The crystallization of amorphous silicon films deposited on glass, using the flash lamp annealing process was realized and studied. The duration of the flash is 20 ms, about two orders of magnitude shorter than the standard rapid thermal annealing process. The a-Si films deposited on Coming glass were irradiated with different energy densities and crystallized exhibiting grains with a mean size up to 6 mum. In order to reduce the strain due to the thermal gradient, the samples were preheated from the backside. The ability of the FLA process to eliminate the ingrain defects in already crystallized poly-Si films at 600 degreesC is also demonstrated. (C) 2004 Elsevier B.V. All rights reserved.