Nongeometric field enhancement in semiconducting cold cathodes and in metal-insulator-semiconductor structures

We extend the usual one-dimensional equilibrium theory of the surface space charge region that screens a semiconductor from an external electric field in order to admit perturbations in three dimensions and time. We identify a class of perturbations of the one-dimensional equilibrium that grow exponentially in time at least until our first-order perturbation theory fails. The resulting spontaneous field enhancement may explain enhancement factors observed in electron emission from semiconducting cathodes and may similarly contribute to gate leakage in metal-oxide-semiconductor field effect transistors.