Spectroellipsometry for characterization of Zn1-xCdxSe multilayered structures on GaAs

The dielectric functions of 0.5-1.5-mu m-thick Zn1-xCdxSe (0 less than or equal to x less than or equal to 0.34) epilayers on (100) GaAs were measured by spectroellipsometry (SE) over the photon energy range 1.5 less than or equal to E less than or equal to 5.3 eV. These spectra were parameterized using the Sellmeier and Lorentz equations for photon energies below and above the fundamental gap region, respectively. We have demonstrated the usefulness of this parameterization in analyses of SE data collected on a ZnSe heterostructure and a Zn1-xCdxSe quantum well that provide accurate layer thicknesses and compositions. (C) 1996 American Institute of Physics.