Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Surfaces and Interfaces, Electrical and Electronic Engineering
20
Scopus Publications
309
Scholar Citations
11
Scholar h-index
13
Scholar i10-index
Scopus Publications
E-beam metrology and line local critical dimension uniformity of thin dry resist films for high numerical aperture extreme ultraviolet lithography Mohamed Zidan, Gian Francesco Lorusso, Danilo De Simone, Anuja De Silva, Ali Haider, Elisseos Verveniotis, Alain Moussa, Stefan De Gendt Journal of Micro Nanopatterning Materials and Metrology, 2023 BackgroundLithography advancements require resist layer thickness reduction, essential to cope with the low depth of focus characteristic of high numerical aperture extreme ultraviolet lithography (High NA EUVL). However, such a requirement poses serious challenges in terms of resist process metrology and characterization, as patterns in thin resist suffer from low contrast, which may affect the performance of the edge detection algorithms used for image analysis, ultimately impacting metrology.AimWe aim to investigate the impact of reducing the film thickness of the dry photoresist on the E-beam metrology and line local critical dimension uniformity (LCDU).ApproachThin dry resist films from 10 to 30 nm are patterned at pitches 24, 28, and 32 nm using EUVL. A standard critical dimension scanning electron microscope (CDSEM) is used to perform E-beam metrology. The captured SEM images are analyzed using software to extract the parameters of interest, such as the critical dimension (CD), power spectral density (PSD), unbiased line width roughness (uLWR), LWR correlation length, signal-to-noise ratio (SNR), and line LCDU for a range of features with lengths from 12 to 50 nm. Furthermore, the experimental results of the line LCDU of a range of feature lengths and roughness parameters are plotted for different process conditions of thickness and pitch in a normalized way.ResultsThe results indicate that the dry resist shows good CDSEM imaging contrast and high SNR even at the thinnest resist thickness. This enables extracting a reliable uLWR measurement without the need to increase the number of frames to modulate the SNR. Moreover, it has LWR correlation length of around 2.5 nm. By thinning the resist thickness, the uLWR and line LCDU increase, and the SNR and the LWR correlation length decrease. Finally, when normalizing the line LCDU to uLWR and the feature length to the correlation length, the resulting curves of the different process conditions of the thickness and pitch overlap with each other, following an analytical model that relates the line LCDU to the resist roughness parameters.ConclusionWe showed the impact of reducing the dry resist thickness on E-beam metrology and line LCDU for features foreseen for High NA EUVL. The dry resist has good imaging contrast, LWR correlation length of around 2.5 nm, and the line LCDU depends on the resist thickness (uLWR and LWR correlation length for each particular thickness). With such a dataset, we demonstrated an overlap between the normalized curves of the line LCDU to the uLWR and the feature length to the correlation length for the different process conditions of thickness and pitch. The uLWR and correlation length are the knobs to achieve good patterning uniformity for a given feature length.
Study on the Surface Morphology of Thermochromic Rf-Sputtered VO2 Films Using Temperature-Dependent Atomic Force Microscopy Emmanouil Gagaoudakis, Elisseos Verveniotis, Yuji Okawa, Giannis Michail, Elias Aperathitis, Eleni Mantsiou, George Kiriakidis, Vassilios Binas Applied Sciences Switzerland, 2023 Vanadium dioxide (VO2) is a well-known phase-changing material that goes from a semiconducting state to a metallic one at a critical temperature of 68 °C, which is the closest to room temperature (25 °C). The electrical transition is also accompanied by structural and optical changes. The optical transition upon heating-also known as thermochromism-makes VO2 a possible coating for “intelligent” windows. In this work, the relationship between the thermochromic performance of VO2 films and the surface morphology was investigated using Temperature-dependent Atomic Force Microscopy (T-AFM) in conjunction with the X-ray Diffraction technique and Scanning Electron Microscopy. In particular, VO2 films were deposited using the rf sputtering technique on Silicon and glass substrates at a substrate temperature of 300 °C, which is one of the lowest for this technique to grow the thermochromic monoclinic phase of VO2. It was found that upon heating (25–100 °C), there was a decrease in RMS roughness for all films independent from the substrate; the value of RMS roughness, however, varied depending on the substrate. Finally, the thermochromic parameters of the VO2 films were correlated with the surface morphology and appeared to be dependent on the kind of substrate used.
Dry Resist Metrology Readiness for High-NA EUVL Gian Francesco Lorusso, Dieter Van Den Heuvel, Mohamed Zidan, Alain Moussa, Christophe Beral, Anne-Laure Charley, Danilo De Simone, Anuja De Silva, Elisseos Verveniotis, Ali Haider, Tsuyoshi Kondo, hiroyuki shindo, yasushi ebizuka, miki isawa Proceedings of SPIE the International Society for Optical Engineering, 2023 As High Numerical Aperture Extreme Ultraviolet Lithography (High NA EUVL) gets ready to step in the integrated circuit manufacturing (ICM) world, more and more work is being devoted to ensuring that all the elements involved in the process, from materials to equipment, will be ready to meet the required specifications when the time comes. One of the most critical pieces in such an ecosystem is the photoresist (PR), the material used to accurately transfer the design to the wafer. In the last years we have observed the introduction of various effective alternative approaches, such as dry metal oxide photoresist. PR always had to meet daunting specifications in terms of resolution, roughness, and sensitivity. However, in the brave new world of High NA EUVL, this is not enough. In fact, as the size of the printed features shrink, it is essential to limit the aspect ratio to avoid pattern collapse. Furthermore, the larger NA will reduce the Depth of Focus (DOF), thus requiring the use of ultra-thin resist films. The direct consequence of that is that the resist thicknesses used nowadays will not be suitable for High NA EUVL, where target thickness is expected to drop down to 20nm or less. Such a dramatic reduction in thickness has the potential to negatively impact, beside printing performances, the quality of the metrology and inspection as well, as discussed in our previous work. In the present work, we study the effects of reducing thickness in the case dry resist using various metrology and inspection techniques, such as Critical Dimension Scanning Electron Microscope (CDSEM), Atomic Force Microscopy (AFM), and e-beam defect inspection. As resist thickness decreases, noise level and image contrast are expected to be reduced, with a potential negative impact on the quality of the CD measurements both in terms of accuracy and precision.
Observation of room temperature electronic localization through a single graphene layer on sapphire Elisseos Verveniotis, Yuji Okawa, Shu Nakaharai, Shinichi Ogawa, Tomonobu Nakayama, Masakazu Aono, Christian Joachim Japanese Journal of Applied Physics, 2019 A He + ion beam is used to induce electronic localization, on a single graphene layer exfoliated on an ultra-flat sapphire substrate, based on crystalline defects and with a lateral irradiation precision of 1 nm. Inducing a 1% carbon defect density by step by step irradiation of a 100-nm-wide band on the supported graphene increases its electrical resistance from 0.90 to 133 kΩ. The resistance build-up was monitored in situ and in real time by measuring the I ( t ) current intensity through the graphene monolayer flake during its irradiation. The whole process takes place on an ultra-polished sapphire surface used to retain the planarity of the graphene. We propose that local heating of the graphene by irradiation promotes the migration of the created atomic carbon defects to the edge of the flake. This inherently moderates the increase of resistance with time during He + irradiation due to the gradual re-opening of low-voltage graphene ballistic channels.
Self-sensitization and photo-polymerization of diacetylene molecules self-assembled on a hexagonal-boron nitride nanosheet Elisseos Verveniotis, Yuji Okawa, Kenji Watanabe, Takashi Taniguchi, Takaaki Taniguchi, Minoru Osada, Christian Joachim, Masakazu Aono Polymers, 2018 Long poly-diacetylene chains are excellent candidates for planar, on-surface synthesized molecular electronic wires. Since hexagonal-Boron Nitride (h-BN) was identified as the best available atomically flat insulator for the deposition of poly-diacetylene precursors, we demonstrate the polymerization patterns and rate on it under UV-light irradiation, with subsequent polymer identification by atomic force microscopy. The results on h-BN indicate self-sensitization which yields blocks comprised of several polymers, unlike on the well-studied graphite/diacetylene system, where the polymers are always isolated. In addition, the photo-polymerization proceeds at least 170 times faster on h-BN, where it also results in longer polymers. Both effects are explained by the h-BN bandgap, which is larger than the diacetylene electronic excitation energy, thus allowing the transfer of excess energy absorbed by polymerized wires to adjacent monomers, triggering their polymerization. This work sets the stage for conductance measurements of single molecular poly-diacetylene wires on h-BN.
Quantum transport localization through graphene Saurabh Srivastava, Hiori Kino, Shu Nakaharai, Elisseos Verveniotis, Yuji Okawa, Shinichi Ogawa, Christian Joachim, Masakazu Aono Nanotechnology, 2017 Localization of atomic defect-induced electronic transport through a single graphene layer is calculated using a full-valence electronic structure description as a function of the defect density and taking into account the atomic-scale deformations of the layer. The elementary electronic destructive interferences leading to Anderson localization are analyzed. The low-voltage current intensity decreases with increasing length and defect density, with a calculated localization length ζ = 3.5 nm for a defect density of 5%. The difference from the experimental defect density of 0.5% required for an oxide surface-supported graphene to obtain the same ζ is discussed, pointing out how interactions of the graphene supporting surface and surface chemical modifications also control electronic transport localization.
Ultrathin monomolecular films and robust assemblies based on cyclic catechols Markus M. Zieger, Ognen Pop-Georgievski, Andres de los Santos Pereira, Elisseos Verveniotis, Corinna M. Preuss, Matthias Zorn, Bernd Reck, Anja S. Goldmann, Cesar Rodriguez-Emmenegger, Christopher Barner-Kowollik Langmuir, 2017 We introduce a newly designed catechol-based compound and its application for the preparation of homogeneous monomolecular layers as well as for robust assemblies on various substrates. The precisely defined cyclic catechol material (CyCat) was prepared from ortho-dimethoxybenzene in a phenolic resin-like synthesis and subsequent deprotection, featuring molecules with up to 32 catechol units. The CyCat’s chemical structure was carefully assessed via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), proton nuclear magnetic resonance (1H NMR), diffusion ordered spectroscopy (2D DOSY) and high resolution electrospray ionization mass spectrometry (ESI MS) experiments. The formation of colloidal aggregates of the CyCat material in alkaline solution was followed by dynamic light scattering (DLS) and further verified by dropcasting CyCat from solution on highly oriented pyrolytic graphite (HOPG), which was examined by Kelvin probe force microscopy (KPFM). The adsorption behavior of the CyCat to form monomolecular layers was investigated in real time by surface plasmon resonance (SPR). Formation of these thin CyCat layers (1.6–2.1 nm) on Au, SiO2 and TiO2 substrates was corroborated by spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS). The prepared coating perfectly reflects the surface structure of the underlying substrate and does not exhibit CyCat colloidal aggregates as verified by atomic force microscopy (AFM). The functional nature of the prepared catechol monolayers was evidenced by reaction with 4-bromophenethylamine and bis(3-aminopropyl)-terminated poly(ethylene oxide) (PEO). Multilayer assemblies were prepared by a simple procedure of iterative immersion in solutions of CyCat and a multifunctional amine on Au, SiO2 and TiO2 substrates forming thicker coatings (up to 12 nm). Postmodification with small organic molecules was performed to covalently attach trifluoroacetyl, tetrazole and 2-bromo-2-methylpropanoyl moieties to the amine groups of the multilayer assembly coating. Furthermore, the versatility of the novel multilayer coating was underpinned by “grafting-to” of phenacyl sulfide–terminated PEO and “grafting-from” of poly(methyl methacrylate) via surface-initiated atom transfer radical polymerization (ATRP).
Self-assembled diacetylene molecular wire polymerization on an insulating hexagonal boron nitride (0001) surface Marina V Makarova, Yuji Okawa, Elisseos Verveniotis, Kenji Watanabe, Takashi Taniguchi, Christian Joachim, Masakazu Aono Nanotechnology, 2016 The electrical characterization of single-polymer chains on a surface is an important step towards novel molecular device development. The main challenge is the lack of appropriate atomically flat insulating substrates for fabricating single-polymer chains. Here, using atomic force microscopy, we demonstrate that the (0001) surface of an insulating hexagonal boron nitride (h-BN) substrate leads to a flat-lying self-assembled monolayer of diacetylene compounds. The subsequent heating or ultraviolet irradiation can initiate an on-surface polymerization process leading to the formation of long polydiacetylene chains. The frequency of photo-polymerization occurrence on h-BN(0001) is two orders of magnitude higher than that on graphite(0001). This is explained by the enhanced lifetime of the molecular excited state, because relaxation via the h-BN is suppressed due to a large band gap. We also demonstrate that on-surface polymerization on h-BN(0001) is possible even after the lithography process, which opens up the possibility of further electrical investigations.
Self-assembling diacetylene molecules on atomically flat insulators Elisseos Verveniotis, Yuji Okawa, Marina V. Makarova, Yasuo Koide, Jiangwei Liu, Břetislav Šmíd, Kenji Watanabe, Takashi Taniguchi, Katsuyoshi Komatsu, Takeo Minari, Xuying Liu, Christian Joachim, Masakazu Aono Physical Chemistry Chemical Physics, 2016 The diacetylene self-assembly mechanism on atomically flat insulators is elucidated, towards using polydiacetylene wires in molecular electronic devices.
Low temperature diamond growth Rsc Nanoscience and Nanotechnology, 2014
E-beam metrology and line local critical dimension uniformity of thin dry resist films for high numerical aperture extreme ultraviolet lithography M Zidan, GF Lorusso, D De Simone, A De Silva, A Haider, E Verveniotis, ... Journal of Micro/Nanopatterning, Materials, and Metrology 22 (4), 044001-044001 , 2023 2023 Citations: 2
Study on the Surface Morphology of Thermochromic Rf-Sputtered VO 2 Films Using Temperature-Dependent Atomic Force Microscopy E Gagaoudakis, E Verveniotis, Y Okawa, G Michail, E Aperathitis, ... Applied Sciences 13 (13), 7662 , 2023 2023 Citations: 3
Dry resist patterning readiness towards high-NA EUV lithography HS Suh, D De Simone, C Beral, M Gupta, N Vandenbroeck, A De Silva, ... Advances in Patterning Materials and Processes XL 12498, 1249803 , 2023 2023 Citations: 17
Dry resist metrology readiness for high-NA EUVL GF Lorusso, D Van Den Heuvel, M Zidan, A Moussa, C Beral, AL Charley, ... Metrology, Inspection, and Process Control XXXVII 12496, 290-299 , 2023 2023 Citations: 5
Achieving zero EUV patterning defect with dry photoresist system M Alvi, R Gottscho, A Haider, S Heo, PY Hsieh, CC Huang, G Jurczak, ... Advances in Patterning Materials and Processes XXXIX, PC120550B , 2022 2022 Citations: 11
Observation of room temperature electronic localization through a single graphene layer on sapphire E Verveniotis, Y Okawa, S Nakaharai, S Ogawa, T Nakayama, M Aono, ... Japanese Journal of Applied Physics 58 (5), 055007 , 2019 2019 Citations: 4
Self-sensitization and photo-polymerization of diacetylene molecules self-assembled on a hexagonal-boron nitride nanosheet E Verveniotis, Y Okawa, K Watanabe, T Taniguchi, T Taniguchi, M Osada, ... Polymers 10 (2), 206 , 2018 2018 Citations: 9
Ultrathin monomolecular films and robust assemblies based on cyclic catechols MM Zieger, O Pop-Georgievski, A de los Santos Pereira, E Verveniotis, ... Langmuir 33 (3), 670-679 , 2017 2017 Citations: 15
Quantum transport localization through graphene S Srivastava, H Kino, S Nakaharai, E Verveniotis, Y Okawa, S Ogawa, ... Nanotechnology 28 (3), 035703 , 2017 2017 Citations: 8
Self-assembled diacetylene molecular wire polymerization on an insulating hexagonal boron nitride (0001) surface MV Makarova, Y Okawa, E Verveniotis, K Watanabe, T Taniguchi, ... Nanotechnology 27 (39), 395303 , 2016 2016 Citations: 27
On-Surface Synthesis of Single Conjugated Polymer Chains for Single-Molecule Devices Y Okawa, SK Mandal, M Makarova, E Verveniotis, M Aono On-Surface Synthesis: Proceedings of the International Workshop On-Surface … , 2016 2016
Self-assembling diacetylene molecules on atomically flat insulators E Verveniotis, Y Okawa, MV Makarova, Y Koide, J Liu, B Šmíd, ... Physical Chemistry Chemical Physics 18 (46), 31600-31605 , 2016 2016 Citations: 12
Low temperature diamond growth T Izak, O Babchenko, S Potocky, Z Remes, H Kozak, E Verveniotis, ... 2014 Citations: 9
Controlling electrostatic charging of nanocrystalline diamond at nanoscale E Verveniotis, A Kromka, B Rezek Langmuir 29 (23), 7111-7117 , 2013 2013 Citations: 9
Structuring and study of electronic and chemical properties of semiconductor surfaces E Verveniotis Univerzita Karlova, Matematicko-fyzikální fakulta , 2013 2013
A facile avenue to conductive polymer brushes via cyclopentadiene–maleimide Diels–Alder ligation B Yameen, C Rodriguez-Emmenegger, CM Preuss, O Pop-Georgievski, ... Chemical Communications 49 (77), 8623-8625 , 2013 2013 Citations: 47
Generating ordered Si nanocrystals via atomic force microscopy E Verveniotis, E Šípek, J Stuchlík, J Kočka, B Rezek Journal of non-crystalline solids 358 (17), 2118-2121 , 2012 2012 Citations: 4
How nanocrystalline diamond films become charged in nanoscale E Verveniotis, A Kromka, M Ledinský, B Rezek Diamond and related materials 24, 39-43 , 2012 2012 Citations: 14
Comparative study on dry etching of polycrystalline diamond thin films T Izak, A Kromka, O Babchenko, M Ledinsky, K Hruska, E Verveniotis Vacuum 86 (6), 799-802 , 2012 2012 Citations: 39
Direct growth of sub-micron diamond structures O Babchenko, E Verveniotis, K Hruska, M Ledinsky, A Kromka, B Rezek Vacuum 86 (6), 693-695 , 2012 2012 Citations: 14
MOST CITED SCHOLAR PUBLICATIONS
A facile avenue to conductive polymer brushes via cyclopentadiene–maleimide Diels–Alder ligation B Yameen, C Rodriguez-Emmenegger, CM Preuss, O Pop-Georgievski, ... Chemical Communications 49 (77), 8623-8625 , 2013 2013 Citations: 47
Comparative study on dry etching of polycrystalline diamond thin films T Izak, A Kromka, O Babchenko, M Ledinsky, K Hruska, E Verveniotis Vacuum 86 (6), 799-802 , 2012 2012 Citations: 39
Self-assembled diacetylene molecular wire polymerization on an insulating hexagonal boron nitride (0001) surface MV Makarova, Y Okawa, E Verveniotis, K Watanabe, T Taniguchi, ... Nanotechnology 27 (39), 395303 , 2016 2016 Citations: 27
Guided assembly of nanoparticles on electrostatically charged nanocrystalline diamond thin films E Verveniotis, A Kromka, M Ledinský, J Čermák, B Rezek Nanoscale research letters 6 (1), 144 , 2011 2011 Citations: 21
Dry resist patterning readiness towards high-NA EUV lithography HS Suh, D De Simone, C Beral, M Gupta, N Vandenbroeck, A De Silva, ... Advances in Patterning Materials and Processes XL 12498, 1249803 , 2023 2023 Citations: 17
Ultrathin monomolecular films and robust assemblies based on cyclic catechols MM Zieger, O Pop-Georgievski, A de los Santos Pereira, E Verveniotis, ... Langmuir 33 (3), 670-679 , 2017 2017 Citations: 15
How nanocrystalline diamond films become charged in nanoscale E Verveniotis, A Kromka, M Ledinský, B Rezek Diamond and related materials 24, 39-43 , 2012 2012 Citations: 14
Direct growth of sub-micron diamond structures O Babchenko, E Verveniotis, K Hruska, M Ledinsky, A Kromka, B Rezek Vacuum 86 (6), 693-695 , 2012 2012 Citations: 14
Self-assembling diacetylene molecules on atomically flat insulators E Verveniotis, Y Okawa, MV Makarova, Y Koide, J Liu, B Šmíd, ... Physical Chemistry Chemical Physics 18 (46), 31600-31605 , 2016 2016 Citations: 12
Local electrostatic charging differences of sub‐100 nm nanocrystalline diamond films E Verveniotis, J Čermák, A Kromka, M Ledinský, Z Remeš, B Rezek physica status solidi (a) 207 (9), 2040-2044 , 2010 2010 Citations: 12
Achieving zero EUV patterning defect with dry photoresist system M Alvi, R Gottscho, A Haider, S Heo, PY Hsieh, CC Huang, G Jurczak, ... Advances in Patterning Materials and Processes XXXIX, PC120550B , 2022 2022 Citations: 11
AFM induced electrostatic charging of nanocrystalline diamond on silicon E Verveniotis, J Čermák, A Kromka, B Rezek physica status solidi (b) 246 (11‐12), 2798-2801 , 2009 2009 Citations: 11
Role of current profiles and atomic force microscope tips on local electric crystallization of amorphous silicon E Verveniotis, B Rezek, E Šípek, J Stuchlik, J Kočka Thin Solid Films 518 (21), 5965-5970 , 2010 2010 Citations: 10
Self-sensitization and photo-polymerization of diacetylene molecules self-assembled on a hexagonal-boron nitride nanosheet E Verveniotis, Y Okawa, K Watanabe, T Taniguchi, T Taniguchi, M Osada, ... Polymers 10 (2), 206 , 2018 2018 Citations: 9
Low temperature diamond growth T Izak, O Babchenko, S Potocky, Z Remes, H Kozak, E Verveniotis, ... 2014 Citations: 9
Controlling electrostatic charging of nanocrystalline diamond at nanoscale E Verveniotis, A Kromka, B Rezek Langmuir 29 (23), 7111-7117 , 2013 2013 Citations: 9
Quantum transport localization through graphene S Srivastava, H Kino, S Nakaharai, E Verveniotis, Y Okawa, S Ogawa, ... Nanotechnology 28 (3), 035703 , 2017 2017 Citations: 8
Impact of AFM-induced nano-pits in a-Si: H films on silicon crystal growth E Verveniotis, B Rezek, E Šípek, J Stuchlík, M Ledinský, J Kočka Nanoscale research letters 6 (1), 145 , 2011 2011 Citations: 6
Dry resist metrology readiness for high-NA EUVL GF Lorusso, D Van Den Heuvel, M Zidan, A Moussa, C Beral, AL Charley, ... Metrology, Inspection, and Process Control XXXVII 12496, 290-299 , 2023 2023 Citations: 5
Observation of room temperature electronic localization through a single graphene layer on sapphire E Verveniotis, Y Okawa, S Nakaharai, S Ogawa, T Nakayama, M Aono, ... Japanese Journal of Applied Physics 58 (5), 055007 , 2019 2019 Citations: 4
