Remote Plasma Oxidation and Atomic Layer Etching of MoS2
| Autor: | Lanxia Cheng, Angelica Azcatl, Robert M. Wallace, Xiaoye Qin, Hui Zhu, Jiyoung Kim |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Low-energy electron diffraction Fermi level Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Amorphous solid law.invention symbols.namesake Band bending X-ray photoelectron spectroscopy law Monolayer symbols Remote plasma General Materials Science Scanning tunneling microscope 0210 nano-technology |
| Zdroj: | ACS Applied Materials & Interfaces. 8:19119-19126 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | Exfoliated molybdenum disulfide (MoS2) is shown to chemically oxidize in a layered manner upon exposure to a remote O2 plasma. X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and atomic force microscopy (AFM) are employed to characterize the surface chemistry, structure, and topography of the oxidation process and indicate that the oxidation mainly occurs on the topmost layer without altering the chemical composition of underlying layer. The formation of S-O bonds upon short, remote plasma exposure pins the surface Fermi level to the conduction band edge, while the MoOx formation at high temperature modulates the Fermi level toward the valence band through band alignment. A uniform coverage of monolayer amorphous MoO3 is obtained after 5 min or longer remote O2 plasma exposure at 200 °C, and the MoO3 can be completely removed by annealing at 500 °C, leaving a clean ordered MoS2 lattice structure as verified by XPS, LEED, AFM, and scanning tunneling microscopy. This work shows that a remote O2 plasma can be useful for both surface functionalization and a controlled thinning method for MoS2 device fabrication processes. |
| Databáze: | OpenAIRE |
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