### Abstract

Recently a novel approach for achieving separate control of ion flux and energy in capacitively coupled radio frequency (CCRF) discharges based on the electrical asymmetry effect (EAE) was proposed (Heil et al 2008 J. Phys. D: Appl. Phys. 41 165202). If the applied, temporally symmetric voltage waveform contains an even harmonic of the fundamental frequency, the sheaths in front of the two electrodes are necessarily asymmetric. A dc self-bias develops and is a function of the phase angle between the driving voltages. By tuning the phase, precise and convenient control of the ion energy can be achieved while the ion flux stays constant. This effect works even in geometrically symmetric discharges and the role of the two electrodes can be reversed electrically. In this work the EAE is verified using a particle in cell simulation of a geometrically symmetric dual-frequency CCRF discharge operated at 13.56 and 27.12 MHz. The self-bias is a nearly linear function of the phase angle. It is shown explicitly that the ion flux stays constant within 5%, while the self-bias reaches values of up to 80% of the applied voltage amplitude and the maximum ion energy is changed by a factor of 3 for a set of low pressure discharge conditions investigated. The EAE is investigated at different pressures and electrode gaps. As geometrically symmetric discharges can be made electrically asymmetric via the EAE, the plasma series resonance effect is observed for the first time in simulations of a geometrically symmetric discharge.

Original language | English |
---|---|

Article number | 025205 |

Journal | Journal of Physics D: Applied Physics |

Volume | 42 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2009 |

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### ASJC Scopus subject areas

- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films

### Cite this

*Journal of Physics D: Applied Physics*,

*42*(2), [025205]. https://doi.org/10.1088/0022-3727/42/2/025205

**PIC simulations of the separate control of ion flux and energy in CCRF discharges via the electrical asymmetry effect.** / Donkó, Z.; Schulze, J.; Heil, B. G.; Czarnetzki, U.

Research output: Contribution to journal › Article

*Journal of Physics D: Applied Physics*, vol. 42, no. 2, 025205. https://doi.org/10.1088/0022-3727/42/2/025205

}

TY - JOUR

T1 - PIC simulations of the separate control of ion flux and energy in CCRF discharges via the electrical asymmetry effect

AU - Donkó, Z.

AU - Schulze, J.

AU - Heil, B. G.

AU - Czarnetzki, U.

PY - 2009

Y1 - 2009

N2 - Recently a novel approach for achieving separate control of ion flux and energy in capacitively coupled radio frequency (CCRF) discharges based on the electrical asymmetry effect (EAE) was proposed (Heil et al 2008 J. Phys. D: Appl. Phys. 41 165202). If the applied, temporally symmetric voltage waveform contains an even harmonic of the fundamental frequency, the sheaths in front of the two electrodes are necessarily asymmetric. A dc self-bias develops and is a function of the phase angle between the driving voltages. By tuning the phase, precise and convenient control of the ion energy can be achieved while the ion flux stays constant. This effect works even in geometrically symmetric discharges and the role of the two electrodes can be reversed electrically. In this work the EAE is verified using a particle in cell simulation of a geometrically symmetric dual-frequency CCRF discharge operated at 13.56 and 27.12 MHz. The self-bias is a nearly linear function of the phase angle. It is shown explicitly that the ion flux stays constant within 5%, while the self-bias reaches values of up to 80% of the applied voltage amplitude and the maximum ion energy is changed by a factor of 3 for a set of low pressure discharge conditions investigated. The EAE is investigated at different pressures and electrode gaps. As geometrically symmetric discharges can be made electrically asymmetric via the EAE, the plasma series resonance effect is observed for the first time in simulations of a geometrically symmetric discharge.

AB - Recently a novel approach for achieving separate control of ion flux and energy in capacitively coupled radio frequency (CCRF) discharges based on the electrical asymmetry effect (EAE) was proposed (Heil et al 2008 J. Phys. D: Appl. Phys. 41 165202). If the applied, temporally symmetric voltage waveform contains an even harmonic of the fundamental frequency, the sheaths in front of the two electrodes are necessarily asymmetric. A dc self-bias develops and is a function of the phase angle between the driving voltages. By tuning the phase, precise and convenient control of the ion energy can be achieved while the ion flux stays constant. This effect works even in geometrically symmetric discharges and the role of the two electrodes can be reversed electrically. In this work the EAE is verified using a particle in cell simulation of a geometrically symmetric dual-frequency CCRF discharge operated at 13.56 and 27.12 MHz. The self-bias is a nearly linear function of the phase angle. It is shown explicitly that the ion flux stays constant within 5%, while the self-bias reaches values of up to 80% of the applied voltage amplitude and the maximum ion energy is changed by a factor of 3 for a set of low pressure discharge conditions investigated. The EAE is investigated at different pressures and electrode gaps. As geometrically symmetric discharges can be made electrically asymmetric via the EAE, the plasma series resonance effect is observed for the first time in simulations of a geometrically symmetric discharge.

UR - http://www.scopus.com/inward/record.url?scp=63649163274&partnerID=8YFLogxK

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U2 - 10.1088/0022-3727/42/2/025205

DO - 10.1088/0022-3727/42/2/025205

M3 - Article

VL - 42

JO - Journal Physics D: Applied Physics

JF - Journal Physics D: Applied Physics

SN - 0022-3727

IS - 2

M1 - 025205

ER -