Effects of sputtering pressure on properties of Al doped ZnO thin films dynamically deposited by rf magnetron sputtering

Abstract

AbstractAluminium doped zinc oxide (AZO) films were dynamically deposited by rf magnetron sputtering under various sputtering pressures in the range of 0·3–2·0 Pa. The effect of the Ar sputtering pressure on the structural, electrical and optical properties of the AZO films was systematically investigated by X-ray diffractometry, scanning electron microscope, four-point probe measurement and UV–vis spectrophotometer. As the sputtering pressures decrease, the crystallite sizes of the films became larger, while their deposition rate turns higher. Under the condition of lower sputtering pressures, a decrease in the resistivity was observed due to an increase in carrier concentration. The AZO film deposited at 0·5 Pa in the dynamic mode has shown the lowest resistivity of 9·5×10−4 Ω cm. This work was performed in a dynamic deposition system in order to produce a large area of AZO films, which is more important in practical fields to improve productivity.Keywords: AZO thin filmsRF magnetron sputteringPressureDynamic depositionPhotoconductivityPhotovoltaics AcknowledgementsThis project was supported by the International Science & Technology Cooperation Program of Sino-Russian (grant nos. 2009DFR50160 and 2009DFR50350) and the Key Technologies R&D Program of Harbin City (grant nos. 2009AA2BG022 and 2009AA1BE093). This work was also financially supported by Shenzhen Public Science & Technology Research Plan (No. SY200806260033A), Cooperation Research Plan between Shenzhen & Hongkong (No.SG200810100007A), and Shenzhen Fundamental Research Plan (No. JC201104220174A & No. JC201105191001A).