The effect of N 2 partial pressure on the properties of Nb–Si–N films by RF reactive magnetron sputtering

Abstract

Nb–Si–N films were sputtered by RF reactive magnetron sputtering with various N 2 partial pressure in argon and nitrogen gas mixture. The characterizers of Nb–Si–N films were performed with energy dispersive spectroscopy, four-point probe method, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope, and transmission electron microscope, respectively. The results reveal that the Nb/Si ratio of Nb–Si–N films decreases as N 2 partial pressure increases. The microstructure of Nb–Si–N films is of a nano-composite that consists of amorphous SiN x phase and nano-sized NbN crystallites embedding in amorphous SiN x matrix. When sputtered with high N 2 partial pressure there is more amorphous SiN x phase in Nb–Si–N films and the grain size of NbN decreases. High N 2 partial pressure is in favor of the growth of hcp ε-NbN phase in the Nb–Si–N films. The value of surface roughness of Nb–Si–N films decreases as N 2 partial pressure increases.