| Home | << 1 2 3 >> |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Tinck, S.; Bogaerts, A. | ||||
| Title | Role of vibrationally excited HBr in a HBr/He inductively coupled plasma used for etching of silicon | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 49 | Issue | 49 | Pages | 245204 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | In this work, the role of vibrationally excited HBr (HBr(vib)) is computationally investigated for a HBr/He inductively coupled plasma applied for Si etching. It is found that at least 50% of all dissociations of HBr occur through HBr(vib). This additional dissociation pathway through HBr(vib) makes the plasma significantly more atomic. It also results in a slightly higher electron temperature (i.e. about 0.2 eV higher compared to simulation results where HBr(vib) is not included), as well as a higher gas temperature (i.e. about 50 K higher than without including HBr(vib)), due to the enhanced Franck–Condon heating through HBr(vib) dissociation, at the conditions investigated. Most importantly, the calculated etch rate with HBr(vib) included in the model is a factor 3 higher than in the case without HBr(vib), due to the higher fluxes of etching species (i.e. H and Br), while the chemical composition of the wafer surface shows no significant difference. Our calculations clearly show the importance of including HBr(vib) for accurate modeling of HBr-containing plasmas. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000377427100020 | Publication Date | 2016-05-17 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.588 | Times cited | Open Access | ||
| Notes | The Fund for Scientific Research Flanders (FWO) is acknowledged for financial support of this work (Grant no. 0880.212.840). This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. Prof. Mark Kushner is also gratefully acknowledged for the useful discussions and for providing the HPEM code. | Approved | Most recent IF: 2.588 | ||
Call Number  |
c:irua:133457 | Serial | 4072 | ||
| Permanent link to this record | |||||
| Author | Tinck, S.; Bogaerts, A. | ||||
| Title | Computational study of the CF4 /CHF3 / H2 /Cl2 /O2 /HBr gas phase plasma chemistry | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 49 | Issue | 49 | Pages | 195203 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | A modelling study is performed of high-density low-pressure inductively coupled CF4/CHF3/H2/Cl2/O2/HBr plasmas under different gas mixing ratios. A reaction set describing the complete plasma chemistry is presented and discussed. The gas fraction of each component in this mixture is varied to investigate the sensitivity of the plasma properties, like electron density, plasma potential and species densities, towards the gas mixing ratios. This research is of great interest for microelectronics applications because these gases are often combined in two (or more)-component mixtures, and mixing gases or changing the fraction of a gas can sometimes yield unwanted reaction products or unexpected changes in the overall plasma properties due to the increased chemical complexity of the system. Increasing the CF4 fraction produces more F atoms for chemical etching as expected, but also more prominently lowers the density of Cl atoms, resulting in an actual drop in the etch rate under certain conditions. Furthermore, CF4 decreases the free electron density when mixed with Cl2. However, depending on the other gas components, CF4 gas can also sometimes enhance free electron density. This is the case when HBr is added to the mixture. The addition of H2 to the gas mixture will lower the sputtering process, not only due to the lower overall positive ion density at higher H2 fractions, but also because more H+, H2 + and H3 + are present and they have very low sputter yields. In contrast, a larger Cl2 fraction results in more chemical etching but also in less physical sputtering due to a smaller abundance of positive ions. Increasing the O2 fraction in the plasma will always lower the etch rate due to more oxidation of the wafer surface and due to a lower plasma density. However, it is also observed that the density of F atoms can actually increase with rising O2 gas fraction. This is relevant to note because the exact balance between fluorination and oxidation is important for fine-tuning the overall etch rate and for control of the sidewall profile. Finally, HBr is often used as a chemical etcher, but when mixed with F- or Cl-containing gases, HBr creates the same diluting effects as Ar or He, because a higher fraction results in less chemical etching but more (physical) sputtering. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000375255500017 | Publication Date | 2016-04-13 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.588 | Times cited | 5 | Open Access | |
| Notes | We acknowledge the Fund for Scientific Research Flanders (FWO) for financial support of this work. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. | Approved | Most recent IF: 2.588 | ||
| Call Number |
c:irua:132890 | Serial | 4062 | ||
| Permanent link to this record | |||||
| Author | Bogaerts, A.; Khosravian, N.; Van der Paal, J.; Verlackt, C.C.W.; Yusupov, M.; Kamaraj, B.; Neyts, E.C. | ||||
| Title | Multi-level molecular modelling for plasma medicine | Type | A1 Journal article | ||
| Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 49 | Issue | 49 | Pages | 054002 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | Modelling at the molecular or atomic scale can be very useful for obtaining a better insight in plasma medicine. This paper gives an overview of different atomic/molecular scale modelling approaches that can be used to study the direct interaction of plasma species with biomolecules or the consequences of these interactions for the biomolecules on a somewhat longer time-scale. These approaches include density functional theory (DFT), density functional based tight binding (DFTB), classical reactive and non-reactive molecular dynamics (MD) and united-atom or coarse-grained MD, as well as hybrid quantum mechanics/molecular mechanics (QM/MM) methods. Specific examples will be given for three important types of biomolecules, present in human cells, i.e. proteins, DNA and phospholipids found in the cell membrane. The results show that each of these modelling approaches has its specific strengths and limitations, and is particularly useful for certain applications. A multi-level approach is therefore most suitable for obtaining a global picture of the plasma–biomolecule interactions. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000368944100003 | Publication Date | 2015-12-16 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.588 | Times cited | 11 | Open Access | |
| Notes | This work is financially supported by the Fund for Scientific Research Flanders (FWO) and the Francqui Foundation. The calculations were carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. | Approved | Most recent IF: 2.588 | ||
| Call Number |
c:irua:131571 | Serial | 3985 | ||
| Permanent link to this record | |||||
| Author | Van der Paal, J.; Verlackt, C.C.; Yusupov, M.; Neyts, E.C.; Bogaerts, A. | ||||
| Title | Structural modification of the skin barrier by OH radicals : a reactive molecular dynamics study for plasma medicine | Type | A1 Journal article | ||
| Year | 2015 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 48 | Issue | 48 | Pages | 155202 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | While plasma treatment of skin diseases and wound healing has been proven highly effective, the underlying mechanisms, and more generally the effect of plasma radicals on skin tissue, are not yet completely understood. In this paper, we perform ReaxFF-based reactive molecular dynamics simulations to investigate the interaction of plasma generated OH radicals with a model system composed of free fatty acids, ceramides, and cholesterol molecules. This model system is an approximation of the upper layer of the skin (stratum corneum). All interaction mechanisms observed in our simulations are initiated by H-abstraction from one of the ceramides. This reaction, in turn, often starts a cascade of other reactions, which eventually lead to the formation of aldehydes, the dissociation of ceramides or the elimination of formaldehyde, and thus eventually to the degradation of the skin barrier function. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000351856600007 | Publication Date | 2015-03-25 | |
| 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 | 20 | Open Access | |
| Notes | Approved | Most recent IF: 2.588; 2015 IF: 2.721 | |||
| Call Number |
c:irua:124230 | Serial | 3242 | ||
| Permanent link to this record | |||||
| Author | Tinck, S.; Tillocher, T.; Dussart, R.; Bogaerts, A. | ||||
| Title | Cryogenic etching of silicon with SF6 inductively coupled plasmas: a combined modelling and experimental study | Type | A1 Journal article | ||
| Year | 2015 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 48 | Issue | 48 | Pages | 155204 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | A hybrid Monte Carlofluid model is applied to simulate the wafer-temperature-dependent etching of silicon with SF6 inductively coupled plasmas (ICP). The bulk plasma within the ICP reactor volume as well as the surface reactions occurring at the wafer are self-consistently described. The calculated etch rates are validated by experiments. The calculations and experiments are performed at two different wafer temperatures, i.e. 300 and 173 K, resembling conventional etching and cryoetching, respectively. In the case of cryoetching, a physisorbed SFx layer (x = 06) is formed on the wafer, which is negligible at room temperature, because of fast thermal desorption, However, even in the case of cryoetching, this layer can easily be disintegrated by low-energy ions, so it does not affect the etch rates. In the investigated pressure range of 19 Pa, the etch rate is always slightly higher at cryogenic conditions, both in the experiments and in the model, and this could be explained in the model due to a local cooling of the gas above the wafer, making the gas denser and increasing the flux of reactive neutrals, like F and F2, towards the wafer. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000351856600009 | Publication Date | 2015-03-25 | |
| 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 | 9 | Open Access | |
| Notes | Approved | Most recent IF: 2.588; 2015 IF: 2.721 | |||
| Call Number |
c:irua:124209 | Serial | 551 | ||
| Permanent link to this record | |||||
| Author | Gul, B.; Tinck, S.; De Schepper, P.; Aman-ur-Rehman; Bogaerts, A. | ||||
| Title | Numerical investigation of HBr/He transformer coupled plasmas used for silicon etching | Type | A1 Journal article | ||
| Year | 2015 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
| Volume | 48 | Issue | 48 | Pages | 025202 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | A two-dimensional hybrid Monte Carlofluid model is applied to study HBr/He inductively coupled plasmas used for etching of Si. Complete sets of gas-phase and surface reactions are presented and the effects of the gas mixing ratio on the plasma characteristics and on the etch rates are discussed. A comparison with experimentally measured etch rates is made to validate the modelling results. The etch rate in the HBr plasma is found to be quite low under the investigated conditions compared to typical etch rates of Si with F- or Cl-containing gases. This allows for a higher control and fine-tuning of the etch rate when creating ultra-small features. Our calculations predict a higher electron temperature at higher He fraction, because the electrons do not lose their energy so efficiently in vibrational and rotational excitations. As a consequence, electron impact ionization and dissociation become more important, yielding higher densities of ions, electrons and H atoms. This results in more pronounced sputtering of the surface. Nevertheless, the overall etch rate decreases upon increasing He fraction, suggesting that chemical etching is still the determining factor for the overall etch rate. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | London | Editor | ||
| Language | Wos | 000347980100011 | Publication Date | 2014-12-10 | |
| 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 | 7 | Open Access | |
| Notes | Approved | Most recent IF: 2.588; 2015 IF: 2.721 | |||
| Call Number |
c:irua:121335 | Serial | 2394 | ||
| Permanent link to this record | |||||