Effect of impurity atom size on grown-in dislocation density of crystals of III–V compounds

Abstract

Abstract A study of the literature on reduction of grown-in dislocation density in crystals of III-V compounds by heavy doping with various impurities has uncovered errors and probable misinterpretation. On re-evaluation of the available data from the viewpoint of atomic size, a rather consistent picture has been obtained. Impurity atoms smaller than the host atoms they displace bring about a major reduction in etch pit density while those larger than the host atoms also have a beneficial effect, though of a lesser magnitude. The new interpretation leads to a suggested method for preparation of dislocation-free and precipitate-free crystals with a lower impurity concentration.