Theory of Low-Temperature Breakdown in Compensated Germanium

Abstract

A theoretical investigation of the low-temperature breakdown phenomena in compensated germanium which shows a negative resistance is presented. The breakdown field is calculated under two different conditions; (1) The density of carriers is so small that the collision between them is negligible. (2) The density is large and the collision is important. The breakdown field in the former case is shown to be larger than that of the latter case. The calculation shows that the optical phonon plays an important role in heavily compensated crystals. The dependence of the breakdown fields on the impurity density, the degree of compensation and the temperature is calculated and the results are in good qualitative agreement with experiments. The energy loss mechanism by the impurity pair suggested by McWhorter is not considered in the present calculation.