Properties of copper in gallium arsenide and indium phosphide

This dissertation describes a comprehensive investigation of the properties of Cu as an impurity in the III-V semiconductors InP and GaAs. This study involves structural, ion-beam/channeling, magnetic, and electrical measurements that were made after a systematic set of Cu diffusions in both semiconductors.;It was found that in both materials, most of the Cu precipitates even after rapid quenching, forming Cu-In and Cu-Ga precipitates in InP and GaAs respectively. Atomic resolution microscopy was used to determine the structure of these precipitates in InP, while conventional Selected Area Diffraction analysis gave this information in GaAs. The high diffusivity of Cu suggesting an interstitial diffusion mechanism in both these materials and its precipitating behavior are similar than in Si:Cu.;It is shown that in InP, the introduction of Cu makes this semiconductor semi-insulating after relatively low diffusion temperatures, that both originally n- and p-type InP become semi-insulating upon Cu diffusion, and that there is a negligible concentration of deep-level defects introduced by Cu. Further observations include an abnormal reduction in both electron and hole mobilities resulting from the introduction of Cu, and the occurrence of isolated pockets of conductive InP in otherwise semi-insulating material. The concurrence of these experimental observations can best be explained using the buried Schottky-barrier model instead of the commonly observed compensation by deep levels. The concentration of Cu-In precipitates was found to be comparable with what preliminary calculations show would achieve intrinsic behavior by the effect of the metallic inclusions.;In GaAs, the substitutional portion of Cu, presumably Cu...