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Numerical Simulation of Thermal Field in Czochralski Monocrystalline Silicon Shoulder

The shoulder is a process of maintaining dislocation-free growth in a Czochralski grown monocrystalline silicon, which is the key to the smooth entry of the crystal into the body. It has been found in production practice that crystal-change often occurs in the middle section of the shoulder. In this paper, the dynamic distribution of the thermal field, flow field, thermal stress and crystal-melt interface shape of the shoulder process is analyzed by numerical simulation. Theoretically, the phenomenon of easy crystal-change in the process of shouldering is explained, and the heater power adjustment process of the shoulder process is proposed. The comparison between the simulation and the actual crystal pulling data shows the correctness of the analysis and provides guidance for the actual crystal pulling.