Light absorptive underlayer enhanced excimer-laser crystallization of Si thin-film

Abstract

A sample structure and method for superlateral-growth (SLG) enhancement in excimer-laser crystallization has been implemented and realized. The proposed sample structure is a Si film/buffer film/light-absorptive (LA) film/glass-stacked structure, with the irradiation of laser light from underneath a substrate. The influence of the absorption coefficient α of the LA film has been found to be critical in this structure. By increasing α from 0 to 12,000 cm−1, diameter of SLG grain has increased from 0.8 to 10 μm, with the solidification term increased from 75 to 1050 ns, respectively. The radius of SLG grain was shown to be proportional to the solidification term with a slope of 5 m/s. This result suggests the average SLG growth rate is constant at 5 m/s, irrespective of the solidification term of Si film. The applicability of present method to both sequential lateral solidification method and micromelt seeding method was demonstrated. Overcoming of Si agglomeration has been shown to be important for applying the present method to the sequential lateral solidification (SLS) method.