High-performance low-temperature poly-Si TFTs crystallized by excimer laser irradiation with recessed-channel structure

High-performance low-temperature poly-Si (LTPS) thin-film transistors (TFTs ) have been fabricated by excimer laser crystallization (ELC) with recessed -channel (RC) structure, The TFTs made by this method possessed large longi tudinal grains in the channel regions, therefore, they exhibited better ele ctrical char acteristics as compared with the conventional ones. The averag e field-effect mobility above 300 cm(2)/V-s and on/off current ratio higher than 10(9) were achieved in these RC-structure devices, In addition, since grain growth could be artificially controlled by this method, the device e lectrical characteristics were less sensitive to laser energy density varia tion, and therefore the uniformity of device performance could be improved.