9413245 Seiberling The influence of impurities (surfactants) on the heteroepitaxial growth of germanium on the (100) surface of silicon will be investigated. This materials system has been chosen because it represents a model strained heteroepitaxial system, about which much is already known. Surface impurities, such as H or Sb, have been found to dramatically alter the morphology and structure of a growing layer. The transmission ion channeling technique will be applied to investigate the atomic structure and composition of monolayer germanium films growing on silicon in order to understand the microscopic role played by the impurity atoms. % % % % An important goal in materials science is to be able to build tailor-made materials with specific desirable properties. A major step in fulfilling this goal is to learn how to grow high quality crystalline layers of one material on another. Perfect growth can be inhibited by various factors, including a tendency of the overlayer to form islands, the creation of defects, etc. It has recently been shown that certain impurities, often referred to as surfactants, can have a dramatic effect on the structure and properties of a growing film. The mechanism by which surfactants influence growth of germanium on silicon, an important technological system, will be studied using a novel ion scattering technique. With this technique it is possible to measure the atomic structure and the composition of the growing film. ***
