Effect of Insulating-Film-Thickness Nonuniformity on Tunnel Characteristics

In all theoretical investigations of the electric-tunnel effect through a thin insulating film between two electrodes, it is commonly assumed that the insulating film is of uniform thickness. In practice, it is reasonable to expect that this assumption is not always valid. The present paper demonstrates that nonuniformity in film thickness can have an important effect upon the terminal current—voltage characteristics of tunneling devices. This effect can, at least in part, account for the discrepancy between calculated and measured values of tunnel current.