Oxygen as a Donor Element in Germanium

Abstract

THERE have been a number of studies of the germanium–oxygen system from the point of view of compound formation, thermodynamics and crystal structure. Some workers have studied the effects of oxide films on the surface properties of germanium, with particular reference to conduction and rectification. However, little seems to have been published on the behaviour of oxygen as a significant doping impurity in bulk germanium. Clarke¹ observed, during experiments on the effect of oxygen on surface conduction, that after repeated exposure to oxygen, followed by heating in a high vacuum, a high resistivity germanium sample acquired a permanent larger n-type conductivity. This appeared to be due to the diffusion of n-type centres deep into the sample, and he suggested that oxygen might be responsible for these donor centres in the bulk while at the same time producing electron traps at the surface.