Reversal of the Asymmetry in a Cylindrical Coaxial Capacitively Coupled Ar/Cl2 Plasma
| Autor: | Janardan Upadhyay, Leposava Vuskovic, Do Jin Im, Larry Phillips, Svetozar Popovic, Anne Marie Valente-Feliciano |
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| Rok vydání: | 2015 |
| Předmět: |
Accelerator Physics (physics.acc-ph)
Debye sheath Materials science Plasma etching Condensed Matter - Superconductivity Superconducting radio frequency FOS: Physical sciences Surfaces and Interfaces Plasma Condensed Matter Physics Molecular physics Physics - Plasma Physics Surfaces Coatings and Films Superconductivity (cond-mat.supr-con) Plasma Physics (physics.plasm-ph) Bellows symbols.namesake Physics::Plasma Physics Electrode symbols Surface modification Physics - Accelerator Physics Coaxial |
| DOI: | 10.48550/arxiv.1507.00059 |
| Popis: | The reduction of the asymmetry in the plasma sheath voltages of a cylindrical coaxial capacitively coupled plasma is crucial for efficient surface modification of the inner surfaces of concave three-dimensional structures, including superconducting radio frequency cavities. One critical asymmetry effect is the negative dc self-bias, formed across the inner electrode plasma sheath due to its lower surface area compared to the outer electrode. The effect on the self-bias potential with the surface enhancement by geometric modification on the inner electrode structure is studied. The shapes of the inner electrodes are chosen as cylindrical tube, large and small pitch bellows, and disc-loaded corrugated structure (DLCS). The dc self-bias measurements for all these shapes were taken at different process parameters in Ar/Cl2 discharge. The reversal of the negative dc self-bias potential to become positive for a DLCS inner electrode was observed and the best etch rate is achieved due to the reduction in plasma asymmetry. Comment: 5 pages, 8 figures |
| Databáze: | OpenAIRE |
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