3D coupled electromagnetic and thermal modelling of EFG silicon tube growth

The edge-defined film-fed growth (EFG) process is mainly used to grow silicon ribbons and hollow cylinders as well as hollow polygons of various geometries. The development of the EFG process is primarily focused on technology improvements and cost reduction of wafers for photovoltaic applications. In case of the growth of hollow polygons, three-dimensional (3D) numerical analysis is extensively used because the system of polygonal geometry cannot be adequately described in axisymmetric model. Electromagnetic simulation predicts a 3D distribution of electromagnetic energy in all the system. The calculated three-dimensional temperature fields allow the analysis of the temperature profiles along and across the growing silicon tubes and the investigation of thermally induced stress and strain in different cases. The non-linear model consisting on electromagnetic, thermal and structural simulations has been adjusted and successfully validated by experimental tests with industrial installations.