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

Abstract

This article analyzes the reactive magnetron sputtering process, using a two-element Zn-Al target, for depositing aluminum-doped zinc oxide (AZO) layers, aimed at transparent electronics. AZO films were deposited on Corning 7059 glass, flexible Corning Willow® glass and amorphous silica substrates. To optimize the process, the study examined the target surface state across varying argon/oxygen ratios. The gas mixture significantly influenced the Al/Zn atomic ratio in the films, affecting their structural, optical and electrical performance. Films deposited at 80/20 argon/oxygen ratio—near the dielectric mode—showed high light transmission (84%) but high resistivity (47.4·10−3 Ω·cm). Films deposited at ratio of 84/16—close to metallic mode—exhibited lower resistivity (1.9·10−3 Ω·cm) but reduced light transmission (65%). The best balance was achieved with an 82/18 ratio, yielding high light transmission (83%) and low resistivity (1.4·10−3 Ω·cm). These findings highlight the critical role of sputtering atmosphere in tailoring AZO layer properties for use in transparent electronics.