Zinc nitride films prepared by reactive RF magnetron sputtering of zinc in nitrogen containing atmosphere

Zinc nitride films were deposited on glass or silicon substrates by reactive magnetron RF sputtering of zinc in N-2-Ar ambient. The deposition conditions were optimized in terms of substrate temperature and N-2/Ar sputtering gas ratio, and representative films were then studied by structure, optical and spectroscopy techniques, and electrical measurements. Spectroscopic ellipsometry and spectrophotometry measurements revealed that the material has a direct band gap close to 1.26 eV. Hall effect and resistivity measurements indicated n-type conductivity with a very high carrier concentration of about 10(21) cm(-3), mobility of up to 90 cm(2) V-1 s(-1), and resistivity of similar to 10(-3) Omega cm. X-ray photoelectron spectroscopy spectra clearly showed the existence of not only Zn-N bonding but also of a fraction of N-N bonding configurations, together with an oxidized surface. According to energy-dispersive x-ray spectroscopy analysis, the as-deposited films were almost stoichiometric and contained only a small fraction of oxygen.