Local Vibrational Mode Spectroscopy of Impurities in Semiconductors

Abstract

AbstractInfrared band—mode and LVM absorption is illustrated for a range of impurities and impurity—complexes in silicon and gallium arsenide. We discuss the effects of changes in the local force constants and contributions to the dipole moment resulting from displacements of host lattice atoms. The difficulties in establishing absolute calibrations relating the strength of the absorption to the concentration of defects are highlighted. Our purpose is to show how the measurements lead to characterization of crystals and how they complement other diagnostic techniques to evaluate effects of irradiation, heat treatments, diffusions etc.