Mechanism of Laser Cleaning of Alumina Particles on the Surface of Silicon Wafers: Multiphysics Coupling Simulation

The COMSOL Multiphysics finite element simulation software was used to simulate the process of nanosecond pulse laser cleaning of alumina particles on the surface of silicon wafers, simulate the energy distribution and heat conduction process on the surface of silicon wafers during laser cleaning, analyze the effects of different laser power and spot overlap rate on the thermal effect and substrate damage of laser cleaning, and optimize the laser cleaning parameters. The results show that the laser cleaning depth is positively correlated with the laser power, and the excessive accumulation of thermal effect will occur after the threshold is exceeded, resulting in substrate damage. The laser cleaning speed is negatively correlated with the spot lap rate, when the spot lap rate is 0%, there is an obvious gap between the spots, in order to optimize the cleaning effect, it is necessary to increase the spot lap rate, but too high the lap rate will lead to the accumulated thermal effect and damage the substrate. When the average power is 30 W and the lap rate is 70%, the effect of removing alumina particles on the surface of the silicon wafer is the best. These results demonstrate the feasibility and effectiveness of laser cleaning of alumina particles on the surface of silicon wafers, and have important reference significance for the parameter selection of industrial laser cleaning of alumina particles on the surface of silicon wafers.