Band alignment of HfO_2/In_(0.18)Al_(0.82)N determined by angle-resolved x-ray photoelectron spectroscopy

摘要

The band-alignment of atomic layer deposited (ALD)-HfO_2/In_(0.18)Al_(0.82)N was studied by high resolution angle-resolved X-ray photoelectron spectroscopy measurements. The band bending near the HfO_2/In_(0.18)Al_(0.82)N 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 In_(0.18)Al_(0.82)N decreases and the corresponding extracted valence band offsets increases with increasing θ (i.e., closer to the HfO_2/In_(0.18)Al_(0.82)N interface), as a result of an upward energy band bending towards the HfO_2/In_(0.18)Al_(0.82)N interface. The resultant valence band offset and the conduction band offset for the ALD-HfO_2/In_(0.18)Al_(0.82)N interface calculated was found to be 0.69eV and 1.01 eV, respectively.