Growth kinetics of CoSi₂ and Ge islands observed with in situ transmission electron microscopy

We describe observations of the growth kinetics of nanosize islands in two heteroepitaxial systems, Ge/Si and CoSi2/Si. Growth was carried out during continuous observation in a modified ultra high vacuum transmission electron microscope. Ge islands were grown on Si(100) at 650°C using chemical vapour deposition and CoSi2 islands were grown by reactive epitaxy by evaporating Co onto a Si(111) substrate heated to 900°C. By analysing real-time observations of the development of individual islands, we show how the factors controlling island nucleation, growth and relaxation in these systems can be identified and understood. We discuss how the growth of these 'quantum dots' may be controlled for novel electronic and optoelectronic applications.