Determination of cathode fall thickness in magnetized dc plasma for argon gas discharge Determination of cathode fall thickness in magnetized dc plasma for argon gas discharge (original) (raw)
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The Magnetized Plasma Effect on Cathode Fall Thickness for Helium Gas Discharge
Physical Science International Journal, 2014
Our previous study showed that the thickness of the cathode fall region in magnetized DC argon plasma was about 3.3mm has been investigated using two different methods, namely: the axial potential distribution and the current density distribution along the glow discharge regions. The present study demonstrates the same measurements but carried out for Helium gas discharge at the edge and center of the cathode surface for the same characteristic of the DC (cold cathode) magnetron sputtering unit. The I a -V a characteristic curves of the glow discharge and the axial potential distribution and the current density distribution have been investigated. Under the influence of magnetic field, the thickness of the cathode fall region for he discharge is about 2.5mm for the two methods in pressure (P) range of 1-4mbar. Apparently for helium gas discharge, a reduction of the cathode fall thickness (about 20%) has been found in the presence of a magnetic field at the center of the cathode and (about 37%) at the edge, furthermore stronger electric field at the edge of the cathode fall, and hence high rates of sputtering are expected.
Influence of Discharge Pressure on the Plasma Parameter in a Planar Dc-Sputtering Discharge of Argon
2013
Plasma parameters in a planar dc-sputtering discharge in argon were measured by cylindrical electrostatic probe (Langmuir probe).Electron density, electron temperature, floating potential, and space potential were monitored as a function of working discharge pressure. Electrostatic probe and supporting circuit were described and used to plot the current – voltage characteristics. Plasma properties were inferred from the current-voltage characteristics of a single probe positioned at the inter-cathode space. Typical values are in the range of (10 -16 -10 -17 ) m -3 and (2.93 – 5.3) eV for the electron density and the electron temperature respectively. KeywordsElectrical discharges, plasma parameter, dcsputtering, Electron density, Electron temperature.
Measurement of Some Argon Plasma Parameters Glow Discharge Under Axial Magnetic Field
2019
This paper investigates the characteristics some of argon plasma parameters of glow discharge under axial magnetic field. The DC power supply of range (0-6000) V is used as a breakdown voltage to obtain the discharge of argon gas. The discharge voltage-current (V-I) characteristic curves and Paschen’s curves as well as the electrical conductivity were studied with the presents of magnetic field confinement at different gas pressures. The magnetic field up to 25 mT was obtained using four coils of radius 6 cm and 320 turn by passing A.C current up to 5 Amperes. Spectroscopic measurements are employed for purpose of estimating two main plasma parameters electron temperature (Te) and electron density (ne). Emission spectra from positive column (PC) zone of the discharge have been studies at different values of magnetic field and pressures at constant discharge currents of 1.5 mA. Electron temperature (Te) and its density are calculated from the ratio of the intensity of two emission li...
Measurements of Some Argon Plasma Parameters Glow Discharge Under Axial Magnetic Field
2019
This paper investigates the characteristics some of argon plasma parameters of glow discharge under axial magnetic field. The DC power supply of range (0-6000) V is used as a breakdown voltage to obtain the discharge of argon gas. The discharge voltagecurrent (V-I) characteristic curves and Paschen’s curves as well as the electrical conductivity were studied with the presents of magnetic field confinement at different gas pressures. The magnetic field up to 25 mT was obtained using four coils of radius 6 cm and 320 turn by passing A.C current up to 5 Amperes. Spectroscopic measurements are employed for purpose of estimating two main plasma parameters electron temperature (Te) and electron density (ne). Emission spectra from positive column (PC) zone of the discharge have been studies at different values of magnetic field and pressures at constant discharge currents of 1.5 mA. Electron temperature (Te) and its density are calculated from the ratio of the intensity of two emission lin...
2018
In this work, plasma parameters can be accurately calculated when the intensities of two spectral lines are experimentally known. The magnetic field effect on the plasma parameters and the intensity spectrum for glow discharge in argon at low pressures has been investigated by using optical emission spectroscopy technique .The longitudinal magnetron system used in this work, where the open field unbalanced magnetron was employed at the cathode and anode electrode. The plasma parameters have been studied in presence of magnetic field of 855 Gandargon gas pressure ranges from (0.25 to 0.85) mbar. Applying a longitudinal magnetic field yields confining the plasma near discharge electrodes .This confining corresponds to the maximum enhancement of the spectral lines intensity (ArI 750.3nm and ArII 434.7nm) and the electron density is a maximum. In the presence of the magnetic field, the values of the electron temperature T e are smaller than that without magnetic field. An increase in gas pressure, rustling slightly decrease of plasma density at low gas pressure (0.33 mbar) but it increased at higher gas pressure. Also, results show that the electron temperature drops slowly as pressure is increased from (0.25 to 0.5) mbar, but is relatively drops rapidly at higher pressures of 0.85 mbar and the maximum values of this parameter are obtained at 0.33 mbar pressure.
Science Journal of University of Zakho
Hollow anode argon glow discharge plasma has been investigated experimentally at different argon gas pressure from constant discharge current. A sufficient high voltage has been applied among the electrodes to obtain breakdown. Firstly, we studied the influence of hollow anode diameter on the breakdown voltage and Paschens law. The inner diameters of hollow anodes used in our work were (10, 15, 20, 25, 30, 35, and 40) mm. Secondly under the same conditions we extended our study to measure some plasma parameters in the negative glow region using direct current argon glow discharge. The temperature and density of electrons in the negative glow were measured using double probes. From the (Ip-Vp) characteristics of double probes, we obtained plasma parameters by using computer MATLAB program. The results showed that the measured Pashence's curve closes to the well-known theoretical Pashence's law. The breakdown voltage and its minimum value decreased with increasing the hollow a...
Iraqi Journal of Physics (IJP)
Experimental study on the effect of cylindrical hollow cathode, working pressure and magnetic field on spatial glow distribution and the characteristics of plasma produced by dc discharge in Argon gas, were investigated by image analyses for the plume within the plasma. It was found that the emission intensity appears as a periodic structure with many peaks appeared between the electrodes. Increasing the pressure leads to increase the number of intensity peaks finally converted to continuous form at high pressure, especially with applied of magnetic field, i.e. the plasma is more stable with the presence of magnetic field. The emission intensity study of plasma showed that the intensity has a maximum value at 1.07 mbar pressure and decrease with more pressure.
Study the Effect of the Magnetic Field on the Electrical Characteristics of the Glow Discharge
Low-density plasma is generated in a cylindrical DC magnetron discharge tube. The radial and axial distributions of the magnetic field strengths are drawn. The discharge current and voltage (I a-V a) characteristic curves of the glow discharge have been measured for Ar and He gases pressures. The effect of the applied magnetic field on the (I a-V a) characteristic curves and on the cathode fall thickness is discussed. The breakdown potentials (V B) of the discharge are lower when the magnetic field is applied.
The Effect Hollow Cathode Depth on Plasma Characteristics
2018
Experimental study on the effect of hollow cathode depth on spatial glow distribution and the characteristics of plasma produced by dc discharge in Argon gas, were investigated bycurrent-voltage characteristic and image analyses for the glows within the plasma. It was found that the increasing the pressure leads to compress the cathode regions while increase the positive column, which appeared with periodic structure. increasing hollow depth from 19 to 40 mm reduce the positive column fluctuation and converted to continuous form at high pressure. The hollow cathode configurationalters the Paschen curves parameters, the emission intensity distribution and the currentpressure curve.
Current-Voltage Characteristics of DC Plasma Discharges Employed in Sputtering Techniques
2016
1 Ministry of Science and Technology, Baghdad, IRAQ 2 Department of Physics, College of Education, Al-Iraqia University, Baghdad, IRAQ 3 Department of Physics, College of Science, University of Baghdad, Baghdad, IRAQ In this work, the current-voltage characteristics of dc plasma discharges were studied. The current-voltage characteristics of argon gas discharge at different inter-electrode distances and working pressure of 0.7mbar without magnetrons were introduced. Then the variation of discharge current with inter-electrode distance at certain discharge voltages without using magnetron was determined. The current-voltage characteristics of discharge plasma at inter-electrode distance of 4cm without magnetron, with only one magnetron and with dual magnetrons were also determined. The variation of discharge current with interelectrode distance at certain discharge voltage (400V) for the cases without magnetron, using one magnetron and dual magnetrons were studied. Finally, the disch...