Band alignment of HfO2/In0.18Al0.82N determined by angle-resolved x-ray photoelectron spectroscopy

Abstract

The band-alignment of atomic layer deposited (ALD)-HfO2/In0.18Al0.82N was studied by high resolution angle-resolved X-ray photoelectron spectroscopy measurements. The band bending near the HfO2/In0.18Al0.82N interface was investigated, and the potential variation across the interface was taken into account in the band alignment calculation. It is observed that the binding energies for N 1s and Al 2p in In0.18Al0.82N decreases and the corresponding extracted valence band offsets increases with increasing θ (i.e., closer to the HfO2/In0.18Al0.82N interface), as a result of an upward energy band bending towards the HfO2/In0.18Al0.82N interface. The resultant valence band offset and the conduction band offset for the ALD-HfO2/In0.18Al0.82N interface calculated was found to be 0.69 eV and 1.01 eV, respectively.