Effects of the Growth Temperature and Substrate Orientation on the Incorporation of Si, Ge and Sn into Vapour Epitaxial GaAs

Abstract

Undoped and doped epitaxial layers with carrier concentrations from 1015 to 1017 cm-3 were grown by using the AsCl3/Ga/GaAs/H2 transport system. Electrical and photoluminescence measurements showed that Si, Ge and Sn were incorporated amphoterically from the dopant source GaAs into epitaxial layers. Evidence is given indicating that the major electrically active impurity in undoped layer is Si. The growth temperature dependence of the impurity incorporation is well described by the Arrhenius relation. The activation energies Ei's vary systematically with the impurity species. They decrease in the order of Si>Ge>Sn. Also Ei's vary with the substrate orientation, decreasing in the order of (100)>(111)B>(110). These dependences can be described satisfactorily in terms of the kinetic reactions between the impurity and the growing surface.