Effect of Pulse Duration on Formation of Ultrashallow Junction by Excimer Laser Annealing

An ultrashallow junction (USJ) was formed by KrF excimer laser annealing. The effect of laser pulse duration on USJ formation was discussed through the evaluations of junction depth, sheet resistance and crystal defects. The possibility of reducing crystal defects by long-pulse laser annealing was discussed. A simple one-dimensional thermal diffusion model was used to analyze the results considering the solidification velocity after melting. The calculated results for the relationship between melt depth and laser energy density qualitatively agreed well with the experimental results. The results also showed that longer pulse duration made solidification velocity lower. Lower solidification velocity is the key to reducing the residual defects.