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Characterization of wet‐etched GaAs (100) surfaces
Author(s) -
Rei Vilar M.,
El Beghdadi J.,
Debontridder F.,
Artzi R.,
Naaman R.,
Ferraria A. M.,
Botelho do Rego A. M.
Publication year - 2005
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.2062
Subject(s) - x ray photoelectron spectroscopy , etching (microfabrication) , attenuated total reflection , analytical chemistry (journal) , chemistry , dissolution , isotropic etching , adsorption , spectroscopy , oxide , gallium , infrared spectroscopy , arsenic , scanning electron microscope , layer (electronics) , materials science , chemical engineering , organic chemistry , physics , quantum mechanics , engineering , composite material
Abstract To enable the use of GaAs‐based devices as chemical sensors, their surfaces must be chemically modified. Reproducible adsorption of molecules in the liquid phase on the GaAs surfaces requires controlled etching procedures. Several analytical methods were applied, including Fourier transform infrared spectroscopy (FTIRS) in attenuated total reflection and multiple internal reflection mode (ATR/MIR), high‐resolution electron energy loss spectroscopy (HREELS), X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) for the analysis of GaAs (100) samples treated with different wet‐etching procedures. The assignment of the different features due to surface oxides present in the vibrational and XPS spectra was made by comparison with those of powdered oxides (Ga 2 O 3 , As 2 O 3 and As 2 O 5 ). The etching procedures here described, namely, those using low concentration HF solutions, substantially decrease the amount of arsenic oxides and aliphatic contaminants present in the GaAs (100) surfaces and completely remove gallium oxides. The mean thickness of the surface oxide layer drops from 1.6 nm in the raw sample to 0.1 nm after etching. However, in presence of light, water dissolution of arsenic oxides is enhanced, and oxidized species of gallium cover the surface. Copyright © 2005 John Wiley & Sons, Ltd.