X-ray diffraction study of GaSb grown by molecular beam epitaxy on silicon substrates

We report on the molecular beam epitaxy and characterization by X-ray diffraction techniques of GaSb layers grown on silicon substrates. AlSb and Al nucleation layers were used with different thicknesses and growth temperatures. Reciprocal space maps and a modified version of the Williamson-Hall analysis allowed for a characterization of the misfit dislocations properties. Finally, a post-growth annealing step is studied in order to further improve the material quality. Using this technique, a full-width-at-half-maximum of the GaSb peak of 235arcsec was obtained for a layer thickness of 1µm, which is comparable to the best results for GaAs or Ge on Si. •An X-ray diffraction study of GaSb grown on Si by MBE is presented.•Various growth conditions were applied for the AlSb nucleation layer.•The use of pure Al as a nucleation layer instead of AlSb was demonstrated.•GaSb peak FWHM of 235arcsec was obtained for a 1µm thick layer.