THERMAL OXIDATION AS A METHOD OF FORMATION OF NANOSCALE FUNCTIONAL FILMS ON AIIIBV SEMICONDUCTORS: CHEMOSTIMULATED INFLUENCE OF METAL OXIDES OVERVIEW

Abstract

The use of oxides as chemostimulators of A^IIIB^V thermal oxidation alters the mechanism of the process of thermal oxidation of semiconductors from its own to that of transit or catalytic. The mechanism of the process is determined by the chemical nature of the oxide-chemostimulator and the way it is introduced into the system (from the gas phase or deposition on the semiconductor surface).

The oxides of p-metal (PbO, Sb₂O₃, Bi₂O₃), having predominantly one stable oxidation state, realize a transit mechanism of semiconductors oxidation, regardless of the way they are introduced into the system. The oxides of d-metals (MnO₂, V₂O₅, CrO₃) introduced through the gas phase act on the processes of thermal oxidation of GaAs and InP as the chemostimulator-transitors. The effect of nanosized NiO and Co₃O₄ layers in the processes of InP and GaAs thermal oxidation develops as a transit type, which is confirmed by EEA values, which are of the same order of magnitude as the EEA of own oxidation of semiconductors, the consumption of oxide-chemostimulators with the passing of the process in time, a significant decrease in the relative increase in film thickness during the advanced stage of the process.

For nanosized layers of vanadium oxide (V) the mechanism of their effect on the process of oxidation of A^IIIB^V is determined to a large extent by the deposition method (within the framework of one way). Thermal oxidation of A^IIIB^V under the influence of vanadium pentoxide layers deposited by soft methods implements the transit mechanism of the process, this is indicated by the expenditure of V₂O₅ in films during thermal oxidation without subsequent regeneration. The catalytic nature of the effect of the magnetron-deposited (hard method) layers of V₂O₅ in the oxidation processes of InP and GaAs is confirmed by a sharp decrease in EEA in comparison with the own oxidation of semiconductors and the independence of its value from the thickness of the deposited V₂O₅ layer, the cyclic regeneration of vanadium V⁵⁺ « V⁴⁺, and the dynamics of the change in the relative increase in film thicknesses. In this case, the processes of phosphate and arsenate formation take place at low temperatures (450-480 °C), an effective kinetic and chemical blocking of the diffusion of unoxidized indium into a film occurs, and segregation of arsenic at the inner interface prevented. All of the above leads to a significant improvement in the electrophysical parameters of the films.

ACKNOWLEDGMENTS

The research results were obtained using the equipment of the Center for Collective Use of Equipment Voronezh State University. URL: http://ckp.vsu.ru

The reported study was supported by a grant from the Russian Foundation for Basic Research (project No. 16-43-360595 р_а)