Initial Growth Mechanism of Si on GaAs Studied by Reflection High-Energy Electron Diffraction Oscillations

Publisher Website
Google Scholar
Abstract
We have studied the initial growth mechanism of Si on GaAs(100) and GaAs(111)B substrates by observing the behavior of the reflection high-energy electron diffraction (RHEED) specular beam intensity and the changes in the RHEED patterns. During the growth on just exactly substrates, we infer two-dimensional growth with nucleation on the terraces from the presence of RHEED oscillations. For the growth of Si on GaAs(100), a flat surface with bilayer steps (single domain) was obtained at ∼0.8 monolayers (ML) of growth. This structure was conserved up to ∼3 ML by a bilayer growth mode. With further growth, monolayer steps were formed on the surface and a double domain structure was observed. It is suggested that this change could be related to an alteration of the Si surface migration due to the high strain energy caused by the 4% lattice mismatch. A model is presented which includes some of the possible reactions between Si, Ga and As at the interface.