Analysis of the variation in the field-dependent behavior of thermally oxidized tantalum oxide films

The field-dependent behavior of the conductivity (σ) of thermally oxidized tantalum oxide films has been analyzed based on a model we developed previously [W. K. Choi, J. J. Delima, and A. E. Owen, Phys. Status Solidi B 137, 345 (1986)]. Comparison with published data shows that the agreement in the log(σ) versus the square root of the applied field is very good. The relative dielectric constants obtained from the simulations compared very favorably with the published results. The donor density for the tantalum oxide films were estimated to be between 1.7×1014 and 2×1017 cm−3 depending on the films preparation conditions.