UV pulsed laser annealing of Si+ implanted silicon film and low-temperature super-thin film transistors

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 200mJ/cm2. 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 1x10-13 (A/μm). (author)