Measurements of the negative ion density in SF6/Ar plasma using a plane electrostatic probe

2001 ◽  
Vol 72 (5) ◽  
pp. 2288-2293 ◽  
Author(s):  
Masako Shindo ◽  
Satoshi Uchino ◽  
Ryuta Ichiki ◽  
Shinji Yoshimura ◽  
Yoshinobu Kawai
Keyword(s):  
Negative Ion ◽  
Ion Density ◽  
Electrostatic Probe ◽  
Ar Plasma

AlN Etching under ICP Cl2/BCl3/Ar Plasma Mixture: Experimental Characterization and Plasma Kinetic Model

MRS Advances ◽  
2019 ◽  
Vol 4 (27) ◽  
pp. 1579-1587
Author(s):  
Mohammad Rammal ◽  
Ahmed Rhallabi ◽  
Delphine Néel ◽  
Dalila Make ◽  
Alexandre Shen ◽  
...  
Keyword(s):  
Electron Density ◽  
Density Ratio ◽  
Flux Ratio ◽  
Laser Cavity ◽  
Low Pressure ◽  
Negative Ion ◽  
Ion Density ◽  
Dc Bias ◽  
Ar Plasma ◽  
Atomic Chlorine

AbstractAlN etching with chloride plasmas is studied. The experimental results show that the etching of AlN under a low pressure Cl2/Ar plasma mixture in moderate DC bias is not possible. The addition of BCl3 gas to Cl2/Ar mixture allows the etching of AlN materials. However the obtained properties of etched AlN is still not in conformity with the technological specification especially for the condition which the etched AlN must be kept only along the sidewall of the InP laser cavity and be removed elsewhere (selective etching). To know more about the effect of the BCl3 addition to the Cl2/Ar plasma mixture, global model of BCl3/Cl2/Ar is developed to quantify the neutral and ion densities as well as the electron density and temperature. The simulation results show that the electron density and low pressure linearly varies with the RF power. The negative ion density decreases with the percentage of BCl3 leading to the diminution of the electronegativity which is represented by negative ion to electron density ratio. The simulation shows that the positive ion to atomic chlorine flux ratio increases with the %BCl3. Such parameters could play an important role in the ion neutral synergy during the etching process.

Positive Corona and Atmospheric Negative Ion Density under Repetitive Impulse Conditions

1987 ◽  
Vol IA-23 (6) ◽  
pp. 990-994 ◽  
Author(s):  
Norman L. Allen ◽  
Gerard Berger ◽  
Derek Dring
Keyword(s):  
Negative Ion ◽  
Ion Density

Cavity ring-down spectroscopy to measure negative ion density in a helicon plasma source for fusion neutral beams

2018 ◽  
Vol 89 (10) ◽  
pp. 103504 ◽  
Author(s):  
R. Agnello ◽  
M. Barbisan ◽  
I. Furno ◽  
Ph. Guittienne ◽  
A. A. Howling ◽  
...  
Keyword(s):  
Plasma Source ◽  
Negative Ion ◽  
Cavity Ring Down Spectroscopy ◽  
Helicon Plasma ◽  
Ion Density ◽  
Neutral Beams ◽  
Cavity Ring Down

scholarly journals Effects of Negative Ion Density Control on Statistical Three Lags of Positive Impulse Corona in Dry Air

1999 ◽  
Vol 119 (4) ◽  
pp. 451-457 ◽  
Author(s):  
Jian-bo Yang ◽  
Hiroyasu Katase ◽  
Tatsuya Mori ◽  
Yasuji Izawa ◽  
Kiyoto Nishijima
Keyword(s):  
Negative Ion ◽  
Ion Density ◽  
Dry Air ◽  
Density Control

Experimental evidence for the role of ions in particle nucleation under atmospheric conditions

2006 ◽  
Vol 463 (2078) ◽  
pp. 385-396 ◽  
Author(s):  
Henrik Svensmark ◽  
Jens Olaf P Pedersen ◽  
Nigel D Marsh ◽  
Martin B Enghoff ◽  
Ulrik I Uggerhøj
Keyword(s):  
Sulphur Dioxide ◽  
Aerosol Particles ◽  
Experimental Studies ◽  
Negative Ion ◽  
Cloud Formation ◽  
Particle Nucleation ◽  
Atmospheric Conditions ◽  
Ion Density ◽  
Stable Clusters

Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide and water vapour at concentrations relevant for the Earth's atmosphere, are reported. The production of new aerosol particles is found to be proportional to the negative ion density and yields nucleation rates of the order of 0.1–1 cm −3  s −1 . This suggests that the ions are active in generating an atmospheric reservoir of small thermodynamically stable clusters, which are important for nucleation processes in the atmosphere and ultimately for cloud formation.

Spatial distribution of negative ion density near the plasma grid

2020 ◽  
Vol 91 (1) ◽  
pp. 013512 ◽  
Author(s):  
S. Masaki ◽  
H. Nakano ◽  
M. Kisaki ◽  
Y. Haba ◽  
K. Nagaoka ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Negative Ion ◽  
Ion Density

Fluid Model Analysis of the Distribution of the Negative Ion Density before the Extraction from a Tandem Type of a Plasma Source

2011 ◽  
Author(s):  
Stiliyan St. Lishev ◽  
Antonia P. Shivarova ◽  
Khristo Ts. Tarnev ◽  
Yasuhiko Takeiri ◽  
Katsuyoshi Tsumori
Keyword(s):  
Fluid Model ◽  
Plasma Source ◽  
Model Analysis ◽  
Negative Ion ◽  
Ion Density

The Boltzmann relation in electronegative plasmas: When is it permissible to use it?

2000 ◽  
Vol 64 (2) ◽  
pp. 131-153 ◽  
Author(s):  
R. N. FRANKLIN ◽  
J. SNELL
Keyword(s):  
Fluid Model ◽  
Negative Ions ◽  
Ionization Rate ◽  
Negative Ion ◽  
Simple Relationship ◽  
Ion Temperature ◽  
Ion Density ◽  
Positive Ions ◽  
Electronegative Plasmas ◽  
Low Pressures

This paper reports the results of computations to obtain the spatial distributions of the charged particles in a bounded active plasma dominated by negative ions. Using the fluid model with a constant collision frequency for electrons, positive ions and negative ions the cases of both detachment-dominated gases (such as oxygen) and recombination-dominated gases (such as chlorine) are examined. It is concluded that it is valid to use a Boltzmann relation ne = ne0exp(eV/kT) for the electrons of density ne, where the temperature T is approximately the electron temperature Te, and that the density nn of the negative ions at low pressures obeys nn = nn0exp(eV/kTn), where Tn is the negative-ion temperature. However, at high pressure in detachment-dominated gases where the ratio of negative-ion density to electron density is constant and greater than unity, and when the attachment rate is larger than the ionization rate, the negative ions are distributed with the same effective temperature as the electrons. In all other cases there is no simple relationship. Thus to put nn/ne = const, nn = ne0exp(eV/kTe) and nn = nn0exp(eV/kTn) simultaneously is mathematically inconsistent and physically unsound. Accordingly, expressions deduced for ambipolar diffusion coefficients based on these assumptions have no validity. The correct expressions for the situation where nn/ne = const are obtained without invoking a Boltzmann relation for the negative ions.

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