Estimation of the band alignment of metal/AlScN interfaces by hard X-ray photoelectron spectroscopy

Abstract This paper describes the band alignment of metal/AlSc(O)N measured using hard X-ray photoelectron spectroscopy. The band offset was determined by using the difference in binding energy from the core level to the upper edge of the VB, and the bandgap was determined from the energy loss spectrum of photoelectrons. The introduction of oxygen into AlScN to make AlScON decreases both the conduction band and VB offsets. The change in barrier height of the metal/AlScN structure is very small relative to the difference in the work function of the metal. This suggests that Fermi-level pinning occurs at the metal/AlScN interface.