Abstract: A biasing method for and IC with enhanced reverse bias breakdown. A field plate covering the surface PN junction and extending laterally therefrom is biased to partially deplete the island under the field plate and the substrate supporting the island is biased to complete the total depletion of the island under the field plate, establishing a substantially merged vertical field at less than critical for avalanche. Because most of the charge is required to support the vertical component of the field, the rate of change in the horizontal component is small per unit of additional terminal voltage and the lateral extension of the field plate increases the breakdown voltage beyond the plane breakdown for a PN junction of a given doping profile.