Effect of Epitaxial Layer Thickness on Built-in Electric Field in Region of AlGaAs/SI-GaAs Interface: A Photoreflectance Study |
| T.J. Ochalski, J. Żuk Institute of Physics, M. Curie-Skłodowska University, Pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland and L.A. Vlasukova Institute of Applied Physics, State University, Minsk, Belarus |
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| We present a study of detailed line shapes of photoreflectance spectra for Al0.3Ga0.7 As/SI-GaAs epitaxial layers grown by MBE. All measurements were performed at 80 K under UHV conditions with a special care for the samples surface quality. A set of the photoreflectance spectra was collected for photon energies close to the GaAs and Al0.3Ga0.7As band gaps (E0). The photoreflectance spectra originated in the vicinity of the Al0.3Ga0.7As/SI-GaAs interface were analyzed using the complex Airy function model of Franz-Keldysh oscillations. To examine the effect of the epitaxial layer thickness on parameters characterizing the interface, a step-by-step chemical etching was applied for stripping the top layers. The built-in electric field intensity, field inhomogeneity and phenomenological broadening parameter for interface regions were determined as a function of the epilayer thickness. |
| DOI: 10.12693/APhysPolA.92.935 PACS numbers: 78.66.Fd, 78.20.-e |