DFT Modeling of Chemical Reactions Occurring Under the Influence of Positive Ionic Complexes of Aqueous HF Solutions During Electrochemical Etching of Silicon

Authors F. Ptashchenko

National University Odessa Maritime Academy, 8, Didrikhson Str., 65029 Odessa, Ukraine

Е-mail fed.ptas@gmail.com
Issue Volume 16, Year 2024, Number 2
Dates Received 16 January 2024; revised manuscript received 21 April 2024; published online 29 April 2024
Citation F. Ptashchenko, J. Nano- Electron. Phys. 16 No 2, 02005 (2024)
DOI https://doi.org/10.21272/jnep.16(2).02005
PACS Number(s) 82.45. – h, 82.65. + r
Keywords Porous Silicon (3) , Electrochemical Etching, DFT-Calculations, Nanomaterials (4) .

Based on quantum chemical calculations, the restoration of the hydrogen coating occurring during the first stages of silicon etching in HF solutions under the influence of positive ionic complexes of the electrolyte have been studied. It has been shown that in aqueous solutions of HF, restoration of the hydrogen coating can occur both with and without current flowing through the silicon/electrolyte system. It is shown that the parallel occurrence of mutually inverse reactions of removal of surface hydrogen atoms and restoration of the hydrogen coating explains the low rate of purely chemical etching of silicon in aqueous solutions of HF. A method has been created for reliable assessment of the energy parameters of chemical reactions with a variable charge state of a cluster that occur on the surface of bulk silicon based on the results of calculations carried out on clusters of finite sizes. The energy yields of the restoration of the hydrogen coating under the influence of ionic complexes Н3О+ and 3(Н2О)(Н3О)+ are calculated when current flows and without injection of free holes into silicon.

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