Self-compensation of donors in high-purity GaAs

Abstract

Column-IV (Si, Ge, and Sn) and column-VI (S, Se, and Te) impurities are used to dope high-purity layers of vapor epitaxial GaAs. Resistivity and Hall data on a large number of samples show that the common donors in GaAs (assumed to be column-IV impurities on gallium sites and column-VI impurities on arsenic sites) are compensated by acceptor centers which are donor impurity-vacancy complexes. These acceptor complexes are tentatively identified as column-IV impurities on gallium sites associated with single gallium vacancies and column-VI impurities on arsenic sites associated with single arsenic vacancies.