Effect of Heavy Doping on the Self-Diffusion of Germanium

Abstract

The germanium self-diffusion coefficients for intrinsic, heavily-doped $n$- and $p$-type germanium were measured at several temperatures. It was found that the self-diffusion coefficient is greater for heavily-doped $n$-type than for intrinsic germanium and that the self-diffusion coefficient for intrinsic germanium is greater than for heavily-doped $p$-type. If one assumes that a vacancy acts as an acceptor and that germanium self-diffusion goes by the vacancy mechanism, the observed changes in the value of the self-diffusion coefficient with doping are in the direction and of the order of magnitude of changes calculated from the shift in the Fermi level alone. It is concluded that germanium self-diffusion probably proceeds by the vacancy mechanism.