Effects Of Pressure And Power On The Ionic Saturation Current And Self-Bias Voltage In A RF Discharge 13.56 MHz Of (SF[sub 6], O[sub 2]) At Low Pressure

AbstractStarting from an analytical macroscopic/phenomenological model yielding the self-bias voltage as a function of the absorbed radio-frequency (rf) power of an asymmetric capacitively coupled discharge in NF3 this paper studies the dependence of the ion flux onto the powered electrode on the gas pressure. An essential feature of the model is the assumption that the ions' drift velocity in the sheath near the powered electrode is proportional to E α, where E=−ΔU (U being the self-bias potential), and α is a coefficient depending on the gas pressure and cross section of elastic ion-neutral collisions. The model also considers the role of γ-electrons, stochastic heating as well as the contribution of the active electron current to the global discharge power balance. Numerically solving the model's basic equations one can extract the magnitude of the ion flux (at three different gas pressures) in a technological etching device (Alcatel GIR 220) by using easily measurable quantities, notably the self-bias voltage and absorbed rf power.

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On the analysis of surface free energy of DLC coatings deposited in low pressure RF discharge

Czechoslovak Journal of Physics ◽

10.1007/bf03166502 ◽

2004 ◽

Vol 54 (S3) ◽

pp. C877-C882 ◽

Cited By ~ 17

Author(s):

Z. Navrátil ◽

V. Buršíková ◽

P. St’ahel ◽

M. Šíra ◽

P. Zvěřina

Keyword(s):

Free Energy ◽

Surface Free Energy ◽

Low Pressure ◽

Rf Discharge ◽

Dlc Coatings

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Estimation of Ion Impact Energies and Electrode Self-Bias Voltage in Capacitive RF Discharges

MRS Proceedings ◽

10.1557/proc-98-35 ◽

1987 ◽

Vol 98 ◽

Cited By ~ 2

Author(s):

S. E. Savas

Keyword(s):

Bias Voltage ◽

Capacitively Coupled ◽

Ion Flow ◽

Rf Discharges ◽

Self Bias ◽

Ion Energies ◽

Bias Ratio ◽

Ionization Model ◽

Ion Impact ◽

Impact Energies

ABSTRACTThe dependences of the electrode self-bias voltage and the ratio of ion energies on electrode area ratio are calculated for a model of capacitively coupled rf discharges. It is assumed that concentric spherical elecrodes with fluid-like radial ion flow adequately models the ion motion, that sheath impedances are dominant, and that ionization processes in the glow are due to ohmically heated electrons. Results show that the ratio of ion energies impacting the smaller electrode to those on the larger depends on the ratio of electrode areas in a more complex manner than a power law.The reason for this is that sheath impedances are more resistive or capacitive at different times in the rf cycle. The self-bias ratio is found to depend relatively little on the ionization model or the pressure but differs substantially from the “power law” result. The agreement of measurements with the model is fairly good.

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The Modification of Carbon Included Polyethylene Surface by Plasma Treatment for Metallizing Using a Low Pressure RF Discharge Plasma

Journal of Advanced Oxidation Technologies ◽

10.1515/jaots-2005-0111 ◽

2005 ◽

Vol 8 (1) ◽

Author(s):

Jeou-Long Lee ◽

Chung-Ming Liu ◽

Kuen Ting ◽

Wei-Kung Cheng ◽

Takayoshi Tsuchida ◽

...

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Surface Layer ◽

Discharge Plasma ◽

Treatment Time ◽

Low Pressure ◽

Rf Discharge ◽

Nickel Layer ◽

Good Adhesion ◽

Polyethylene Surface

AbstractSurface modification of the carbon included polyethylene (semi-conductive PE) surface for metallizing using a low pressure RF discharge plasma has been carried out. The contact angle was used as a measure of the wettability of the PE surface. The roughness and the chemical bondings in PE surface layer were analized by DFM and XPS, respectively. Typical results show that the contact angle decreases from approximately 94° to below 10° after several minutes' treatment and recovers to a saturation value when it was put open to the air after treatment. The saturation value of the contact angle is smaller as the gas pressure for treatment is higher and the treatment time is longer but all are below approximately 60° which is still smaller than that of untreated. DFM and XPS results show that the surface roughness and the bondings C-O and C=O in the PE surface layer also increase with increasing the treatment time and seem to be responsible for improving the hydrophilic property of PE. After pretreatment process, nickel was coated on the PE sheet by electrodeposition method and a good adhesion between the nickel layer and the PE surface compared with that of untreated was obtained.

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Diagnostics of low-pressure capacitively coupled RF discharge argon plasma

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v13i27.266 ◽

2019 ◽

Vol 13 (27) ◽

pp. 76-82

Author(s):

Kadhim A. Aadim

Keyword(s):

Electron Temperature ◽

Electron Density ◽

Langmuir Probe ◽

Gas Flow ◽

Low Pressure ◽

Gas Pressure ◽

Rf Discharge ◽

Electrode Gap ◽

Probe Characteristic ◽

Capacitively Coupled

Low-pressure capacitively coupled RF discharge Ar plasma has been studied using Langmuir probe. The electron temperature, electron density and Debay length were calculated under different pressures and electrode gap. In this work the RF Langmuir probe is designed using 4MHz filter as compensation circuit and I-V probe characteristic have been investigated. The pressure varied from 0.07 mbar to 0.1 mbar while electrode gap varied from 2-5 cm. The plasma was generated using power supply at 4MHz frequency with power 300 W. The flowmeter is used to control Argon gas flow in the range of 600 standard cubic centimeters per minute (sccm). The electron temperature drops slowly with pressure and it's gradually decreased when expanding the electrode gap. As the gas pressure increases, the plasma density rises slightly at low gas pressure while it drops little at higher gas pressure. The electron density decreases rapidly with expand distances between electrodes.

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