Spectroellipsometry for characterization of Zn1−<i>x</i>Cd<i>x</i>Se multilayered structures on GaAs

Abstract

The dielectric functions of 0.5–1.5-μm-thick Zn1−xCdxSe (0≤x≤0.34) epilayers on (100) GaAs were measured by spectroellipsometry (SE) over the photon energy range 1.5≤E≤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.