{"title":"Ab Initio Molecular Dynamics Approach for Oxidation of SiC Surface in Contact with Aqueous H2O2 Solutions","authors":"Tetsuya Morishita, Megumi Kayanuma, Tomohisa Kato","doi":"10.1021/acs.jpcc.4c03112","DOIUrl":null,"url":null,"abstract":"Controlling the oxidation of silicon carbide (SiC) is a key factor in fabricating SiC-based devices, such as power-integrated circuits and thermal protection systems. Oxidation is particularly utilized for machining SiC in conjunction with chemical–mechanical polishing. However, a thorough understanding of SiC oxidation at the microscopic level is lacking. Here, we performed <i>ab initio</i> molecular dynamics simulations to elucidate the microscopic mechanisms of the oxidation of OH- and H-terminated SiC surfaces in contact with an oxidizing solution─aqueous H<sub>2</sub>O<sub>2</sub> solution. We found that the OH-terminated (000<span>1</span>) C-face surface of SiC is more easily oxidized than the OH-terminated (0001) Si-face and H-terminated C- and Si-faces. The stability of the C–O and Si–O species on the surface plays a key role in the oxidation of the OH-terminated surfaces. The effect of H<sub>2</sub>O<sub>2</sub> concentration on the oxidation of the C-face was also examined. We found that the OH radicals generated from H<sub>2</sub>O<sub>2</sub> molecules undergo a facile conversion to H<sub>2</sub>O molecules in a pure H<sub>2</sub>O<sub>2</sub> solution. This phenomenon may explain the counterintuitive dependence of oxidation on the H<sub>2</sub>O<sub>2</sub> concentration observed in the experiments.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Physical Chemistry C","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.jpcc.4c03112","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Controlling the oxidation of silicon carbide (SiC) is a key factor in fabricating SiC-based devices, such as power-integrated circuits and thermal protection systems. Oxidation is particularly utilized for machining SiC in conjunction with chemical–mechanical polishing. However, a thorough understanding of SiC oxidation at the microscopic level is lacking. Here, we performed ab initio molecular dynamics simulations to elucidate the microscopic mechanisms of the oxidation of OH- and H-terminated SiC surfaces in contact with an oxidizing solution─aqueous H2O2 solution. We found that the OH-terminated (0001) C-face surface of SiC is more easily oxidized than the OH-terminated (0001) Si-face and H-terminated C- and Si-faces. The stability of the C–O and Si–O species on the surface plays a key role in the oxidation of the OH-terminated surfaces. The effect of H2O2 concentration on the oxidation of the C-face was also examined. We found that the OH radicals generated from H2O2 molecules undergo a facile conversion to H2O molecules in a pure H2O2 solution. This phenomenon may explain the counterintuitive dependence of oxidation on the H2O2 concentration observed in the experiments.
期刊介绍:
The Journal of Physical Chemistry A/B/C is devoted to reporting new and original experimental and theoretical basic research of interest to physical chemists, biophysical chemists, and chemical physicists.