Characteristics of 2.45GHz Microwave Plasma by Langmuir Probe Measurements

2007 ◽  
Vol 124-126 ◽  
pp. 1621-1624 ◽  
Author(s):  
Sun Yong Choi ◽  
Wataru Minami ◽  
Lae Hyun Kim ◽  
Hee Joon Kim
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Microwave Power ◽  
Langmuir Probe ◽  
Microwave Plasma ◽  
Debye Length ◽  
Plasma Source ◽  
Mean Free Path ◽  
High Energy ◽  
Langmuir Probe Measurements

The characteristics, such as electron temperature and the electron density, of CF4/Ar discharge in 2.45GHz microwave has been investigated by using a Langmuir probe with the microwave power and position. The results showed that the electron temperature and the electron density decrease with increasing distance from the plasma source. Increasing power enhances the dissociation and ionization of gas, and increases the electron densities. The electron temperature was decreased by reducing the mean free path of electrons with increasing microwave power. The electron temperature is 7.63 ~ 2.49 eV, and the electron density is 0.85×1011 ~ 4.3×1011 cm-3. From obtained electron energy distribution function, we known that high energy electron decreased with increasing microwave power and distance from the plasma source. The generated plasma by developed our system has good quality as results of Debye length λD = 35.8 ~ 67.3 μm, and Ln(ND) = 33.4 ~ 35.2.

scholarly journals Langmuir Probe Diagnostics with Optical Emission Spectrometry (OES) for Coaxial Line Microwave Plasma

2020 ◽  
Vol 10 (22) ◽  
pp. 8117
Author(s):  
Chi Chen ◽  
Wenjie Fu ◽  
Chaoyang Zhang ◽  
Dun Lu ◽  
Meng Han ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Langmuir Probe ◽  
Microwave Plasma ◽  
Optical Emission ◽  
Coaxial Line ◽  
Plasma Source ◽  
Optical Emission Spectrometry ◽  
Emission Spectrometry ◽  
Plasma Parameters ◽  
Current Voltage

The Langmuir probe is a feasible method to measure plasma parameters. However, as the reaction progresses in the discharged plasma, the contamination would be attached to the probe surface and lead to a higher incorrect electron temperature. Then, the electron density cannot be obtained. This paper reports a simple approach to combining the Langmuir probe and the optical emission spectrometry (OES), which can be used to obtain the electron temperature to solve this problem. Even the Langmuir probe is contaminative, the probe current–voltage (I–V) curve with the OES spectra also gives the approximate electron temperature and density. A homemade coaxial line microwave plasma source driven by a 2.45 GHz magnetron was adopted to verify this mothed, and the electron temperature and density in different pressure (40–80 Pa) and microwave power (400–800 W) were measured to verify that it is feasible.

Decomposition Characteristic of Carbon Tetrafluoride Using 2.45GHz Microwave at Various Gases

2007 ◽  
Vol 544-545 ◽  
pp. 701-704
Author(s):  
Sun Yong Choi ◽  
Yuko Taguchi ◽  
Wataru Minami ◽  
Lae Hyun Kim ◽  
Hee Joon Kim
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Microwave Power ◽  
Inelastic Collision ◽  
Mean Free Path ◽  
Chamber Pressure ◽  
Ion Density ◽  
Oxygen Ion ◽  
Density Decrease ◽  
The Mean

The decomposition characteristics of CF4 with Argon or oxygen in 2.45GHz microwave has been investigated by using a Langmuir probe with variation of the microwave power and chamber pressure. For CF4/Ar and CF4/O2/Ar discharges, the ion density and the electron density decrease with increasing microwave power. The electron temperature was decreased by reducing the mean free path of electrons with increasing microwave power. Also with increasing pressure, the electron temperature increase, and ion and electron density decrease by increase of inelastic collision frequency and of collision with the walls in the chamber. The electron temperature is 13.6 ~ 5.9 [eV], the electron density is 4.4×1010 ~ 2.2×1010 [cm-3] and ion density is 5.2×1011 ~ 4×1010 [cm-3]. According as add oxygen, ion and electron density increased relatively comparing to CF4/Ar discharge. The electron temperature is 8.5 ~ 6.2 [eV], the electron and ion density is 5.1×1010 ~ 2.1×1010 [cm-3] and 3.7×1011 ~ 7.3×1010 [cm-3], respectively.

scholarly journals A Linear Microwave Plasma Source Using a Circular Waveguide Filled with a Relatively High-Permittivity Dielectric: Comparison with a Conventional Quasi-Coaxial Line Waveguide

2021 ◽  
Vol 11 (12) ◽  
pp. 5358
Author(s):  
Ju-Hong Cha ◽  
Sang-Woo Kim ◽  
Ho-Jun Lee
Keyword(s):  
Electron Density ◽  
Microwave Plasma ◽  
Circular Waveguide ◽  
Coaxial Line ◽  
Plasma Source ◽  
Tangential Plane ◽  
High Permittivity ◽  
Deposition Area ◽  
Extended Plasma ◽  
Transverse Electromagnetic

For a conventional linear microwave plasma source (LMPS) with a quasi-coaxial line transverse electromagnetic (TEM) waveguide, a linearly extended plasma is sustained by the surface wave outside the tube. Due to the characteristics of the quasi-coaxial line MPS, it is easy to generate a uniform plasma with radially omnidirectional surfaces, but it is difficult to maximize the electron density in a curved selected region. For the purpose of concentrating the plasma density in the deposition area, a novel LMPS which is suitable for curved structure deposition has been developed and compared with the conventional LMPS. As the shape of a circular waveguide, it is filled with relatively high-permittivity dielectric instead of a quasi-coaxial line waveguide. Microwave power at 2.45 GHz is transferred to the plasma through the continuous cylindrical-slotted line antenna, and the radiated electric field in the radial direction is made almost parallel to the tangential plane of the window surface. This research includes the advanced 3D numerical analysis and compares the results with the experiment. It shows that the electron density in the deposition area is higher than that of the conventional quasi-coaxial line plasma MPS.

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.

New algorithms to estimate electron temperature and electron density with contaminated DC Langmuir probe onboard CubeSat

2020 ◽  
Vol 66 (1) ◽  
pp. 148-161
Author(s):  
Shyh-Biau Jiang ◽  
Tse-Liang Yeh ◽  
Jann-Yenq Liu ◽  
Chi-Kuang Chao ◽  
Loren C. Chang ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Langmuir Probe ◽  
New Algorithms

Characterization of Argon Plasma by Use of Optical Emission Spectroscopy and Langmuir Probe Measurements

2003 ◽  
Vol 17 (14) ◽  
pp. 2749-2759 ◽  
Author(s):  
Abdul Qayyum ◽  
M. Ikram ◽  
M. Zakaullah ◽  
A. Waheed ◽  
G. Murtaza ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Flow Rate ◽  
Langmuir Probe ◽  
Gas Flow ◽  
Optical Emission ◽  
Filling Pressure ◽  
Emission Lines ◽  
Gas Flow Rate ◽  
Langmuir Probe Measurements ◽  
Probe Measurements

Spectroscopic and Langmuir probe measurements are presented to characterize the argon glow discharge plasma generated by a cost-effective 50 Hz AC power source. Optical emission spectra (400–700 nm) are recorded for different gas flow rates and filling pressures at constant power level. The plasma parameters (electron temperature and density) are deduced from the relative intensities of Ar-I and Ar-II lines. The variation in the intensity ratio of the selected emission lines, electron temperature and density is studied as a function of gas flow rate and filling pressure. Slight increase in the intensity ratio I2(426.62 nm )/I1(404.44 nm ) of the emission lines is observed whereas the electron temperature and density are found to decrease with increase in gas flow rate and filling pressure.

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