Effect of As2 and As4 fluxes on the morphology of GaSb(001) surface during growth of GaSb/InAs heterojunction by MBE

Interaction of GaSb(001) surface with fluxes of As₂, As₄ and Sb₄ molecules was investigated on the basis of the reflection high energy electron diffraction (RHEED) method. Exposure of GaSb surface to As₂ and As₄ fluxes results in substitution of antimony atoms by arsenic atoms. It is shown that As₂ molecules interact with GaSb surface mostly on the basis of the direct substitution mechanism, while As₄ molecules interact with it on the basis of the vacancy mechanism. It has been found that for reproducible generation of In-Sb heteroboundaries in InAs/GaSb super-lattices it is necessary to use As₄ flux rather than As₂ one. The research results have allowed optimizing the technology for growth of short-period InAs/GaSb superlattices that have high potential for development of IR photodetectors.