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 $\times$ 10$^{10}$ cm$^{-2}$eV$^{-1}$ and $\sim$ 3 $\times$ 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.