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Author Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N. pdf  doi
openurl 
  Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 1 : transient behaviour of electrodynamics and power deposition Type A1 Journal article
  Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys  
  Volume 45 Issue 1 Pages 015202-015202,11  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A two-dimensional self-consistent fluid model coupled with the full set of Maxwell equations is established to investigate the phase-shift effect on the transient behaviour of electrodynamics and power deposition in a hydrogen capacitively coupled plasma. The effect has been examined at 13.56 MHz and 100 MHz, respectively, because of the different phase-shift modulation when the electromagnetic effects are dominant. The results indicate that the spatiotemporal distributions of the plasma characteristics obtained for various phase-shift cases are obviously different both in shape and especially in absolute values. Indeed, when the phase difference varies from 0 to π, there is an increase in the electron flux, thus the power deposition becomes more pronounced. At the frequency of 13.56 MHz, the axial electron flux in the bulk plasma becomes uniform along the z-axis, and the radial electron flux exhibits two peaks within one period at the reverse-phase case, whereas the oscillation is less pronounced at the in-phase case. Furthermore, in the very high frequency discharge, the radial electron flux is alternately positive and negative with four peaks during one period, and the ionization mainly occurs in the sheath region, due to the prominent power deposition there at a phase difference equal to π.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000298290000011 Publication Date (down) 2011-12-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.588 Times cited 57 Open Access  
  Notes Approved Most recent IF: 2.588; 2012 IF: 2.528  
  Call Number UA @ lucian @ c:irua:92851 Serial 1230  
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Author Zhang, Y.-R.; Xu, X.; Bogaerts, A.; Wang, Y.-N. pdf  doi
openurl 
  Title Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: 2 : radial uniformity of the plasma characteristics Type A1 Journal article
  Year 2012 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys  
  Volume 45 Issue 1 Pages 015203-015203,13  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A two-dimensional fluid model, including the full set of Maxwell equations, has been developed and applied to investigate the effect of a phase shift between two power sources on the radial uniformity of several plasma characteristics in a hydrogen capacitively coupled plasma. This study was carried out at various frequencies in the range 13.56200 MHz. When the frequency is low, at 13.56 MHz, the plasma density is characterized by an off-axis peak when both power sources are in-phase (phgr = 0), and the best radial uniformity is obtained at phgr = π. This trend can be explained because the radial nonuniformity caused by the electrostatic edge effect can be effectively suppressed by the phase-shift effect at a phase difference equal to π. When the frequency rises to 60 MHz, the plasma density profiles shift smoothly from edge-peaked over uniform to centre-peaked as the phase difference increases, due to the pronounced standing-wave effect, and the best radial uniformity is reached at phgr = 0.3π. At a frequency of 100 MHz, a similar behaviour is observed, except that the maximum of the plasma density moves again towards the radial edge at the reverse-phase case (phgr = π), because of the dominant skin effect. When the frequency is 200 MHz, the bulk plasma density increases significantly with increasing phase-shift values, and a better uniformity is obtained at phgr = 0.4π. This is because the density in the centre increases faster than at the radial edge as the phase difference rises, due to the increasing power deposition Pz in the centre and the decreasing power density Pr at the radial edge. As the phase difference increases to π, the maximum near the radial edge becomes obvious again. This is because the skin effect has a predominant influence on the plasma density under this condition, resulting in a high density at the radial edge. Moreover, the axial ion flux increases monotonically with phase difference, and exhibits similar profiles to the plasma density. The calculation results illustrate that the radial uniformity of the various plasma characteristics is strongly dependent on the applied frequency and the phase shift between both power sources, which is important to realize, for controlling the uniformity of the plasma etch and deposition processes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000298290000012 Publication Date (down) 2011-12-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.588 Times cited 15 Open Access  
  Notes Approved Most recent IF: 2.588; 2012 IF: 2.528  
  Call Number UA @ lucian @ c:irua:92852 Serial 1231  
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Author Zhang, Y.-R.; Xu, X.; Zhao, S.-X.; Bogaerts, A.; Wang, Y.-N. pdf  doi
openurl 
  Title Comparison of electrostatic and electromagnetic simulations for very high frequency plasmas Type A1 Journal article
  Year 2010 Publication Physics of plasmas Abbreviated Journal Phys Plasmas  
  Volume 17 Issue 11 Pages 113512-113512,11  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A two-dimensional self-consistent fluid model combined with the full set of Maxwell equations is developed to investigate an argon capacitively coupled plasma, focusing on the electromagnetic effects on the discharge characteristics at various discharge conditions. The results indicate that there exist distinct differences in plasma characteristics calculated with the so-called electrostatic model (i.e., without taking into account the electromagnetic effects) and the electromagnetic model (which includes the electromagnetic effects), especially at very high frequencies. Indeed, when the excitation source is in the high frequency regime and the electromagnetic effects are taken into account, the plasma density increases significantly and meanwhile the ionization rate evolves to a very different distribution when the electromagnetic effects are dominant. Furthermore, the dependence of the plasma characteristics on the voltage and pressure is also investigated, at constant frequency. It is observed that when the voltage is low, the difference between these two models becomes more obvious than at higher voltages. As the pressure increases, the plasma density profiles obtained from the electromagnetic model smoothly shift from edge-peaked over uniform to a broad maximum in the center. In addition, the edge effect becomes less pronounced with increasing frequency and pressure, and the skin effect rather than the standing-wave effect becomes dominant when the voltage is high.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Woodbury, N.Y. Editor  
  Language Wos 000285486500105 Publication Date (down) 2010-11-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.115 Times cited 30 Open Access  
  Notes Approved Most recent IF: 2.115; 2010 IF: 2.320  
  Call Number UA @ lucian @ c:irua:84763 Serial 429  
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Author Zhang, Y.; Fischetti, M.V.; Sorée, B.; Magnus, W.; Heyns, M.; Meuris, M. doi  openurl
  Title Physical modeling of strain-dependent hole mobility in Ge p-channel inversion layers Type A1 Journal article
  Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 106 Issue 8 Pages 083704,1-083704,9  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present comprehensive calculations of the low-field hole mobility in Ge p-channel inversion layers with SiO2 insulator using a six-band k·p band-structure model. The cases of relaxed, biaxially, and uniaxially (both tensily and compressively) strained Ge are studied employing an efficient self-consistent methodmaking use of a nonuniform spatial mesh and of the Broyden second methodto solve the coupled envelope-wave function k·p and Poisson equations. The hole mobility is computed using the KuboGreenwood formalism accounting for nonpolar hole-phonon scattering and scattering with interfacial roughness. Different approximations to handle dielectric screening are also investigated. As our main result, we find a large enhancement (up to a factor of 10 with respect to Si) of the mobility in the case of uniaxial compressive stress similarly to the well-known case of Si. Comparison with experimental data shows overall qualitative agreement but with significant deviations due mainly to the unknown morphology of the rough Ge-insulator interface, to additional scattering with surface optical phonon from the high- insulator, to Coulomb scattering interface traps or oxide chargesignored in our calculationsand to different channel structures employed.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000271358100050 Publication Date (down) 2009-10-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 29 Open Access  
  Notes Approved Most recent IF: 2.068; 2009 IF: 2.072  
  Call Number UA @ lucian @ c:irua:80137 Serial 2617  
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Author Zhang, Y.; Grünewald, L.; Cao, X.; Abdelbarey, D.; Zheng, X.; Rugeramigabo, E.P.; Zopf, M.; Verbeeck, J.; Ding, F. doi  openurl
  Title Supplementary Information and Data for “Unveiling the 3D Morphology of Epitaxial GaAs/AlGaAs Quantum Dots” Type Dataset
  Year 2024 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Dataset; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Raw and processed TEM and AFM data for the article Unveiling the 3D Morphology of Epitaxial GaAs/AlGaAs Quantum Dots.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date (down)  
  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 @ admin @ c:irua:208086 Serial 9319  
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