Surface Conduction Channel Phenomena in Germanium

Abstract

Surface conduction channels on both the n-type and the p-type region of a p-n junction of germanium have been produced and investigated. Channels on the n-type region were produced by an oxygen rich surface environment and those on the p-side were produced by high humidity. At an intermediate, 75 per cent relative humidity, a condition of high surface leakage and no channel was found. A model, based on bending of energy levels at the surface to produce opposite type majority carrier conductivity than is found for the body of the germanium is used to explain the results. The particular channels studied simulate trouble conditions in transistor fabrication and in reliability problems and provide a good linkage for explanation of anomalous effects that are frequently found.