Kinetic simulation of a 50 mTorr capacitively coupled argon discharge over a range of frequencies and comparison to experiments
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- Purdue Univ., West Lafayette, IN (United States); Purdue University
- Institute for Plasma Research and Homi Bhabha National Institute (HBNI), Gandhinagar (India)
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Purdue Univ., West Lafayette, IN (United States)
The effect of driving frequency in the range of 13.56–73 MHz on electron energy distribution and electron heating modes in a 50 mTorr capacitively coupled argon plasma discharge is studied using 1D-3V particle-in-cell simulations. Calculated electron energy probability functions exhibit three distinct “temperatures” for low-, mid-, and high-energy electrons at all the studied driving frequencies. When compared to published experimental data, the calculated probability functions show a reasonable agreement for the energy range resolved in the measurements (about 2–10 eV). Discrepancies due to limitations in experimental energy resolution outside this range lead to differences between computational and experimental values of the electron number density determined from the distribution functions, and the predicted effective electron temperature is within 25% of experimental values. The impedance of the discharge is interpreted in terms of a homogeneous equivalent circuit model, and the driving frequency dependence of the inferred combined sheath thickness is found to obey a known, theoretically derived, power law. The average power transferred from the field to the electrons (electron heating) is computed, and a region of negative heating near the sheath edge, particularly at higher driving frequencies, is identified. Analysis of the electron momentum equation shows that electron inertia, which on temporal averaging would be zero in a linear regime, is responsible for negative values of power deposition near the sheath edge at high driving frequencies due to the highly nonlinear behavior of the discharge.
- Research Organization:
- Purdue Univ., West Lafayette, IN (United States). Princeton Collaborative Research Facility (PCRF); Purdue University, West Lafayette, IN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- Grant/Contract Number:
- AC02-09CH11466; SC0021076; SC0021153
- OSTI ID:
- 1995406
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 30; ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Capacitively Coupled Discharge
Electric fields
Electron Energy Distribution Functions
Electron Heating
Electron energy distribution functions
Electronic circuits
Joule heating
Low Temperature Plasma
Newtonian mechanics
Particle-in-cell method
Plasma Etching
Plasma discharges
Plasma sheaths