| A transmission electron microscopy study of the pulsed laser beam crystallized silicon thin film, deposited on SiO₂ at 520℃ by low pressure chemical vapor deposition, has been carried out. It has been shown that the amorphous silicon thin film irradiated by a pulsed laser beam was crystallized by an explosive crystallization process. The resulting polycrystalline matrix contained crystals which had either a diamond cubic or a hexagonal crystal structure. In the interior of the grains which have a hexagonal crystal structure, dislocations, extrinsic type stacking faults, and intrinsic type stacking faults were observed, but the defect density was apparently decreased compared with that in the grains crystallized by a soild phase crystallization. It is thought that the hexagonal crystal structure and many defects were formed by high temperature gradients at the liquid/solid interfaces and the growth breakdown. |
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