The effect of fluorine on the density of states at the anodic oxide layer/In$_{0.53}$Ga$_{0.47}$As interface

It is shown that the fluorine-containing anodic layers on the $n$-In$_{0.53}$Ga$_{0.47}$As surface, in contrast to the anodic layers without fluorine, form a SiO$_2$/InGaAs interface with an unpinned Fermi level, the state density on which decreases during annealing at a temperature of 300$^{\circ}$C to values (2 – 4) $\times$ 10$^{11}$ and (4 – 5) $\times$ 10$^{12}$ eV$^{-1}$cm$^{-2}$ near conduction band bottom and the band gap middle, respectively. An increase in the annealing temperature leads to a reverse increase in the state density (350$^\circ$С) and pinning of the Fermi level (400$^\circ$С).