Influence of GaAs(001) pregrowth surface morphology and reconstruction on the growth of InGaAs layers

摘要

The influence of pregrowth surface morphology and reconstruction upon the growth of In_(0.15)Ga_(0.85)As alloy layers was investigated. After obtaining different pregrowth surfaces, depositions of InGaAs were carried out by molecular-beam epitaxy (MBE). The real space ultrahigh vacuum scanning tunneling microscopy (STM) images showed the disciplinary changes between GaAs and InGaAs surface morphology. Reflection high energy electron diffraction (RHEED) has also been used to estimate InGaAs deposition. As STM images and RHEED oscillations showed, heteroepitaxial surface quality greatly depends on initial state of surface even form the earliest stages of deposition. Two reasons of the effects are proposed, a conjecture for the formation of surfaces morphology and its influence on subsequent growth is also proposed.