Plasma State of Pulse Reactive Magnetron Sputtering ZnO: Al Thin Films

Sputtering plasma state intensely depends on the variation of deposition parameters. It results in different properties of sputtering thin films finally. Here, we use reactive sputter gas controller (Lambda sensor) to control oxygen partial pressure in the process, so that we can achieve the same sputtering plasma state during the process of sputtering aluminium doped zinc oxide (AZO) thin films. At the same time, we use the intensity of Zn (470 nm) and O (780 nm) plasma emission peak signal to estimate the variation of the sputtering plasma state at different Lambda sensor value. In this experiment, AZO thin films are also prepared by pulse reactive magnetron sputtering on CORNING Eagle 2000 glasses. High purity metallic Zn-Al (Al 2 wt. %) alloy target and oxygen are used as source materials. The microstructure and surface morphology, optical and electrical properties of AZO films with various substrate temperatures are investigated in detail. Sputtering plasma state affects the properties of sputtering AZO thin films. At the optimized plasma state and substrate temperate, we get the AZO thin films with more than 85% average transmissions in the visible and near-infrared range and the resistivity less than 8.5×10-4 Ocm.