Laser crystallization of silicon for high-performance thin-film transistors

We crystallize amorphous silicon films by a frequency doubled Nd:YVO4 laser with a pulse energy of 18.5 µJ and a repetition frequency of 20 kHz. A sequential lateral solidification process yields polycrystalline silicon with grains longer than the channel of thin-film transistors. The resulting electron field effect mobility of 410 cm2 V-1 s-1 shows the superiority of our process compared with excimer laser crystallization. A calculation results in a possible throughput of 35 cm2 s-1 for our laser crystallization process if one used a laser with a pulse energy of 1.25 mJ and a repetition frequency of 100 kHz.