Application of Nd:YLF laser to amorphous silicon crystallization process

Polysilicon thin films have been obtained by Laser Induced Crystallization utilizing a Q-switched diode pumped, frequency-doubled Nd:YLF laser at 523-nm wavelength. Intrinsic and n-doped amorphous materials, of different thickness, have been deposited on Corning 1737 by LPCVD technique. The irradiation conditions have been varied in order to study their influence on crystallized material properties. Electrical and optical properties of as-deposited and crystallized films have been determined. Structural characterization has been performed to evaluate average grain size and distribution. Larger grain size has been observed in intrinsic materials compared to n-doped materials and the largest grain size (≈1 μm) has been obtained on materials having thickness of 50 nm. Critical role of doping in the crystallization process has been pointed out.