Local interface composition and native stacking fault density in ZnSe/GaAs(001) heterostructures

We performed a comparative investigation of interface structure and composition in pseudomorphic ZnSe/GaAs(001) heterostructures grown using interface fabrication procedures that produce epilayers with minimum stacking fault densities (below 10(4) cm(-2)). We detected in all cases a 1 nm thick intermixed region at the interface that is depleted of As and is comprised of a (Zn,Ga)As alloy with zincblende structure. No ZnAs formation was found in any of the interfaces examined. Our results imply that Ga-Se reactions at the ZnSe/GaAs interface do not necessarily lead to nucleation of high densities of stacking faults and that ZnAs formation plays no role in the observed reduction of the native defect density. (C) 2004 American Institute of Physics.