TESTING OF NICKEL-CHROME ALLOY AS A TIP MATERIAL FOR MULTI-TIP LANGMUIR PROBES

2014 ◽  
Vol 21 (04) ◽  
pp. 1450056 ◽  
Author(s):  
MUHAMMAD YASIN NAZ ◽  
SHAZIA SHUKRULLAH ◽  
ABDUL GHAFFAR ◽  
IMRAN SHAKIR ◽  
SAMI ULLAH ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Inductively Coupled Plasma ◽  
Electron Number Density ◽  
Diagnostic System ◽  
Input Power ◽  
Repeated Measurements ◽  
Gas Pressure ◽  
Rf Discharge ◽  
Number Density ◽  
Electron Number

The electrostatic probes are considered to be the most powerful and experimentally simplest technique for plasma characterization. The objective of the work was to test the nickel-chrome alloy as probe tip material for characterization of RF discharge plasmas. In order to meet the objective, a triple Langmuir probe diagnostic system and associated driving circuit was designed and tested in inductively coupled plasma (ICP) generated by a 13.56 MHz radio frequency (RF) source. Using this probe diagnostic, the electron temperature, electron number density and ion saturation current were measured as a function of input RF power and filling gas pressure. An increasing trend was noticed in electron temperature and electron number density with input power whilst a decreasing trend was evident in these parameters for increasing nitrogen gas pressure. The overall variations in electron temperature and electron number density after repeated measurements were ranging from 5% to 12% and 3% to 13%, respectively.

scholarly journals Development of Simple Designs of Multitip Probe Diagnostic Systems for RF Plasma Characterization

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. Y. Naz ◽  
S. Shukrullah ◽  
A. Ghaffar ◽  
N. U. Rehman
Keyword(s):  
Radio Frequency ◽  
Electron Temperature ◽  
Inductively Coupled Plasma ◽  
Electron Number Density ◽  
Gas Pressure ◽  
Rf Plasma ◽  
Number Density ◽  
Diagnostic Systems ◽  
Electron Number ◽  
Double Probe

Multitip probes are very useful diagnostics for analyzing and controlling the physical phenomena occurring in low temperature discharge plasmas. However, DC biased probes often fail to perform well in processing plasmas. The objective of the work was to deduce simple designs of DC biased multitip probes for parametric study of radio frequency plasmas. For this purpose, symmetric double probe, asymmetric double probe, and symmetric triple probe diagnostic systems and their driving circuits were designed and tested in an inductively coupled plasma (ICP) generated by a 13.56 MHz radio frequency (RF) source. UsingI-Vcharacteristics of these probes, electron temperature, electron number density, and ion saturation current was measured as a function of input power and filling gas pressure. An increasing trend was noticed in electron temperature and electron number density for increasing input RF power whilst a decreasing trend was evident in these parameters when measured against filling gas pressure. In addition, the electron energy probability function (EEPF) was also studied by using an asymmetric double probe. These studies confirmed the non-Maxwellian nature of the EEPF and the presence of two groups of the energetic electrons at low filling gas pressures.

scholarly journals Influence of the Distance between Focusing Lens and Target Surface on the Characteristics of Laser-excited Lead Plasma

2021 ◽  
pp. 4694-4701
Author(s):  
Qusay Adnan Abbas
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Electron Number Density ◽  
Laser Energy ◽  
Pulse Length ◽  
Target Surface ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Number Density ◽  
Electron Number

      The present work investigated the effect of distance from target surface on the parameters of lead plasma excited by 1064nm Q-switched Nd:YAG laser. The excitation was conducted in air, at atmospheric pressure, with pulse length of 5 ns, and at different pulse laser energies. Electron temperature was calculated by Boltzmann plot method based on the PbI emission spectral lines (369.03 nm, 416.98 nm, 523.48, and 561.94 nm). The PbI lines were recorded at different distances from the target surface at laser pulse energies of 260 and 280 mJ. The emission intensity of plasma increased with increasing the lens-to-target distance. The results also detected an increase in electron temperature with increasing the distance between the focal lens and the surface of the target in all laser energies under study. In addition, the electron number density was determined by using the Stark broadening method. The data illustrated that the electron number density was increased with increasing the distance from target surface, reaching the maximum at a distance of 11 cm for all pulse laser energy levels under study.

Electron temperature and electron number density measurements in laser ablation Z-pinch experiments of Al2O3

2019 ◽  
Vol 26 (8) ◽  
pp. 083506
Author(s):  
E. C. Dutra ◽  
J. A. Koch ◽  
R. Presura ◽  
P. Wiewior ◽  
A. M. Covington
Keyword(s):  
Laser Ablation ◽  
Electron Temperature ◽  
Electron Number Density ◽  
Number Density ◽  
Electron Number ◽  
Density Measurements ◽  
Z Pinch

A Kinetic Model for Low-Pressure RF Discharge Etching of Silicon Using SF6

1987 ◽  
Vol 98 ◽  
Author(s):  
Arit P. Paranjpe ◽  
George Kychakoff ◽  
Sidney A. Self
Keyword(s):  
Boltzmann Equation ◽  
Electron Impact ◽  
Etch Rate ◽  
Electron Number Density ◽  
Kinetics Model ◽  
Rf Discharge ◽  
Number Density ◽  
Electron Number ◽  
The Boltzmann Equation ◽  
Impact Processes

ABSTRACTThe variation of etch rate with power, pressure and flow is studied using a coupled electron and chemical kinetics model. The electron kinetics model involves a solution of the electron continuity and current continuity equations in conjunction with the Boltzmann equation. The temporal variation of the electric field, electron energy distribution function (EEDF) and electron number density in the bulk of an RF discharge, is calculated using measured current waveforms, and calculated species concentrations. Electron generation through electron-impact ionization, is balanced by attachment and diffusion losses. A time-dependent solution of the Boltzmann equation is employed to investigate the problem of non-equilibrium, between the EEDF and the instantaneous field. Rates for electron impact processes are calculated using the EEDF.Rate equations for the different species are solved to obtain steady state species concentrations. Radicals and ions produced by electron-impact processes are lost through neutral recombination, ion-ion neutralization, diffusion to reactor surfaces and flow losses. The calculated ion number densities far exceed the electron number density. A transport model that considers the diffusion of etchant species to the wafer and subsequent reaction, is used to compute the etch rate.

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