2003 年 24 巻 6 号 p. 375-382
The liquid-solid interface motion and the temperature history of thin Si films during short pulse (FWHM = 25 ns) excimer laser annealing are observed by in-situ diagnostics. Substantial supercooling (> 200 K) followed by spontaneous nucleation into fine-grained material is observed. Lateral crystal growth is limited by the triggering of spontaneous nucleation in supercooled liquid Si, and the lateral solidification velocity is measured to be about 7.0 m/s. To enhance the lateral growth, the pulse-duration-controlled solid-state laser is utilized. This sequential crystal growth is found to extend over 5 μm in the lateral direction. The validity of the method is confirmed by superior TFT characteristics of high field-effect mobility (n-ch μ > 460 cm2/Vs).