Reflectance-difference spectroscopy: a technique for characterization of dislocations in semiconductors Conference Paper uri icon

abstract

  • We report on the application of reflectance-difference (RD) spectroscopy to the characterization of 60 degree dislocations in zincblend semiconductors. We discuss a physical model based on dislocation induced anisotropic strains which predict a RD lineshape proportional to the first energy derivative of the semiconductor reflectance spectrum. We present RD spectra for semi-insulating GaAs:Cr (100) crystals in the 1.2 - 3.5 eV energy range, which show a first derivative component in accordance to our model. From a fitting of the experimental RD spectra to the theoretical lineshape we obtain average values for the strains associated to 60 degree dislocations. We also show that for the samples reported in this paper the dislocation-induced anisotropic strain results in a normalized effective change in lattice constant in the range from 10-5 to 10-4.

publication date

  • 1996-01-01