Effects of Deposition Temperature and Hydrogen Plasma on the Properties of the Radio-Frequency Magnetron Sputtering Deposition of ZnO-Al_2O_3 Films

摘要

A 98 mol % ZnO-1 mol % Al_2O_3 (AZO) compound was sintered at 1,350 °C as a target and deposited on glass substrates using a radio-frequency magnetron (r.f.) sputtering system, under the 30 sccm 98 % Ar + 2 % H_2 ambient. The effect of deposition temperature (25-300 °C) on carrier concentration, carrier mobility, resistivity, and optical transmission spectrum of the AZO films was studied. The Burstein-Moss shift was observed and used to prove that defects in the AZO films decreased with increasing deposition temperature. The effect of hydrogen (H_2) plasma on carrier concentration, carrier mobility, resistivity, and optical transmission spectrum of the different temperature-deposited AZO films was also studied. The value variations in the optical band gap (E_g value) of the AZO films were evaluated from the plots of I = I_(0e)~(-at) where α~2 = hv - E_g. The measured E_g value of the as-deposited AZO films increased with increasing deposition temperature and had no apparent trend difference as the H_2 plasma was used.