2011 年 32 巻 6 号 p. 325-330
Reflection high-energy electron diffraction (RHEED) method is one of the powerful techniques for a surface structural analysis and is conventionally used for an atomically flat crystal surface. In the case of nano crystal islands such as nano clusters or nano dots on a flat substrate, transmission pattern is observed especially on a grazing incident condition. Morphology of such nano clusters influences the spot shape of the transmission electron diffraction due to the effects of refraction and Laue function. It is shown that the chevron shape of the diffraction spots observed from Ge hut clusters grown on Si(001) substrate can be reproduced well by kinematic calculation. Relation between the spot shape and the cluster's morphology is summarized. It has been confirmed that the diffraction spots are shifted to downward normal to the facets where electrons enter or exit and their intensity distributions are prolonged by the effect of Laue function for the cluster's edge region where electrons can transmit.