ABSTRACT
In addition to true self-diffusion, the chapter deals with 'impurity' diffusion of group III and group V elements. Arsenic self-diffusion was also studied in the earlier work of Goldstein. The depths of the phosphorus profiles were considerably greater than those for arsenic self-diffusion taken under similar conditions, possibly due to the fact that phosphorus atoms are smaller than arsenic. The diffusion coefficients followed the relation and, in common with the GaAs system, it was found that the values of the coefficient for phosphorus were very much greater than the self-diffusion coefficients of arsenic, the difference amounting to two to three orders of magnitude. It was pointed out by Shaw that diffusion via a mixed divacancy had previously been proposed by Kendall and Huggins to explain their results on the self-diffusion of In in InSb. Studies of the diffusion of zinc into superlattices yielded a quite remarkable result.
