Comparison of effects between large-area-beam ELA and SPC on TFT characteristics

Thin film transistors (TFTs) with channel dimensions between 0.5 /spl mu/m and 5 /spl mu/m were fabricated using a low-temperature process of 600/spl deg/C with single-shot excimer laser annealing (ELA) having a large-area beam of 45/spl times/45 mm/sup 2/. The uniformity in device characteristics across the ELA-treated region was studied. As the channel size decreases, TFT performance and their uniformity for ELA devices were superior compared to those formed with solid phase crystallization (SPC). The superior characteristics by ELA can be explained by the resulting grains with higher crystallinity. TFTs fabricated using ELA having a uniform beam are promising candidates for future LCD peripheral circuits on inexpensive glass and for LSI.