Tsybulenko V. Development of scanning liquid phase epitaxy method

The thesis is devoted to development of a new method of liquid phase growth. For this purpose the analysis of liquid phase growth methods was carried out to ground basic requirements for the new method. The method developed was named "scanning liquid phase epitaxy". The technique of epitaxial layers growing by new method was proposed and described in the thesis manuscript. The mathematical modeling was carried out as well as the computer program was developed for calculation of technological modes of epitaxial layer obtaining by the new method taking into account: stress, inhomogeneous current spreading in the growth capillary, Peltier effect, Joule heating, electromigration, wetting angle between a solution-melt and a substrate, different conditions of the heat removal from the front and rear sides of the substrate. The apparatus for scanning liquid phase epitaxy was designed and built. According to the modelling results the optimal parameters and regimes of experiments were determined. To confirm the efficiency of the new method, as well as the experimental apparatus for it and the mathematical modelling results, the experiments on heteroepitaxial layers growing and contact grid deposition were carried out. Ge epitaxial layer with thickness 12.6 um was grown on GaAs substrate from Ga-Ge solution-melt in the temperature gradient. Ge continuous heteroepitaxial layers were grown on GaP and GaAs substrates in conditions of ultrafast deposition at the initial growth stage and crystallization times 1 s and 20 s. Al/SnAl contact layer was deposited on Si wafer from Al-Sn solution-melt through the mask with narrow slits. Its contact resistivity made 7.2•10-4 Om•cm2. The validity of heat and mass transfer modelling in the method of scanning liquid phase epitaxy was confirmed by the comparison between the calculated heteroepitaxial layer thickness and the one obtained experimentally in the process of Ga epitaxy on GaP and GaAs substrates.