Optimization of Process Parameters for Silicon Casting Manufacturing Using Fully Transient 3D Modeling Approach

During the last three years, the world experienced a silicon-wafer shortage due to the COVID-19 pandemic and competition for technology between different countries. Direct silicon casting could be the solution for this issue because of low operation costs and ease of production. In this study, the direct casting of silicon was simulated using a fully transient three-dimensional model including the energy equation, Naiver-Stokes equations, moving mesh theory, and thermal stress equations. The heater power ratios and speed of the side insulation wall were considered as major parameters during the casting. To evaluate the simulation, the crystal-front shape and heater power were validated using experimental results. The simulation results show that by increasing the side heater power, the crystal-front shape changed from concave to almost flat or slightly convex. Additionally, the thermal stress can be decreased about 19% by altering the side heater power. The speed of the side insulation wall was found to have great effect on the casting speed, but the effect of the crystal-front shape was minor.