Microstructural control of amorphous silicon films crystallized using an excimer laser

A technique for microstructural control of excimer laser-annealed silicon thin films on SiO2 substrates has been developed. By using single-crystal photolithographically etched silicon seed wafers in intimate contact with the silicon films, we have shown that it is possible to spatially control nucleation. Transmission electron micrographs show the resultant microstructure to consist of large (∼1 µm) grain structures in the area surrounding the seed contact, with distinct organization not previously observed. A theoretical discussion is presented to explain the observed phenomena. Also, results from a numerical simulation are given which outline the effects of the seed wafer on the resultant microstructure of the laser-annealed film, as compared to nonseeded areas.