Silicon grain arrays prepared using a pattern crystallization technique of pulsed-excimer laser irradiation

Silicon grain arrays were prepared using a pattern crystallization technique of pulsed KrF excimer laser irradiation. The precursor material was hydrogenated amorphous silicon (a-Si:H) thin films deposited on single crystal Si wafers by plasma-enhanced chemical vapor deposition. It was shown that Si grains with a uniform size and a well-defined periodicity embedded in the a-Si:H matrix were obtained by this simple technique. The grain size was less than 2 mum. Relativly strong photo-luminescence with two peaks at 720 and 750nm was observed at room temperature. We expect to reduce Si grain sizes by optimizing the growth conditions of a-Si:H thin films and controlling the temperature distribution in the film during laser irradiation.