Solid Solubilities of Impurity Elements in Germanium and Silicon

111 recent years a large amount of data has been obtained on the solid solubilities of impurity elements in germanium and silicon. Such data are of obvious practical importance in the semiconductor device field, where controlled impurity distributions are required. Of theoretical interest is the fact that, in favorable cases, these data can be used to provide information on heats and entropies of solution, binding energies and other thermodynamic properties of the solid solutions. In addition, one might hope that the attempts to interpret and correlate the relatively large amount of data on germanium and silicon will lead to a better understanding of the factors affecting solid solubility in other materials. The purpose of this paper is to summarize and evaluate the experimental solid solubility data for germanium and silicon binary alloy systems. Included in this summary are some new data derived from crystal pulling and thermal gradient crystallization experiments. The use of a modified form of the distribution coefficient is illustrated by considering the empirical correlation of solid solubility with atom sizes and heats of sublimation of the impurity elements. A detailed consideration of the theoretical interpretation of the solid solubility data will be presented in a subsequent paper. * P r e s e n t e d in p a r t at t h e meeting of t h e Electrochemical Society, Philadelphia, M a y 4, 1959. 205