High resolution synchrotron radiation core level photoemission measurements have been used to undertake a comparative study ofthe high temperature thermal stability ofthe ammonium sulphide passivated InGaAs surface and the same surface following the atomic layer deposition (ALD) of an ultrathin (∼1 nm) Al2O3 layer. The solution based ex situ sulphur passivation was found to be effective at removing a significant amount of the native oxides and protecting the surface against re-oxidation upon air exposure. The residual interfacial oxides which form between sulphur passivated InGaAs and the ultrathin Al2O3 layer can be substantially removed at high temperature (up to 700 ◦C) without impacting on the InGaAs stoichiometry while significant loss of indium was recorded at this temperature on the uncovered sulphur passivated InGaAs surface.
Chauhan, L., Gajula, D. R., McNeill, D., & Hughes, G. (2014). High temperature thermal stability investigations of ammonium sulphide passivated InGaAs and interface formation with Al2O3 studied by synchrotron radiation based photoemission. Applied Surface Science, 317, 696-700. https://doi.org/10.1016/j.apsusc.2014.08.180