Effect of the rapid thermal annealing on the structure and optical properties of TaOxNy thin films deposited by reactive magnetron sputtering

Abstract

Tantalum oxynitride thin films are deposited by radio-frequency magnetron sputtering using a pure tantalum target under argon/oxygen/nitrogen gas mixture. The argon flow is kept constant while the oxygen and nitrogen flows are changed simultaneously in a way to keep constant the total flow of these reactive gases. We succeed to deposit TaOxNy films with stoichiometry ranging between those of TaN and Ta2O5. All films are deposited at room temperature without any biasing. A thermal annealing in a RTA furnace was applied to all the films in a nitrogen atmosphere. A phase transition was detected by XRD investigations and SEM scanning from as deposited to annealed films, noticing the crystallisation of all films which depends on the composition of each film.