Morphological Evaluation of Ge Nanoclusters by Spot Shape of Surface Electron Diffraction

Nanoclusters of Ge, such as hut clusters and pyramidal clusters, were grown on Si(001) substrates and evaluated by surface electron diffraction methods such as reflection high-energy electron diffraction (RHEED) and low-energy electron diffraction (LEED). Observations of the same sample by both RHEED and LEED were carried out for the first time. The diffraction spots had a characteristic shape and intensity distribution depending on the morphology of the clusters. The spot shapes in RHEED and LEED were simulated by kinematic calculations, which reproduced the experimental results fairly well. It was confirmed that the characteristic spot shapes can be explained by refraction effects and Laue function of diffraction intensity. [DOI: 10.1380/ejssnt.2012.18]