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Your search keyword '"Bruneau, B."' showing total 175 results
Start Over Author "Bruneau, B." Publication Type Academic Journals
175 results on '"Bruneau, B."'

20. Slope and amplitude asymmetry effects on low frequency capacitively coupled carbon tetrafluoride plasmas.

Author

Bruneau, B., Korolov, I., Lafleur, T., Gans, T., O'Connell, D., Greb, A., Derzsi, A., Donkó, Z., Brandt, S., Schüngel, E., Schulze, J., Johnson, E., and Booth, J.-P.

Subjects
*PLASMA gases, *ELECTRIC fields, *IONIZATION (Atomic physics), *CHEMICAL reactors, *ION energy
Abstract

We report investigations of capacitively coupled carbon tetrafluoride (CF4) plasmas excited with tailored voltage waveforms containing up to five harmonics of a base frequency of 5.5 MHz. The impact of both the slope asymmetry, and the amplitude asymmetry, of these waveforms on the discharge is examined by combining experiments with particle-in-cell simulations. For all conditions studied herein, the discharge is shown to operate in the drift-ambipolar mode, where a comparatively large electric field in the plasma bulk (outside the sheaths) is the main mechanism for electron power absorption leading to ionization. We show that both types of waveform asymmetries strongly influence the ion energy at the electrodes, with the particularity of having the highest ion flux on the electrode where the lowest ion energy is observed. Even at the comparatively high pressure (600?mTorr) and low fundamental frequency of 5.5?MHz used here, tailoring the voltage waveforms is shown to efficiently create an asymmetry of both the ion energy and the ion flux in geometrically symmetric reactors. [ABSTRACT FROM AUTHOR]

Published
2016
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23. Growth mechanisms study of microcrystalline silicon deposited by SiH4/H2 plasma using tailored voltage waveforms.

Author

Bruneau, B., J. Wang, Dornstetter, J.-C., and Johnson, E. V.

Subjects
*ION bombardment, *SILICON research, *PLASMA gas research, *ATOMIC force microscopy, *HYDROGENATION
Abstract

The use of Tailored Voltage Waveforms is a technique wherein one uses non-sinusoidal waveforms with a period equivalent to RF frequencies to excite a plasma. It has been shown to be an effective technique to decouple maximum Ion Bombardment Energy (IBE) from the ion flux at the surface of the electrodes. In this paper, we use it for the first time as a way to scan through the IBE in order to study the growth mechanism of hydrogenated microcrystalline silicon using a SiH4/H2 chemistry. We find that at critical energies, a stepwise increase in the amorphous to microcrystalline transition thickness is observed, as detected by Real Time Spectroscopic Ellipsometry. The same energy thresholds (30 eV and 70 eV) are found to be very influential on the final surface morphology of the samples, as observed by Atomic Force Microscopy. These thresholds correspond to SiHx+ bulk displacement (30 eV) and Hx+ (70 eV) surface displacement energies. A model is therefore proposed to account for the impact of these ions on the morphology of µc-Si:H growth. [ABSTRACT FROM AUTHOR]

Published
2014
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33. Influence of Cysteamine on In Vitro Maturation, In Vitro and In Vivo Fertilization of Equine Oocytes.

Author

Deleuze, S., Dubois, C. S., Caillaud, M., Bruneau, B., Goudet, G., and Duchamp, G.

Subjects
FERTILIZATION in vitro, MEDICAL imaging systems, NUCLEIC acids, GERM cells, ANTICOAGULANTS
Abstract

Contents The effect of cysteamine on in vitro nuclear and cytoplasmic maturation of equine oocytes collected by transvaginal ultrasound guided follicular aspiration was assessed. Oocytes were matured in vitro with (cysteamine group) or without (control group) cysteamine. The nuclear stage after DNA Hoechst staining, penetration rates after two different in vitro fertilization (IVF) techniques (IVF media with ionophore and Hepes buffer with heparin) and the embryo yield following oocyte intra-oviductal transfer were used as a criterion for assessing nuclear and cytoplasmic maturation, respectively. Contrary to the data described in other domestic species, there was no effect of cysteamine on in vitro nuclear maturation, IVF or in vivo embryonic development under our conditions. Ovum pick up yields (52%) and maturation rates (control group: 47% and cysteamine group: 55%) were similar to those previously reported. From 57 oocytes transferred to the oviduct in each group, the number of embryos collected was 10 (17%) in the control group and five in the cysteamine group (9%). Those two percentages were not statistically different (p > 0.05). No effect of IVF technique was seen on the success rate (6%) in each group. [ABSTRACT FROM AUTHOR]

Published
2010
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