Metalorganic vapor phase epitaxial growth of GaAs on ZnSe; on the flow sequence of source precursors at the interface

Abstract

Metalorganic vapor phase epitaxy of GaAs onto ZnSe was studied. To optimize the flow sequence of Ga and As source precursors at the beginning of GaAs growth, they were separately supplied to the ZnSe surfaces at 450–550°C. The Ga precursor dissociates into Ga metal, which deposits three-dimensionally on ZnSe, while the As precursor drastically etches the ZnSe layers. The flow sequence was determined according to these results as not to expose the ZnSe surface to the Ga or As precursors alone for a long time. The growth rate of GaAs on ZnSe is slower than that of a thick GaAs layer at the very initial stage and recovers gradually as the growth continues.