Properties of Ta₂O₅-Al₂O₃Mixture Films

Abstract

Mixture films of Ta2O5 and Al2O3 deposited by means of hydrolysis in the temperature range of 800–900°C are studied. Structural, optical, physico-chemical and dielectrical characteristics of the mixture films are measured, yielding the following results; (a) the film structure is amorphous, when the weight ratio of Ta2O5 in the films is about 0.05 to 0.5, (b) the film can be etched by NH4F acid solution, (c) the values of the optical energy gap are range between 5.50 to 4.42, (d) dielectric constants of the films range from 11 to 16, and one frequency independent, (e) the dielectric strength of this films is about 5×106 V/cm. The d-c conductivity of the films is investigated and an activation energy of 0.64 eV is obtained from the slope of the log J vs. 1/T plot, and the barrier height φ1 is found to be 1.3 eV.