Improving the material quality of silicon ingots by aluminum gettering during crystal growth
| Autor: | Jonas Schön, Stephan Riepe, Christian Stieghorst, Florian Schindler, Patricia Krenckel, Martin C. Schubert, Norbert Wiehl, Johannes Giesecke, Barbara Karches |
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| Přispěvatelé: | Publica |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Silicon chemistry.chemical_element Crucible Crystal growth 02 engineering and technology 01 natural sciences law.invention Materialoptimierung Siliciumcharakterisierung Siliciumkristallisation Getter law Impurity 0103 physical sciences General Materials Science Wafer Crystallization Ingot Solarzellen - Entwicklung und Charakterisierung 010302 applied physics Metallurgy Feedstock 021001 nanoscience & nanotechnology Condensed Matter Physics Kristallisation und Wafering Silicium-Photovoltaik chemistry Photovoltaik 0210 nano-technology Charakterisierung von Prozess- und Silicium-Materialien |
| Popis: | We present a method for the purification of silicon ingots during the crystallization process that reduces significantly the width of the low charge carrier lifetime region at the ingot top. The back-diffusion of impurities from the ingot top is suppressed by adding a small amount of pure aluminum into the silicon melt right at the end of the solidification. We study the aluminum gettering effect by instrumental neutron activation analysis (INAA) and Fei imaging. Furthermore, we present a model for aluminum gettering of Fe in the silicon ingot that is in agreement with literature data for aluminum gettering at lower temperature. The distribution of iron in the ingots with and without aluminum is fairly well predicted by a combination of this model with a model for Fe contamination from the crucible system. A simulation with varying Al content exhibits further potential for an increased yield of silicon wafers with high charge carrier lifetime. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) |
| Databáze: | OpenAIRE |
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