A combined TEM and time-resolved optical reflectivity investigation into the excimer-laser crystallization of a-Si films

Results are presented of cross-sectional transmission-electron microscopy a nd optical reflectivity investigations into the excimer-laser annealing of a-Si films. It is found that, in the initial stages of the excimer pulse, e xplosive crystallization leads to small, columnar and defect-rich grains. W e discuss the evolution of this microstructure as the laser energy is slowl y increased up to and beyond the super-lateral growth regime. We argue that melting along grain boundaries and defects is a crucial step in obtaining large single-crystalline grains. (C) 2001 Elsevier Science B.V. All rights reserved.