AVS 60th International Symposium and Exhibition
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP9
Effect of Growth Temperature and Post-Deposition Annealing on the Structure and Optical Properties of Yttrium Oxide Thin Films

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Session: Thin Films Poster Session
Presenter: C.V. Ramana, University of Texas at El Paso
Authors: C.V. Ramana, University of Texas at El Paso
L. Sanchez, University of Texas at El Paso
V. Atuchin, A.V. Rzhanov Institute of Semiconductor Physics, Russian Federation
V.N. Kruchinin, Institute of Semiconductor Physics, Russian Federation
I.P. Prosvirin, Boreskov Institute of Catalysis, Russian Federation
Correspondent: Click to Email
Yttrium oxide (Y2O3) has received significant attention in recent years in view of its possible integration into a wide range of scientific and technological applications. Y2O3 films exhibit excellent electronic properties such as transparency over a broad spectral range (0.2–8 μm), high dielectric constant (~14–18), high refractive index (~2), large band gap (~5.8 eV), low absorption (from near-UV to IR), and superior electrical break-down strength (>3 MV/cm). These properties make Y2O3 films interesting for various electrical, optical and electro-optic devices. Therefore, controlled growth and manipulation of microstructure, particularly at the nanoscale dimensions, has important implications for the design and applications of Y2O3 films. The present work was performed on the growth and optical characterization of nanocrystalline Y2O3 films made by magnetron sputter-deposition. The Y2O3 thin films were grown onto Si(100) substrates using reactive magnetron sputter-deposition at temperatures (Ts) ranging from room temperature (RT) to 500 oC. In addition, post-depositon annealing (Ta) in air was also performed in the temperature range of 500-1000 oC. The effect of Ts and Ta on the microstructure and optical properties of Y2O3 films were investigated. The structural studies employing X-ray diffraction (XRD) and reflection high-energy electron diffraction (RHEED) indicate that the films grown at room temperature (RT) are amorphous while the films grown at Ts=300-500 ºC are nanocrystalline. Depth profiling has been produced with Ar+ ion bombardment and XPS analysis. Spectroscopic ellipsometry measurements indicate that the size-effects and ultra-microstructure were significant on the dispersive optical constants. A significant enhancement in the index of refraction (n) (from 2.03 to 2.25) is observed in well-defined Y2O3 nanocrystalline films compared to that of amorphous Y2O3. The changes in the optical constants were explained on the basis of increased packing density and crystallinity of the films with increasing Ts. The optical properties of Y2O3 films were also found to be affected upon annealing due to structural transformation and/or interfacial compound formation.