In situ optical monitoring of the interface strain relaxation of InGaAs/GaAs grown by molecular-beam epitaxy Conference Paper uri icon

abstract

  • The evolution of the surface morphology during the MBE growth of In xGa1-xAs on GaAs (001) is studied by in situ Reflectance-difference (RD) spectroscopy and reflection high-energy electron diffraction (RHEED). InxGa1-xAs layers with x = 0.3 nominal compositions were growth under different arsenic overpressures. For arsenic-rich conditions RHEED measurements show that the growth mode is largely two-dimensional (2D). In contrast, under As-deficient conditions a 2D-3D growth morphology transition is observed upon closing the In and Ga shutters. Concurrently with this transition, the RD intensity at 2.5 eV shows a sharp increase, indicating the formation of anisotropic InxGa 1-xAs islands. We further show that low growth rates (0.3 ML/s) result in higher RD amplitudes and thus in InGaAs islands with enhanced anisotropy. © 2003 WILEY-VCH Verlag GmbH %26amp; Co. KGaA.

publication date

  • 2003-01-01