Sequential lateral solidification of thin silicon films on SiO2

We report on a low-temperature excimer-laser-crystallization process that produces a previously unattainable directionally solidified microstructure in thin Si films. The process involves (1) inducing complete melting of selected regions of the film via irradiation through a patterned mas, and (2) precisely controlled between-pulse microtranslation of the sample with respect to the mask over a distance short than the single-pulse lateral solidification distance, so that lateral growth can be extended over a number of iterative steps. Grains up to 200 mu m in length were demonstrated; in principle, grains of unlimited length can be produced. We discuss how the technique can be extended to produce large single-crystal regions on glass substrates. (C) 1996 American Institute of Physics.