Electron binding energy XPS control of n-GaAs with the atomically clean surface etched by Ar+ ions

Cleaning the n-GaAs surface with low-energy Ar+ ions, required in X-ray photoelectron spectroscopy (XPS), has been recently shown to drastically change the core-level binding energies (BEs) of the irradiated surface layer, which prevents the diagnostics of the n-GaAs based semiconductors by the ordinary XPS. Synchrotron-based XPS measurements and modeling of As3d and Ga3d photoemission spectra for an Ar+ - etched n-GaAs wafer made it possible to find conditions for XPS testing the unmodified deep n-GaAs bulk. XPS resolution should be better than 0.5 eV and Ar+ ion energy should be less than 0.5 keV. Control of the Ga3d and As3d BEs in unmodified n-GaAs is important for chemical analysis since they are close to Ga2O3 and elemental arsenic BEs, respectively, which appear in oxidation, nitridation and other important chemical processes.

Automated summary

Cleaning the n-GaAs surface with low-energy Ar+ ions can change the core-level binding energies and prevent the diagnostics of n-GaAs based semiconductors, but synchrotron-based XPS measurements can find conditions for testing unmodified n-GaAs bulk.