Effect of fluorine on the electrical properties of anodic oxide/InAs(111)A interface

The electrical properties of metal-insulator-semiconductor structures based on InAs(111)A with thin anodic insulator layers of various thicknesses (7–20 nm) are investigated. It is established that the oxidation of InAs in a fluorinated acid electrolyte results in decreasing density of surface states and fixed charge in the anodic layer to values of < 2 × 10 10 cm −2 eV −1 and ∼3 × 10 11 cm −2 , respectively. Comparison of the electrical parameters with the chemical composition of the layers shows that an improvement in the parameters of the fluorinated anodic oxide/InAs(111)A interface is caused by the substitution of oxygen atoms for fluorine in the anode layers with the formation of indium and arsenic oxifluorides and In-F bonds on the InAs surface.