Preparation Of AZO Thin Films By RF Magnetron Sputtering And Research Of Their Properties

Transparent conducting thin films have attracted people's attention as much as they can in recent years, and they are becoming one kind of the key materials to produce thin film displays, touch panels and solar cells. With the development of LCD technology and the enhancement of solar cells'efficiency, the quality demand is much more rigorously for transparent conducting thin films, such as:low resistivity, high transmittance, and low depositing temperature, good thermal stability, high sharpness, good surface condition, high adhesive quality, low price and so on.Aluminum doped zinc oxide has similar electrical and optical properties to ITO, but it is a non-toxic material, has high temperature stability, and cost less to manufacture, which in turn makes AZO as an ideal alternative material for ITO and draws great attention nowadays.In this paper, high-quality ZnO:Al(AZO)films were prepared by using RF magnetron sputtering method with home-made AZO ceramic target by changing the sputtering conditions, and their surface morphology, electrical and optical properties were studied. The results are as follows:1) All the films prepared show good (002) diffraction peaks; in this study, the crystallization and conductivity of AZO films improves when the sputtering power increases;as the working pressure goes up, the intensity of (002) diffraction peak falls, the same to the films'conductivity and the film with optimum conductivity is found when the working pressure is 0.4Pa;The film thickness also has an influence on the conductivity and transmittance of AZO thin films.The films'resistance and transmittance falls when the films' thickness rises.2) The crystallization of AZO films deposited at room temperature is good with proper conductivity and transmittance; however, when the depositing temperature increases, the conductivity falls sharply, the films'optical property is also improved.3) All the films deposited with different aluminum doping concentration have the wurtzite crystal structure; with the increasing of Al doping concentration, the films' conductivity decreases, and the minimum sheet resistance was obtained at the doping concentration of 2at%.4) Annealing at air circumstance does not improve the conductivity and crystallization of AZO films, while the transmittance is a little better than before.