Evolution of vacancy ordering and defect structure in epitaxial YSi 2-x thinfilms on (111)Si

Conventional and high-resolution transmission electronmicroscopy were used to analyze the evolution of vacancy ordering and defect structure in epitaxial YSi thin films on Si. Epitaxial YSi 2-x were formed whensamples were annealed at 500 degrees celsius for 120 seconds. When the temperature reached 600 degrees celsius for a period of 15 seconds, an ordered vacancy superstructure was formed and additional diffraction spots appeared. Atthe same temperature but for longer periods, or at higher temperatures, an out-of-step structure was formed and the extra diffraction spots were split.