Influence of Arsenic Pressure on the Doping of Gallium Arsenide with Germanium

Abstract

THE doping of III-V compounds with elements from the IVth column of the periodic table has been studied under standard conditions of preparation by several investigators. In most cases, the IV element was found to act as an n-type dopant of low doping efficiency, a result that is usually interpreted to mean that more of the impurity atoms are located on the III element sublattice than on the V element sublattice. Causes for the unequal distribution of impurity atoms between the two sublattices have been sought in the sizes of the atoms and in their binding energies. An additional influence on the impurity atom distribution, namely, the vapor pressure of the V element, is considered in this note. A simple estimate will be given of the magnitude expected for the pressure effect, followed by some qualitative results for Ge-doped GaAs.