Computational study of plasma dynamics and reactive chemistry in a low-pressure inductively coupled CF4/O2 plasma

Levko, Dmitry; Shukla, Chandrasekhar; Upadhyay, Rochan; Raja, Laxminarayan L.

doi:10.1116/6.0001028

Cited by 8 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rauf and Kushner [41] conducted a study on the density of metastable sub-atoms in Ar + CF 4 RF discharge. Levko et al [42] studied the dynamics and chemical characteristics of the low voltage inductively coupled CF 4 + O 2 plasma discharge using a two-dimensional (2D) self-consistent symmetric fluid model. They determined the main negative ion species and ionization mechanism in the reaction process.…”

Section: Introductionmentioning

confidence: 99%

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Zhao,

Wang,

Liu

2023

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Based on a two dimensional (2D) self-consistent model, the effect of different CF4 concentrations on the discharge dynamics characteristics, F-containing species distribution and the distribution of the axial and radial ionization rates of He atmospheric pressure plasma jet (APPJ) has been investigated. In addition, the accuracy of the simulation is verified by comparing the experimental results. The ionization rate of He APPJ enhances with the increase of CF4 from 0 to 2% because of the Penning ionization of CF4 with metastable He while decreases in the case of 3% CF4 owing to the electronegativity and the electron excitation energy loss of CF4. The increase of CF4 concentration and the decrease of the electron density leads to the decrease of CF4+ density at 3%CF4. CF3+ density is determined by the Penning ionization rate of CF4 and the reaction rate of He+ + CF4 → CF3+ + F + He. As CF4 concentration increases from 2% to 3%, the decrease of metastable He and He+ concentration results in the significant decrease of CF3+ density. The densities of CF3⁻ and F⁻ keep increasing from 1% to 3%CF4 due to the effect of the electron attachment reaction of CF4. With the addition of CF4, the ionization reaction of CF4 is gradually playing the major role in the streamer head, the Penning ionization of CF4 is the main source of electron ionization inside the jet and dominates in the formation of ionization wave tail. As the concentration of CF4 increases from 0 to 2%, the electron impact ionization rates of He and CF4 near the axis increase, resulting in the more uniform radial ionization rate distribution of He + 2%CF4 APPJ.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Zhao,

Wang,

Liu

2023

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

Numerical study of the influence of O2 admixture on the propagation and F-containing species distribution of He/CF4 atmospheric pressure plasma jet

Liu

Wang

Zhang

et al. 2022

Journal of Applied Physics

View full text Add to dashboard Cite

O2 impurity in the working gas of an He/CF4 atmospheric pressure plasma jet (APPJ) can affect the discharge dynamics and the density of reactive species. Therefore, a two-dimensional (2D) fluid model is built in order to explore the influence of an O2 admixture on the propagation and F-containing species distribution of He/CF4 APPJ. The addition of 0.1% O2 accelerates the ionization rates of APPJ due to the increase of Penning ionization reactions of O2, resulting in the increases of axial speed and F-containing reactive species (CF4+, CF3+, CF2+, CF+, F+, CF3, F, CF3−) when APPJ approaches the dielectric surface. The addition of O2 has the inhibitory effect on the rise of some F-containing reactive species (CF3+ and F). As O2 concentration increases to 2%, the concentration of F-containing reactive species shows a downward trend due to the increase of excitation energy loss and an electron attachment reaction of O2. Different from the axial speed, the radial speed decreases continuously with the increase of O2 because of the high O2 concentration on the dielectric surface when APPJ propagates radially. This also results in a reduced distribution of reactive species fluxes. The excitation energy loss and electronegativity of O2 and CF4 in the case of He + 0.5% CF4 + 0.5% O2 have been presented in this paper. It is discovered that excitation energy loss of O2 is stronger than that of CF4, but the electronegativity of CF4 is stronger than that of O2.

show abstract

Towards atomic-scale smooth surface manufacturing of β-Ga₂O₃ via highly efficient atmospheric plasma etching

Zhang,

Xiao,

Liang

et al. 2024

Int. J. Extrem. Manuf.

View full text Add to dashboard Cite

The highly efficient manufacturing of atomic-scale smooth β-Ga2O3 surface is fairly challenging because β-Ga2O3 is a typical difficult-to-machine material. In this study, a novel plasma dry etching method named plasma-based atom-selective etching (PASE) is proposed to achieve the highly efficient, atomic-scale, and damage-free polishing of β-Ga2O3. The plasma is excited through the inductive coupling principle and carbon tetrafluoride is utilized as the main reaction gas to etch β-Ga2O3. The core of PASE polishing of β-Ga2O3 is the remarkable lateral etching effect, which is ensured by both the intrinsic property of the surface and the extrinsic temperature condition. As revealed by density functional theory-based calculations, the intrinsic difference in the etching energy barrier of atoms at the step edge (2.36 eV) and in the terrace plane (4.37 eV) determines their difference in the etching rate, and their etching rate difference can be greatly enlarged by increasing the extrinsic temperature. The polishing of β-Ga2O3 based on the lateral etching effect is further verified in the etching experiments. The Sa roughness of β-Ga2O3 (001) substrate is decreased from 14.8 to 0.057 nm within 120 s, and the corresponding material removal rate reaches up to 20.96 μm/min. The polished β-Ga2O3 displays significantly improved crystalline quality and photoluminescence intensity, and the polishing effect of PASE is independent of the crystal faces of β-Ga2O3. In addition, the competition between chemical etching and physical reconstruction, which is determined by temperature and greatly affects the surface state of β-Ga2O3, is deeply studied for the first time. These findings not only demonstrate the high-efficiency and high-quality polishing of β-Ga2O3 via atmospheric plasma etching but also hold significant implications for guiding future plasma-based surface manufacturing of β-Ga2O3.

show abstract

Computational study of plasma dynamics and reactive chemistry in a low-pressure inductively coupled CF4/O2 plasma

Cited by 8 publications

References 26 publications

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Numerical study of the influence of O2 admixture on the propagation and F-containing species distribution of He/CF4 atmospheric pressure plasma jet

Towards atomic-scale smooth surface manufacturing of β-Ga₂O₃ via highly efficient atmospheric plasma etching

Contact Info

Product

Resources

About

Computational study of plasma dynamics and reactive chemistry in a low-pressure inductively coupled CF4/O2 plasma

Cited by 8 publications

References 26 publications

Effect of CF4 concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Effect of CF4 concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Numerical study of the influence of O2 admixture on the propagation and F-containing species distribution of He/CF4 atmospheric pressure plasma jet

Towards atomic-scale smooth surface manufacturing of β-Ga2O3 via highly efficient atmospheric plasma etching

Contact Info

Product

Resources

About

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Effect of CF₄ concentration on the discharge dynamics and reactive species distribution of atmospheric nanosecond pulsed He plasma jet

Towards atomic-scale smooth surface manufacturing of β-Ga₂O₃ via highly efficient atmospheric plasma etching