Transport of argon ions in an inductively coupled high-density plasma reactor

Sadeghi, N.; Grift, van de M Marc; Vender, D.; Kroesen, Gmw Gerrit; Hoog, de Fj Frits

doi:10.1063/1.118218

Cited by 49 publications

(44 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the field of lowtemperature plasma research, the velocity and the corresponding kinetic energy of plasma particles is an important parameter, for instance, to determine particle and/or energy fluxes in plasma processing. Nevertheless, only a few studies exist in which the LIF technique is applied to measure velocities of particles in plasmas, 30,31 and to the best of our knowledge our group was the first to report velocity measurements of ground-state atoms using the two-photon LIF technique. 32 In this study, two-photon excitation laser-induced fluorescence is applied to perform quantitative and spatially resolved measurements of the density, temperature, and velocity of ground-state hydrogen atoms in an expanding thermal Ar-H plasma created by a cascaded arc.…”

Section: Introductionmentioning

confidence: 99%

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Boogaarts

Mazouffre

Brinkman

et al. 2002

Review of Scientific Instruments

View full text Add to dashboard Cite

We report on quantitative, spatially resolved density, temperature, and velocity measurements on ground-state atomic hydrogen in an expanding thermal Ar-H plasma using two-photon excitation laser-induced fluorescence ͑LIF͒. The method's diagnostic value for application in this plasma is assessed by identifying and evaluating the possibly disturbing factors on the interpretation of the LIF signal in terms of density, temperature, and velocity. In order to obtain quantitative density numbers, the LIF setup is calibrated for H measurements using two different methods. A commonly applied calibration method, in which the LIF signal from a, by titration, known amount of H generated by a flow-tube reactor is used as a reference, is compared to a rather new calibration method, in which the H density in the plasma jet is derived from a measurement of the two-photon LIF signal generated from krypton at a well-known pressure, using a known Kr to H detection sensitivity ratio. The two methods yield nearly the same result, which validates the new H density calibration. Gauging the new ''rare gas method'' by the ''flow-tube reactor method,'' we find a krypton to hydrogen two-photon excitation cross section ratio Kr ͑2͒ / H (2) of 0.56, close to the reported value of 0.62. Since the H density calibration via two-photon LIF of krypton is experimentally far more easy than the one using a flow-tube reactor, it is foreseen that the ''rare gas method'' will become the method of choice in two-photon LIF experiments. The current two-photon LIF detection limit for H in the Ar-H plasma jet is 10 15 m Ϫ3 . The accuracy of the density measurements depends on the accuracy of the calibration, which is currently limited to 33%. The reproducibility depends on the signal-to-noise ͑S/N͒ ratio in the LIF measurements and is orders of magnitude better. The accuracy in the temperature determination also depends on the S/N ratio of the LIF signal and on the ratio between the Doppler-width of the transition and the linewidth of the excitation laser. Due to the small H mass, the current linewidth of the UV laser radiation is never the accuracy limiting factor in the H temperature determination, even not at room temperature. Quantitative velocity numbers are obtained by measuring the Doppler shift in the H two-photon excitation spectrum. Both the radial and axial velocity components are obtained by applying a perpendicular and an antiparallel excitation configuration, respectively. The required laser frequency calibration is accomplished by simultaneously recording the I 2 absorption spectrum with the fundamental frequency component of the laser system. This method, which is well-established in spectroscopic applications, enables us to achieve a relative accuracy in the transition frequency measurement below 10 Ϫ6 , corresponding to an accuracy in the velocity of approximately 200 m/s. This accuracy is nearly laser linewidth limited.

show abstract

Section: Introductionmentioning

confidence: 99%

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Boogaarts

Mazouffre

Brinkman

et al. 2002

Review of Scientific Instruments

View full text Add to dashboard Cite

show abstract

“…Spatially resolved and in situ measurements of the tIVDFs were performed in various sources of plasmas [13][14][15][16][17][18][19] using the LIF technique, but some of these measurements were made at a single point in the plasma, and none were correlated with plasma potential measurements along the presheath. In the vicinity of a glass boundary plate, however, Sadeghi et al 18 measured tIVDFs at a variety of locations, which demonstrated considerable broadening ͑heating͒ as the ions transited the presheath.…”

Section: Experimental Studies Of Transverse Metastable Ion Velocity Dmentioning

confidence: 99%

Experimental studies of transverse metastable ion velocity distribution functions in the presheath of a weakly collisional argon plasma

2008

View full text Add to dashboard Cite

Laser-induced fluorescence measurements of the transverse metastable ion velocity distribution function near a negatively biased plate in a low temperature (Te<1eV), low pressure (p0<1mTorr) dc multi-dipole argon discharge plasma have been made with a diode laser. The metastable argon ions in the 3s23p4(P3)3d4F7∕2 state are found to be characterized by a Maxwellian temperature transverse to the direction normal to the plate. For a neutral pressure of 0.3mTorr, the transverse temperature increases along the presheath from 0.026eV in the bulk plasma to 0.058eV at the presheath sheath boundary.

show abstract

“…Consequently, we can conclude that spatial potential plays an important role in ion heating. 13,21 It may be doubted that the ion temperature increases due to the relative measurement position change in the presheath when biased. However, in this experiment this bias increases the total spatial potential including sheath potential in the axial direction, …”

Section: B DC Bias Effectmentioning

confidence: 99%

“…LIF has such good spectral resolution ͑ϳ0.0025 eV ion or neutral temperature͒ 10 that many experiments on ion or neutral heating have been conducted in low-temperature processing plasmas. These efforts explained ion heating qualitatively from electron-ion collisions, 17 potential in the presheath, 13,21 and wave interaction, 18 but these were not enough to explain why ion temperature is much higher than room temperature in the center of the plasma. In this study, we have used the diode LIF scheme to measure metastable argon ion velocity distribution functions in magnetized inductively coupled plasma to obtain metastable ion density and temperature.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Boivin and Scime determined that a different, newer diode laser also works for 668.61 nm argon LIF. 6,7 LIF has been used widely to measure ion or neutral density, temperature and velocity distribution functions in order to understand ion or neutral dynamics in tokamak plasma, 8,9 multidipole filament plasma, 10,11 ICP, [12][13][14][15][16] helicon plasma, [17][18][19][20] ECR plasma, [21][22][23] etc. LIF has such good spectral resolution ͑ϳ0.0025 eV ion or neutral temperature͒ 10 that many experiments on ion or neutral heating have been conducted in low-temperature processing plasmas.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Diode laser-induced fluorescence measurements of metastable argon ions in a magnetized inductively coupled plasma

2006

View full text Add to dashboard Cite

Velocity distribution functions of metastable argon ions ͑3dЈ4 F 7/2 ͒ have been measured to obtain metastable ion density and temperature by the diode laser-induced fluorescence ͑LIF͒ technique in magnetized inductively coupled plasma as a function of pressure, rf power, and magnetic field strength. Calculated density from a rate equation agrees with the trends observed in the experimental data. From the calculation, the metastable ion density should be over 10 7 cm −3 to obtain a LIF signal. From a dc bias experiment, it is suggested that the spatial potential can be the dominant ion heating source, and a simple global model for ion temperature is constructed. In this model, approximately 0.01% and 10% of total spatial potential energy can contribute to ion and neutral temperatures, respectively. The measured ion temperature agrees with the calculation.

show abstract

Transport of argon ions in an inductively coupled high-density plasma reactor

Cited by 49 publications

References 15 publications

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Experimental studies of transverse metastable ion velocity distribution functions in the presheath of a weakly collisional argon plasma

Diode laser-induced fluorescence measurements of metastable argon ions in a magnetized inductively coupled plasma

Contact Info

Product

Resources

About