Crystallization of long polycrystalline silicon with a long duration pulse from a Nd:YAG laser system

We have investigated the crystallization of a long polycrystalline silicon (poly-Si) annealed by a single-shot laser pulse, which is generated from a novel variable-pulse-duration laser system. We report a quantitative study of the correlation between the crystal length and the laser pulse parameters (in particular, pulse energy per unit area and duration). The laser system consists of two laser sources: a constant short-duration pulsed laser (λ = 532 nm, duration = 20 ns) and a variable-duration pulsed laser (λ = 1064 nm, duration = 80–1300 ns). The two pulses, which were generated from separate laser sources, were incident on the substrate at almost the same time. By using the laser system, it is experimentally found that there is a proportional relationship between the crystal length and the pulse energy per unit area of the 1064 nm pulse, and we obtained poly-Si crystals with an average length of more than 10 µm by increasing the pulse energy per unit area of the 1064 nm pulse and expanding the pulse duration. To interpret the experimental results, we have also qualitatively considered the crystallization of a long poly-Si.