Low-Temperature Irradiation of n-Type Germanium

Abstract

The rate of change of conductivity of n‐type single crystal plates of germanium at a temperature of ∼16°K during fast neutron irradiation is enhanced over that previously observed at higher temperatures. Annealing studies subsequent to irradiation reveal no evidence of thermally unstable defect states between ∼10 and ∼95°K. Annealing above ∼95°K indicates the presence of thermally unstable minority carrier traps of the type previously observed following irradiation at 120°K. The enhanced decrease in conductivity at 16°K compared to that observed at higher temperatures is believed to reflect a greater rate of introduction of defects, many of which anneal at temperatures above ∼95°K.