Dynamic processes at InP(110) surfaces studied by UHV reflection electron microscopy

Dynamic events occurring at InP(110) surfaces as a result of thermal annealing have been observed in situ by reflection electron microscopy using a modified ultrahigh-vacuum transmission electron microscope equipped with a specimen heating holder. The motion of screw dislocations across the surface was observed at temperatures in excess of 550°C, resulting in the formation of new surface steps. Thermal dissociation led to desorption of P with consequent visible growth of In particles at 650°C. Initially most in particles grew with hemispherical shapes and linear rates of expansion. Later changes in growth rate were associated with changes in particle shape. Three distinct particle shapes were observed at the end of the annealing suggesting departure from self-similar growth. Cooling to room temperature and overnight ambient annealing in ultrahigh-vacuum resulted in significant changes in particle morphology. Genuine thermal effects were separated from those due to electron irradiation.