Bonding structure and morphology of chromium oxide films grown by pulsed-DC reactive magnetron sputter deposition

作者：Gago R^*; Vinnichenko M; Huebner R; Redondo Cubero A

来源：Journal of Alloys and Compounds, 2016, 672: 529-535.

DOI：10.1016/j.jallcom.2016.02.194

• Oxide materials
• Vapour deposition
• Atomic scale structure
• NEXAFS/XANES

Chromium oxide (CrOx) thin films were grown by pulsed-DC reactive magnetron sputter deposition in an Ar/O-2 discharge as a function of the O-2 fraction in the gas mixture (f) and for substrate temperatures, T-s, up to 450 degrees C. The samples were analysed by Rutherford backscattering spectrometry (RBS), spectroscopic ellipsometry (SE), atomic force microscopy (AFM), scanning (SEM) and transmission (TEM) electron microscopy, X-ray diffraction (XRD), and X-ray absorption near-edge structure (XANES). On unheated substrates, by increasing G the growth rate is higher and the O/Cr ratio (x) rises from similar to 2 up to similar to 2.5. Inversely, by increasing Ts the atomic incorporation rate drops and x falls to similar to 1.8. XRD shows that samples grown on unheated substrates are amorphous and that nanocrystalline Cr2O3 (x = 1.5) is formed by increasing T-s. In amorphous CrOx, XANES reveals the presence of multiple Cr environments that indicate the growth of mixed-valence oxides, with progressive promotion of hexavalent states with f. XANES data also confirms the formation of single-phase nanocrystalline Cr2O3 at elevated T-s. These structural changes also reflect on the optical and morphological properties of the films.

• 出版日期2016-7-5