INSITU CRYSTALLIZATION OF AMORPHOUS-SILICON IN THE TRANSMISSION ELECTRON-MICROSCOPE

Amorphous Si thin films have been crystallized by in situ annealing in the transmission electron microscope. Crystallization occurred at about 700-degrees-C in electron-beam-deposited Si films, 400 angstrom thick, on amorphous Si3N4 substrates. Dendritic Si crystallites were observed with [110] and [111] orientations. The fast growth direction was parallel to [112]. All crystallites were internally twinned with SIGMA = 3, {111} twin boundaries providing nucleation sites for atom attachment. The amorphous-crystal interface propagation was recorded on videotape to study the mechanism of crystallization. Interface velocities were measured at several temperatures and an activation energy of 3.36+/-0.23 eV was obtained for crystal growth.