Tunable composition and properties of Al-O-N films prepared by reactive deep oscillation magnetron sputtering

Abstract We report a low-temperature deposition of Al-O-N films in a wide range of compositions. We use and explain the advantages of reactive deep oscillation magnetron sputtering (leading to suppressed arcing on the Al target) with a pulsed reactive gas flow control and optimized reactive gas inlet position (leading to a very smooth composition control, despite the different reactivities of O2 and N2). Next, we focus on the relationships between film composition, structure and functional properties. We demonstrate a smoothly controlled refractive index at a very low extinction coefficient, and identify the Al-O-N composition leading to the highest hardness, elastic recovery and elastic strain to failure. We discuss some of the technological applications which these properties are useful for.