ELECTRICAL-PROPERTIES, DIELECTRIC-PROPERTIES AND OPTICAL-PROPERTIES OF M-Y2O3-M DEVICES

Thin film capacitors of metal/yttrium oxide/metal sandwich structure have been prepared by the e-beam flash evaporation technique. The surface morphology of the films has been studied using scanning electron microscopy. The current-voltage characteristics at various temperatures showed that the conduction mechanism is of Schottky type. This has been further confirmed by comparing the values of field-lowering coefficient beta obtained from I-V characteristics and capacitance measurements and changing the counterelectrode material. It has also been shown that the capacitance and dielectric constant are almost independent of frequency in the range 20-120 kHz. The height of the Schottky barrier is evaluated as 0.46 eV. The optical absorption coefficient a and refractive index n(1) of Y2O3, film are evaluated in the wavelength region of 300-800 nm from analyses of the reflectance and transmittance spectra by an approach which eliminates the interference effect. The refractive index has been found to be 1.53 at a wavelength of 700 nm. Two indirect transitions with band gaps of 2.19 and 2.80 eV respectively have been identified from an analysis of the absorption spectra.