Search academic texts

Information × Registration Number 0308U001335, 0106U004199 , R & D reports Title Transients and self-organizing during crystallization in conditions of mismatched crystal-chemical parameters of materials. popup.stage_title Створення кінетичної моделі та розрахунок умов самоузгодженого росту когерентних островків при гетероепітаксії. Розробка критеріїв стійкості для багатокомпонентних систем. Експериментальна перевірка розроблених моделей. Head Shutov Stanilav, Registration Date 29-01-2008 Organization Kherson national technical university popup.description2 For analysis of conditions of the contact of liquid and solid phases at heteroepitaxy of multicompanent layers from the liquid phase it was carried out the adaptation of the Small and Ghez approach for the examnation of thermodynamic stability of the considered system, which based on analysis of perturbation of the liquid phase and its relaxation by crystallization of protective epitaxial layer, been in equilibrium to the solutin-melt. Worked out algorithm gives the possibility to define initial composition of the liquid phase and its necessary supercooling for the crystallization of heteroepitaxial layer that is equilibrium to the liquid phase depending on the epitaxy temperature. It is considered the possibility of using of electroepitaxy methods for the control of growth conditions and additional stabilization of the substrate. The mathematical model and test computer algorithm of the calculation of the kinetic model of the island growth mode of heteroepitaxial layer was worked out. This algorithm allows to estimate dependences of the growth rate, island dimensions, and islands surface density on technological conditions of the epitaxy process. Preliminary results of simulation show the stabilization of nuclei density and its saturation that shows self-assembling in the system. The experiments in liquid phase epitaxy of the GaAs(Si) layers in the growth capillary gaps limited with source of GaAs and substrate of Si(111) KDB-2,5 were carried out. The forced cooling technique with the periodic oscillations of the temperature was used. By the methods of optical and electron microscopy the influence of the thickness of the growth gap on nucleation processes of the GaAs islands on the surface of the Si substrate and their lateral growth into continuous planar layer was investigated. It was defined that at the thickness of the growth gap about 0,5 - 0,7 mm the density of the GaAs nuclei achieves values 500 … 2000 cm-2. At decreasing of the thickness of the growth gap the effectiveness of lateral growth also decreases. The complex of the experimental investigations of the selective growth Of GaAs layers on the Si substrates of the (100), (110), and (111) orientations by the method of epitaxial lateral overgrowth were carried out. Based on these experiments the technique of obtaining of the GaAs epitaxial layers on the Si substrates of the (100), (110), and (111) orientations was worked out. Product Description popup.authors popup.nrat_date 2020-04-02 Close