UV Pulsed Laser Annealing of Si⁺ Implanted Silicon Film and Low-Temperature Super-Thin Film Transistors

Abstract

A UV pulsed excimer laser was irradiated onto Si + -implantated thin silicon films. The resultant crystallized state was investigated by UV reflectance measurement and TEM observation. As a result, we found that the grain size depended on the irradiated pulse energy, and that the grain growth was more effective for a smaller Si + dose, in the low-pulse-energy region of less than 200 mJ/cm 2 . Moreover, for efficient annealing, the back-side irradiation through the quartz substrate was preferable to the front-side irradiation upon the silicon surface. Using this method, TFT's were fabricated in a low-temperature process, and excellent device characteristics were obtained. The leakage current was below 1×10 -13 (A/µm).