SHORT PULSE FIBER LASER FOR LTPS CRYSTALLIZATION

摘要

Laser pulses from pulsed fiber lasers are directed to an amorphous silicon layer to produce a polysilicon layer comprising a disordered arrangement of crystalline regions by repeated melting and recrystallization. Laser pulse durations of about 0.5 to 5 ns at wavelength range between about 500 nm and 1000 nm, at repetition rates of 10 kHz to 10 MHz can be used. Line beam intensity uniformity can be improved by spectrally broadening the laser pulses by Raman scattering in a multimode fiber or by applying varying phase delays to different portions of a beam formed with the laser pulses to reduce beam coherence.

主权项

1. A method of processing a substrate, comprising:
producing an optical line beam based on repetitive laser pulses from a fiber laser at a repetition frequency between about 1 kHz and 10 MHz and having pulse durations less than about 25 ns; and scanning a least one of a substrate that includes a silicon layer and the optical line beam so as to produce silicon crystal grains in the silicon layer such that the processed silicon layer has a mobility of at least about 5 cm2/V-sec.