Influence of Solution Volume on the Dissolution Rate of Silicon Dioxide in Hydrofluoric Acid |
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Authors: | Boris Shvartsev Danny Gelman Ilia Komissarov Alon Epshtein Dr. David Starosvetsky Prof. Yair Ein‐Eli |
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Affiliation: | 1. Department of Materials Science and Engineering, Technion—Israeli Institute of Technology, Haifa (Israel);2. The Nancy and Stephen Grand Technion Energy Program, Technion—Israeli Institute of Technology, Haifa (Israel) |
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Abstract: | Experimental data and modeling of the dissolution of various Si/SiO2 thermal coatings in different volumes of hydrofluoric acid (HF) are reported. The rates of SiO2‐film dissolution, measured by means of various electrochemical techniques, and alteration in HF activity depend on the thickness of the film coating. Despite the small volumes (0.6–1.2 mL) of the HF solution, an effect of SiO2‐coating thickness on the dissolution rate was detected. To explain alterations detected in HF activity after SiO2 dissolution, spectroscopic analyses (NMR and FTIR) of the chemical composition of the solutions were conducted. This is associated with a modification in the chemical composition of the HF solution, which results in either the formation of an oxidized species in solution or the precipitation of dissolution products. HF2? accumulation in the HF solution, owing to SiO2 dissolution was identified as the source of the chemical alteration. |
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Keywords: | electrochemistry etching rate hydrofluoric acid silicon dioxide thin films |
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