Title: Effect of annealing on the structural and optical properties of sputtered HfN_x thin films

Authors: H. Gueddaoui; G. Schmerber

Addresses: Semi-Conductors and Dioxides Metallic Laboratory, Faculty of Physics, USTHB, Bab-Ezzouar, 16123 Alger, Algeria; IPCMS, UMR 7504 CNRS, UDS-ECPM, 23 rue du Loess, B.P.43, 67034 Strasbourg Cedex 2, France ' Semi-Conductors and Dioxides Metallic Laboratory, Faculty of Physics, USTHB, Bab-Ezzouar, 16123 Alger, Algeria; IPCMS, UMR 7504 CNRS, UDS-ECPM, 23 rue du Loess, B.P.43, 67034 Strasbourg Cedex 2, France

Abstract: HfN_x films deposited by dc reactive magnetron sputtering at 150°C were annealed for 60 minutes at 400°C under a continuous 4.5 sccm argon gas flow. The X-ray diffraction (XRD) analysis of annealed films showed the existence of hexagonal (hcp-HfN_x) and rock-salt (fcc-HfN_x) phases in the chemical composition range 0.34 ≤ × ≤ 1.25. By using the Drude-Lorentz model, good agreement was found between experimental and calculated reflectance spectra in the energy range extending from 0.5 to 6.5 eV. The annealing treatment has two main effects: the first to increase the damping factor of the conduction of free carriers for x > 1.19 with a significant change in the plasma frequency, and the second to shift the screened plasma frequency towards lower energies.

Keywords: hafnium nitrides; crystallographic structure; reflectance; annealing process; plasma frequency.

DOI: 10.1504/IJNP.2013.054991

International Journal of Nanoparticles, 2013 Vol.6 No.2/3, pp.161 - 168

Published online: 31 Mar 2014 *

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