NONLINEAR EFFECTS OF OXIDES OF p- AND d-ELEMENTS’ COACTIONS IN FORMATION OF THIN FILMS ON THE GaAs AND InP SURFACES OVERVIEW

Abstract

The thermal oxidation process of gallium arsenide and indium phosphide under the infl uence of binary oxides compositions has been studied (chemostimulator+chemostimulator and chemostimulator+inert component). Oxides-chemostimulators were oxides of p- and d-elements’ (Sb2O3, Bi2O3, PbO, CrO3, V2O5, MnO2, MnO), inerts components were – Ga2O3, Al2O3и Y2O3. The nonlinear effects of the oxide fi lm thickness on the GaAs and InP surfaces from the compositions oxides-chemostimulators have been studied and interpreted. Nonlinear effects are characterized by different signs of deviation from the additive straight – negative, positive and alternating. There is a clear correlation between the existence of acid-base and oxidation-reduction interactions in the compositions chemostimulators and nonlinear effect’s sign. If there is acid-base and oxidation-reduction interactions between the compositions of the oxides, then a positive nonlinear effect will be observed, increasing with growing time and temperature of oxidation. With the weakening of acid-base and oxidation-reduction interactions, a positive deviation from additive function is replaced by alternating signs. In case of the complete absence of interaction between the oxides in the composition, there is a negative deviation from additive function, increasing with growing time and temperature of oxidation. The possibility of obtaining the additive function for the entire range of compositions action of the oxide fi lm thickness on the GaAs surfaces from the compositions oxide-chemostimulator+inert component has been proven (inert component – Y2O3). The study of GaAs thermal oxidation under the infl uence of Sb2O3+ Ga2O3 compositions showed a signifi cant negative departure of the oxide fi lm thickness from the additive line for low Ga2O3 concentrations. When the Ga2O3 concentration in the compositions was higher than 40 mol %, the oxide fi lm thickness grown on GaAs was an additive function of the activator composition. The nonlinear effects observed were caused by the infl uence of small Ga2O3 additions on the vaporization dynamics of antimony oxide through the enhancement of Sb2O3 sintering during the experiment. The spation localization of binding interactions between oxideschemostimulators was revealed, which leads to the nonlinear effects. The solid-phase interactions enhance the chemostimulating activities of both oxides (a positive nonlinear effect takes place). The gas-phase interactions cause a marked negative deviation from the additive chemical stimulation effect The solid-phase interactions between the chemostimulators (during the evaporation of their mixtures) somewhat extend the lifetime of molecular oxide species in the vapor, giving rise to a positive thermal oxidation effect. The gas-phase interactions between the (chemostimulators are mainly dissociative. They reduce the chemostimulating effect and make a negative contribution to the nonlinear effects. The thin fi lms of the GaAs and InP surfaces synthesized using this method have better electrophysical properties and exhibit a gas-sensitive response in a reducing gases atmosphere.

Keywords

• gallium arsenide
• indium phosphide
• thermal oxidation
• chemostimulators
• nanoscale fi lms
• nonlinear effects
• heterostructures
• gas sensitivity.