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ARXPS and LEISS characterizations for chemically etched and ion‐bombarded GaAs(100) surfaces
Author(s) -
Sullivan J. L.,
Yu W.,
Saied S. O.
Publication year - 1994
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.7402201109
Subject(s) - x ray photoelectron spectroscopy , ion , oxide , etching (microfabrication) , analytical chemistry (journal) , chemical state , materials science , low energy ion scattering , layer (electronics) , spectroscopy , ion beam , chemistry , chemical engineering , nanotechnology , physics , organic chemistry , chromatography , quantum mechanics , engineering , metallurgy
Abstract The effects of chemical etching and noble gas ion bombardment on GaAs(100) surfaces were investigated by angular resolved x‐ray photoelectron spectroscopy (ARXPS) and low energy ion scattering spectroscopy (LEISS). The results show that at the As received GaAs surface, Ga oxide is the major component, resulting in a Ga concentration slightly higher than As. Chemical cleaning by hydrochloride acid (HCl(conc.) to H 2 O1:1) followed by solvent washing efficiently removed the oxide layer, but ARXPS showed a strong As enrichment occurs at the cleaned GaAs surface. Ion bombardment was carried out using 3 keV Ar ions with a beam current of 1 mA for 50 min. XPS results show that at steady state the ion‐bombarded GaAs surface is depleted in As (As/Ga ∼ 0.8), but ARXPS indicates an As increase at the very surface. This is further confirmed by Ne + LEISS analysis, which shows the top layer As concentration is increased by 40% after ion bombardment. The results indicate that bombardment‐induced compositional changes are due to Gibbsian segregation.