DOPING OF EPITAXIAL SILICON - BEHAVIOR OF SOLID SOLUTIONS

This paper presents a theoretical model for the behavior of solid solutions of group III and V impurities in silicon. The impurities are considered as weak electrolytes dissolved in an ionizing medium. The Fermi level, the activity coefficient and the dissociation equilibrium constants for the dopants are calculated, using Fermi-Dirac statistics, as functions of temperature and doping level. The solid solutions obey Henry's law at very low concentrations and exhibit positive deviations as the concentration is increased. Ionization of impurities or dopants as a function of their concentrations are discussed. © 1969.