Electrical Properties of Thin Polymer Films. Part II. Thickness 50–150 Å

Abstract

The current I through silicone polymer films formed by electron‐beam bombardment in the thickness range 50–150 Å has been measured as a function of voltage V and temperature between 77° and 300°K. The electrodes were evaporated silver films. The behavior is Ohmic at low voltage, and log I varies as V ½ at higher voltages up to about 1 V. The voltage dependence is insensitive to temperature, although the total current depends rather strongly on temperature. The current decreases with time, as a result of the diffusion of oxygen into the dielectric film. Changes in the current are closely correlated with capacity changes. Simple tunneling theory, including the effects of image force and dielectric constant, fails to account for all the data.