Numerical Study of the Upgraded Hot Zone in Silicon Directional Solidification Process

2D global transient model for generation‐six (G6) GT‐style furnace and upgraded generation‐seven (G7) ALD‐style furnace in which all types of heat transfer and flow are included is established to investigate the thermal field, melt convection, melt–crystal (m–c) interface shape, thermal stress, growth rate, and Voronkov ratios in the growing silicon ingot. The modeling is verified by the heater power and temperature experiment. Simulation results show that the melt flow is relatively stronger as the furnace upgrades. For G7, a relatively higher thermal stress and growth rate are found due to the higher temperature gradient both in the horizontal and axial directions. Furthermore, unlike the optimized G6, G7 shows the overly convex m–c interface in the initial stage and edge nucleation throughout crystal growth stage.