Nature of the ZnSe/GaAs interface investigated by atom probe tomography

A ZnSe layer grown on a GaAs substrate by molecular beam epitaxy has been analysed by atom probe tomography. The one-dimensional concentration profile shows separation between Zn and Se and between Ga and As at the interface. A comparison of the concentration profile with different interface models suggests that the formation of a Ga2 + xSe3 compound at the ZnSe/GaAs interface with fewer vacancies than Ga2Se3 (x = 0.7). These results show the ability of atom probe tomography to characterize the interface at the atomic scale.