Formation of anodic layers on InAsIII. Study of the chemical composition

The chemical composition of ~20-nm-thick anodic layers grown on InAs in alkaline and acid electrolytes containing or not containing [NH.sub.4]F is studied by X-ray photoelectron spectroscopy. It is shown that the composition of fluorinated layers is controlled by the relation between the concentrations of fluorine and hydroxide ions in the electrolyte and by diffusion processes in the growing layer. Fluorine accumulates at the (anodic layer)/InAs interface. Oxidation of InAs in an acid electrolyte with a low oxygen content and a high [NH.sub.4]F content brings about the formation of anodic layers with a high content of fluorine and elemental arsenic and the formation of an oxygen-free [InF.sub.x]/InAs interface. Fluorinated layers grown in an alkaline electrolyte with a high content of [O.sup.2-] and/or OH- groups contain approximately three times less fluorine and consist of indium and arsenic oxyfluorides. No distinction between the compositions of the layers grown in both types of fluorine-free electrolytes is established. DOI: 10.1134/S1063782612040239