Surface passivation of InAs(001) with thioacetamide

We describe the passivation of InAs(001) surfaces with thioacetamide ( CH 3 CSNH 2 or TAM) as an alternative to the standard sulfur passivation using inorganic sulfide ( NH 4 ) 2 S x . Quantitative comparison using x-ray photoelectron spectroscopy (XPS) demonstrates that TAM passivation dramatically improves the stability against reoxidation in air compared with the inorganic sulfide, with little to no etching during the treatment. We find that TAM passivation preserves the intrinsic surface charge accumulation layer, as directly confirmed with laser-induced photoemission. Overall, TAM appears to provide superior passivation for electronic device and sensing applications.