GROWTH INFORMATION CARRIED BY REFLECTION HIGH-ENERGY ELECTRON DIFFRACTION

摘要

Scientific and technological developments have made it possible to grow materials with different properties onto each other, and this way we can build quantum wells, quantum islands, quantum dots (QDs), etc., which leads to the possibility of creating novel devices and applications. Molecular-beam-epitaxy (MBE) is the nearly exclusive technique of growth of the above mentioned low-dimensional structures. The technology of growth under UHV made the in-situ observation of the growth process possible, which is widely realized by reflection high-energy electron-diffraction (RHEED). The growth of perfect crystal layers and low-dimensional structures is basically conditioned by the control of epitaxy. We need the knowledge and understanding of the growth mechanism for this, and the RHEED pattern and its intensity oscillations carry information to help us attain this goal. We will briefly deal with the basic information that is carried by RHEED. After that we investigate the dependence of mechanical strain appearing in the layer, material dependence, and other particular behaviour on RHEED. Finally, we discuss the relation between observed RHEED and the QD formation.