Microstructural, optical and spectroscopic studies of laser ablated nanostructured tantalum oxide thin films

作者：Krishnan Renju R; Gopchandran K G; MahadevanPillai V P^*; Ganesan V; Sathe Vasant

来源：Applied Surface Science, 2009, 255(16): 7126-7135.

DOI：10.1016/j.apsusc.2009.03.059

• Tantalum oxide thin films
• Nanostructures
• Atomic force microscopy
• Raman spectra
• Pulsed laser ablation
• X-ray diffraction
• FTIR studies
• UV-visible spectra

Thin films of tantalum oxide (Ta(2)O(5)) have been prepared by pulsed laser deposition technique at different substrate temperatures (300-973 K) under vacuum and under oxygen background (pO(2) = 2 x 10 (3) mbar) conditions. The films are annealed at a temperature of 1173 K. The as-deposited films are amorphous irrespective of the substrate temperature. XRD patterns show that on annealing, the films get crystallized in orthorhombic phase of tantalum pentoxide (beta-Ta(2)O(5)). The annealed films deposited at substrate temperatures 300 K and 673 K have a preferred orientation along (0 0 1) plane, whereas the films deposited at substrate temperatures above 673 K show a preferred orientation along (2 0 0) crystal plane. The deposited films are characterized using techniques such as grazing incidence Xray diffraction (GIXRD), atomic force microscopy (AFM), micro-Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy. FTIR and micro-Raman measurements confirm the presence of Ta-O, Ta-O-Ta and O-Ta-O bands in the films. Grain size calculations from Xray diffraction and AFM show a decrease with increase in substrate temperature. The variation of transmittance and band gap with film growth parameters are also discussed.

• 出版日期2009-5-30