In Situ Monitoring of Surface Kinetics in GaAs Atomic Layer Epitaxy by Surface Photo-Absorption Method

Abstract
The epitaxial growth reactions that proceed on the substrate surface during halogen transport atomic layer epitaxy (ALE) are observed directly with a surface photo-absorption method. The heat of desorption (48.5 kcal/mol) is obtained from the reflective intensity change. The value agrees well with the activation energy reported in classical halogen transport vapor-phase epitaxy. Based on the observation, a reaction mechanism is proposed. The self-limiting mechanism of halogen transport ALE is ascribed to the complete coverage of surface As sites by the adsorbed complex.