Mechanism for etching of exfoliated graphene on substrates by low-energy electron irradiation from helium plasma electron sources
| Autor: | Ashley Mhlanga, John D. Femi-Oyetoro, Duncan L. Weathers, Jose M. Perez, Guido F. Verbeck, P.A. Ecton, Kevin M. Roccapriore, Kevin Yao, Runtian Tang |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
business.industry Graphene fungi technology industry and agriculture macromolecular substances Surfaces and Interfaces Substrate (electronics) Condensed Matter Physics Surfaces Coatings and Films Indium tin oxide law.invention chemistry.chemical_compound stomatognathic system chemistry Sputtering Etching (microfabrication) law Vacancy defect Silicon carbide Electron beam processing Optoelectronics business |
| Zdroj: | Journal of Vacuum Science & Technology A. 37:021401 |
| ISSN: | 1520-8559 0734-2101 |
| Popis: | The authors investigate the mechanism for etching of exfoliated graphene multilayers on SiO2 by low-energy (50 eV) electron irradiation using He plasma systems for electron sources. A mechanism for this etching has been previously proposed in which the incident electrons traverse the graphene and dissociate oxygen from the SiO2 substrate at the graphene/SiO2 interface. The dissociated oxygen reacts with carbon defects formed by the electron irradiation and thereby etches the graphene from below. They study etching using graphene flakes of various thicknesses on SiO2, low and higher resistivity Si, indium tin oxide (ITO), and silicon carbide (SiC). They find that thicker layer graphene on SiO2 does not etch less than thinner layers, contrary to the previously proposed model. They find that etching does not occur on low-resistivity Si and ITO. Etching occurs on higher resistivity Si and SiC, although much less than on SiO2. This is attributed to He ion sputtering and vacancy formation. From these observations, they propose that oxygen etches graphene from above rather than below. In addition, they propose He ions instead of incident electrons cause the defects that oxygen reacts with and etches.The authors investigate the mechanism for etching of exfoliated graphene multilayers on SiO2 by low-energy (50 eV) electron irradiation using He plasma systems for electron sources. A mechanism for this etching has been previously proposed in which the incident electrons traverse the graphene and dissociate oxygen from the SiO2 substrate at the graphene/SiO2 interface. The dissociated oxygen reacts with carbon defects formed by the electron irradiation and thereby etches the graphene from below. They study etching using graphene flakes of various thicknesses on SiO2, low and higher resistivity Si, indium tin oxide (ITO), and silicon carbide (SiC). They find that thicker layer graphene on SiO2 does not etch less than thinner layers, contrary to the previously proposed model. They find that etching does not occur on low-resistivity Si and ITO. Etching occurs on higher resistivity Si and SiC, although much less than on SiO2. This is attributed to He ion sputtering and vacancy formation. From these observatio... |
| Databáze: | OpenAIRE |
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