Effect of nitrogen concentration to the structural, chemical and electrical properties of tantalum zirconium nitride films

Tantalum zirconium nitride films with different nitrogen concentrations were deposited by reactive co-sputtering. Systematical material characterization was done to study the effect of nitrogen concentration to the ternary nitride films’ composition, microstructure, chemical and electrical properties. XRD and TEM showed that the microstructure of the films was mainly modulated by the Ta/Zr atomic ratio and nitrogen concentration, and amorphous structure formed in the nitrogen deficient films. XPS showed the chemical state of tantalum and zirconium atoms shifted systematically from metallic to ionic bonding state with the increasing of nitrogen. The stoichiometric ternary TaZrN films showed better conductivity than the binary TaN or ZrN constituents, because each tantalum atom contribute one excess d-orbital valence electron when the zirconium atom was substituted.