Effect of electron energy distributions on the electron density in nitrogen inductively coupled plasmas

Kim, Kwan-Yong; Kim, Jung-Hyung; Chung, Chin-Wook; Lee, Hyo-Chang

doi:10.1088/1361-6595/ac942b

Cited by 3 publications

(5 citation statements)

References 78 publications

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“…As the Ar concentration increases from 10% to 50%, the EEPF curve shifts from non-Maxwellian to bi-Maxwellian distribution, and thereafter the EEPF again becomes Maxwellian type when the Ar reaches 80%. With the increase in Ar concentration, the electron density also increases and that is the reason that at a lower Ar percentage the EEPF takes the form of a non-Maxwellian distribution, and thereafter, as Ar concentration grows, the EEPF starts approaching the Maxwellian form [29,46].…”

Section: Lp Measurementsmentioning

confidence: 99%

“…Here, τ stands for the electron residence time. The equation that governs the relationship among ν ee , electron density (n e ) and electron temperature (T e ) is represented as [29,45] ν ee = 2.91 × 10 (…”

Section: Lp Measurementsmentioning

confidence: 99%

“…Here, L is the dimension of the discharge chamber. Therefore, the electron residence time (τ ) becomes [29,47]…”

Section: Lp Measurementsmentioning

confidence: 99%

“…The behaviour of the electrons and their kinetic nature can be analysed with the help of electron energy probability function (EEPF) patterns. The EEPF, together with electron temperature, mostly influence the generation of radicals also [29]. The electrons lose their energy through inelastic collision reactions (ionization or excitation) and because of this collision, long-lived excited states known as metastable states are created.…”

Section: Introductionmentioning

confidence: 99%

“…For some gases, however, it is found that the transition between E-and H-modes is not distinct and in such cases both modes can coexist for a particular power range. Also, in the E-mode, a very small number of electronic collisions occur, and the EEPF profile shows a non-Maxwellian pattern, whereas for H-mode, the EEPF transforms into a Maxwellian as the collisions increase [29]. Therefore, it is worth investigating the complex plasma properties during the mode transition.…”

Section: Introductionmentioning

confidence: 99%

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Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition

Mukherjee¹,

Chakraborty²,

Sharma³

et al. 2023

Plasma Sources Sci. Technol.

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The behaviour of nitrogen plasma mixed with varying proportions of argon (10%-80%) has been investigated under different RF discharge conditions. It is observed that at a relatively low RF power of 200 W (E-mode) the dissociation fraction (DF) of nitrogen increases with the growing concentration of argon whereas the opposite happens for a higher RF power of 1000 W (H-mode) when the DF rapidly falls from a high value as argon percentage starts moving upwards. This rising trend of DF closely follows the argon metastable fraction (MF) in the E-mode and for H-mode it does not follow until the argon percentage crosses 20% mark. The electron density, temperature and electron energy probability function (EEPF) has been obtained using a RF compensated Langmuir probe and to evaluate the vibrational and rotational temperature, DF, MF etc. a separate optical emission spectroscopy technique is incorporated. At 5×10-3 mbar of working pressure and 10% argon content the EEPF profile reveals that the plasma changes from non-Maxwellian to Maxwellian as the RF power jumps from 200 W to 1000 W, and for a fixed RF power the high energy tail tends to move upwards with the gradual increment of argon. These observations have been re-verified theoretically by considering electron-electron collision frequency and electron bounce frequency as a function of electron temperature. Overall, all the major experimental phenomena in this study have been explained in terms of EEPF profile, electron-electron collision effect, electron and gas temperature, electron density and argon metastable population.

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Section: Lp Measurementsmentioning

confidence: 99%

Section: Lp Measurementsmentioning

confidence: 99%

“…Here, L is the dimension of the discharge chamber. Therefore, the electron residence time (τ ) becomes [29,47]…”

Section: Lp Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition

Mukherjee¹,

Chakraborty²,

Sharma³

et al. 2023

Plasma Sources Sci. Technol.

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Investigation of spatial distribution of EEPFs and neutral species in nitrogen inductively coupled plasmas by 2D hybrid simulation

Huang,

Zhou,

et al. 2023

Physics of Plasmas

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Neutral species in nitrogen plasmas play a crucial role in many applications related to semiconductor fabrication. In this research, a two-dimensional fluid/electron Monte Carlo hybrid model is employed to simulate nitrogen inductively coupled plasmas, and the spatial distributions of electron energy probability distributions (EEPFs), as well as their influence on the neutral species, are discussed under various pressures. It is found that the EEPF in the bulk region is relatively uniform, and it exhibits a bi-Maxwellian distribution at 3 mTorr. As pressure increases, the high energy tail declines due to the more frequent collisions. Moreover, a hole appears at around 3 eV in the EEPF above the substrate, and it becomes less obvious toward the skin layer below the dielectric window. Moreover, the maxima of metastable species densities, i.e., N2(A3Σu+), N(2D), and N(2P), are located at the center of the chamber at low pressure, and they gradually move to the skin layer under the coils as pressure increases. The behaviors of neutral species can be understood by examining the reactant densities of the main generation and loss mechanisms, as well as the corresponding rate coefficients which are calculated according to EEPFs. In addition, since the ground state N(4S) is mainly produced by the quenching of metastable atoms and neutralization of ions at the walls, the maximum of the N(4S) density appears below the dielectric window and above the substrate at 3 mTorr, and the peak under the dielectric window becomes more obvious at higher pressure due to the stronger locality.

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Abnormal behavior of the plasma potential in an inductively coupled plasma with a DC-biased grid

Kim,

Jung,

Park

et al. 2024

Plasma Sources Sci. Technol.

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The formation of the plasma potential and the generation mechanism of very low electron temperature plasma are investigated in an inductively coupled plasma (ICP) with a DC biased grid. The electron temperature is controlled from 2.4 eV to 0.2 eV according to the grid voltage (10 V to -40 V). Interestingly, when the grid voltage is negatively biased, the electron temperature decreases and the plasma potential decreases with the grid voltage, but then increases below -10 V which is abnormal. This behavior of the plasma potential is abnormal since the plasma potential is generally proportional to the electron temperature. The main reason for the abnormal increase of the plasma potential is the difference in the flux of electrons and ions below the grid. As the grid is negatively biased, the electron flux is greatly reduced compared to the ion flux, leading to an increase in plasma potential. After -20 V, the plasma potential saturates, because although the number of electrons entering the grid decreases, the electron flux is maintained by secondary electrons generated in the grid mesh. This abnormal increase in plasma potential decreases with pressure. An increase in plasma potential with gas species is also observed. The same behavior is observed for Ar, He, and N2 gases. The abnormal behavior of the plasma potential is explained with the current continuity.

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Effect of electron energy distributions on the electron density in nitrogen inductively coupled plasmas

Cited by 3 publications

References 78 publications

Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition

Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition

Investigation of spatial distribution of EEPFs and neutral species in nitrogen inductively coupled plasmas by 2D hybrid simulation

Abnormal behavior of the plasma potential in an inductively coupled plasma with a DC-biased grid

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Effect of electron energy distributions on the electron density in nitrogen inductively coupled plasmas

Cited by 3 publications

References 78 publications

Changing pattern of N2 dissociation in N2–Ar RF plasma during E–H mode transition

Changing pattern of N2 dissociation in N2–Ar RF plasma during E–H mode transition

Investigation of spatial distribution of EEPFs and neutral species in nitrogen inductively coupled plasmas by 2D hybrid simulation

Abnormal behavior of the plasma potential in an inductively coupled plasma with a DC-biased grid

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Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition

Changing pattern of N₂ dissociation in N₂–Ar RF plasma during E–H mode transition