We present a self‐consistent 1D model of the discharge initiated in an ac plasma display panel cell. The model is based on a two‐moments fluid description of electron and ion transport, coupled with Poisson’s equation, and with a set of kinetic equations characterizing the evolution of the population of excited states leading to UV emission in neon‐xenon mixtures. Results are presented in a 90% neon, 10% xenon gas mixture, for a gap length of 100 μm and a gas pressure of 560 Torr at ambient temperature. Under the conditions above, and for typical sustaining voltages, the duration of the discharge current pulse predicted by the model is on the order of 10 ns while the UV emission lasts for about 5 μs. The UV production efficiency in the discharge is about 10% for a Ne‐Xe (90‐10) mixture. Results for other neon‐xenon mixtures are also discussed. The model also shows that a non‐negligible part of the UV production occurs in the transient ‘‘plasma column’’ and not only in the sheath region. Voltage transfer curves and margin obtained with this model are presented and compared with available experimental measurements.

Numerical model of an ac plasma display panel cell in neon‐xenon mixtures

An extensive collisional-radiative model for the argon atoms in a glow discharge has been developed. Sixty-five effective argon atomic levels are considered. The processes taken into account are radiative decay, electron, fast argon ion and argon atom and thermal argon atom impact ionization, excitation and deexcitation between all the levels, electron-ion radiative recombination, and electron-ion three-body recombination where the third body is an electron, fast argon ion or atom, or a thermal argon atom. Some additional processes are incorporated for the two 4s metastable levels, i.e., Penning ionization of sputtered atoms, two- and three-body collisions with argon ground state atoms, collisions between two atoms in a metastable level, and diffusion and subsequent deexcitation at the walls. Typical results of the model are the populations of the various excited levels as a function of distance, and the relative contributions of different populating and depopulating processes for all levels.

Collisional-radiative model for an argon glow discharge

A new approach to mass spectrometric measurement and analysis has been used to study the electron impact ionization of the rare gases in the low electron energy regime (<180 eV). Critical considerations are given to the problems of ion extraction from the ion source (Nier‐type) and the transmission of the extracted ions through the mass spectrometer system (double focusing sector field Varian MAT CH5). Accurate relative partial cross section functions were obtained for production of He+ and He2+ from He; Ne+, Ne2+, and Ne3+ from Ne; Ar+, Ar2+, Ar3+ from Ar, and Kr+, Kr2+, Kr3+ and Kr4+ from Kr. In addition, the cross section ratios for the partial ionization cross sections of each individual gas were determined. These ratios were used to sum up the relative partial cross section functions for each gas, hence obtaining relative total ionization cross section functions by weighting each partial cross section function with the respective charge number. The shape of the relative total ionization cross section...

Mass spectrometric determination of partial electron impact ionization cross sections of He, Ne, Ar and Kr from threshold up to 180 eV

Recommended values are presented for qm, qt and QT (momentum transfer cross-sections for elastic collisions, total cross-sections for elastic collisions and total collision cross-sections, respectively) of electrons in xenon for electron energies from 0 to 104 eV. Recommended values of ionisation cross-sections qi are also presented. Using these values of qm together with values of qi and Townsend ionisation coefficients alpha , recommended values of total excitation cross-sections qe are determined. The values of qm for electron energies from 5 to 20 eV are smaller than those of Frost and Phelps (1964) by a considerable amount. The values of qe for energies from about 20 to 100 eV are much larger than those of de Heer et al. (1979).

https://iopscience.iop.org/article/10.1088/0022-3727/16/4/018/pdf

Determination of electron-xenon total excitation cross-sections, from threshold to 100 eV, from experimental values of Townsend's α

A simple model for ionization of sputtered metals by a high‐density plasma is presented. Experimentally, ion flux fractions of greater than 80% can be obtained by sputtering aluminum into a region of dense plasma (ne∼1012 cm−3). Such a process has important applications in the filling of high‐aspect‐ratio features encountered in microelectronics fabrication. Both electron‐impact and Penning ionization mechanisms are considered in this model. Under conditions of low electron density (ne≪1011 cm−3), Penning ionization is found to be the dominant ionization path. This is consistent with the accepted ionization mechanism for conventional diode sputtering. When high electron densities are generated, however, electron‐impact ionization plays a significant ionization role. Langmuir probe measurements of the inductively coupled plasma indicate that the electron density lies between 2×1011 and 2×1012 cm−3. The model, in combination with measured plasma density, is used to calculate ion fractions. Modeled and exper...

Mechanisms for highly ionized magnetron sputtering

A set of total cross sections for scattering of electrons by Ne, Ar, Kr and Xe has been evaluated over the energy range of about 20 to 3000 eV by means of the analysis of experiments and theories on total cross sections for elastic scattering, ionisation and excitation, and on differential cross sections for elastic and inelastic scattering. The total cross sections for scattering of electrons are evaluated by adding those for ionisation, excitation and elastic scattering and they are accurate to about 5-10%. They appear to be in very good agreement with the recent experimental results on total electron scattering of Wagenaar et al. (1978).

https://iopscience.iop.org/article/10.1088/0022-3700/12/6/016/pdf

W van der Kaay

Papers

Total cross sections for electron scattering by Ne, Ar, Kr and Xe