Diffusion of Antimony Out of Germanium and Some Properties of the Antimony-Germanium System

Abstract

In a recent paper, a rate limitation at the surface for impurity diffusion into semiconductors was discussed. The rate limitation leads to a radiation-type boundary condition for the diffusion differential equation. Experiments on the diffusion of radioactive antimony out of germanium have shown that the solution to the diffusion differential equation appropriate to this boundary condition does indeed agree with the experimental data. The constant which describes the rate limitation has been measured as a function of temperature and has an activation energy close to that of the diffusion constant of antimony in germanium. The diffusion constants found in this work are in agreement with those found in other experiments in which antimony was diffused into germanium. By a proper choice of the diffusion-system geometry, an increased rate limitation was produced which provided data from which sticking coefficients and partition coefficients were calculated for the system gaseous antimony-solid germanium. These data have also been used to estimate the binding energy of an antimony atom in the germanium lattice.