Interface study of hydrogenated amorphous silicon nitride on hydrogenated amorphous silicon by x-ray photoelectron spectroscopy

The interface between near stoichiometric hydrogenated amorphous silicon nitride (a-SiNx :H) deposited on hydrogenated amorphous silicon (a-Si:H) is studied using x-ray photoelectron spectroscopy as a function of the electron escape angle. This method allows the study of a-SiNx :H overlayers of about 40 Å thickness which is typical of the thicknesses used for well and barrier layers in superlattices and quantum well structures. Within the instrument’s resolution, subnitride components constitute less than 1% of the interface bonds. It is therefore concluded that the interface is atomically abrupt.