Interface composition of atomic layer deposited HfO2 and Al2O3 thin films on InAs studied by X-ray photoemission spectroscopy

We present a synchrotron-based XPS investigation on the interface between InAs and Al2O3 or HfO2 layers, deposited by ALD at different temperatures, for InAs substrates with different surface orientations as well as for InAs nanowires. We reveal the composition of the native Oxide and how the high-κ layer deposition reduces Oxide components. We demonstrate some of the advantages in using synchrotron radiation revealing the variation in Oxide composition as a function of depth into the subsurface region and how we can indentify Oxides even on nanowires covering only a small fraction of the surface.

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► Interface between InAs and HfO2 or Al2O3 examined by X-ray photoemission spectroscopy.
► Depth profile of the interfacial oxide shows a variation in Oxide composition.
► Native oxide reduction by high-κ deposition depends on the InAs surface orientation.
► Using synchrotron XPS even the Oxide composition of InAs nanowires is revealed.