Comparison between experimental results and CFD model calculations for high-throughout continuous silicon chemical vapour deposition epitaxy

Low-cost high-throughput epitaxy is one of the keystones for reducing the PV module cost to far below 50 ect/Wp by new ""kerfless"" cell concepts. At Fraunhofer ISE the ProConCVD (Production Continuous Chemical Vapour Deposition) was developed to demonstrate feasibility of such a process. First long term experiments could proof the reliability and the reproducibility of the tool. 1300 multicrystaline silicon (mc-Si) wafers of 156 mm x 156 mm size were coated during 24 experiments in 4 weeks. With SiCl4 as a precursor it was possible to deposit 9 mm thick epitaxial layers within 45 minutes. Thickness homogeneity higher than 90% was achieved over nearly 270 mm deposition width. Since at the edges of the reaction chamber a reduction of the deposited Si film can be observed, we investigated in Computational Fluid Dynamic (CFD) to identify the underlying reasons. The purpose of this work is to report the potential and the limitations of the current models. It could be shown that the gas inlet setup of the ProConCVD already uses 80 % of its theoretical potential in reference to the growth rate and the layer thickness homogeneity in transport direction is higher than 87 %.