Spatial distribution of the neutral gas temperature in rf and dc magnetron sputter discharges determined by fitting rotational spectra of the N2+ using a two-temperature fit

Linss, V.

doi:10.1016/j.sab.2005.01.004

Cited by 19 publications

(13 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It clearly illustrates the necessity of accurate fits for partially resolved rotational spectra. Note the small deviation for the single temperature fit, while a two-temperature fit yields a rotational temperature of 200 K lower [59].…”

Section: Influence Of Spectral Resolutionmentioning

confidence: 94%

See 1 more Smart Citation

Gas temperature determination from rotational lines in non-equilibrium plasmas: a review

Bruggeman

Sadeghi

Schram

et al. 2014

Plasma Sources Sci. Technol.

435

431

View full text Add to dashboard Cite

The gas temperature in non-equilibrium plasmas is often obtained from the plasma-induced emission by measuring the rotational temperature of a diatomic molecule in its excited state. This is motivated by both tradition and the availability of low budget spectrometers. However, non-thermal plasmas do not automatically guarantee that the rotational distribution in the monitored vibrational level of the diatomic molecule is in equilibrium with the translational (gas) temperature. Often non-Boltzmann rotational molecular spectra are found in non-equilibrium plasmas. The deduction of a gas temperature from these non-thermal distributions must be done with care as clearly the equilibrium between translational and rotational degrees of freedom cannot be achieved. In this contribution different methods and approaches to determine the gas temperature are evaluated and discussed. A detailed analysis of the gas temperature determination from rotational spectra is performed. The physical and chemical background of non-equilibrium rotational population distributions in molecular spectra is discussed and a large range of conditions for which non-equilibrium occurs are identified. Fitting procedures which are used to fit (non-equilibrium) rotational distributions are analyzed in detail. Lastly, recommendations concerning the conditions for which the gas temperatures can be obtained from diatomic spectra are formulated.

show abstract

Section: Influence Of Spectral Resolutionmentioning

confidence: 94%

“…Interestingly, at 77 K, a non-Boltzmann distribution was found for N + 2 (B). In addition, excitation from N + 2 (X) to N + 2 (B) by highly vibrationally excited nitrogen molecules has been suggested by Linss to produce a non-thermal rotational population distribution [59].…”

Section: Excitation (And Ionization) Processesmentioning

confidence: 99%

Gas temperature determination from rotational lines in non-equilibrium plasmas: a review

Bruggeman

Sadeghi

Schram

et al. 2014

Plasma Sources Sci. Technol.

435

431

View full text Add to dashboard Cite

show abstract

“…Even though the sputtered species in a HiPIMS discharge are far from thermalization, and only partial thermalization can be assumed for the bulk gas, the thermalized part of the discharge species (mainly Ar atoms) still may be associated with certain temperature. The estimations of this temperature can be done by measuring rotational temperature ( T rot ) of any diatomic molecules added to the discharge using their ro‐vibrational spectrum and assuming rotational‐translational equilibrium between the molecular and atomic species in the discharge . Note that the kinetic temperature of thermalized gas species might be different from the rotational temperature of the added molecules.…”

Section: Time‐resolved Characterization Of Hipims Dischargementioning

confidence: 99%

An Overview on Time‐Resolved Optical Analysis of HiPIMS Discharge

Britun

Konstantinidis

Snyders

2015

Plasma Processes & Polymers

View full text Add to dashboard Cite

The progress in the time-resolved characterization of HiPIMS discharges performed during the last decade in our group is overviewed. Optical emission and absorption spectroscopy, as well as laser-induced fluorescence-based techniques have been mainly utilized. The results covering such important aspects of the HiPIMS discharge as the density evolution of the discharge species, their ionization and excitation, propagation of secondary electrons in the discharge volume, dynamics of velocity distribution of the discharge species, gas rarefaction, etc. are discussed.

show abstract

“…These predictions are also valid for infinitely long cylindrical probes. In figure 13 we plot the theoretical current ratio I -/ I + normalized by the ratio in the total absence of negative ions as a function of assuming = 5, which is realistic for our case (since we assume T -~Tgas = 300-800 K [23,24]). In figure 13 we also plot the same relationship for the current ratio derived from planar fluid theory [25] the normalized solution for the particle and fluid models are in almost exact agreement and we can use either of them to determine for our measured ion and electron saturation currents.…”

Section: Langmuir Probe Study Of the Extended Off-phasementioning

confidence: 99%

A study of the plasma electronegativity in an argon–oxygen pulsed-dc sputter magnetron

You¹,

Dodd²,

Edwards³

et al. 2010

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Using Langmuir probe-assisted laser photodetachment, the temporal evolution of the Odensity has been determined in the bulk plasma of a unipolar pulsed-dc magnetron. The source was operated in reactive mode, at a fixed nominal on-time power of 100 W, sputtering Ti in argon-oxygen atmospheres at 1.3 Pa pressure, but over a variation of duty cycles from 5 to 50 % and oxygen partial pressures of 10 and 50 % of the total pressure. In the plasma on-time, for all duty cycles the negative ion density (n-) rises marginally reaching values typically less than 2 x 10 15 m-3 with negative ion-to-electron density ratios, < 1. However, immediately after the transition from pulse onto off , nfalls by about 20-30% as fast Ospecies created at the cathode exit the system, however this is followed a rapid rise in nto values at least 2 or 3 times that in the on-time. The rate of rise of nand its maximum value both increase with decreasing duty cycle. In the off-time, the electron density falls rapidly (initial decay rates of several 10's of µs), and therefore the afterglow plasma becomes highly electronegative, with reaching 4.6 and 14.4 for 10 and 50 % oxygen partial pressure respectively. The rapid rise in nin the afterglow (in which the electron temperature falls from about 5 to 0.5 eV) is attributed to the dissociative attachment of highly-excited oxygen matastables, which themselves are created in the pulse on-time. At the lowest duty of 5 %, the long-term Odecay times are several 100's of µs. Langmuir probe characteristics show the clear signature that negative ions dominate over the electrons in the off-time. From the ion and electron saturation current ratios, has been estimated in some chosen cases and found to agree within a factor between 2 and 10 with those obtained more directly from the photodetachment method.

show abstract

Spatial distribution of the neutral gas temperature in rf and dc magnetron sputter discharges determined by fitting rotational spectra of the N2+ using a two-temperature fit

Cited by 19 publications

References 41 publications

Gas temperature determination from rotational lines in non-equilibrium plasmas: a review

Gas temperature determination from rotational lines in non-equilibrium plasmas: a review

An Overview on Time‐Resolved Optical Analysis of HiPIMS Discharge

A study of the plasma electronegativity in an argon–oxygen pulsed-dc sputter magnetron

Contact Info

Product

Resources

About