Grain growth induced by micro-thermal-plasma-jet irradiation to narrow amorphous silicon strips

Amorphous silicon (a-Si) strips were crystallized by micro-thermal-plasma-jet (μ-TPJ) irradiation. The formation of random grain boundaries (GBs) induced by the collision of liquid-solid interfaces was observed by using a high-speed camera. When Si strip thickness (t_Si) was 50 nm, total GB length significantly decreased with the decrease in strip width (W) from 2 to 1 μm, especially random GBs decreased with the decrease in W. Total and low angle GB length were decreased in the thicker Si strips of t_Si = 100 and 200 nm, and electrically active GBs such as random and Σ9 crystal site lattice hardly formed in all W. The grains longer than 50 μm had the tendency to face to {111} at surface direction, {110} at strip width direction, and {100} at strip length direction. These long growth grains rotated very slowly to growth direction, and the rotation axis was strip width direction. The maximum growth length was 977 μm, and the grain showed very small crystal plane rotation of 0.032 degrees/μm.