A synchrotron radiation photoelectron spectroscopy study on atomic-scale wet etching of InAs (111)-A and (111)-B in acidic peroxide solutions: surface chemistry versus kinetics

Abstract

Anisotropy in the wet-chemical surface oxidation of indium arsenide (InAs) (111) in HCl/H2O2 and H2SO4/H2O2 was investigated. The atomic-scale etching kinetics was determined by inductively coupled plasma mass spectrometry and the surface chemistry, and electronic property transformation was probed by post operando synchrotron X-ray photoelectron spectroscopy. The oxidation rate is found to be larger for the (111)-B surface (As-terminated) than for the (111)-A surface (In-terminated). HCl/H2O2 solution has shown lower InAs etch rates than H2SO4/H2O2. The nature of etchant plays a role in the band bending, which is attributed to the formation of different species (sulfates/sulfides, chlorides, and hydroxides) on the surface.