Global simulation of the Czochralski silicon crystal growth in ANSYS FLUENT

Silicon crystals for high efficiency solar cells are produced mainly by the Czochralski (CZ) crystal growth method. Computer simulations of the CZ process established themselves as a basic tool for optimization of the growth process which allows to reduce production costs keeping high quality of the crystalline material. The author shows the application of the general Computational Fluid Dynamics (CFD) code ANSYS FLUENT to solution of the static two-dimensional (2D) axisymmetric global model of the small industrial furnace for growing of silicon crystals with a diameter of 100 mm. The presented numerical model is self-sufficient and incorporates the most important physical phenomena of the CZ growth process including latent heat generation during crystallization, crystal–melt interface deflection, turbulent heat and mass transport, oxygen transport, etc. The demonstrated approach allows to find the heater power for the specified pulling rate of the crystal but the obtained power values are smaller than those found in the literature for the studied furnace. However, the described approach is successfully verified with the respect to the heater power by its application for the numerical simulations of the real CZ pullers by “Bosch Solar Energy AG”.

► 2D axisymmetric global model for CZ process simulation is created in ANSYS FLUENT.
► The results show some discrepancy to literature values with respect to the found heater power.
► The found heater power is almost independent on the selected turbulence model.
► The computed temperature difference in the melt is strongly influenced by the turbulence model.
► This computational approach can be adapted for the global 3D simulations of the CZ process.