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43 results on '"Emiliano Pallecchi"'

1. A Broadband Active Microwave Monolithically Integrated Circuit Balun in Graphene Technology

Author

Dalal Fadil, Vikram Passi, Wei Wei, Soukaina Ben Salk, Di Zhou, Wlodek Strupinski, Max C. Lemme, Thomas Zimmer, Emiliano Pallecchi, Henri Happy, and Sebastien Fregonese

Subjects
graphene, microwave, mmic, integrated circuits, active balun, 2d materials, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract

This paper presents the first graphene radiofrequency (RF) monolithic integrated balun circuit. It is composed of four integrated graphene field effect transistors (GFETs). This innovative active balun concept takes advantage of the GFET ambipolar behavior. It is realized using an advanced silicon carbide (SiC) based bilayer graphene FET technology having RF performances of about 20 GHz. Balun circuit measurement demonstrates its high frequency capability. An upper limit of 6 GHz has been achieved when considering a phase difference lower than 10° and a magnitude of amplitude imbalance less than 0.5 dB. Hence, this circuit topology shows excellent performance with large broadband performance and a functionality of up to one-third of the transit frequency of the transistor.

Published
2020
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2. High-Frequency Noise Characterization and Modeling of Graphene Field-Effect Transistors

Author

Gilles Dambrine, Emiliano Pallecchi, Marina Deng, Thomas Zimmer, Wei Wei, Dalal Fadil, Sebastien Fregonese, Magali De Matos, Henri Happy, Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Advanced NanOmeter DEvices - IEMN (ANODE - IEMN), NANOELECTRONIQUE/MODEL, Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Renatech Network, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Carbon - IEMN (CARBON - IEMN), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)

Subjects
Radiation, Materials science, Noise measurement, Graphene, business.industry, Transistor, 020206 networking & telecommunications, 02 engineering and technology, Chemical vapor deposition, Condensed Matter Physics, Noise figure, 7. Clean energy, law.invention, chemistry.chemical_compound, chemistry, law, 0202 electrical engineering, electronic engineering, information engineering, Scattering parameters, Silicon carbide, Optoelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Electrical and Electronic Engineering, business, Noise (radio)
Abstract

International audience; This article presents the small-signal and noise characterization of different technologies based on chemical vapor deposition (CVD) and silicon-carbide (SiC) graphene field-effect transistors (GFETs). The noise model, built on noise figure measurements under 50 Ω using the F 50 method, was verified by additional source-pull measurements, with special care for the GFET stability. The four noise parameters were then extracted by using the validated F 50 model up to 18 GHz, and the correlations between noise and small-signal parameters were shown for two different configurations: top-gated and back-gated GFETs.

Published
2020
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3. Author Correction: Optoelectronic mixing with high-frequency graphene transistors

Author

U. Sassi, Pierre Legagneux, Domenico De Fazio, Henri Happy, P. Aversa, Andrea C. Ferrari, Alberto Montanaro, Wei Wei, Giancarlo Soavi, and Emiliano Pallecchi

Subjects
Hardware_MEMORYSTRUCTURES, Multidisciplinary, Materials science, business.industry, Graphene, Science, Transistor, Bandwidth (signal processing), General Physics and Astronomy, General Chemistry, Graphene field effect transistors, General Biochemistry, Genetics and Molecular Biology, law.invention, Wavelength, Optics and photonics, Optical properties and devices, Hardware_GENERAL, law, Hardware_INTEGRATEDCIRCUITS, Optoelectronics, business, Absorption (electromagnetic radiation), Author Correction, Mixing (physics)
Abstract

Graphene is ideally suited for optoelectronics. It offers absorption at telecom wavelengths, high-frequency operation and CMOS-compatibility. We show how high speed optoelectronic mixing can be achieved with high frequency (~20 GHz bandwidth) graphene field effect transistors (GFETs). These devices mix an electrical signal injected into the GFET gate and a modulated optical signal onto a single layer graphene (SLG) channel. The photodetection mechanism and the resulting photocurrent sign depend on the SLG Fermi level (E

Published
2021

4. Bias-dependent intrinsic rf thermal noise modeling and characterization of single-layer graphene fets

Author

Nikolaos Mavredakis, David Jiménez, Wei Wei, Paulius Sakalas, Anibal Pacheco-Sanchez, Henri Happy, Emiliano Pallecchi, Universitat Autònoma de Barcelona (UAB), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Carbon - IEMN (CARBON - IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), This work was funded by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. GrapheneCore2 785219 and No. GrapheneCore3 881603. We also acknowledge financial support by Spanish government under the projects RTI2018-097876-B-C21 (MCIU/AEI/FEDER, UE) and project 001-P-001702- GraphCat: Comunitat Emergent de Grafè a Catalunya, co-funded by FEDER within the framework of Programa Operatiu FEDER de Catalunya 2014-2020. This work was partly supported by the French RENATECH network., Renatech Network, European Project: 785219,H2020,GrapheneCore2(2018), and European Project: 881603,H2020,H2020-SGA-FET-GRAPHENE-2019, GrapheneCore3(2020)

Subjects
Thermal noise, Bias dependence, Semiconductor device modeling, FOS: Physical sciences, 02 engineering and technology, Intrinsic channel, Noise (electronics), law.invention, law, MOSFET, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Compact model, 0202 electrical engineering, electronic engineering, information engineering, Figure of merit, Electrical and Electronic Engineering, Excess noise factor, Velocity saturation (vs), Electronic circuit, Physics, Radiation, Condensed Matter - Mesoscale and Nanoscale Physics, business.industry, Graphene, Velocity saturation, Transistor, 020206 networking & telecommunications, Condensed Matter Physics, [SPI.TRON]Engineering Sciences [physics]/Electronics, Graphene transistor (gfet), Optoelectronics, business
Abstract

International audience; In this article, the bias dependence of intrinsic channel thermal noise of single-layer (SL) graphene field-effect transistors (GFETs) is thoroughly investigated by experimental observations and compact modeling. The findings indicate an increase of the specific noise as drain current increases, whereas a saturation trend is observed at very high carrier density regime. Besides, short-channel effects, such as velocity saturation (VS) also result in an increment of noise at higher electric fields. The main goal of this work is to propose a physics-based compact model that accounts for and accurately predicts the above experimental observations in short-channel GFETs. In contrast to long-channel MOSFET-based models adopted previously to describe thermal noise in graphene devices without considering the degenerate nature of graphene, in this work, a model for short-channel GFETs embracing the 2-D material's underlying physics and including a bias dependence is presented. The implemented model is validated with deembedded high-frequency data from two short-channel devices at quasi-static (QS) region of operation. The model precisely describes the experimental data for a wide range of low-to-high drain current values without the need of any fitting parameter. Moreover, the consideration of the degenerate nature of graphene reveals a significant decrease of noise in comparison with the nondegenerate case and the model accurately captures this behavior. This work can also be of utmost significance from the circuit designers' aspect since noise excess factor, a very important figure of merit for RF circuits implementation, is defined and characterized for the first time in graphene transistors. © 1963-2012 IEEE.

Published
2021
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5. A Broadband Active Microwave Monolithically Integrated Circuit Balun in Graphene Technology

Author

Emiliano Pallecchi, Thomas Zimmer, Max C. Lemme, Vikram Passi, Di Zhou, Soukaina Ben Salk, Henri Happy, Dalal Fadil, Sebastien Fregonese, Wei Wei, Wlodek Strupinski, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), School of Computer and Electronic Information [Guangxi University], Guangxi University [Nanning], Warsaw University of Technology [Warsaw], Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Carbon - IEMN (CARBON - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), EU Horizon2020 research and innovation programe (Graphene Flagship – Graphene Core2 785219) for financial supports. This work was partially supported by the French RENATECH network, Renatech Network, European Project: 785219,H2020,GrapheneCore2(2018), Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), and Carbon-IEMN (CARBON-IEMN)

Subjects
Materials science, microwave, mmic, 02 engineering and technology, Integrated circuit, 01 natural sciences, lcsh:Technology, law.invention, lcsh:Chemistry, chemistry.chemical_compound, law, Balun, 0103 physical sciences, Silicon carbide, General Materials Science, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Instrumentation, lcsh:QH301-705.5, Monolithic microwave integrated circuit, 010302 applied physics, Fluid Flow and Transfer Processes, Graphene, business.industry, lcsh:T, Process Chemistry and Technology, 2d materials, Transistor, graphene, General Engineering, 021001 nanoscience & nanotechnology, active balun, lcsh:QC1-999, Computer Science Applications, chemistry, lcsh:Biology (General), lcsh:QD1-999, lcsh:TA1-2040, Optoelectronics, 0210 nano-technology, Bilayer graphene, business, lcsh:Engineering (General). Civil engineering (General), ddc:600, integrated circuits, Microwave, lcsh:Physics
Abstract

Applied Sciences 10(6), 2183 (2020). doi:10.3390/app10062183, Published by MDPI, Basel

Published
2020
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6. Graphene for Radio Frequency Electronics

Author

Sebastien Fregonese, Emiliano Pallecchi, Henri Happy, Wlodek Strupinski, Wei Wei, and Fadil Dalal

Subjects
Materials science, Fabrication, Graphene, business.industry, Transistor, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, law.invention, chemistry.chemical_compound, chemistry, law, Logic gate, Hardware_INTEGRATEDCIRCUITS, Silicon carbide, Optoelectronics, Electronics, Radio frequency, 0210 nano-technology, business, Electronic circuit
Abstract

In the framework of the European project Flagship Graphene, we have developed several process technologies, for fabricating graphene field-effect transistors, for radio frequency (RF) applications. Depending on the technique used to synthesize graphene, different transistors topologies were designed, given rise to different applications. Graphene materials under consideration include graphene growth on silicon carbide, graphene growth by chemical vapor deposition (CVD) on copper foil. After fabrication of transistors on rigid and on flexible substrates, high frequency characterization of devices is made. Based on the performance of transistors, RF circuits where designed and fabricated.

Published
2020
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7. Experimental observation and modeling of the impact of traps on static and analog/HF performance of graphene transistors

Author

Anibal Pacheco-Sanchez, Nikolaos Mavredakis, Henri Happy, David Jiménez, Wei Wei, Emiliano Pallecchi, P. C. Feijoo, Universitat Autònoma de Barcelona (UAB), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon - IEMN (CARBON - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), European UnionEuropean Commission [GrapheneCore2 785219, GrapheneCore3 881603], Ministerio de Ciencia, Innovacion y Universidades [RTI2018-097876-B-C21], European Regional Development Funds (ERDF) through the Programa Operatiu FEDER de Catalunya 2014-2020, Secretaria d'Universitats i Recerca of the Departament d'Empresa i Coneixement of the Generalitat de CatalunyaGeneralitat de Catalunya, GraphCAT [001-P-001702], Renatech Network, European Project: 785219,H2020,GrapheneCore2(2018), Universidad Autónoma de Barcelona, and Carbon-IEMN (CARBON-IEMN)

Subjects
Materials science, FOS: Physical sciences, Applied Physics (physics.app-ph), graphene field-effect transistor (GFET), Transistors, 01 natural sciences, Analytical model, law.invention, [SPI]Engineering Sciences [physics], law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, high-frequency (HF) performance, Figure of merit, Electrical and Electronic Engineering, Polarity (mutual inductance), Pulse measurements, Condensed Matter::Quantum Gases, 010302 applied physics, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, business.industry, Hysteresis, Transistor, Experimental data, Logic gates, Voltage measurement, Physics - Applied Physics, Electronic, Optical and Magnetic Materials, [SPI.TRON]Engineering Sciences [physics]/Electronics, Logic gate, Performance evaluation, Optoelectronics, opposing pulses, channel potential, traps, business, Voltage
Abstract

International audience; The trap-induced hysteresis on the performance of a graphene field-effect transistor is experimentally diminished here by applying consecutive gate-to-source voltage pulses of opposing polarity. This measurement scheme is a practical and suitable approach to obtain reproducible device characteristics. Trap-affected and trap-reduced experimental data enable a discussion regarding the impact of traps on static and dynamic device performance. An analytical drain current model calibrated with the experimental data enables the study of the trap effects on the channel potential within the device. High-frequency (HF) figures of merit and the intrinsic gain of the device obtained from both experimental and synthetic data with and without hysteresis show the importance of considering the generally overlooked impact of traps for analog and HF applications.

Published
2020
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8. Gigahertz frequency graphene transistor, high yield process and good stability under strain

Author

T. Levert, Emiliano Pallecchi, S. B. Salk, Henri Happy, O. Txoperena, S. Mhedhbi, Wei Wei, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Renatech Network, and Carbon - IEMN (CARBON - IEMN)

Subjects
Materials science, Fabrication, Yield (engineering), Strain (chemistry), business.industry, Graphene, 020208 electrical & electronic engineering, Transistor, 020206 networking & telecommunications, 02 engineering and technology, Substrate (electronics), 7. Clean energy, Stability (probability), law.invention, Kapton, [SPI]Engineering Sciences [physics], law, 0202 electrical engineering, electronic engineering, information engineering, Optoelectronics, business
Abstract

We report a bonding free fabrication process suitable for flexible substrate based graphene field effect transistors (GFETs). Transistors with different gate length (100 nm, 200 nm and 300 nm) and different channel width $(12 \mu \mathrm{m}, 24 \mu \mathrm{m}$ and $50 \mu \mathrm{m})$ are successfully fabricated on Kapton substrate. The transistor yield is more than 80%. Our GFETs exhibit good stability with 0.5% strain applied. Our finding ensures for next application of RF circuit based on graphene transistor.

Published
2019
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9. Velocity Saturation Effect on Low Frequency Noise in Short Channel Single Layer Graphene Field Effect Transistors

Author

Jose A. Garrido, Andrea Bonaccini Calia, Ramon Garcia Cortadella, Wei Wei, D. Vignaud, Nikolaos Mavredakis, Emiliano Pallecchi, Henri Happy, David Jiménez, Departament d'Enginyeria Electrònica [Barcelona], Universitat Autònoma de Barcelona (UAB), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Carbon - IEMN (CARBON - IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Advanced NanOmeter DEvices - IEMN (ANODE - IEMN), EPItaxie et PHYsique des hétérostructures - IEMN (EPIPHY - IEMN), Catalan Institute of Nanoscience and Nanotechnology (ICN2), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Barcelona Institute of Science and Technology (BIST), Institució Catalana de Recerca i Estudis Avançats (ICREA), Renatech Network, European Project: 785219,H2020,GrapheneCore2(2018), European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon-IEMN (CARBON-IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
Materials science, Infrasound, 02 engineering and technology, low frequency noise, graphene field effect transistor, 01 natural sciences, Noise (electronics), Analytical model, [SPI]Engineering Sciences [physics], 0103 physical sciences, Phase noise, Materials Chemistry, Electrochemistry, Low frequency noise, 010302 applied physics, business.industry, Graphene field effect transistor, Velocity saturation, Contact resistance, graphene, analytical model, 021001 nanoscience & nanotechnology, velocity saturation, Electronic, Optical and Magnetic Materials, Optoelectronics, Field-effect transistor, Radio frequency, Graphene, 0210 nano-technology, business, Voltage
Abstract

Graphene devices for analog and radio frequency (RF) applications are prone to low frequency noise (LFN) due to its up conversion to undesired phase noise at higher frequencies. Such applications demand the use of short channel graphene transistors (GFETs) that operate at high electric fields in order to ensure a high speed. Electric field is inversely proportional to device length and proportional to channel potential, so it gets maximized as the drain voltage increases and the transistor's length shrinks. Under these conditions though, short channel effects like velocity saturation (VS) should be considered. The reduction of LFN data due to the VS effect at short channel GFETs operating at high drain potential is for the first time shown in the present work. Carrier number and mobility fluctuations have been proven to be the main sources that generate LFN in GFETs. While their contribution to the bias dependence of LFN in long channels has been thoroughly investigated, the way in which VS phenomenon affects LFN in short channel devices under high drain voltage conditions has not been well understood. In this paper we have proposed a physics-based analytical LFN model that works under both low and high electric field conditions. The implemented model is validated with experimental data from CVD grown back-gated single layer GFETs operating at gigahertz frequencies. The model accurately captures the reduction of LFN especially near the charge neutrality point because of the effect of the VS mechanism. Moreover, an analytical expression for the effect of contact resistance on LFN is derived. This contact resistance contribution is experimentally shown to be dominant at high gate voltages and is accurately described by the proposed model. The noise parameter related to LFN at contacts is found to have an exponential dependence with contact resistance, and to our knowledge, this is shown for the first time., This work was funded by the Ministerio de Economía y Competitividad under the project TEC2015-67462-C2-1-R and the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. GrapheneCore2 785219 (Graphene Flagship), Marie Skłodowska-Curie Grant Agreement No 665919 and Grant Agreement No. 732032 (BrainCom). This work was also partly supported by the French RENATECH network. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706).

Published
2019
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10. Croissance et caractérisation de graphène au Pôle CNFM de Lille

Author

Virginie Hoel, S. Ben Salk, Emiliano Pallecchi, Henri Happy, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Circuits Systèmes Applications des Micro-ondes - IEMN (CSAM - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Institut TELECOM/TELECOM Lille1, Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Carbon - IEMN (CARBON - IEMN)

Subjects
[SPI]Engineering Sciences [physics], 0103 physical sciences, graphene, 02 engineering and technology, 021001 nanoscience & nanotechnology, 010306 general physics, 0210 nano-technology, 01 natural sciences, [PHYS.PHYS.PHYS-ED-PH]Physics [physics]/Physics [physics]/Physics Education [physics.ed-ph]
Abstract

National audience; Le graphène en particulier, et les matériaux 2D en général, sont une nouvelle filière de matériaux aux propriétés physiques très intéressantes. Leurs propriétés électroniques, thermiques et mécaniques en font des matériaux de choix pour de nombreuses applications, dans les domaines aussi que les technologies de l’information et de la communication, la santé, l’énergie, le transport. Compte tenu des potentialités de ces matériaux, de nombreux grands programmes de recherche se sont développés au niveau international, pour étudier ces matériaux, et bénéficier des innovations qui en découleraient pour le développement de nouveaux emplois et de nouvelles richesses. Sur le plan de la formation, avec le soutien du GIP CNFM et de l’IDEFI FINMINA obtenu par le réseau du CNFM, le pôle CNFM de Lille s’est doté de nouveaux équipements qui permettent d’explorer, d’analyser, et de fabriquer des composants et systèmes avec ces matériaux 2D. Il s’agit notamment d’un four de croissance de graphène, d’un spectromètre Raman permettant de caractériser les matériaux 2D, du développement d’un système de transfert du graphène sur un matériau hôte. Cette communication va présenter la méthodologies mise en place, pour sensibiliser les étudiants du master 2 sur la manipulation de ces nouveaux matériaux.

Published
2018
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11. Fatigue test on flexible graphene field effect transistors with bottom gate electrode

Author

S. Bensalk, Dalal Fadil, Wei Wei, S. Mhedhbi, Emiliano Pallecchi, Henri Happy, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
Materials science, 02 engineering and technology, Channel width, Transistors, 01 natural sciences, law.invention, [SPI]Engineering Sciences [physics], Robustness (computer science), law, 0103 physical sciences, Radio frequency, Fatigue, 010302 applied physics, Substrates, Graphene, business.industry, Logic gates, 021001 nanoscience & nanotechnology, Graphene field effect transistors, Bottom gate, Electrode, Performance evaluation, Optoelectronics, Double gate, 0210 nano-technology, business
Abstract

International audience; Graphene is a promising candidate as channel material for flexible wearable radio frequency devices. In this work we fabricated double gate flexible graphene field effect transistors and characterized their DC and RF performance. Moreover, we performed a fatigue test consisting on a 1000 times dynamical bending at 1 Hz. The banding radius was 40 mm, which correspond to a strain of 0.16%. The DC and RF characterization shows the device performance variation is around 10%. The finding demonstrates the robustness of our GFETs, further work will be needed to determine the physical mechanism that cause the performance change.

Published
2018
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12. 2D-Graphene Epitaxy on SiC for RF Application: Fabrication, Electrical Characterization and Noise Performance

Author

Henri Happy, Marina Deng, W. Strupinski, Sebastien Fregonese, Emiliano Pallecchi, Wei Wei, Dalal Fadil, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Warsaw University of Technology [Warsaw], Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), and Carbon - IEMN (CARBON - IEMN)

Subjects
010302 applied physics, Materials science, Condensed matter physics, Silicon, Graphene, Transconductance, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, Epitaxy, Noise figure, 7. Clean energy, 01 natural sciences, law.invention, symbols.namesake, chemistry, law, 0103 physical sciences, symbols, Field-effect transistor, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Raman spectroscopy, Microwave, ComputingMilieux_MISCELLANEOUS
Abstract

Two-dimensional graphene grown by chemical vapor deposition (CVD) without the sublimation of the silicon of SiC substrate was used to fabricate field effect transistors. Atomic force microscopy and Raman spectroscopy measurements show the high quality of the graphene. The study of DC, radio frequency and microwave noise characteristics demonstrate reasonable extrinsic value of transconductance $(g_{m})$ , current gain cut-off frequency $(f_{T})$ and minimum noise figure $(NF_{min})$ related to the transistor dimension. For devices with gate length $\pmb{L_{g}=150}$ nm, the transistors show extrinsic current gain cut-off frequency $\pmb{f_{T_{-}extr}=65\mathrm{GHz}}$ associated to the maximum frequency of oscillation $\pmb{f_{max}=28\mathrm{GHz}}$ . The measurement of noise performance shows $\pmb{NF_{min}=4\mathrm{dB}}$ @ 10 GHz.

Published
2018
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13. Record high bandwidth integrated graphene photodetectors for communication beyond 180 Gb/s

Author

Daniel Neumaier, Daniel Schall, Guillaume Ducournau, Emiliano Pallecchi, Vanessa Avramovic, and Martin Otto

Subjects
Materials science, Silicon, Physics::Instrumentation and Detectors, Optical communication, Photodetector, chemistry.chemical_element, FOS: Physical sciences, Physics::Optics, 02 engineering and technology, Applied Physics (physics.app-ph), Hardware_PERFORMANCEANDRELIABILITY, 010402 general chemistry, 7. Clean energy, 01 natural sciences, law.invention, law, Hardware_INTEGRATEDCIRCUITS, Physics::Atomic and Molecular Clusters, Wafer, Physics::Chemical Physics, business.industry, Graphene, Bandwidth (signal processing), Physics - Applied Physics, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Semiconductor, chemistry, Optoelectronics, 0210 nano-technology, business, Ultrashort pulse
Abstract

We report on the fastest silicon waveguide integrated photodetectors with a bandwidth larger than 128 GHz for ultrafast optical communication. The photodetectors are based on CVD graphene that is compatible to wafer scale production methods., 3 pages, 2 figures

Published
2018

14. Transport mechanisms in a puckered graphene-on-lattice

Author

François Vaurette, D. Vignaud, Jean-Francois Lampin, Maxime Berthe, O. Lancry, Tao Xu, Bin Wei, Jimmy Xu, S. Eliet, Damien Eschimese, Bruno Grandidier, Wei Wei, Elisabeth Galopin, Henri Happy, Emiliano Pallecchi, A. Díaz Álvarez, D. Desremes, University of Shanghai [Shanghai], Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Physique - IEMN (PHYSIQUE - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon - IEMN (CARBON - IEMN), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN), Northwestern Polytechnical University [Xi'an] (NPU), Transduction, Propagation et Imagerie Acoustique - IEMN (TPIA - IEMN), Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520 (IEMN-DOAE), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Photonique THz - IEMN (PHOTONIQUE THz - IEMN), EPItaxie et PHYsique des hétérostructures - IEMN (EPIPHY - IEMN), AcknowledgementsWe thank C. Delerue, D. Stiévenard and L. Wirtz for fruitful discussions. This study was financially supported by the European Community's Seventh Framework Program (Grant No. PITN-GA-2012-316751, 'Nanoembrace' Project), the EQUIPEX program Excelsior (Grant No. ANR-11-EQPX-0015), and the RENATECH network. T. Xu acknowledges the supports of the National Natural Science Foundation of China (Grant No. 61775130) and of the Region Nord-Pas-de-Calais (Grant No. 2013_11806). J. Xu acknowledges the financial support of the University of Lille., Renatech Network, ANR-11-EQPX-0015,Excelsior,Centre expérimental pour l'étude des propriétés des nanodispositifs dans un large spectre du DC au moyen Infra-rouge.(2011), European Project: 316751,EC:FP7:PEOPLE,FP7-PEOPLE-2012-ITN,NANOEMBRACE(2013), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Centrale de Micro Nano Fabrication - IEMN (CMNF-IEMN), Photonique THz - IEMN (PHOTONIQ THz - IEMN), Carbon-IEMN (CARBON-IEMN), and Physique-IEMN (PHYSIQUE-IEMN)

Subjects
[PHYS]Physics [physics], Materials science, Graphene, business.industry, Compliant substrate, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Graphene monolayer, [SPI]Engineering Sciences [physics], Electrical transport, Electrical resistivity and conductivity, law, Lattice (order), 0103 physical sciences, Optoelectronics, [CHIM]Chemical Sciences, General Materials Science, [NLIN]Nonlinear Sciences [physics], 010306 general physics, 0210 nano-technology, business, Nanoscopic scale, Nanopillar
Abstract

International audience; Understanding the fundamental properties of graphene when its topography is patterned by the use of a compliant substrate is essential to improve the performances of graphene sensors. Here we suspend a graphene monolayer on SiO2 nanopillar arrays to form a puckered graphene-on-lattice and investigate the strain and electrical transport at the nanoscale. Despite a nonuniform strain in the graphene-on-lattice, the resistivity is governed by thermally activated transport and not the strain. We show that the high thermal activation energy results from a low charge carrier density and a periodic change of the chemical potential induced by the interaction of the graphene monolayer with the nanopillars, making the use of graphene-on-lattice attractive to further increase the electrical response of graphene sensors.

Published
2018
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15. Graphene FETs With Aluminum Bottom-Gate Electrodes and Its Natural Oxide as Dielectrics

Author

Haechon Kim, Mohamed Belhaj, Wei Wei, Geetanjali Deokar, Emiliano Pallecchi, Elisabeth Galopin, Xin Zhou, Henri Happy, D. Vignaud, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
Fabrication, Materials science, [SDV]Life Sciences [q-bio], Nanotechnology, 02 engineering and technology, Dielectric, 7. Clean energy, 01 natural sciences, Capacitance, law.invention, [SPI]Engineering Sciences [physics], law, 0103 physical sciences, [CHIM]Chemical Sciences, [NLIN]Nonlinear Sciences [physics], Electrical and Electronic Engineering, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], 010302 applied physics, business.industry, Graphene, Transistor, 021001 nanoscience & nanotechnology, Cutoff frequency, Flexible electronics, Electronic, Optical and Magnetic Materials, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, Optoelectronics, 0210 nano-technology, business, Graphene nanoribbons
Abstract

In this paper, we present a fabrication process of graphene field effect transistors (GFETs) using natural oxidation of aluminum as dielectrics, which provide an alternative fabrication choice for future flexible electronics with the large scale and arbitrary substrates. The high-quality monolayer graphene is preserved by our process, and the mobility up to 3250 cm2/Vs is measured after whole device fabrication. GFETs with double bottom-gate structure varying from 300 to 100 nm in gate length have been characterized by both static and dynamic measurements. The total gate capacitances of our device structure are evaluated based on the measurement results of scattering parameters. We report an intrinsic current gain cutoff frequency $(f_{t{\hbox{-}}\text {int}})$ of 11 GHz and a maximum oscillation frequency $(f_{\max })$ of 8 GHz in devices with 100 nm gate length. Moreover, both the values of $f_{t{\hbox{-}}\text {int}}$ and $f_{\max }$ for different gate lengths are also discussed. Our results indicate that the full process exhibits great potential, especially for graphene-based flexible electronics.

Published
2015
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16. Graphene FETs Based on High Resolution Nanoribbons for HF Low Power Applications

Author

David Mele, Wei Wei, Emiliano Pallecchi, Henri Happy, Abdelkarim Ouerghi, Dalal Fadil, Sarah Mehdhbi, Sylvie Lepilliet, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and Carbon - IEMN (CARBON - IEMN)

Subjects
Materials science, Band gap, Graphene, business.industry, Transistor, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, law.invention, [SPI]Engineering Sciences [physics], law, Optoelectronics, Field-effect transistor, Dry etching, 0210 nano-technology, business, Saturation (magnetic), Lithography, Graphene nanoribbons
Abstract

International audience; In this paper we present high frequency field effect transistors based on graphene nanoribbons arrays (GNRFETs). The nanoribbons serve as a channel for the transistors and are fabricated with a process based on e-beam lithography and dry etching of high mobility hydrogen intercalated epitaxial graphene. The widths of the nanoribbons vary from 50 to 20 nm, less than half those measured in previous reports for GNRFETs. Hall measurements reveal that the devices are p-doped, with mobility on the order of 2300 cm(2)/Vs. From DC characteristics, we find that the maximum ratio I-MAX/I-MIN is 5 obtained at 50 nm ribbons width. The IV characteristics of the GNRFETs are slightly non-linear at high bias without a full saturation. Therefore, despite the aggressive scaling of the graphene nanoribbon width, a bandgap is still not observed in our measurements. The high frequency performances of our GNRFETs are already significant at low bias. At 300 mV drain source voltage, the highest intrinsic (extrinsic) cut-off frequency f(t) reaches 82 (18) GHz and the extrinsic maximum oscillation frequency f(max) is 20 GHz, which is promising for low power applications.

Published
2018
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17. Graphene field effect transistors with optimized contact resistance for current gain

Author

Wei Wei, Domenico De Fazio, Henri Happy, Andrea C. Ferrari, U. Sassi, Emiliano Pallecchi, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and Cambridge Graphene Centre (Cambridge, UK)

Subjects
Materials science, Graphene, Ambipolar diffusion, business.industry, 020208 electrical & electronic engineering, Contact resistance, Transistor, Electrical engineering, Saturation velocity, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, law.invention, [SPI]Engineering Sciences [physics], law, 0202 electrical engineering, electronic engineering, information engineering, Scattering parameters, Optoelectronics, Field-effect transistor, Radio frequency, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS
Abstract

Graphene is a promising two dimensional channel material for radio frequency field effect transistors (RF-FET)[1]. It has ambipolar carriers with high mobility and high saturation velocity. It also has excellent mechanical robustness and flexibility. Due to these intrinsic properties, graphene based FETs can be applied to flexible, wearable components for RF applications such as high speed wireless communication. GFETs fabricated on rigid and flexible substrate have been demonstrated by several groups [2-4]. Nevertheless, the high metal-to-graphene contact resistance remains a bottleneck factor for RF performance. i.e, current gain cut-off frequency, ft. In this work, we report a process and full characterization of GFETs based on CVD graphene on Si/SiO 2 substrate. A low contact resistance (Rc) of 125 ohm·μm with high reliability was obtained by using pure Au. From the measurement of scattering parameters, we extracted the high frequency performances of our GFETs. Best intrinsic transit frequency have been observed for transistor with 180 nm channel length, with intrinsic ft of 100 GHz at low bias of 0.5V.

Published
2017
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18. High frequency and noise performance of GFETs

Author

Wei Wei, Emiliano Pallecchi, Sebastien Fregonese, Marina Deng, Gilles Dambrine, Thomas Zimmer, Dalal Fadil, Henri Happy, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Advanced NanOmeter DEvices - IEMN (ANODE - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Circuits Systèmes Applications des Micro-ondes - IEMN (CSAM - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Institut TELECOM/TELECOM Lille1, Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Carbon-IEMN (CARBON-IEMN), Renatech Network, European Project: 785219,H2020,GrapheneCore2(2018), and Carbon - IEMN (CARBON - IEMN)

Subjects
010302 applied physics, Materials science, business.industry, Terahertz radiation, Graphene, Amplifier, Contact resistance, Electrical engineering, Linearity, 02 engineering and technology, 021001 nanoscience & nanotechnology, Graphene field effect transistors, 01 natural sciences, Noise (electronics), Low noise, law.invention, law, 0103 physical sciences, Hardware_INTEGRATEDCIRCUITS, Optoelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS
Abstract

Graphene material exhibits a number of outstanding electronic and mechanical properties that make it very attractive for micro and nanoelectronic applications. Considering graphene field effect transistors (GFETs), considerable efforts were made during the recent years, and the devices at state of the art show impressive high frequency cut-off frequencies. The interest of GFET is particularly strong for some high frequency (HF) applications such as high linearity mixer in W-band, THz detection, …. In this paper we will give an overview on the GFETs and will present the devices developed in our Lab. Based on high frequency measurements of noise characteristics of our GFETs, we will point out the impact of technological aspects (such as contact resistance, device structure) on the HF noise performances. The implications of our findings for the development of graphene-based circuit such as low noise amplifiers will be also discussed.

Published
2017
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19. Single step fabrication of N-doped graphene/Si3N4/SiC heterostructures

Author

Abdelkarim Ouerghi, Emiliano Pallecchi, Mounib Bahri, Fausto Sirotti, Gilles Patriarche, Mathieu G. Silly, E. Velez-Fort, and Abhay Shukla

Subjects
Materials science, Photoemission spectroscopy, business.industry, Graphene, Heteroatom, Physics::Optics, Nanotechnology, Substrate (electronics), Condensed Matter Physics, Atomic and Molecular Physics, and Optics, law.invention, Condensed Matter::Materials Science, Electron diffraction, law, Physics::Atomic and Molecular Clusters, Optoelectronics, Condensed Matter::Strongly Correlated Electrons, General Materials Science, Physics::Chemical Physics, Electrical and Electronic Engineering, business, Bilayer graphene, Graphene nanoribbons, Graphene oxide paper
Abstract

In-plane heteroatom substitution of graphene is a promising strategy to modify its properties. The ability to dope graphene with electron-donor nitrogen heteroatoms is highly important for modulating electrical properties of graphene. Here we demonstrate a transfer-free method to directly grow large area quasi free-standing N-doped graphene bilayers on an insulating substrate (Si3N4). Electron-bombardment heating under nitrogen flux results in simultaneous growth of N-doped graphene and a Si3N4 layer on the SiC surface. The decoupling of N-doped graphene from the substrate and the presence of Si3N4 are identified by X-ray photoemission spectroscopy and low-energy electron diffraction. The substitution of nitrogen atoms in the graphene planes was confirmed using high resolution X-ray photoemission spectroscopy which reveals several atomic configurations for the nitrogen atoms: Graphitic-like, pyridine-like, and pyrroliclike. Furthermore, we demonstrated for the first time that N-doped graphene could be used to efficiently probe oxygen molecules via nitrogen atom defects. Open image in new window

Published
2014
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20. 2.5GHz integrated graphene RF power amplifier on SiC substrate

Author

T. Hanna, Emiliano Pallecchi, Sebastien Fregonese, M.S. Khenissa, Nathalie Deltimple, Henri Happy, Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), ANR-12-NANO-0004,GRACY,Electronique graphene pour amplificateur faible bruit(2012), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)

Subjects
Power gain, Power-added efficiency, Materials science, Circuit design, 02 engineering and technology, 01 natural sciences, law.invention, [SPI]Engineering Sciences [physics], law, 0103 physical sciences, Materials Chemistry, Figure of merit, Electrical and Electronic Engineering, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, business.industry, Graphene, Amplifier, RF power amplifier, Electrical engineering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Power (physics), [SPI.TRON]Engineering Sciences [physics]/Electronics, Optoelectronics, 0210 nano-technology, business
Abstract

In this work, we report the design of 2.5 GHz integrated power amplifier based on a graphene FET fabricated with thermal deposition on SiC. In this first large signal study of graphene radiofrequency power amplifiers, a power gain of 8.9 dB is achieved, the maximum reported output power and power added efficiency are 5.1 dBm and 2.2% respectively. Furthermore, graphene and Si CMOS amplifiers are compared; conclusions are drawn towards the technology enhancements to optimize the amplifiers figures of merit.

Published
2016
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21. Graphene field effect transistors on flexible substrate : stable process and high RF performance

Author

Z. Amaia, Alba Centeno, Wei Wei, Henri Happy, Emiliano Pallecchi, Mohamed Belhaj, D. Vignaud, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), EPItaxie et PHYsique des hétérostructures - IEMN (EPIPHY - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Renatech Network, and Graphenea S.A.

Subjects
Materials science, Fabrication, Yield (engineering), 02 engineering and technology, Substrate (electronics), Transistors, 01 natural sciences, 7. Clean energy, law.invention, Stable process, [SPI]Engineering Sciences [physics], law, Radio frequency, 0103 physical sciences, 010302 applied physics, Substrates, Graphene, Oscillation, business.industry, Transistor, Logic gates, 021001 nanoscience & nanotechnology, Kapton, Performance evaluation, Optoelectronics, 0210 nano-technology, business
Abstract

International audience; We report a simple and low temperature fabrication process suitable for flexible substrate based graphene field effect transistors (GFETs). Transistors with 300 nm gate length and different channel width (12 mu m and 24 mu m) were successfully fabricated on Kapton substrate. We report asmeasured current gain cut-off frequency of 27 GHz and maximum oscillation frequency of 12 GHz. The high performance transistors with high yield in this work demonstrate the great potential of our full process for flexible GFETs.

Published
2016
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22. Contact resistance study of 'edge-contacted' metal-graphene interfaces

Author

Satender Kataria, Emiliano Pallecchi, Amit Gahoi, Jasper Ruhkopf, Henri Happy, Max C. Lemme, François Vaurette, Vikram Passi, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Centrale de Micro Nano Fabrication - IEMN (CMNF-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Renatech Network, and Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN)

Subjects
010302 applied physics, Fabrication, Materials science, business.industry, Graphene, Contact resistance, Dirac point, Nanotechnology, 02 engineering and technology, Edge (geometry), Parameter space, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Metal, [SPI]Engineering Sciences [physics], law, visual_art, 0103 physical sciences, visual_art.visual_art_medium, Optoelectronics, Point (geometry), 0210 nano-technology, business
Abstract

2016 46th European Solid-State Device Research Conference (ESSDERC) : 12-15 Sept. 2016 / [organizers and partner institutions: École Polytechnique Fédérale de Lausanne [und 6 andere] 46th European Solid-State Device Research Conference, ESSDERC 2016, Lausanne, Switzerland, 12 Sep 2016 - 15 Sep 2016; [Piscataway, NJ] : IEEE 7599629, 236-239 (2016). doi:10.1109/ESSDERC.2016.7599629, Published by IEEE, [Piscataway, NJ]

Published
2016
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23. Mechanically robust 39 GHz cut-off frequency graphene field effect transistors on flexible substrates

Author

Zurutuza Amaia, Vanessa Avramovic, Stefano Borini, Alba Centeno, Henri Happy, Emiliano Pallecchi, Samiul Haque, Wei Wei, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Carbon-IEMN (CARBON-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Graphenea S.A., EU European Commission [604391], French RENATECH network, Renatech Network, European Project: 604391,EC:FP7:ICT,FP7-ICT-2013-FET-F,GRAPHENE(2013), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Carbon - IEMN (CARBON - IEMN), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
010302 applied physics, chemistry.chemical_classification, Materials science, business.industry, Graphene, Bend radius, 02 engineering and technology, Polymer, 021001 nanoscience & nanotechnology, Graphene field effect transistors, Polarization (waves), 01 natural sciences, 7. Clean energy, Flexible electronics, Cutoff frequency, law.invention, [SPI]Engineering Sciences [physics], chemistry, Robustness (computer science), law, 0103 physical sciences, Optoelectronics, General Materials Science, 0210 nano-technology, business
Abstract

International audience; Graphene has been regarded as a promising candidate channel material for flexible devices operating at radio-frequency (RF). In this work we fabricated and fully characterized double bottom-gate graphene field effect transistors on flexible polymer substrates for high frequency applications. We report a record high as-measured current gain cut-off frequency (f(t)) of 39 GHz. The corresponding maximum oscillation frequency (f(max)) is 13.5 GHz. These state of the art high frequency performances are stable against bending, with a typical variation of around 10%, for a bending radius of up to 12 mm. To demonstrate the reliability of our devices, we performed a fatigue stress test for RF-GFETs which were dynamically bend tested 1000 times at 1 Hz. The devices are mechanically robust, and performances are stable with typical variations of 15%. Finally we investigate thermal dissipation, which is a critical parameter for flexible electronics. We show that at the optimum polarization the normalized power dissipated by the GFETs is about 0.35 mW mu m(-2) and that the substrate temperature is around 200 degree centigrade. At a higher power, irreversible degradations of the performances are observed. Our study on state of the art flexible GFETs demonstrates mechanical robustness and stability upon heating, two important elements to assess the potential of GFETs for flexible electronics.

Published
2016
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24. Correction: Transport mechanisms in a puckered graphene-on-lattice

Author

A. Díaz Álvarez, D. Desremes, Damien Eschimese, Jimmy Xu, J-F. Lampin, Bruno Grandidier, François Vaurette, Maxime Berthe, Emiliano Pallecchi, D. Vignaud, Elisabeth Galopin, Wei Wei, Henri Happy, C Brillard, S. Eliet, O. Lancry, Tao Xu, and Bin Wei

Subjects
Materials science, Condensed matter physics, Graphene, law, Lattice (order), Hardware_INTEGRATEDCIRCUITS, General Materials Science, Nanoscopic scale, law.invention
Abstract

Correction for ‘Transport mechanisms in a puckered graphene-on-lattice’ by T. Xu et al., Nanoscale, 2018, 10, 7519–7525.

Published
2019
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25. Laterally inhomogeneous Au intercalation in epitaxial graphene on SiC(0001): a multimethod electron microscopy study

Author

Claire Mathieu, Tevfik Onur Menteş, Rachid Belkhou, Andrea Locatelli, Emiliano Pallecchi, Gilles Patriarche, Abdelkarim Ouerghi, Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Elettra Sincrotrone Trieste, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), and Synchrotron SOLEIL (SSOLEIL)

Subjects
[PHYS]Physics [physics], Materials science, Graphene, business.industry, Doping, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, chemistry.chemical_compound, chemistry, law, Transmission electron microscopy, 0103 physical sciences, Silicon carbide, Optoelectronics, 010306 general physics, 0210 nano-technology, Bilayer graphene, business, Layer (electronics), Graphene nanoribbons, Graphene oxide paper
Abstract

International audience; Epitaxial graphene is of particular interest because of its tunable electronic structure. One important approach to tune the electronic properties of graphene relays on intercalating atomic species between graphene and the topmost silicon carbide layer. Here, we investigated the morphology and electronic structure of gold-intercalated epitaxial graphene using a multitechnique approach combining spectroscopic photoemission low-energy electron microscopy (SPELEEM) for chemical and structural characterization at mesoscopic length scale and with transmission electron microscopy (STEM) at the atomic level. Deposition of gold on ex situ prepared graphene on SiC(0 0 0 1) results in the partial intercalation of Au adatoms under graphene, with the formation of a buffer layer of variable thickness. Gold has also shown to aggregate in nanometer-sized clusters lying on top of the same graphene film. X-ray photo-emission electron microscopy measurements indicate that Au induces only small changes in the doping of the graphene layer, which does not develop a quasi free-standing behavior.

Published
2016
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26. Fabrication and characterization of CVD grown graphene based field-effect transistor

Author

Wei Wei, Henri Happy, Mohamed Belhaj, Emmanuelle Pichonat, David Mele, Emiliano Pallecchi, D. Vignaud, Geetanjali Deokar, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), EPItaxie et PHYsique des hétérostructures - IEMN (EPIPHY - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and Renatech Network

Subjects
Fabrication, Materials science, Substrates, Graphene, Logic gates, Nanotechnology, Transistors, Characterization (materials science), law.invention, Cutoff frequency, [SPI]Engineering Sciences [physics], law, Field-effect transistor, Bilayer graphene, Scanning electron microscopy, Graphene nanoribbons, Graphene oxide paper
Abstract

International audience; In this work, we present both fabrication process and characterization of graphene field-effect transistors. Large scale monolayer graphene was grown by chemical vapor deposition (CVD) on Cu foils and transferred over pre-patterned back-gated devices on Si/SiO2 substrate. Scanning electron microscopy, Raman spectroscopy and Hall effect measurement were used for characterizing graphene quality before and after the transfer. It was found that monolayer graphene with a low defect density and hole mobility up to 3180cm(2)/Vs at n=1.3.10(12) cm(-2), could be obtained. For device characterization, devices with different gate length were discussed. We report an intrinsic current gain cut-off frequency (ft) of 15.5 GHz and maximum oscillation frequency of 12 GHz, deduced from the S-parameters measurements for device with gate length of 100 nm. This study demonstrates the potential of CVD-grown graphene for high speed electronics in combination with a technological process compatible with arbitrary substrates.

Published
2014
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27. Graphene field effect transistors on SiC with T-Shaped gate: Homogeneity and RF performance

Author

Mohamed Salah Khenissa, Emiliano Pallecchi, Mohamed Belhaj, Ivy Colambo, Henri Happy, D. Vignaud, David Mele, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
Materials science, business.industry, Graphene, Gate dielectric, Contact resistance, Electrical engineering, law.invention, [SPI]Engineering Sciences [physics], chemistry.chemical_compound, chemistry, law, Gate oxide, Logic gate, Silicon carbide, Optoelectronics, Field-effect transistor, business, Graphene nanoribbons
Abstract

In this letter we present our work on top-gated graphene field-effect transistors GFET. The Transistors have been processed on epitaxial graphene synthesized on the Si-face of a SiC substrate, using a high-k dielectric Al 2 O 3 as a gate oxide. In order to reduce the gate access resistance, we chosed a T-gate geometry. The Hall mobility is on the order 780 cm2/vs at room temperature, for an intrinsic carrier concentration of the order of 8.7 10+12 /cm2. We used Nickel as a contact material, The contact resistance was measured by the Transmission Line Method (TLM) where the value of ρ c is 2 × 10−6 Ω.cm2. We characterized our devices from DC up to 67 GHz. Cut-off frequency f t as high as 90 GHz has been obtained for the 170 nm gate length transistors. The maximum value of f t is 43 GHz and the maximum value of f max is 23 GHz. Finally, we studied the homogeneity of the GFETS realized across the whole sample surface (1/4 of inch).

Published
2014
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28. High frequency characterization and compact electrical modelling of Graphene Field Effect Transistors

Author

Mohamed Salah Khenissa, Poornakarthik Nakkala, Henri Happy, Emiliano Pallecchi, Mohamed Belhaj, D. Vignaud, Michel Campovecchio, David Mele, Audrey Martin, Ivy Colambo, C2S2 (XLIM-C2S2), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
Materials science, Oscillation, business.industry, Graphene, Transistor, Logic gates, Nanotechnology, Field effect transistors, Current measurement, Signal, [SPI.TRON]Engineering Sciences [physics]/Electronics, law.invention, Cutoff frequency, law, Frequency measurement, Solid modeling, Nonlinear modelling, Nano, Optoelectronics, business, Graphene nanoribbons, Microwave
Abstract

International audience; This paper deals with both DC and high frequency characterization of graphene devices, associated to compact electrical modelling. Pulsed I-V and microwave characterization of several Graphene Field-Effect Transistor (GFET) generations fabricated on SiC substrates were investigated in order to derive a first approach for non-linear device modelling. As illustrated here with a Graphene Nano Ribbon FET (GNR FET), a compact electrical model was presented accounting the DC and HF characteristics in broad range of operating conditions. The differences between DC and pulsed I-V characterizations of the GNR FET are investigated and compared to simulations. The small signal behavior and some figure of merits (FOM) like current gain cut-off frequency ft maximum oscillation frequency fmax. The nonlinear modelling of GNR FET is becoming of prime importance along with technological efforts to demonstrate the actual potential of this promising technology. This approach was also applied to conventional GFET, with a large flake of graphene used as a device channel.

Published
2014
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29. High Electron Mobility in Epitaxial Graphene on 4H-SiC(0001) via post-growth annealing under hydrogen

Author

V. Cavaliere, Emiliano Pallecchi, Abdelkarim Ouerghi, F. Lafont, W. Poirier, Félicien Schopfer, and Dominique Mailly

Subjects
Electron mobility, Multidisciplinary, Materials science, Condensed Matter - Mesoscale and Nanoscale Physics, Atmospheric pressure, Condensed matter physics, Graphene, Dangling bond, FOS: Physical sciences, Landau quantization, Quantum Hall effect, Article, law.invention, Electrical resistivity and conductivity, law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Bar (unit)
Abstract

We investigate the magneto-transport properties of epitaxial graphene single-layer on 4H-SiC(0001), grown by atmospheric pressure graphitization in Ar, followed by H2 intercalation. We directly demonstrate the importance of saturating the Si dangling bonds at the graphene/SiC(0001) interface to achieve high carrier mobility. Upon successful Si dangling bonds elimination, carrier mobility increases from 3 000 cm2V−1s−1 to >11 000 cm2V−1s−1 at 0.3 K. Additionally, graphene electron concentration tends to decrease from a few 1012 cm−2 to less than 1012 cm−2. For a typical large (30 × 280 μm2) Hall bar, we report the observation of the integer quantum Hall states at 0.3 K with well developed transversal resistance plateaus at Landau level filling factors of ν = 2, 6, 10, 14… 42 and Shubnikov de Haas oscillation of the longitudinal resistivity observed from about 1 T. In such a device, the Hall state quantization at ν = 2, at 19 T and 0.3 K, can be very robust: the dissipation in electronic transport can stay very low, with the longitudinal resistivity lower than 5 mΩ, for measurement currents as high as 250 μA. This is very promising in the view of an application in metrology.

Published
2014
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30. Flower-Shaped Domains and Wrinkles in Trilayer Epitaxial Graphene on Silicon Carbide

Author

Jules Girard, B. Lalmi, C. David, Emiliano Pallecchi, Abdelkarim Ouerghi, Sylvain Latil, Mathieu G. Silly, Fausto Sirotti, Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Groupe Modélisation et Théorie (GMT), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Service de physique de l'état condensé (SPEC - UMR3680), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Multidisciplinary, Materials science, business.industry, Graphene, 02 engineering and technology, Electronic structure, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Article, law.invention, chemistry.chemical_compound, chemistry, law, 0103 physical sciences, Silicon carbide, Optoelectronics, Epitaxial graphene, Scanning tunneling microscope, 010306 general physics, 0210 nano-technology, business, Spectroscopy, Graphene nanoribbons
Abstract

Trilayer graphene is of particular interest to the 2D materials community because of its unique tunable electronic structure. However, to date, there is a lack of fundamental understanding of the properties of epitaxial trilayer graphene on silicon carbide. Here, following successful synthesis of large-area uniform trilayer graphene, atomic force microscopy (AFM) showed that the trilayer graphene on 6H-SiC(0001) was uniform over a large scale. Additionally, distinct defects, identified as flower-shaped domains and isolated wrinkle structures, were observed randomly on the surface using scanning tunneling microscopy and spectroscopy (STM/STS). These carbon nanostructures formed during growth, has different structural and electronic properties when compared with the adjacent flat regions of the graphene. Finally, using low temperature STM/STS at 4K, we found that the isolated wrinkles showed an irreversible rotational motion between two 60° configurations at different densities of states.

Published
2014
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31. Disorder-perturbed Landau levels in high-electron-mobility epitaxial graphene

Author

Abderrezak Torche, Simon Maëro, Emiliano Pallecchi, Robson Ferreira, Louis-Anne de Vaulchier, Thanyanan Phuphachong, Abdelkarim Ouerghi, Yves Guldner, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Condensed matter physics, Absorption spectroscopy, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, Annealing (metallurgy), FOS: Physical sciences, Landau quantization, Condensed Matter Physics, 7. Clean energy, Electronic, Optical and Magnetic Materials, Electronic states, law.invention, law, Impurity, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Epitaxial graphene, High electron
Abstract

International audience; We show that the Landau levels in epitaxial graphene in the presence of localized defects are significantly modified compared to those of an ideal system. We report on magnetospectroscopy experiments performed on high-quality samples. Besides typical interband magneto-optical transitions, we clearly observe additional transitions that involve perturbed states associated with short-range impurities such as vacancies. Their intensity is found to decrease with an annealing process and a partial self-healing over time is observed. Calculations of the perturbed Landau levels by using a delta-like potential show electronic states both between and at the same energies as the Laudau levels of ideal graphene. The calculated absorption spectra involving all perturbed and unperturbed states are in very good agreement with the experiments.

Published
2014

32. Graphene nanotransistors for RF charge detection

Author

S. Lepillet, Henri Happy, Gilles Dambrine, Jean-Marc Berroir, Quentin Wilmart, Gwendal Fève, Bernard Plaçais, S. H. Jhang, Emiliano Pallecchi, Andreas Betz, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), The research has been supported by the Cnano contracts 'GraFet-e', 'Topin's and Grav's', the ANR-2010- MIGRAQUEL. The work of Q Wilmart is supported by the DGA., Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Electron mobility, Materials science, Acoustics and Ultrasonics, Transconductance, Analytical chemistry, 02 engineering and technology, 7. Clean energy, 01 natural sciences, Noise (electronics), law.invention, [SPI]Engineering Sciences [physics], law, 0103 physical sciences, Scattering parameters, 010306 general physics, business.industry, Graphene, Transistor, Biasing, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Optoelectronics, 0210 nano-technology, business, Microwave
Abstract

We have studied the static and dynamical properties of a graphene microwave nanotransistor to be used as sensitive fast charge detectors. The channel consists of exfoliated graphene on SiO2 with a 120 nm long, 900–1500 nm wide top-gate deposited on 5 nm AlOx dielectric. The scattering parameters were measured up to 60 GHz from which we deduce the gate capacitance, the drain conductance and the transconductance as a function of gate voltage. The broad measuring band allows us to measure the current gain and to map its full spectrum so as to extract reliable values of the transit frequency fT. From these measurements, we could estimate the carrier mobility, the doping of the access leads, the gate capacitance and the transconductance. The transconductance per unit width and bias voltage is larger than 1 mS µm−1 V−1 which compares with the performance of high electron mobility transistors. High-frequency characterization is achieved using microwave probe stations. Finally, using recent noise thermometry measurements, we estimate the charge resolution of graphene nanotransistors.

Published
2014
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33. Insulating to relativistic quantum Hall transition in disordered graphene

Author

W. Poirier, Félicien Schopfer, Emiliano Pallecchi, Dominique Mailly, Dimitrios Kazazis, Abdelkarim Ouerghi, M. Ridene, F. Lafont, and M. O. Goerbig

Subjects
Quantum phase transition, Physics, Mesoscopic physics, Multidisciplinary, Condensed matter physics, Graphene, Quantum Hall effect, Article, Electron localization function, Magnetic field, law.invention, Weak localization, symbols.namesake, Dirac fermion, law, symbols
Abstract

Quasi-particle excitations in graphene exhibit a unique behavior concerning two key phenomena of mesoscopic physics: electron localization and the quantum Hall effect. A direct transition between these two states has been found in disordered two-dimensional electron gases at low magnetic field. It has been suggested that it is a quantum phase transition, but the nature of the transition is still debated. Despite the large number of works studying either the localization or the quantum Hall regime in graphene, such a transition has not been investigated for Dirac fermions. Here we discuss measurements on low-mobility graphene where the localized state at low magnetic fields and a quantum Hall state at higher fields are observed. We find that the system undergoes a direct transition from the insulating to the Hall conductor regime. Remarkably, the transverse magneto-conductance shows a temperature independent crossing point, pointing to the existence of a genuine quantum phase transition.

Published
2013
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34. Supercollision cooling in undoped graphene

Author

Gwendal Fève, Jean-Marc Berroir, Sung Ho Jhang, Andreas Betz, Robson Ferreira, Bernard Plaçais, Emiliano Pallecchi, Berroir, Jean-Marc, Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, Phonon, FOS: Physical sciences, General Physics and Astronomy, Charge (physics), 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, law.invention, [PHYS.COND.CM-MSQHE] Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], law, Impurity, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, Nuclear Experiment, 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
Abstract

Carrier mobility in solids is generally limited by electron-impurity or electron-phonon scattering depending on the most frequently occurring event. Three body collisions between carriers and both phonons and impurities are rare; they are denoted supercollisions (SCs). Elusive in electronic transport they should emerge in relaxation processes as they allow for large energy transfers. As pointed out in Ref. \onlinecite{Song2012PRL}, this is the case in undoped graphene where the small Fermi surface drastically restricts the allowed phonon energy in ordinary collisions. Using electrical heating and sensitive noise thermometry we report on SC-cooling in diffusive monolayer graphene. At low carrier density and high phonon temperature the Joule power $P$ obeys a $P\propto T_e^3$ law as a function of electronic temperature $T_e$. It overrules the linear law expected for ordinary collisions which has recently been observed in resistivity measurements. The cubic law is characteristic of SCs and departs from the $T_e^4$ dependence recently reported for metallic graphene below the Bloch-Gr\"{u}neisen temperature. These supercollisions are important for applications of graphene in bolometry and photo-detection.

Published
2013

35. Effect of Oxygen Adsorption on the Local Properties of Epitaxial Graphene on SiC (0001)

Author

Claire Mathieu, Sylvain Latil, Tevfik Onur Menteş, B. Lalmi, R. Belkhou, Andrea Locatelli, Abdelkarim Ouerghi, and Emiliano Pallecchi

Subjects
Chemical Physics (physics.chem-ph), Microprobe, Condensed Matter - Materials Science, Materials science, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, Analytical chemistry, Dangling bond, chemistry.chemical_element, Charge density, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Angle-resolved photoemission spectroscopy, Condensed Matter Physics, Oxygen, Electronic, Optical and Magnetic Materials, law.invention, Electron diffraction, chemistry, law, Physics - Chemical Physics, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Layer (electronics)
Abstract

The effect of oxygen adsorption on the local structure and electronic properties of monolayer graphene grown on SiC(0001) has been studied by means of Low Energy Electron Microscopy (LEEM), microprobe Low Energy Electron Diffraction (\muLEED) and microprobe Angle Resolved Photoemission (\muARPES). We show that the buffer layer of epitaxial graphene on SiC(0001) is partially decoupled after oxidation. The monitoring of the oxidation process demonstrates that the oxygen saturates the Si dangling bonds, breaks some Si-C bonds at the interface and intercalates the graphene layer. Accurate control over the oxidation parameters enables us to tune the charge density modulation in the layer., 12 pages, 4 figures

Published
2012

36. Observation of the quantum Hall effect in epitaxial graphene on SiC(0001) with oxygen adsorption

Author

Emiliano Pallecchi, Claire Mathieu, M. Ridene, W. Poirier, Félicien Schopfer, Dominique Mailly, Dimitrios Kazazis, and Abdelkarim Ouerghi

Subjects
Mesoscopic physics, Electron density, Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, Photoemission spectroscopy, Doping, FOS: Physical sciences, Quantum Hall effect, law.invention, Adsorption, law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Monolayer
Abstract

In this letter we report on transport measurements of epitaxial graphene on SiC(0001) with oxygen adsorption. In a $50\times 50 \mu\mathrm{m^2}$ size Hall bar we observe the half-integer quantum Hall effect with a transverse resistance plateau quantized at filling factor around $\nu = 2$, an evidence of monolayer graphene. We find low electron concentration of $9\times 10^{11} \textrm{cm}^{-2}$ and we show that a doping of $10^{13}\textrm{cm}^{-2}$ which is characteristic of intrinsic epitaxial graphene can be restored by vacuum annealing. The effect of oxygen adsorption on carrier density is confirmed by local angle-resolved photoemission spectroscopy measurements. These results are important for understanding oxygen adsorption on epitaxial graphene and for its application to metrology and mesoscopic physics where a low carrier concentration is required., Comment: 4 pages, 3 figures

Published
2012

37. Epitaxial Graphene on 4H-SiC(0001) Grown under Nitrogen Flux: Evidence of Low Nitrogen Doping and High Charge Transfer

Author

E. Velez-Fort, Emiliano Pallecchi, Massimiliano Marangolo, Mathieu G. Silly, Abhay Shukla, Fausto Sirotti, Abdelkarim Ouerghi, Rachid Belkhou, Claire Mathieu, Marine Pigneur, Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, N-DOPED GRAPHENE, GRAPHITE, General Physics and Astronomy, Nanotechnology, 02 engineering and technology, Chemical vapor deposition, 010402 general chemistry, 01 natural sciences, law.invention, CARBON, RAMAN-SPECTROSCOPY, law, General Materials Science, Graphite, Graphene oxide paper, Dopant, business.industry, Graphene, Doping, General Engineering, 021001 nanoscience & nanotechnology, 0104 chemical sciences, CHEMICAL-VAPOR-DEPOSITION, Optoelectronics, 0210 nano-technology, Bilayer graphene, business, Graphene nanoribbons
Abstract

International audience; Nitrogen doping of graphene is of great interest for both fundamental research to explore the effect of dopants on a 2D electrical conductor and applications such as lithium storage, composites, and nanoelectronic devices. Here, we report on the modifications of the electronic properties of epitaxial graphene thanks to the introduction, during the growth, of nitrogen-atom substitution in the carbon honeycomb lattice. High-resolution transmission microscopy and low-energy electron microscopy investigations indicate that the nitrogen-doped graphene is uniform at large scale. The substitution of nitrogen atoms in the graphene planes was confirmed by high-resolution X-ray photoelectron spectroscopy, which reveals several atomic configurations for the nitrogen atoms: graphitic-like, pyridine-like, and pyrrolic-like. Angle-resolved photoemission measurements show that the N-doped graphene exhibits large n-type carrier concentrations of 2.6 x 10(13) cm(-1), about 4 times more than what is found for pristine graphene, grown under similar pressure conditions. Our experiments demonstrate that a small amount of dopants (

Published
2012
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38. Hot electron cooling by acoustic phonons in graphene

Author

Jean-Marc Berroir, Emiliano Pallecchi, Ali Madouri, Christophe Voisin, David Brunel, Matthieu Picher, Bernard Plaçais, Antonella Cavanna, Gwendal Fève, Fabien Vialla, Andreas Betz, Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Berroir, Jean-Marc

Subjects
Materials science, Field (physics), Phonon, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, law.invention, law, 0103 physical sciences, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 010306 general physics, ComputingMilieux_MISCELLANEOUS, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Coupling constant, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Graphene, Liquid helium, Bolometer, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-MSQHE] Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Heat equation, Atomic physics, 0210 nano-technology, Noise (radio)
Abstract

We have investigated the energy loss of hot electrons in metallic graphene by means of GHz noise thermometry at liquid helium temperature. We observe the electronic temperature T / V at low bias in agreement with the heat diffusion to the leads described by the Wiedemann-Franz law. We report on $T\propto\sqrt{V}$ behavior at high bias, which corresponds to a T4 dependence of the cooling power. This is the signature of a 2D acoustic phonon cooling mechanism. From a heat equation analysis of the two regimes we extract accurate values of the electron-acoustic phonon coupling constant $\Sigma$ in monolayer graphene. Our measurements point to an important effect of lattice disorder in the reduction of $\Sigma$, not yet considered by theory. Moreover, our study provides a strong and firm support to the rising field of graphene bolometric detectors., Comment: 5 figures

Published
2012
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39. Epitaxial graphene on step bunching of a 6H-SiC(0001) substrate: Aromatic ring pattern and Van Hove singularities

Author

Emiliano Pallecchi, Jules Girard, M. Ridene, T. Wassmann, Abdelkarim Ouerghi, and Guillemin Rodary

Subjects
Materials science, Fullerene, Physics and Astronomy (miscellaneous), Condensed matter physics, law, Graphene, Density functional theory, Substrate (electronics), Scanning tunneling microscope, Spectroscopy, Layer (electronics), Surface reconstruction, law.invention
Abstract

We report on scanning tunneling microscopy and spectroscopy (STM/STS) investigations of graphene grown on a 6H-SiC(0001) substrate. Our STM images of a graphene layer on a step bunching of the SiC feature a (√3 × √3)R30° pattern of aromatic rings and well developed, sharp Van Hove singularities in the corresponding STS spectra. High-resolution STM images show that the flake is discontinuous at the step edge. Simulations based on density functional theory indicate that the graphene edge is terminated armchair.

Published
2013
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40. Graphene microwave transistors on sapphire substrates

Author

Hilbert von Löhneysen, Bernard Plaçais, Romain Danneau, Christian Benz, Emiliano Pallecchi, Andreas Betz, Berroir, Jean-Marc, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Karlsruhe Institute of Technology (KIT), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Power gain, Physics and Astronomy (miscellaneous), Physics::Instrumentation and Detectors, FOS: Physical sciences, Physics::Optics, 02 engineering and technology, 01 natural sciences, 7. Clean energy, law.invention, Condensed Matter::Materials Science, law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, Monolayer, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Physics, Condensed Matter - Mesoscale and Nanoscale Physics, business.industry, Graphene, Amplifier, Transistor, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-MSQHE] Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Sapphire, Optoelectronics, 0210 nano-technology, business, Microwave, Noise (radio)
Abstract

We have developed metal-oxide graphene field-effect transistors (MOGFETs) on sapphire substrates working at microwave frequencies. For monolayers, we obtain a transit frequency up to ~ 80 GHz for a gate length of 200 nm, and a power gain maximum frequency of about ~ 3 GHz for this specific sample. Given the strongly reduced charge noise for nanostructures on sapphire, the high stability and high performance of this material at low temperature, our MOGFETs on sapphire are well suited for a cryogenic broadband low-noise amplifier.

Published
2011
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41. Transport scattering time probed through rf admittance of a graphene capacitor

Author

Jean-Marc Berroir, Emiliano Pallecchi, Takis Kontos, Benjamin Huard, Bernard Plaçais, Julien Chaste, Andreas Betz, Gwendal Fève, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Admittance, FOS: Physical sciences, 02 engineering and technology, 7. Clean energy, 01 natural sciences, law.invention, symbols.namesake, Nuclear magnetic resonance, law, 0103 physical sciences, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 010306 general physics, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Range (particle radiation), Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Scattering, Graphene, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Fick's laws of diffusion, Electronic, Optical and Magnetic Materials, Capacitor, Dirac fermion, Density of states, symbols, 0210 nano-technology
Abstract

We have investigated electron dynamics in top gated graphene by measuring the gate admittance of a diffusive graphene capacitor in a broad frequency range as a function of carrier density. The density of states, conductivity and diffusion constant are deduced from the low frequency gate capacitance, its charging time and their ratio. The admittance evolves from an RC-like to a skin-effect response at GHz frequency with a crossover given by the Thouless energy. The scattering time is found to be independent of energy in the 0 - 200 meV investigated range at room temperature. This is consistent with a random mass model for Dirac Fermions., Comment: 6 pages, 6 figures

42. High-Frequency Limits of Graphene Field-Effect Transistors with Velocity Saturation

Author

Takashi Taniguchi, Bernard Plaçais, Emmanuel Baudin, Quentin Wilmart, Mohamed Boukhicha, Vincent Bouchiat, Emiliano Pallecchi, Kenji Watanabe, Erwann Bocquillon, Gwendal Fève, José Palomo, Holger Graef, M. Rosticher, Jean-Marc Berroir, David Mele, Laboratoire de physique de l'ENS - ENS Paris (LPENS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Physique Mésoscopique, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), National Institute for Materials Science (NIMS), Systèmes hybrides de basse dimensionnalité (NEEL - HYBRID), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Nano-Optique, Carbon - IEMN (CARBON - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), The research leading to these results have received partial funding from the European UnionHorizon 2020 research and innovation programme under grant No. 785219 'Graphene Core 2', and fromthe ANR-14-CE08-018-05 'GoBN'. The work of Q.W. was supported by a DGA-MRIS scholarship, ANR-14-CE08-0018,GoBN,Hétérostructures de graphènes blanc et noir(2014), European Project: 785219,H2020,GrapheneCore2(2018), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Systèmes hybrides de basse dimensionnalité (HYBRID), Carbon-IEMN (CARBON-IEMN), Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris)

Subjects
Materials science, Terahertz radiation, Physics::Optics, 02 engineering and technology, Substrate (electronics), lcsh:Technology, 7. Clean energy, 01 natural sciences, law.invention, lcsh:Chemistry, Graphene transistor, [SPI]Engineering Sciences [physics], Dirac pinch-off, law, 0103 physical sciences, contact gating, General Materials Science, 010306 general physics, lcsh:QH301-705.5, Instrumentation, Fluid Flow and Transfer Processes, [PHYS]Physics [physics], lcsh:T, Scattering, business.industry, Graphene, Oscillation, Process Chemistry and Technology, Velocity saturation, Transistor, General Engineering, 021001 nanoscience & nanotechnology, velocity saturation, lcsh:QC1-999, Computer Science Applications, high-frequency, lcsh:Biology (General), lcsh:QD1-999, lcsh:TA1-2040, Optoelectronics, Field-effect transistor, lcsh:Engineering (General). Civil engineering (General), 0210 nano-technology, business, lcsh:Physics
Abstract

The current understanding of physical principles governing electronic transport in graphene field effect transistors (GFETs) has reached a level where we can model quite accurately device operation and predict intrinsic frequency limits of performance. In this work, we use this knowledge to analyze DC and RF transport properties of bottom-gated graphene on boron nitride field effect transistors exhibiting pronounced velocity saturation by substrate hyperbolic phonon polariton scattering, including Dirac pinch-off effect. We predict and demonstrate a maximum oscillation frequency exceeding 20 &nbsp, GHz . We discuss the intrinsic 0.1 &nbsp, THz limit of GFETs and envision plasma resonance transistors as an alternative for sub-THz narrow-band detection.

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43. Graphène et matériaux 2D : techniques de transfert, fabrication d'hétérostructures et applications

Author

Salk, Soukaina, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Carbon - IEMN (CARBON - IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Université de Lille, Henri Happy, and Emiliano Pallecchi

Subjects
Exfoliation électrochimique, Substrats métalliques, Graphene, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics
Abstract

The high theoretical mobility of graphene makes it an excellent material for radio frequency applications. However, this mobility is limited by structural defects introduced by material growth techniques, the transfer method from metallic substrates to hosting semiconductor substrates, the fabrication processes of devices as well as the interaction of graphene with hosting substrate. This thesis aims to address these issues in order to make graphene practically insensitive to its environment. There are mainly two parts involved in this work: (i) Transfer by electrochemical exfoliation (wet transfer) of millimetre size single domains of graphene (~ 5mm) synthesized by CVD as well as their physical and electrical characterization; this study is part of an exchange program between the IEMN and the University of Irvine-California (PUF-Partner University Funding Program-on the development of flexible electronics). (ii) Fabrication and characterization of hBN/Graphene/hBN heterostructures by dry transfer of exfoliated materials. Although the CVD (Chemical Vapor Deposition) method made it possible to obtain large single crystals of graphene on copper; the mandatory transfer to SiO2 substrate generally introduces defects and contaminations in graphene resulting in low performance devices. A reliable transfer system for CVD graphene is developed and optimized for cleanroom use. The method used is based on an electrochemical exfoliation approach known as Bubble transfer. By optimizing this approach, we were able to transfer graphene single domains without structural defects. Finally, the electrical characterization of devices based on the transferred graphene crystal made it possible to obtain a relatively low contact resistance owing to the good quality of the transferred graphene. In order to limit the interaction of graphene with its environment and thus preserve its high mobility, encapsulation with hexagonal boron nitride hBN makes it possible to satisfy this need. The fabrication of these Van der Waals heterostructures is performed using mechanically exfoliated materials because the growth of large areas hBN is still considered a great scientific challenge. An experimental nano-manipulation platform “Stamping set-up” dedicated to the stacking of 2D materials is developed (from design to realization) as well as a process for graphene encapsulation by dry transfer. Different samples have been successfully fabricated using monolayer and bilayer graphene. Morphological and structural characterizations have shown that graphene after encapsulation shows very low doping values and uniform strain at the nanometre scale; which promises high mobility values. This work paves the way towards obtaining high quality graphene which is an important part for the development of electronic devices based on heterostructures of 2D materials.; L’excellente mobilité du graphène en fait un matériau de choix pour les applications radiofréquence. Cependant, cette mobilité est limitée expérimentalement par les défauts structuraux et environnants introduits par la croissance du matériau sur substrat métallique, la méthode de transfert sur un support hôte, l’interaction du graphène avec le substrat hôte sur lequel il est transféré et par les procédés de fabrication des composants. Cette thèse, cofinancée par la Région Hauts-de-France, a pour objectif de remédier à ces problèmes afin de rendre le graphène pratiquement insensible à son environnement. Elle est constituée de deux grandes parties : (i) Le transfert par exfoliation électrochimique (transfert humide) des monocristaux de graphène millimétriques (~5mm) synthétisés par CVD ainsi que leur caractérisation physique et électrique ; cette étude est réalisée dans le cadre d’un programme d’échange entre l’IEMN et l’Université d’Irvine en Californie (Programme PUF-Partner University Funding-portant sur le développement de l’électronique flexible). (ii) La fabrication et la caractérisation d’hétérostructures hBN/Graphène/hBN par transfert sec de matériaux exfoliés. Bien que la méthode CVD (Chemical Vapor Deposition) ait permis récemment l’obtention de larges monocristaux de graphène ayant une très haute qualité sur cuivre ; le transfert vers un substrat SiO2 introduit généralement des défauts et des contaminations dans le graphène résultant en des dispositifs de basses performances. Une première partie du travail mené dans cette thèse a permis de développer et mettre au point au sein du laboratoire un système de transfert fiable du graphène CVD. La méthode utilisée est basée sur une approche d’exfoliation électrochimique exploitant l’effet des bulles générées à l’interface graphène/Cu. L’optimisation de cette approche nous a permis de transférer des cristaux de graphène en préservant leur qualité. Enfin, la caractérisation électrique de dispositifs fabriqués sur des cristaux de graphène a permis d’obtenir une résistance de contact relativement basse attestant de la bonne qualité du graphène transféré. Afin de limiter l’interaction du graphène avec son environnement et ainsi préserver sa haute mobilité, l’encapsulation par du nitrure de bore hexagonale hBN permet de satisfaire ce besoin. La croissance de grandes surfaces du hBN étant toujours un grand défi scientifique, l’exfoliation mécanique est une approche de synthèse nécessaire pour la réalisation de ces héterotructures de type Van der Waals. La seconde partie du travail mené dans cette thèse a permis de développer (de la conception à la réalisation) et de mettre en place au sein du laboratoire une plateforme de nano manipulation « Stamping Set-up » dédiée à l’empilement des matériaux 2D ainsi que le développement d’un procédé d’encapsulation du graphène par transfert sec. Différents échantillons ont été fabriqués avec succès en utilisant du graphène monocouche et bicouche. Les caractérisations morphologiques et structurelles ont permis de montrer que le graphène après encapsulation présente de très faibles valeurs de dopage et de variations de contraintes à l’échelle nanométrique. Ce qui promet des valeurs de mobilité élevées. Ces travaux fournissent une voie vers l’obtention de graphène de grande qualité qui constitue une brique essentielle pour le développement de dispositifs électroniques à base d’hétérostructures de matériaux 2D.

Published
2020

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