The effect of N2 partial pressure on the properties of Nb-Si-N films

Nb-Si-N films were sputtered by RF reactive magnetron sputtering with different N₂ partial pressure. The effect of N₂ partial pressure on the properties of Nb-Si-N film was studied. Energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscope, and four-point probe method were employed to characterize the microstructure and properties of the Nb-Si-N films. The results reveal that as the N2 partial pressure increases the Nb/Si ratio and the surface roughness decrease. With the increase of N₂ partial pressure the microstructure of Nb-Si-N film changes from the composite that consists of nano-grain NbN and amorphous SiN_x to the composite that consists of amorphous NbN and SiN_x phases. As the bias increased the ε-NbN phase increased. The sheet resistance of Nb-Si-N film also increases as the N2 partial pressure increase.