ABSTRACT
Real-time monitoring of the atomic surface kinetics during the epitaxial growth of compound semiconductors can provide a fair understanding of the surface processes, such as surface diffusion of ad-atoms, nucleation kinetics and growth modes, which can affect the epilayer quality, defect formation, interface abruptness and dopant distribution. During the epitaxial growth of crystals, a variety of growth modes occur. At low temperatures, crystal grows via a rough, three-dimensional mode, which changes to layer-by-layer growth as the temperature is raised. At even higher temperatures, step-flow growth eventually dominates. In the high vacuum MBE process, the different growth modes have been experimentally established a long ago, principally by reflection high-energy electron diffraction (RHEED) studies [1]. For metal organic vapor phase epitaxy (MOVPE), real-time data about the growth modes is still limited, mainly because its high ambient pressures and/or magnetic fields preclude the use of electron diffraction technique. The mechanism of the step-flow growth has been described theoretically long ago in the well-known paper of Burton Cabrera and Franck (BCF) [2].
