TY - GEN A1 - Rietig, Anja A1 - Langner, Thomas A1 - Acker, Jörg T1 - A revised model of silicon oxidation during the dissolution of silicon in HF/HNO₃ mixtures T2 - Physical chemistry, chemical physics N2 - The stoichiometry of wet chemical etching of silicon in concentrated HF/HNO₃ mixtures was investigated. The formation of nitrogen species enriched in the etching mixture and their reactivity during the etching process was studied. The main focus of the investigations was the comprehensive quantification of the gaseous reaction products using mass spectrometry. Whereas previously it could only be speculated that nitrogen was a product, its formation was detected for the first time. The formation of hydrogen, N₂, N₂O and NH₄⁺ showed a dependence on the etching bath volume used, which indicates the formation of nitrogen compounds by side reactions. Simultaneously, the ratio of the nitrogen oxides, NO and NO₂, formed decreases with increasing etching bath volume, while nitric acid consumption increases, so that the formation of NO₂ could also be identified as a side reaction. Based on the stoichiometries obtained, a new reaction scheme for the reduction of nitric acid during etching in HF/HNO₃ mixtures and an electron balance for the oxidation of silicon is presented. KW - silicon KW - etching KW - mechanism KW - nitrogen oxide KW - hydrogen KW - mass spectrometry KW - Raman spectroscopy KW - kinetics Y1 - 2019 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/24478 UR - https://pubs.rsc.org/en/content/articlelanding/2019/CP/C9CP04429A#!divAbstract SN - 1463-9076 VL - 21 SP - 22002 EP - 22013 ER -