A HIGH-PERFORMANCE POLYSILICON THIN-FILM-TRANSISTOR USING XECL EXCIMER-LASER CRYSTALLIZATION OF PRE-PATTERNED AMORPHOUS SI FILMS

A high-performance polysilicon thin-film transistor (TFT) fabricated u sing XeCl excimer laser crystallization of pre-patterned amorphous Si films is presented, The enhanced TFT performance over previous reporte d results is attributed to pre-patterning before laser crystallization leading to enhanced lateral grain growth, Device performance has been systematically investigated as a function of the laser energy density , the repetition rate, and the number of laser shots, Under the optima l laser energy density, poly-Si TFT's fabricated using a simple low- t emperature (less than or equal to 600 degrees C) process have field-ef fect mobilities of 91 cm(2)/V . s (electrons) and 55 cm(2)/V . s (hole s), and ON/OFF current ratios over 10(7) at V-DS = 10 V. The excellent overall TFT performance is achieved without substrate heating during laser crystallization and without hydrogenation, The results also show that poly-Si TFT performance is not sensitive to the laser repetition rate and the number of laser shots above 10.