Growth and characterization of thin anodic oxide films on n-InSb(100) formed in aqueous solutions

Abstract Anodic oxide films were galvanostatically grown on n-InSb(1 0 0) surfaces at various pH in sodium hydroxide (0.1 M NaOH, pH=13), borate buffer (0.075 M Na2B4O7 + 0.3 M H3BO3, pH=8.4) and phosphate buffer (0.3 M NH4H2PO4, pH=4.4). Thickness, composition and morphology of the oxide films were determined by various surface analytical techniques such as Auger electron spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy and atomic force microscopy. The oxides comprise mainly In2O3 and Sb2O3 and the oxide thickness increases with pH. Electrical properties of oxides indicate that the films may be useful as insulators in some device applications.