S passivation of GaAs and band bending reduction upon atomic layer deposition of HfO2/Al2O3 nanolaminates
Date of this VersionAugust 2008
APPLIED PHYSICS LETTERS 93, 061907
This document has been peer-reviewed.
A systematic study of the interface engineering and dielectric properties of nanolaminated hafnium aluminate on GaAs is presented. The dielectrics were deposited using atomic layer deposition of alternating cycles of HfO2 and Al2O3 on GaAs substrates. High resolution x-ray photoelectron spectroscopy (XPS) showed differences in space charge amounts at the interface for the two surface treatments [NH4OH or (NH4)(2)S]. In-situ XPS analysis shows that chemical bonding to oxygen across the nanolaminate film is independent of the interface formation conditions. In addition, the GaAs surface treated with (NH4)(2)S shows a decreased band bending and slightly thinner films with respect to NH4OH. (C) 2008 American Institute of Physics.