Search

Your search keyword '"Gudmundsson, J. T."' showing total 105 results
Start Over Author "Gudmundsson, J. T." Publisher iop publishing
105 results on '"Gudmundsson, J. T."'

8. Influence of the magnetic field on the discharge physics of a high power impulse magnetron sputtering discharge.

Author

Rudolph, M, Brenning, N, Hajihoseini, H, Raadu, M A, Minea, T M, Anders, A, Gudmundsson, J T, and Lundin, D

Subjects
MAGNETRON sputtering, MAGNETIC fields, PHYSICS, ELECTRON density, ELECTRON impact ionization, RESISTANCE heating
Abstract

The magnetic field is a key feature that distinguishes magnetron sputtering from simple diode sputtering. It effectively increases the residence time of electrons close to the cathode surface and by that increases the energy efficiency of the discharge. This becomes apparent in high power impulse magnetron sputtering (HiPIMS) discharges, as small changes in the magnetic field can result in large variations in the discharge characteristics, notably the peak discharge current and/or the discharge voltage during a pulse. Here, we analyze the influence of the magnetic field on the electron density and temperature, how the discharge voltage is split between the cathode sheath and the ionization region, and the electron heating mechanism in a HiPIMS discharge. We relate the results to the energy efficiency of the discharge and discuss them in terms of the probability of target species ionization. The energy efficiency of the discharge is related to the fraction of pulse power absorbed by the electrons. Ohmic heating of electrons in the ionization region leads to higher energy efficiency than electron energization in the sheath. We find that the electron density and ionization probability of the sputtered species depend largely on the discharge current. The results suggest ways to adjust electron density and electron temperature using the discharge current and the magnetic field, respectively, and how they influence the ionization probability. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

19. A global model study of low pressure high density CF4 discharge.

Author

Toneli, D A, Pessoa, R S, Roberto, M, and Gudmundsson, J T

Subjects
CATIONS, METASTABLE states, ANIONS, GLOBAL studies, PLASMA density
Abstract

We present a revised reaction set for low pressure high density CF4 plasma modelling. A global model (volume averaged) was developed to study a CF4 discharge that includes the neutral species CF4, CF3, CF2, CF, F2, F, and C, the metastable states CF(a4Σ−) and CF2(3B1), the positive ions , , CF+, , F+, and C+, the negative ions , , and F−, and electrons. The main reactions that contribute to the production and loss of each species are pointed out with an emphasis on the radicals CF2, CF and F, the dominant positive ion , and the dominant negative ion F−. We find wall processes to have a significant influence on the discharge. The density of F2 is high due to recombination of F atoms at the walls and the losses of the radicals F, CF, and CF3 are mainly through wall recombination. As the pressure is increased, F− becomes the dominant negative charged species. The discharge is found to be weakly electronegative below ∼10 mTorr and the electronegativity decreases with increased absorbed power. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results