Preparation of Large Grain Size Polysilicon Using Long-Pulse Green Laser Annealing for 3-D Integration Technology

Location-controlled single grains were obtai- ned through amorphous silicon grown on substrates embedded with microstructure called grain filters (GFs) using long-pulse green laser annealing. This work demonstrates the significant influence of GF spacing and size on grain quality. Accomplished results in this work evidenced that defects like grain boundary could be decreased by manipulating the GF spacing and dimensions to achieve high-integrity single grains with large grain sizes, which is beneficial for device fabrication. Thin-film transistors (TFTs) (W/L = 0.18/
$0.22~\mu \text{m}$
) fabricated on the grains under optimized conditions exhibit excellent electrical performance, with an extracted field-effect mobility of 336 cm2/V-s and an exceptional
${I}_{\text {on}}/{I}_{\text {off}}$
ratio of
$5.16\times 10^{{6}}$
.