Ion flux's pressure dependence in an asymmetric capacitively coupled rf discharge in NF3

Open Physics ◽  
2004 ◽  
Vol 2 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Emil Mateev ◽  
Ivan Zhelyazkov
Keyword(s):  
Bias Voltage ◽  
Essential Feature ◽  
Gas Pressure ◽  
Ion Flux ◽  
The Self ◽  
Rf Discharge ◽  
Rf Power ◽  
Capacitively Coupled ◽  
Self Bias ◽  
Basic Equations

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.

scholarly journals Redefinition of the self-bias voltage in a dielectrically shielded thin sheath RF discharge

2018 ◽  
Vol 123 (19) ◽  
pp. 193301 ◽  
Author(s):  
Teck Seng Ho ◽  
Christine Charles ◽  
Rod Boswell
Keyword(s):  
Bias Voltage ◽  
The Self ◽  
Rf Discharge ◽  
Self Bias

scholarly journals Study of Power Balance in Electronegative Capacitively Coupled Plasmas

2004 ◽  
Vol 1 (2) ◽  
pp. 5-12
Author(s):  
Laura Swart ◽  
Patrick Verdonck ◽  
Stanislav A. Moshkalev
Keyword(s):  
Bias Voltage ◽  
Average Energy ◽  
Plasma Potential ◽  
Original Model ◽  
Ion Flux ◽  
Plasma Sheath ◽  
The Self ◽  
Total Power ◽  
Self Bias ◽  
Plasma Bulk

The balance of power model is a relatively simple model, which determines the power dissipated both in the plasma bulk and in the plasma sheath, as well as the ion flux and the average energy lost by an electron in the plasma bulk. It requires only the measurement of the total power and the self bias voltage. The original model does not take into account the effect of the plasma potential on the energy of incoming ions, because for most plasmas, the plasma potential is negligible compared with the self bias voltage. In this work, the plasma potential was taken into account. For pure SF6 plasmas, the modification had a significant effect on the ion flux, which increased by more than a factor 2, when compared with the original model. Besides, there are strong indications that the silicon etching with SF6 was mostly determined by the plasma bulk power, but the contribution from ion bombardment was considerable, too. For less electronegative plasmas, the influence of the plasma potential may be neglected.

scholarly journals Characterization and Performance of Carbon Films Deposited by Plasma and Ion Beam Based Techniques

1994 ◽  
Vol 354 ◽  
Author(s):  
K.C. Walter ◽  
H. Kung ◽  
T. Levine ◽  
J.T. Tesmer ◽  
P. Kodali ◽  
...  
Keyword(s):  
Wear Rate ◽  
Surface Area ◽  
Ion Beam ◽  
Carbon Films ◽  
The Self ◽  
Line Of Sight ◽  
Rf Power ◽  
Hard Carbon ◽  
Self Bias ◽  
Cathodic Arc

AbstractPlasma and ion beam based techniques have been used to deposit carbon-based films. The ion beam based method, a cathodic arc process, used a magnetically mass analyzed beam and is inherently a line-of-sight process. Two hydrocarbon plasma-based, non-line-of-sight techniques were also used and have the advantage of being capable of coating complicated geometries. The self-bias technique can produce hard carbon films, but is dependent on rf power and the surface area of the target. The pulsed-bias technique can also produce hard carbon films but has the additional advantage of being independent of rf power and target surface area. Tribological results indicated the coefficient of friction is nearly the same for carbon films from each deposition process, but the wear rate of the cathodic arc film was five times less than for the self-bias or pulsed-bias films. Although the cathodic arc film was the hardest, contained the highest fraction of sp3 bonds and exhibited the lowest wear rate, the cathodic arc film also produced the highest wear on the 440C stainless steel counterface during tribological testing. Thus, for tribological applications requiring low wear rates for both counterfaces, coating one surface with a very hard, wear resistant film may detrimentally affect the tribological behavior of the counterface.

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

1987 ◽  
Vol 98 ◽  
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.

scholarly journals Diagnostics of low-pressure capacitively coupled RF discharge argon plasma

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.

Single Wafer, Anisotropic Etching of Polysilicon with C12/SF6 and Trielectrode Reactor Operation

1986 ◽  
Vol 68 ◽  
Author(s):  
James E. Nulty
Keyword(s):  
Bias Voltage ◽  
Etch Rate ◽  
Proximity Effects ◽  
The Self ◽  
Rf Power ◽  
Reactor Operation ◽  
Lower Electrode ◽  
Dc Bias ◽  
Bias Versus ◽  
Etching System

AbstractA totally anisotropic, highly selective dry poly etch process has been developed that is capable of etching sub-2.0 micron linewidths.Doped poly etch rates of 10,000 A/min.are obtained using C12-only chemistry.Standard novolac or bilevel photoresist is used, depending on the lithography requirements.Anisotropy is achieved without the use of carbon-containing gases; as a result, minimal proximity effects are observed between dense and stand alone etched lines.Wafer maps of etched linewidths on 4-inch wafers are presented, showing mask to final bias and uniformity results.A commercially available triode dry etching system was used for the work.The self-induced dc bias voltage can be selected regardless of the applied rf power.The effect of variable self-induced dc bias versus applied rf power is presented for selectivity, upper and lower electrode interactions, and etch rate uniformity.Characterization by the use of spectroscopy is also presented, showing changes due to varying the self-induced dc bias at a constant rf power.

Deposition process and characterization of chromium-carbon coatings produced by direct sputtering of a magnetron chromium carbide target

1994 ◽  
Vol 9 (7) ◽  
pp. 1820-1828 ◽  
Author(s):  
N. Maréchal ◽  
E. Quesnel ◽  
Y. Pauleau
Keyword(s):  
Electrical Resistivity ◽  
Residual Stresses ◽  
Chromium Carbide ◽  
Bias Voltage ◽  
Bulk Material ◽  
Deposition Process ◽  
Gas Pressure ◽  
Atom Number ◽  
Carbon Coatings ◽  
Self Bias

Chromium-carbon coatings have been deposited on various substrates by direct sputtering of a chromium carbide, Cr3C2, target in pure argon atmosphere. The composition of coatings determined by Rutherford backscattering spectroscopy and the deposition rate were investigated as functions of the sputtering gas pressure and self-bias voltage applied to substrates. The atom number ratio C/Cr in the coatings was equal to 0.7 regardless of the deposition conditions investigated. Oxygen and argon atoms were the major impurities incorporated in the amorphous coatings. Oxygen-free Cr-C coatings were prepared at low argon pressures or on substrates biased to a voltage in the range −100 to −320 V. The Cr-C coatings deposited on biased substrates contained less than 2 at. % of argon. The morphological features of Cr-C coatings examined by scanning electron microscopy were also dependent on the sputtering gas pressure and bias voltage of substrates. Fully dense structures were observed for coatings deposited at low argon pressures or on biased substrates. The electrical resistivity of Cr-C coatings was extremely dependent on the concentration of oxygen atoms incorporated in the coatings. Oxygen-free Cr-C coatings exhibited electrical resistivity values as low as 120 μΩ cm, i.e., less than twice the bulk resistivity of Cr3C2. The residual stresses in the coatings and microhardness of the deposited material were also investigated as functions of the deposition parameters. Tensile residual stresses were lower than 0.8 GPa, and the maximum microhardness of coatings was about 13000 MPa, i.e., similar to that of the bulk material.

scholarly journals Self-bias voltage formation and charged particle dynamics in multi-frequency capacitively coupled plasmas

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075024
Author(s):  
R. U. Masheyeva ◽  
K. N. Dzhumagulova ◽  
M. Myrzaly ◽  
J. Schulze ◽  
Z. Donkó
Keyword(s):  
Charged Particle ◽  
Bias Voltage ◽  
Particle Dynamics ◽  
Capacitively Coupled ◽  
Self Bias ◽  
Coupled Plasmas
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