Kinetic features of the oxide formation on $\{111\}$ polar planes upon anode treatment of $n$-GaAs

The mechanism and kinetics of anode destruction of $\{111\}$ polar planes of $n$-GaAs and morphological features of forming oxide films in the potentiostatic mode of polarization in weakly acid solutions of electrolytes have been studied. It has been found that anode polarization of the gallium plane (111) Ga provides the formation of a porous structure of both the single-crystal matrix and oxide film, which has a planar topology. In this case, the pore density is always commensurable with the surface dope concentration. In contrast to the gallium plane, the anode polarization of the arsenic plane $(\overline{111})$ As provides the tangential mechanism of destruction of the semiconductor matrix and the island-type morphology of the oxide. Equal crystallographic orientation of islands is determined by the directive action of the family of oxidized planes $\{111\}$ GaAs. However, regardless of the crystallographic orientation of the polar plane, the forming oxide is represented by polycrystalline As$_2$O$_3$ and amorphous Ga$_2$O$_3$.