Effect of the Crystallographic Orientation of GaSb Films on Their Structural Properties during MBE Heteroepitaxy on Vicinal Si(001) Substrates

GaSb films are grown by molecular-beam epitaxy using AlSb/As/Si transition layers on vicinal Si(001) substrates miscuted by 6° in (111) plane direction. The effect of GaSb films crystallographic orientation on their structural properties and surface morphology is investigated. It is found that the GaSb(00 )/Si films are characterized by better structural perfection, a lower concentration of point defects, as well as a more planar and isotropic surface morphology as compared with the GaSb(001) films. The possible cause for the observed othernesses between the GaSb films with different orientations is an increased density of antiphase domains in GaSb(001) films. The morphological features of the grown films are caused mainly by the edges of terraces and, to a lesser extent, by anisotropy of the incorporation of Ga adatoms into the edges of the terraces.