Application of two-element Zn-Al metallic target for deposition of aluminum-doped zinc oxide - analysis of sputtering process and properties of obtained transparent conducting films

This article presents an analysis of the reactive magnetron sputtering process using a two-element Zn-Al target, with a particular focus on its application for deposition of aluminum-doped zinc oxide layers for transparent electronics. The research encompasses the deposition of AZO layers on standard Corning 7059 glass and flexible Corning Willow® glass. In order to determine optimal process conditions, a detailed analysis of the target surface state was conducted based on the ratio of working gas to reactive gas (argon/oxygen). Significant influence of the sputtering atmosphere ratio on the Al/Zn atomic ratios in the deposited AZO layers was observed, subsequently affecting their optical and electrical properties. Layers deposited in an atmosphere with an 80/20 (argon/oxygen) ratio exhibited a high light transmission coefficient in the visible range (averaging 84%) and high layer resistivity (47.4 · 10-3 Ωcm). On the other hand, layers deposited in an atmosphere with an 84/16 (argon/oxygen) ratio showed low resistivity (1.9 · 10-3 Ωcm) and a light transmission coefficient in the visible range at 65%. The most promising results were obtained for layers deposited in an atmosphere with an 82/18 ratio, characterized by both high light transmission (83%) and low layer resistivity (1.4 · 10-3 Ωcm).