Radiation Resistance of Epitaxial Structures Based on GaAs

This paper presents the results of a study on the irradiation of heterostructures based on gallium arsenide with neutrons and gamma rays. The horizontal channel of the IRT-2000 reactor with an energy of 2.65 MeV served as a source of neutrons. Two types of structures were considered: autoepitaxial (AES) and heteroepitaxial (HES). They were obtained by the MOC-hydride method under reduced pressure using gallium and aluminum organometallic compounds and arsine. The obtained results show that irradiation with neutrons and gamma-quanta just slightly changes the concentration of the charge carriers of the autoepitaxial structures and the density of the charge carriers of the heteroepitaxial structures. As for the mobility of charge carriers, some increase in their mobility is observed at the initial moment of irradiation. As the irradiation flux density increases, the mobility either stabilizes at a certain level or decreases. The increase in mobility after the first irradiation of the heterostructures indicates an increase in the lifetime of charge carriers, apparently due to a decrease in the concentration of recombination centers in the structures, most likely, the density of structural defects at the heteroboundaries. When irradiating with fast neutrons, a similar picture is observed. Initially, the mobility of charge carriers slightly increases as the concentration of charge carriers slightly changes. Then the characteristics stabilize. An increase in the uniformity of properties over the area of the structures is observed. It is assumed that this is due to the appearance of clusters of defects and impurities.

Особенности начальной стадии гетероэпитаксии слоев кремния на германии при их выращивании из гидридов кремния

Data on the dependence of the growth rate of Si layers deposited onto Ge(111) by the hydride method on their thickness at the initial heteroepitaxy stage are reported. The effect of a Ge substrate within ten grown silicon single layers on the Si-film growth rate is demonstrated. Based on the data obtained, the kinetic coefficients responsible for the rate of the main physicochemical processes related to the interaction of hydride molecular beams with the growth surface are calculated. An analysis of the capture probability and rates of pyrolysis of the adsorbed Si(Ge) hydride molecules on the pure Ge(Si) surfaces reveals the dependence of their behavior on the growing-layer thickness. Comparison of the results obtained during Si-layer growth on Ge shows that the pure germanium surface has higher adsorption and catalytic abilities with respect to silane molecules than the pure Si surface. The unstrained pure Si surface has higher adsorption and catalytic characteristics with respect to Ge-hydride molecules.