Tin nitride thin films fabricated by reactive radio frequency magnetron sputtering at various nitrogen gas ratios

Abstract Sn nitride thin films are remarkable materials that can be implemented in applications such as microelectronic devices and recording media. This paper presents the analysis of the various Sn nitride thin films' structural, electrical, and chemical properties using a surface profiler, X-ray diffraction, a 4-point probe, X-ray photoelectron spectroscopy (XPS), and distilled water and ethylene glycol contact angle measurements. The Sn nitride thin films were prepared via radio frequency magnetron sputtering. The thickness of Sn nitride thin films decreased in the regions where N 2 gas ratios ranged from 20% to 100%. The surface resistance decreased from 6.34 × 10 4 to 56.2 Ω/sq with gradual increasing of N 2 gas ratios from 20% to 100%. Change in crystallinity of the films was observed as N 2 gas was progressively introduced, from metallic Sn to the amorphous Sn nitride phase. The high resolution XPS spectra indicates that the intensity of Sn 2 + increased, while those of Sn 4 + and Sn 0 decreased with increasing N 2 gas ratios, confirming the bond formation of Sn and N. The total surface free energy (SFE) varied by changing the N 2 gas ratio. When the N 2 gas ratio in the sputter gas was low (less than 20%), the dominant contributing factor to the total SFE switched from polar to dispersive SFE. In samples where the N 2 gas ratio was over 20%, the major contribution to the total SFE was dispersive SFE.