Parameters of Plasma and Kinetics of Active Particles in CF4 (CHF3) + Ar Mixtures of a Variable Initial Composition

Efremov, Alexander; Murin, D. B.; Kwon, Kwang‐Ho

doi:10.1134/s1063739718060033

Cited by 11 publications

(7 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to obtain information on the kinetics and densities of plasma active species, we applied a simplified 0-dimensional (global) kinetic model [47,48]. A set of chemical reactions with corresponding rate coefficients was taken from our previous works that dealt with the modeling of CF 4 + Ar/O 2 [40,[47][48][49][50], CHF 3 + Ar/O 2 [50][51][52][53] and C 4 F 8 + Ar/O 2 [36,39,43,48,54] plasmas. The basic model approaches were as follows:…”

Section: Approaches For Analysis Of Gas-phase Chemistrymentioning

confidence: 99%

“…Figure2represents the model-predicted data on the steady-state densities of neutral species in CF 4 + Ar, CHF 3 + Ar and C 4 F 8 + Ar plasmas. From Figure2a, one can see that the dominant neutral components in pure CF 4 plasma are original CF 4 molecules and F atoms[51,53,55]. The decreasing densities of fluorocarbon radicals in the sequence of CF 3 -CF 2 -CF[55,66] are due to both the step-by-step formation pathway in electron-impact processes R6: CF x + e → CF x−1 + F + e as well as higher heterogeneous loss probabilities for less saturated species.…”

mentioning

confidence: 96%

“…The indirect proof for this suggestion is the nearly constant temperature of the external chamber wall obtained for different gas mixing ratios at fixed plasma on time. Since experimental data on T gas were not available in this study, we took 600-700 K as the typical value for close processing conditions, reactor type and geometry [47][48][49][50][51][52][53]. This allowed us to operate with constant rate coefficients for gasphase atom molecular reactions, which were taken from the NIST(National Institute of Standards and Technology) Chemical Kinetics Database [59].…”

mentioning

confidence: 99%

See 2 more Smart Citations

On Relationships between Gas-Phase Chemistry and Reactive Ion Etching Kinetics for Silicon-Based Thin Films (SiC, SiO2 and SixNy) in Multi-Component Fluorocarbon Gas Mixtures

2021

View full text Add to dashboard Cite

This work summarizes the results of our previous studies related to investigations of reactive ion etching kinetics and mechanisms for widely used silicon-based materials (SiC, SiO2, and SixNy) as well as for the silicon itself in multi-component fluorocarbon gas mixtures. The main subjects were the three-component systems composed either by one fluorocarbon component (СF4, C4F8, CHF3) with Ar and O2 or by two fluorocarbon components with one additive gas. The investigation scheme included plasma diagnostics by Langmuir probes and model-based analysis of plasma chemistry and heterogeneous reaction kinetics. The combination of these methods allowed one (a) to figure out key processes which determine the steady-state plasma parameters and densities of active species; (b) to understand relationships between processing conditions and basic heterogeneous process kinetics; (c) to analyze etching mechanisms in terms of process-condition-dependent effective reaction probability and etching yield; and (d) to suggest the set gas-phase-related parameters (fluxes and flux-to-flux ratios) to control the thickness of the fluorocarbon polymer film and the change in the etching/polymerization balance. It was shown that non-monotonic etching rates as functions of gas mixing ratios may result from monotonic but opposite changes in F atoms flux and effective reaction probability. The latter depends either on the fluorocarbon film thickness (in high-polymerizing and oxygen-less gas systems) or on heterogeneous processes with a participation of O atoms (in oxygen-containing plasmas). It was suggested that an increase in O2 fraction in a feed gas may suppress the effective reaction probability through decreasing amounts of free adsorption sites and oxidation of surface atoms.

show abstract

Section: Approaches For Analysis Of Gas-phase Chemistrymentioning

confidence: 99%

mentioning

confidence: 96%

mentioning

confidence: 99%

See 1 more Smart Citation

On Relationships between Gas-Phase Chemistry and Reactive Ion Etching Kinetics for Silicon-Based Thin Films (SiC, SiO2 and SixNy) in Multi-Component Fluorocarbon Gas Mixtures

2021

View full text Add to dashboard Cite

show abstract

“…-The electronegativity of both CHF3 [16,20] and O2 [23] plasmas at p < 20 mTorr is low enough to suggest n+  ne, where ne is the electron density. Such situation is due to both high ionization degrees for neutral species (n+/N > 10 -4 , where N = p/kBTg is the total gas density at the gas temperature of Tg) and low efficiency of dissociative attachment reactions.…”

Section: Plasma Modelingmentioning

confidence: 98%

“…In order to obtain the data on kinetics and densities of plasma active species, we applied a simplified 0-dimensional (global) plasma model. The kinetic scheme (the set of chemical reaction with corresponding rate coefficients) was taken from published works dealt with the modeling of CHF3 + Ar [16,20] and CHF3 + Ar + O2 [18][19][20][21] and Ar + O2 [22] plasmas. Comprehensive information on model assumptions and algorithm may be found in our previous works [16][17][18][19][20].…”

Section: Plasma Modelingmentioning

confidence: 99%

Features of Plasma Composition and Fluorine Atom Kinetics in Chf3 + O2 Gas Mixture

2023

Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.

View full text Add to dashboard Cite

The effects of initial composition of CHF3 + O2 gas mixture on electro-physical plasma parameters, steady-state densities of active species and fluorine atom kinetics were investigated under the condition of constant gas pressure and input power. The combination of plasma diagnostics by Langmuir probes and model-based analysis of plasma chemistry confirmed known from previous work features of plasma composition in the absence of oxygen (in particular, the domination of HF molecules in a gas phase) as well as demonstrated how the oxygen influences steady-state densities of neutral species through kinetics of both electron-impact and atom-molecular reactions. It was shown that the addition of O2 with a proportional decrease in the content of CHF3 a) results in noticeable changes in electrons- and ions-related plasma parameters (electron temperature, electron density, ion flux); b) provides the effective conversion of fluorocarbon radicals (CHFx, CFx) into such compounds as CFxO, FO and COx; and b) causes an increase in the fluorine atom density up to 50% O2. The last phenomenon contradicts with the change in the total F atom formation rate, but reflects a decrease of their loss frequency in the reaction family of CHFx + F → CFx + HF. The model-based analysis of heterogeneous process kinetics was carried out using the set of tracing parameters based on gas-phase plasma characteristics. It was found that the addition of oxygen lowers the plasma polymerizing ability through both decreasing flux of polymerizing species and accelerating the oxidative destruction of deposited polymer film.

show abstract

Etching Kinetics and Surface Conditions for KNbxOy Thin Films with Fluorine- and Chlorine-Based Plasma Chemistries

Lim

Efremov

Hwang

et al. 2020

Plasma Chem Plasma Process

View full text Add to dashboard Cite

Parameters of Plasma and Kinetics of Active Particles in CF4 (CHF3) + Ar Mixtures of a Variable Initial Composition

Cited by 11 publications

References 25 publications

On Relationships between Gas-Phase Chemistry and Reactive Ion Etching Kinetics for Silicon-Based Thin Films (SiC, SiO2 and SixNy) in Multi-Component Fluorocarbon Gas Mixtures

On Relationships between Gas-Phase Chemistry and Reactive Ion Etching Kinetics for Silicon-Based Thin Films (SiC, SiO2 and SixNy) in Multi-Component Fluorocarbon Gas Mixtures

Features of Plasma Composition and Fluorine Atom Kinetics in Chf3 + O2 Gas Mixture

Etching Kinetics and Surface Conditions for KNbxOy Thin Films with Fluorine- and Chlorine-Based Plasma Chemistries

Contact Info

Product

Resources

About