Get access

High-surface-quality nanocrystalline InN layers deposited on GaN templates by RF sputtering

Authors

  • Sirona Valdueza-Felip,

    Corresponding author
    1. Grupo de Ingeniería Fotónica, Departamento de Electrónica, Escuela Politécnica Superior, Universidad de Alcalá, Campus Universitario, 28871 Alcalá de Henares, Madrid, Spain
    • Phone: +34 91 885 6913, Fax: +34 91 885 6591
    Search for more papers by this author
  • Fernando B. Naranjo,

    1. Grupo de Ingeniería Fotónica, Departamento de Electrónica, Escuela Politécnica Superior, Universidad de Alcalá, Campus Universitario, 28871 Alcalá de Henares, Madrid, Spain
    Search for more papers by this author
  • Miguel González-Herráez,

    1. Grupo de Ingeniería Fotónica, Departamento de Electrónica, Escuela Politécnica Superior, Universidad de Alcalá, Campus Universitario, 28871 Alcalá de Henares, Madrid, Spain
    Search for more papers by this author
  • Lise Lahourcade,

    1. Equipe mixte CEA-CNRS-UJF «Nanophysique et Semiconducteurs», INAC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
    Search for more papers by this author
  • Eva Monroy,

    1. Equipe mixte CEA-CNRS-UJF «Nanophysique et Semiconducteurs», INAC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
    Search for more papers by this author
  • Susana Fernández

    1. Departamento de Energías Renovables, Energía Solar Fotovoltaica, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Avda. Complutense 22, 28040 Madrid, Spain
    Search for more papers by this author

Abstract

We report a detailed study of the effect of deposition parameters on optical, structural, and morphological properties of InN films grown by reactive radio-frequency (RF) sputtering on GaN-on-sapphire templates in a pure nitrogen atmosphere. Deposition parameters under study are substrate temperature, RF power, and sputtering pressure. Wurtzite crystallographic structure with c-axis preferred growth orientation is confirmed by X-ray diffraction measurements. For the optimized deposition conditions, namely at a substrate temperature of 450 °C and RF power of 30 W, InN films present a root-mean-square surface roughness as low as ∼0.4 nm, comparable to the underlying substrate. The apparent optical bandgap is estimated at 720 nm (1.7 eV) in all cases. However, the InN absorption band tail is strongly influenced by the sputtering pressure due to a change in the species of the plasma.

Get access to the full text of this article

Ancillary