Silicon Surface Leakage

THE nature and current theory of reverse current leakage in silicon junctions and its dependence upon surface conditions and gaseous ambients are discussed. Results of preliminary experimental studies of the rate at which reverse leakage changes as a function of the nature and pressure of gaseous ambients are presented. Two distinct modes of behavior are observed: (1) for uptake of gas by the surface, both oxygen and water vapor produce an exponential dependence of reverse leakage on time; (2) for removal of the adsorbed species, the leakage shows a power law dependence of reverse leakage on time. This behavior is clearly identified on growth and decay of a surface channel, both being reaction limited. A result which appears anomalous is the dependence of the rate of leak´age decay on the initial value of leakage, and the possible implications of this behavior are developed.