Hybrid co-deposition of nano-crystalline Si3N4:TiN thin films

Nitride nanocomposite thin films, especially Si-Me-N (Me=Ti, Zr, Hf), have generated significant attention as a result of their robust thermal and mechanical properties. Additionally, the mixing of dielectric Si₃N₄ with various metallic nitrides allows for the variation of optical and near-infrared absorption based on the fraction of metallic nitrides present within the Si₃N₄ matrix. This work explores the effects of deposition process parameters on the optical and chemical properties of reactively co-sputtered Si₃N₄-TiN (1-20 at. %) thin films. Note that the Berg model for reactive sputtering is utilized to select the initial conditions for the deposition of the films, which are sputtered from elemental targets within a mixed nitrogen-argon environment and characterized in-situ using spectroscopic ellipsometry. Particular emphasis is placed upon the selection of deposition conditions to ensure control of TiN content without reducing Si₃N­₄. Composition and chemical state data is measured using x-ray photoelectron spectroscopy. In addition, XPS depth profiling is used to determine the composition throughout the thickness of the films, as well as the effects of residual oxygen within the deposition chamber.