Growth of AlN and TiN Structures by Plasma-Enhanced Pulsed Laser Deposition

Abstract

AbstractNitride materials are of interest for a wide variety of applications, including wear-resistant coatings, insulating layers, high-temperature semiconductor devices, and short-wavelength emitters and detectors. TiN and AlN appear to be particularly amenable to crystalline thin film deposition, with stoichiometric material easily obtained even without the use of active nitrogen species. This paper describes the growth of crystalline AlN and TiN thin films on silicon and sapphire substrates using a KrF excimer laser (λ = 248 nm) to ablate elemental metallic targets, and an inductively-coupled RF plasma source to supply active nitrogen species. Growth was monitored in-situ using reflection high-energy electron diffraction (RHEED), and films were characterised using fourier-transform infrared spectroscopy (FTIR) and electron microscopy techniques. Optimised growth conditions led to single-crystal growth of TiN on both substrates, but only polycrystalline AlN was formed directly. Use of a TiN buffer layer on (0001) sapphire led to the successful growth of a single-crystal AlN layer as confirmed by RHEED and high-resolution transmission electron microscopy (HRTEM).