Metalorganic molecular beam epitaxy and etching of AlGaSb using trisdimethylaminoantimony

Metalorganic molecular beam epitaxy and etching of AlGaSb using trisdimethylaminoantimony (TDMASb) are investigated. Etching rate of AlxGa1−xSb by TDMASb rapidly decreases with an increase of x, and no etching is observed for x>0.3. Reflection high-energy electron diffraction (RHEED) intensity oscillation for the etching of AlGaSb is only observed during a few oscillations, and it attenuates rapidly showing a diffused RHEED pattern. This indicates that the etching of AlGaSb (x≠0) stops after a few monolayers of etching due to the formation of AlN layer on the surface by the adsorption of nitrogen related species. No growth of AlSb is observed for the simultaneous supply of trimethylamine alane (TMAAl) and TDMASb. Successful growth of AlSb is achieved only by the supply of TMAAl and thermally precracked TDMASb.