Application of the Amphoteric Native Defect Model to Diffusion and Activation of Shallow Impurities in III-V Semiconductors

Abstract

ABSTRACTThe effects of heavy doping on the formation of charged point defects are considered. It is shown that the Fermi level dependent part of the formation energy of highly localized defects can be determined using a universal energy reference, common to all III-V compound semiconductors. The concept is used to analyze the electrical activity and diffusion of dopant impurities in these compounds. We present model calculations which explain the correlation between the maximum hole concentrations and the acceptor impurity diffusion in InP and in InGaAs alloys, doped with group II acceptors. The calculations account for the redistribution of the impurity atoms at the lattice matched InP/InGaAs interface. It is also demonstrated that an abrupt enhancement of the Fermi level induced defect formation is observed at the onset of highly degenerate statistics in heavily doped semiconductors.