V. R. Pshestanchik

Effect of inert components (Y2O3, Al2O3, and Ga2O3) on the chemistimulating effect of the Sb2O3 activator of GaAs thermal oxidation

Chemistimilated thermal oxidation of gallium arsenide was studied using Sb2O3 activator oxide in compositions with Ga2O3, Al2O3, and Y2O3 inert components. For Sb2O3-Y2O3 compositions, the thickness of the resulting oxide layer on GaAs was found to be a linear function of composition over the enter range of the compositions. For antimony oxide compositions with Ga2O3 and Al2O3 inert components, nonadditivities were observed near the component ordinates. For the Sb2O3-Ga2O3 system, the chemistimulating efficiency noticeably weakened at low concentrations of the inert component. The linear trend observed for this system within 0–60 mol % Sb2O3 is additively determined by the oxide layer thickness on GaAs in the presence of Sb2O3 and in the absence of activator. In the presence of inert Al2O3, the chemistimulating effect was enhanced near the Al2O3 ordinate and the resulting function was nonadditive with respect to the thicknesses reached in the presence of the individual components.

Role of solid- and gas-phase interactions in the coaction of the oxides in MnO2 + PbO and MnO2 + V2O5 compositions activating the thermal oxidation of GaAs

Spatial separation of the oxides in MnO2 + PbO and MnO2 + V2O5 binary compositions activating the thermal oxidation of GaAs has made it possible to locate the interactions between these oxides that are responsible for the nonlinear effects observed in their coaction. 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.

Contribution from the solid-phase interactions of activating oxides to their nonlinear joint effect on the thermal oxidation of GaAs

The contribution from the solid-phase interactions in the PbO + Sb2O3 and PbO + Bi2O3 activating compositions to the multichannel process of GaAs thermal oxidation has been determined by spatial separation of the oxides. The solid-phase interactions make a positive contribution to the overall negative nonlinear effect in the dependence of the oxide film thickness on the GaAs surface on the activator batch composition. The contributions from the oxide interactions on the semiconductor surface and in the gas phase have been evaluated for the PbO + Sb2O3 composition.

Nonadditive Linearity in the Chemostimulating Effect of Activator Oxides + Dlient Compositions on GaAs Thermal Oxidation

The chemostimulation efficiency of the activators Sb2O3 and Bi2O3 in compositions with a diluent (Al2O3) is a linear function of activator percentage over a wide range of temperatures. This function is not, however, additive to the thicknesses achieved in the presence of individual components. The percentage of the activator elements in the resulting oxide layers coincides with that in the initial compositions in the linear region and differs from it in the nonadditivity region. Thermal analysis in combination with X-ray powder diffraction showed that Al2O3 alters the temperature range and character of the intrinsic transformations of activator oxides.

GaAs thermal oxidation with participation of spatially separated activator oxides (MnO + PbO and MnO + V2O5)

Spatial separation of activator oxides in MnO2 + PbO and MnO2 + V2O5 binary compositions helps to locate the interactions between the oxides that lead to nonlinear joint effects of the compositions on GaAs thermal oxidation. The mutual enhancement of the chemostimulating activity (a positive nonlinear effect) was discovered in the solid phase, whereas vapor-phase processes led to a considerable negative nonadditivity of the joint chemostimulating effect.