Influence of the temperature and substrate modification on the formation of continuous GaSb film on Si(111) by solid phase epitaxy

The solid-state formation of gallium antimonide on Si(111) from a stoichiometric mixture of GaSb in the temperature range of 300 degrees C-500 degrees C and thicknesses of 12-40 nm was studied under ultrahigh vacuum conditions. The influence of the preformed GaSb seed islands on the morphology, composition, and structure was studied. It has been found that at 300 degrees C a strained continuous polycrystalline film is formed, which rupture at 350 degrees C. It has been shown that a continuous single-crystal GaSb film grows at 400 degrees C-500 degrees C if the sample is annealed at a weak antimony flow. This is also facilitated by the preliminary formation of a high density of nanosize GaSb seed islands. As a result, a continuous relaxed film with epitaxial relations GaSb(111) divide divide Si(111) and GaSb[1-10] divide divide Si[1-10] was obtained from a GaSb mixture 40 nm thick at 500 degrees C. We demonstrate a possibility of direct formation of GaSb on Si(111) without buffer layers of other chemical elements.