Selected area laser-crystallized polycrystalline silicon thin films by a pulsed Nd:YAG laser with 355 nm wavelength

摘要

Selected area laser-crystallized polycrystalline silicon (p-Si) thin films were prepared by the third harmonics (355 nm wavelength) generated by a solid-state pulsed Nd:YAG laser. Surface morphologies of 400 nm thick films after laser irradiation were analyzed. Raman spectra show that film crystallinity is improved with increase of laser energy. The optimum laser energy density is sensitive to the film thickness. The laser energy density for efficiently crystallizing amorphous silicon films is between 440–634 mJ/cm~2 for 300 nm thick films and between 777–993 mJ/cm~2 for 400 nm thick films. The optimized laser energy density is 634, 975 and 1571 mJ/cm2 for 300, 400 and 500 nm thick films, respectively.