Formation of the charge balanced ZnSe/GaAs(1 1 0) interfaces by molecular beam epitaxy

Abstract

We have investigated ZnSe layers grown by molecular beam epitaxy on vicinal GaAs(1 1 0) substrates misoriented 6° towards (1 1 1)B using reflection high-energy electron diffraction (RHEED), transmission electron microscopy, and high-resolution X-ray diffraction. The RHEED observations reveal that ZnSe growth proceeds in a layer-by-layer fashion on the vicinal GaAs(1 1 0) surfaces and the surfaces consist of regular arrays of monoatomic steps. However, characteristic structures of stacking faults and high density of threading dislocations were observed. We successfully decreased these stacking faults and threading dislocations lower than two or three orders by incorporating GaAs buffer layers. ZnSe(1 1 0) films with high-quality and flat interfaces are coherently grown on vicinal GaAs(1 1 0) surfaces misoriented 6° towards (1 1 1)B with GaAs buffer layers.