###### Abstract
The dual-beam laser spike annealing (DB-LSA) technique was introduced to expand the application space of LSA [18]. In DB-LSA, a second beam is used to preheat the wafer. Based on a series of tests, it was found that the DB-LSA process produces lower thermal stress and has greater defect curing capabilities compared to conventional LSA. The temporal and spatial profiles of the temperature at the annealed area during the LTA process are the key factors determining the degrees of dopant activation and diffusion. In addition, information about the temperature is essential for a proper understanding of the fundamental physical phenomena relating to the process. However, precise measurements of the temperature history in the LTA process are usually very difficult due to the short anneal time and small laser spot. Therefore, a numerical simulation for predicting the temperature distribution reasonably during LTA is necessary. [PERSON] et al. [19] performed numerical simulation of the pulsed laser annealing process to investigate the number of pulses required to form an optimal ultra-shallow junction (USJ). It was found that the optimal USJ was obtained when eight laser pulses were irradiated at an energy density level of 130 mJ/cm\({}^{2}\). [PERSON] et al. [20] carried out experimental and numerical studies of non-melt excimer laser annealing to form the USJ in boron-implanted silicon. The evolution of the temperature distribution along the surface and volume of the material were calculated to analyze the boron kinetics and activation. [PERSON] et al. [21] conducted numerical simulations to predict the melting depth of phosphorus-doped silicon at different laser energy densities. It was found that the total melting (65 nm melt depth) of the phosphorus-doped silicon occurred when the laser energy density was between 620 and 640 mJ/cm\({}^{2}\). [PERSON] et al. [22] undertook a simulation to evaluate thermal pattern effects for various stacks and structures. According to their simulation results, a shallow trench insolation (STI) oxide layer was critical for inducing a large temperature variation. It was also found that the temperature was highly dependent on the STI density and length. As described above, various numerical studies of LTA have been conducted with different purposes. However, in most studies, simulations of the LTA process were carried out under very limited conditions (a fixed beam position or a single pulse), with the results not providing enough information about the phenomena occurring during the actual annealing process. In actual applications of the LTA process, the scanning pattern of the laser beam and the related beam overlap are very important for achieving a uniform temperature and proper dopant activation throughout the wafer area. The purpose of this study is to investigate the temperature distributions created by different laser scan paths and beam overlaps. For a thermal analysis of the LTA process, a numerical simulation of the LTA process was conducted with the time-dependent heat transfer module of COMSOL Multiphysics (commercial software). The spatial and temporal temperature distributions during multi-pass laser annealing were determined through a numerical simulation. Based on the calculated temperature information, the dopant diffusion and concentration in silicon were also predicted.