Determination of Plasma Flow Velocity by Mach Probe and Triple Probe with Correction by Laser-Induced Fluorescence in Unmagnetized Plasmas

Choi, Yongjun; Woo, Hyun-Jong; Chung, Kyu‐Sun; Lee, Myoung‐Jae; Zimmerman, D.; McWilliams, R.

doi:10.1143/jjap.45.5945

Cited by 11 publications

(8 citation statements)

References 12 publications

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“…where n 0 is the density at the exit of the plasma jet (z = 0). Applying the relation by Liebermann for the mean free path λ n = 1/330p (p in Torr, λ n in cm) at T i ~0.01 eV [10,22] to our experimental condition (gas flow rate: 75 sccm at 3.5 × 10 −3 Torr), which is nonthermal plasma with low energy ions, we can obtain the calibration factor of the density profile as CF n = n 0 /n 3cm = 32. This is very close to our experimental calibration factor of plasma density, CF n ∼ 30.…”

Section: Resultsmentioning

confidence: 99%

Investigation of Compact Hollow-Anode Discharge Source for Copper Thin Films by Sputtering Processes

et al. 2021

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A compact hollow-anode discharge (HAD) source with a size of 60 mm in radius and 70 mm in length has been developed to stably generate plasma jets for various sputtering processes in semiconductor and display fabrications. A developed HAD plasma source has been investigated by cylindrical electric probes, and the experimental results were compared to the values of numerical calculations. A uniform density discharge model with a geometry factor was proposed to estimate the profiles of plasma parameters. Owing to the difference of absolute magnitude, even with the similar trend of spatial variation, plasma parameters such as electron temperature (Te) and plasma density (ne) measured at z = 3 cm have been calibrated by the values of numerical calculations at the nozzle entrance (z = 0 cm, at the throat of the jet), and the calibration factors for Te and n0 have been deduced by comparing the experimental values to numerical calculations. These are to be explained by the decay mechanism along the axis of the jet with elastic collisions in terms of the mean free path. The developed HAD plasma source was tested for the deposition of Cu thin films with an optimized condition as a plausible application to sputtering processes.

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Section: Resultsmentioning

confidence: 99%

Investigation of Compact Hollow-Anode Discharge Source for Copper Thin Films by Sputtering Processes

et al. 2021

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“…When an MP is composed of two separate directional probes with strongly negative biased potential, one collects the current density (

) with the upstream plasma flow by MP 1 , and the other collects current density (

) moving against the downstream plasma flow by MP 2 (refer to Figure 3 ) [ 15 ]. Owing to plasma flow, these two currents show asymmetry, producing a measured ratio ( R m ) of current densities that is greater than one:

[ 16 , 17 ]. For dimensional analysis of a Mach probe with ratio of current densities reported by Chung [ 15 , 17 ], the one-dimensional continuity equation for ions is described as:

which leads to

where

, and

are the ion density, plasma flow velocity, and the coordinate for the direction of the flow or magnetic field, respectively.…”

Section: Measurement Of Plasma Flowmentioning

confidence: 99%

“…For the analysis of the experimental Mach probe data on plasma flow velocity by theories of ion collection [ 15 , 16 , 17 ], the ratio of the upstream to downstream current densities is given as

…”

Section: Measurement Of Plasma Flowmentioning

confidence: 99%

“…Figure 5 and Table 1 show the results of the current densities calculated using Equation (9) with pressure variation, which was used to calculate the ratio of upstream to downstream current densities. Using various models [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ] with Equations (8) and (9) for the plasma flow velocity,

was defined as

…”

Section: Measurement Of Plasma Flowmentioning

confidence: 99%

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Characteristics of Plasma Flow for Microwave Plasma Assisted Aerosol Deposition

et al. 2021

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To validate the possibility of the developed microwave plasma source with a novel structure for plasma aerosol deposition, the characteristics of the plasma flow velocity generated from the microwave plasma source were investigated by a Mach probe with pressure variation. Simulation with the turbulent model was introduced to deduce calibration factor of the Mach probe and to compare experimental measurements for analyses of collisional plasma conditions. The results show calibration factor does not seem to be a constant parameter and highly dependent on the collision parameter. The measured plasma flow velocity, which witnessed fluctuations produced by a shock flow, was between 400 and 700 m/s. The optimized conditions for microwave plasma assisted aerosol deposition were derived by the results obtained from analyses of the parameters of microwave plasma jet. Under the optimized conditions, Y2O3 coatings deposited on an aluminum substrate were investigated using scanning electron microscope. The results presented in this study show the microwave plasma assisted aerosol deposition with the developed microwave plasma source is highly feasible for thick films with >50 μm.

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“…Также следует разделять различные ориентации потока по отношению к магнитному полю. Лидирующей [8,12,18] теорией, описывающей измерения сонаправленного магнитному полю потока ионов в незамагниченном режиме зонда, остается теория Хатчинсона [11], основанная на PIC-моделировании и подтвержденная рядом экспериментов [12,19,20].…”

Section: Introductionunclassified

Скорость Вращения Плазмы В Отражательном Разряде С Термокатодом

Ойлер¹,

Лизякин²,

Гавриков³

et al. 2022

Журнал Технической Физики

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This work is devoted to determining the azimuthal ion rotation velocity in a reflex discharge with a thermionic cathode. For the experimental determination of the ion velocity, a Mach probe with directional particle collection was used. The Mach probe rotation velocity measurements are compared with the drift speed in crossed ExB fields, where the radial electric field is measured with an emissive probe. The rotation of the plasma was found to be predominantly due to this drift, corrected for centrifugal effects. One of the important results of the work is the determination of the ion temperature. The obtained value Ti=0.12 eV, agrees with the ion temperature estimates in works with similar experimental conditions. A general parameter has been obtained that makes it possible to estimate the necessity to take into account centrifugal effects under given conditions.

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Determination of Plasma Flow Velocity by Mach Probe and Triple Probe with Correction by Laser-Induced Fluorescence in Unmagnetized Plasmas

Cited by 11 publications

References 12 publications

Investigation of Compact Hollow-Anode Discharge Source for Copper Thin Films by Sputtering Processes

Investigation of Compact Hollow-Anode Discharge Source for Copper Thin Films by Sputtering Processes

Characteristics of Plasma Flow for Microwave Plasma Assisted Aerosol Deposition

Скорость Вращения Плазмы В Отражательном Разряде С Термокатодом

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