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Author Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A.
Title The effect of F2 attachment by low-energy electrons on the electron behaviour in an Ar/CF4 inductively coupled plasma Type A1 Journal article
Year 2012 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 21 Issue 2 Pages 025008-025008,13
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electron behaviour in an Ar/CF4 inductively coupled plasma is investigated by a Langmuir probe and a hybrid model. The simulated and measured results include electron density, temperature and electron energy distribution function for different values of Ar/CF4 ratio, coil power and gas pressure. The hybrid plasma equipment model simulations show qualitative agreement with experiment. The effect of F2 electron attachment on the electron behaviour is explored by comparing two sets of data based on different F atom boundary conditions. It is demonstrated that electron attachment at F2 molecules is responsible for the depletion of low-energy electrons, causing a density decrease as well as a temperature increase when CF4 is added to an Ar plasma.
Address
Corporate Author Thesis
Publisher (up) Institute of Physics Place of Publication Bristol Editor
Language Wos 000302779400022 Publication Date 2012-03-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 23 Open Access
Notes Approved Most recent IF: 3.302; 2012 IF: 2.515
Call Number UA @ lucian @ c:irua:96549 Serial 841
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Author Liu, Y.-X.; Zhang, Q.-Z.; Liu, L.; Song, Y.-H.; Bogaerts, A.; Wang, Y.-N.
Title Electron bounce resonance heating in dual-frequency capacitively coupled oxygen discharges Type A1 Journal article
Year 2013 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 22 Issue 2 Pages 025012-11
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen is studied by different experimental methods and a particle-in-cell/Monte Carlo collision (PIC/MCC) simulation, and compared with the electropositive argon discharge. In comparison with argon, the experimental results show that in an oxygen discharge the resonance peaks in positive-ion density and light intensity tend to occur at larger electrode gaps. Moreover, at electrode gaps L > 2.5 cm, the positive-ion (and electron) density and the light emission drop monotonically in the oxygen discharge upon increasing L, whereas they rise (after an initial drop) in the argon case. At resonance gap the electronegativity reaches its maximum due to the BRH. All these experimental observations are explained by PIC/MCC simulations, which show that in the oxygen discharge the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonance electrons when traversing the bulk, resulting in a suppressed BRH. Both experiment and simulation results show that this effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative. In a pure oxygen discharge, the BRH is suppressed with increasing pressure and almost diminishes at 12 Pa. Finally, the driving frequency significantly affects the BRH, because it determines the phase relation between bulk electric field and sheath electric field.
Address
Corporate Author Thesis
Publisher (up) Institute of Physics Place of Publication Bristol Editor
Language Wos 000317275400014 Publication Date 2013-03-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 20 Open Access
Notes Approved Most recent IF: 3.302; 2013 IF: 3.056
Call Number UA @ lucian @ c:irua:106534 Serial 911
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Author Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A.
Title Gas ratio effects on the Si etch rate and profile uniformity in an inductively coupled Ar/CF4 plasma Type A1 Journal article
Year 2013 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 22 Issue 1 Pages 015017-15018
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work, a hybrid model is used to investigate the effect of different gas ratios on the Si etching and polymer film deposition characteristics in an Ar/CF4 inductively coupled plasma. The influence of the surface processes on the bulk plasma properties is studied, and also the spatial characteristics of important gas phase and etched species. The densities of F and CF2 decrease when the surface module is included in the simulations, due to the species consumption caused by etching and polymer deposition. The influence of the surface processes on the bulk plasma depends on the Ar/CF4 gas ratio. The deposited polymer becomes thicker at high CF4 content because of more abundant CFx radicals. As a result of the competition between the polymer thickness and the F flux, the etch rate first increases and then decreases upon increasing the CF4 content. The electron properties, more specifically the electron density profile, affect the Si etch characteristics substantially by determining the radical density and flux profiles. In fact, the radial profile of the etch rate is more uniform at low CF4 content since the electron density has a smooth distribution. At high CF4 content, the etch rate is less uniform with a minimum halfway along the wafer radius, because the electron density distribution is more localized. Therefore, our calculations predict that it is better to work at relatively high Ar/CF4 gas ratios, in order to obtain high etch rate and good profile uniformity for etch applications. This, in fact, corresponds to the typical experimental etch conditions in Ar/CF4 gas mixtures as found in the literature, where Ar is typically present at a much higher concentration than CF4.
Address
Corporate Author Thesis
Publisher (up) Institute of Physics Place of Publication Bristol Editor
Language Wos 000314966300022 Publication Date 2012-12-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 11 Open Access
Notes Approved Most recent IF: 3.302; 2013 IF: 3.056
Call Number UA @ lucian @ c:irua:102583 Serial 1320
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Author Zhang, Q.-Z.; Liu, Y.-X.; Jiang, W.; Bogaerts, A.; Wang, Y.-N.
Title Heating mechanism in direct current superposed single-frequency and dual-frequency capacitively coupled plasmas Type A1 Journal article
Year 2013 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T
Volume 22 Issue 2 Pages 025014-25018
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work particle-in-cell/Monte Carlo collision simulations are performed to study the heating mechanism and plasma characteristics in direct current (dc) superposed radio-frequency (RF) capacitively coupled plasmas, operated both in single-frequency (SF) and dual-frequency (DF) regimes. An RF (60/2 MHz) source is applied on the bottom electrode to sustain the discharge, and a dc source is fixed on the top electrode. The heating mechanism appears to be very different in dc superposed SF and DF discharges. When only a single source of 60 MHz is applied, the plasma bulk region is reduced by the dc source, thus the ionization rate and hence the electron density decrease with rising dc voltage. However, when a DF source of 60 and 2 MHz is applied, the electron density can increase upon addition of a dc voltage, depending on the gap length and applied dc voltage. This is explained from the spatiotemporal ionization rates in the DF discharge. In fact, a completely different behavior is observed for the ionization rate in the two half-periods of the LF source. In the first LF half-period, the situation resembles the dc superposed SF discharge, and the reduced plasma bulk region due to the negative dc bias results in a very small effective discharge area and a low ionization rate. On the other hand, in the second half-period, the negative dc bias is to some extent counteracted by the LF voltage, and the sheath close to the dc electrode becomes particularly thin. Consequently, the amplitude of the high-frequency sheath oscillations at the top electrode is largely enhanced, while the LF sheath at the bottom electrode is in its expanding phase and can thus well confine the high-energy electrons. Therefore, the ionization rate increases considerably in this second LF half-period. Furthermore, in addition to the comparison between SF and DF discharges and the effect of gap length and dc voltage, the effect of secondary electrons is examined.
Address
Corporate Author Thesis
Publisher (up) Institute of Physics Place of Publication Bristol Editor
Language Wos 000317275400016 Publication Date 2013-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0963-0252;1361-6595; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.302 Times cited 9 Open Access
Notes Approved Most recent IF: 3.302; 2013 IF: 3.056
Call Number UA @ lucian @ c:irua:106877 Serial 1413
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Author Wang, Y.J.; Nichel, H.A.; McCombe, B.D.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Wu, X.G.; Eustis, T.J.; Schaff, W.
Title Resonant magnetopolaron effect in GaAs/AlGaAs multiple quantum well structures Type A1 Journal article
Year 1998 Publication Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E
Volume 2 Issue Pages 161-165
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher (up) North-Holland Place of Publication Amsterdam Editor
Language Wos 000075383500034 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record
Impact Factor 2.221 Times cited Open Access
Notes Approved Most recent IF: 2.221; 1998 IF: NA
Call Number UA @ lucian @ c:irua:24185 Serial 2888
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Author Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.; Reno, J.; Lee, X.Y.; Jiang, H.W.
Title Strong resonant intersubband magnetopolaron effect in heavily modulation-doped GaAs/AlGaAs single quantum wells at high magnetic fields Type A1 Journal article
Year 2000 Publication Physica. E: Low-dimensional systems and nanostructures Abbreviated Journal Physica E
Volume 6 Issue Pages 195-200
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher (up) North-Holland Place of Publication Amsterdam Editor
Language Wos 000085770600048 Publication Date 2002-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.221 Times cited 2 Open Access
Notes Approved Most recent IF: 2.221; 2000 IF: 0.878
Call Number UA @ lucian @ c:irua:28526 Serial 3183
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Author Wang, Y.J.; Nickel, H.A.; McCombe, B.D.; Peeters, F.M.; Hai, G.Q.; Shi, J.M.; Devreese, J.T.; Wu, X.G.
Title Resonant magnetopolaron effects in GaAs/AlGaAs MQWs at high magnetic fields Type P3 Proceeding
Year 1997 Publication Abbreviated Journal
Volume Issue Pages 797-800
Keywords P3 Proceeding; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract
Address
Corporate Author Thesis
Publisher (up) World Scientific Place of Publication Singapore Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:19305 Serial 2890
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