Determination of crystallization conditions of Ge/GaAs heterostructures in scanning LPE method

Abstract

We carried out the modelling of separate technological stages of scanning liquid phase epitaxy (SLPE) technique: wetting the substrate by the solution-melt using Ampere force, growing the epitaxial layer during a short-time contact between the substrate and solution-melt, and removing the solution-melt from the substrate using Ampere force as well. The modelling was carried out for the case of Ge layers growing on GaAs substrate from Ga-Ge solution-melt at the temperature 500 °C. We have ascertained that the Peltier effect and Joule heating practically have no effect on the growth pattern and under certain conditions could be even diminished. The influence of electromigration and convection in the solution-melt can be neglected. It has been shown that the basic technological parameters of SLPE process are as follows: the initial temperatures and sizes of the substrate and the growing vessel, the conditions of heat removal from the substrate back side and the time of the process. It has been also shown that the major contribution into the epitaxial layer thickness distribution over the substrate surface has been made by the heat distribution in the cooled substrate.

Keywords

• scanning liquid phase epitaxy
• ampere force
• heterostructures
• thin films