Defect Model for the Electronic Conduction and Breakdown in Dielectric Thin Films.

A stochastic model of defects has been developed to explain the electronic properties of dielectric thin film systems. Consequently, a reaction-diffusion type of equation is obtained. This model considers the dielectric thin film as an open system, in which nonlinearities play important role for the instabilities of the system. The general experimental observations on the current-voltage characteristics are discussed. The microscopic picture of the conduction processes leading to breakdown is proposed. Several steps of conduction are predicted before the destructive breakdown of the films occurs. These conduction stages correspond to the microscopic states of the system and, consequently, closely related to the defects correlated states. Qualitatively, the microscopic states of the system are correlated with the growth stages of the film. The mechanisms of aging and annealing are also addressed under this reaction-diffusion equation.