Three dimensional coupled simulation of the induction heated EFG crystallization process

H. Kasjanow¹ - A. Nikanorov¹ - B. Nacke¹ - H. Behnken² - D. Franke² - A. Seidl³

¹ Institute for Electrothermal Processes, University of Hannover, Wilhelm-Busch-Str. 4, D-30167 Hannover, Germany
² ACCESS e.V., Intzestr. 5, D-52072 Aachen, Germany
³ Schott Solar GmbH, Carl-Zeiss-Str. 4, D-63755 Alzenau, Germany

Abstract
The edge-defined film-fed growth (EFG) process is used to grow silicon ribbons and hollow cylinders as well as hollow polygons of various geometries. In the case of the hollow polygons growth, three-dimensional (3D) numerical analysis is extensively used because the system of polygonal geometry cannot be adequately described in axisymmetric statement. The paper presents a modelling concept consisting of electromagnetic, thermal and structural simulations. Non-linear effects like temperature dependent material properties and heat exchange conditions are taken into account by numerical coupling of different physics. An extended parametric study includes a sensitivity analysis of one industrial polygonal EFG system to all significant parameters like induction coil currents and their phase relations, position of the coils and geometry of the growth system. Figs 8, Refs 3.