Influence of sputtering pressure on morphological, mechanical and electrical properties of Al-doped ZnO films

Al-doped ZnO (AZO) films were deposited on glass substrates by pulsed DC sputtering technique with various working pressures in the range of 1–15 mTorr. A relationship between the morphological, mechanical and electrical properties of sputtered AZO films was studied as a function of sputtering pressure. The sputtered films were highly c-axis oriented. The n-type conductivity in AZO films was observed due to the substitutional doping of Al. AZO films deposited at 3 mTorr have shown an electrical resistivity of 2.2 × 10−4 Ω cm and high transmittance in visible range with better mechanical properties. For higher sputtering pressures an increase in the resistivity was observed due to a decrease in the mobility and the carrier concentration. The lower sputtering pressure was found suitable for the fabrication of low-cost transparent conductive oxide layer for futuristic electronic devices.