GRAZING-INCIDENCE X-RAY DIFFRACTION FROM SEMICONDUCTOR QUANTUM WIRES
A.Ulyanenkov1,3, N.Darowski1, U.Pietsch1, T.Baumbach2, K.H.Wang4, A.Forchel4
1 Institute of Physics, University of
Potsdam, 14415 Potsdam, Germany
2 Fraunhofer Institut für
Zerstörungsfreie Prüfverfahren,EADQ, Krügerstr. 22, D-01326,
Germany
3 Institute of Nuclear Problems,
220050 Minsk, Belarus
4 Technical Physics, University of
Würzburg, 97074 Würzburg, Germany
The surface wire nanostructures defined on GaAs[001] with buried GaInAs single quantum well were investigated by x-ray grazing-incidence diffraction.
Choosing high-resolution condition and recording (q||, qz) maps within the reciprocal space containing either a angular or a radial in-plane direction $q_\parallel$, the shape and the strain, respectively, of the wires can be evaluated separately [1]. The theoretical analysis is based on distorted-wave Born approximation for grazing-incidence geometry [2]. Using a fitting procedure for a complete set of experimental grating truncation rods (scans towards qz at fixed q||) recorded in azimuthal and radial direction we can determine whether the trapezoidal or triangular shape of the wires, the degree of relaxation and its variation with depth below the sample surface.
[1] N.Darowski, K.Paschke, U.Pietsch, K.Wang,
A.Forchel, D.Luebbert and T.Baumbach, Physica B 1998 ,
in press
[2] G.T.Baumbach and M.Gailhanou, J.Phys.D: Appl.Phys. 28
(1995) 2321