To study the influence of the nitrogen vacancy(V_N)on mechanical and electrical properties of zirconium nitride deeply,Zr N_x films with different V_N concentrations were synthesized on the Si(111)substrates by enhanced magnetic filtering arc ion plating.The morphologies,microstructures,residual stresses,compositions,chemical states,mechanical and electrical properties of the as-deposited films were characterized by field-emission scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectrometry,Nanoindenter and Hall effect measurements.The results showed that Zr N_x films exhibited rocksalt single-phase structure within a V_N concentration ranging from 26 to 5%.The preferred orientation,thickness,grain size and residual stress of the Zr N_x films kept constant at different V_N concentrations.Both the nanohardness and elastic modulus first increased and then decreased with the decrease in V_N concentration,reaching the peaks around 16%.And the electric conductivity of the Zr N_x films showed a similar tendency with nanohardness.The underlying atomic-scale mechanisms of V_N concentration-dependent hardness and electric conductivity enhancements were discussed and attributed to the different electronic band structures,rather than conventional meso-scale factors,such as preferred orientation,grain size and residual stress.