Numerical Analysis of Temperature and Thermal Stress Distribution for Whole Wafers in the Laser Annealing Process

Laser annealing of the silicon wafers has attracted attention from the semiconductor manufacturing industry because it can considerably reduce the thermal budget of the semiconductor devices. In this study, a three-dimensional numerical model of the laser annealing process is developed to predict the thermal behavior generated in the whole area of the wafer. The simulation results indicated that the temperature of the wafer was considerably affected by the preheating induced by the laser beam overlap. The investigation of the temperature uniformity indicated that the scan path of the beam center within the bottom part of the wafer showed the most uniform temperature distribution. In the analysis of the effects of the scan pattern on the temperature uniformity and thermal stress, the line scan pattern showed a better temperature uniformity and lower thermal stress than the arc scan pattern.