NOVASiC

Le Bourget-du-Lac, France
Le Bourget-du-Lac, France
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Lafont F.,French National Laboratory of Metrology and Testing | Ribeiro-Palau R.,French National Laboratory of Metrology and Testing | Kazazis D.,CNRS Optic of Semiconductor nanoStructures Group | Michon A.,French National Center for Scientific Research | And 8 more authors.
Nature Communications | Year: 2015

Replacing GaAs by graphene to realize more practical quantum Hall resistance standards (QHRS), accurate to within 10 â '9 in relative value, but operating at lower magnetic fields than 10â €‰T, is an ongoing goal in metrology. To date, the required accuracy has been reported, only few times, in graphene grown on SiC by Si sublimation, under higher magnetic fields. Here, we report on a graphene device grown by chemical vapour deposition on SiC, which demonstrates such accuracies of the Hall resistance from 10â €‰T up to 19â €‰T at 1.4â €‰K. This is explained by a quantum Hall effect with low dissipation, resulting from strongly localized bulk states at the magnetic length scale, over a wide magnetic field range. Our results show that graphene-based QHRS can replace their GaAs counterparts by operating in as-convenient cryomagnetic conditions, but over an extended magnetic field range. They rely on a promising hybrid and scalable growth method and a fabrication process achieving low-electron-density devices. © 2015 Macmillan Publishers Limited. All rights reserved.


PubMed | CNRS Charles Coulomb Laboratory, French National Center for Scientific Research, French National Laboratory of Metrology and Testing, NOVASiC and CNRS Optic of Semiconductor nanoStructures Group
Type: | Journal: Nature communications | Year: 2015

Replacing GaAs by graphene to realize more practical quantum Hall resistance standards (QHRS), accurate to within 10(-9) in relative value, but operating at lower magnetic fields than 10T, is an ongoing goal in metrology. To date, the required accuracy has been reported, only few times, in graphene grown on SiC by Si sublimation, under higher magnetic fields. Here, we report on a graphene device grown by chemical vapour deposition on SiC, which demonstrates such accuracies of the Hall resistance from 10T up to 19T at 1.4K. This is explained by a quantum Hall effect with low dissipation, resulting from strongly localized bulk states at the magnetic length scale, over a wide magnetic field range. Our results show that graphene-based QHRS can replace their GaAs counterparts by operating in as-convenient cryomagnetic conditions, but over an extended magnetic field range. They rely on a promising hybrid and scalable growth method and a fabrication process achieving low-electron-density devices.


Portail M.,French National Center for Scientific Research | Michon A.,French National Center for Scientific Research | Vezian S.,French National Center for Scientific Research | Lefebvre D.,French National Center for Scientific Research | And 7 more authors.
Journal of Crystal Growth | Year: 2012

The present work is proposing a comparative analysis of the graphitization, achieved by argon-propane assisted chemical vapor deposition, of 6H-SiC(0001) bulk substrates and 3C-SiC heteroepilayers deposited on (111) and (100) silicon. We have investigated the influence of the experimental parameters of the graphitization (pressure, propane flow rate and duration) both on the structural and the electrical properties of the graphitic/graphene phases developed at the samples surface. In particular, the growth mode has been highlighted. It has been shown that, in our experimental conditions, the formation of graphene is only a transitory step followed by a stage of rapid over-deposition of the surface by a highly disordered graphitic phase. This can be understood by a surface chemical potential variation accompanied by a balance between some mass transport at the surface (which could include sublimation) and a deposition regime. It shows that the process time must be properly adjusted to conserve the graphene at the surface. Furthermore, it is shown that the graphene sheet resistance is significantly dependent on the surface uniformity and can be tuned by varying the process pressure. © 2012 Elsevier B.V. All rights reserved.


Michon A.,French National Center for Scientific Research | Vzian S.,French National Center for Scientific Research | Ouerghi A.,CNRS Laboratory for Photonics and Nanostructures | Zielinski M.,NOVASiC | And 2 more authors.
Applied Physics Letters | Year: 2010

We propose to grow graphene on SiC by a direct carbon feeding through propane flow in a chemical vapor deposition reactor. X-ray photoemission and low energy electron diffraction show that propane allows to grow few-layer graphene (FLG) on 6H-SiC(0001). Surprisingly, FLG grown on (0001) face presents a rotational disorder similar to that observed for FLG obtained by annealing on (000-1) face. Thanks to a reduced growth temperature with respect to the classical SiC annealing method, we have also grown FLG/3C-SiC/Si(111) in a single growth sequence. This opens the way for large-scale production of graphene-based devices on silicon substrate. © 2010 American Institute of Physics.


Song X.,University Pierre and Marie Curie | Song X.,STMicroelectronics | Michaud J.F.,University Pierre and Marie Curie | Cayrel F.,University Pierre and Marie Curie | And 5 more authors.
Applied Physics Letters | Year: 2010

In this paper, we demonstrate the high electrical activity of extended defects found in 3C-SiC heteroepitaxially grown layer on (100) silicon substrates. Cross-sectional scanning transmission electron microscopy analysis was performed to reveal the defects while scanning spreading resistance microscopy aimed to study their electrical behavior. Using this technique, complete layer resistance cartography was done. The electrical activity of the extended defects in 3C-SiC was clearly evidenced. Furthermore, the defect activity was estimated to be higher than that of heavily nitrogen doped (5× 1018 cm-3) 3C-SiC layer. © 2010 American Institute of Physics.


Ouerghi A.,CNRS Laboratory for Photonics and Nanostructures | Kahouli A.,CNRS Laboratory for Photonics and Nanostructures | Lucot D.,CNRS Laboratory for Photonics and Nanostructures | Portail M.,French National Center for Scientific Research | And 7 more authors.
Applied Physics Letters | Year: 2010

Epitaxial graphene films grown on silicon carbide (SiC) substrate by solid state graphitization is of great interest for electronic and optoelectronic applications. In this paper, we explore the properties of epitaxial graphene films on 3C-SiC(111)/Si(111) substrate. X-ray photoelectron spectroscopy and scanning tunneling microscopy were extensively used to characterize the quality of the few-layer graphene (FLG) surface. The Raman spectroscopy studies were useful in confirming the graphitic composition and measuring the thickness of the FLG samples. © 2010 American Institute of Physics.


Michon A.,French National Center for Scientific Research | Vezian S.,French National Center for Scientific Research | Roudon E.,French National Center for Scientific Research | Lefebvre D.,French National Center for Scientific Research | And 3 more authors.
Journal of Applied Physics | Year: 2013

Graphene growth from a propane flow in a hydrogen environment (propane-hydrogen chemical vapor deposition (CVD)) on SiC differentiates from other growth methods in that it offers the possibility to obtain various graphene structures on the Si-face depending on growth conditions. The different structures include the (6√3 × 6√3)-R30°reconstruction of the graphene/SiC interface, which is commonly observed on the Si-face, but also the rotational disorder which is generally observed on the C-face. In this work, growth mechanisms leading to the formation of the different structures are studied and discussed. For that purpose, we have grown graphene on SiC(0001) (Si-face) using propane-hydrogen CVD at various pressure and temperature and studied these samples extensively by means of low energy electron diffraction and atomic force microscopy. Pressure and temperature conditions leading to the formation of the different structures are identified and plotted in a pressure-temperature diagram. This diagram, together with other characterizations (X-ray photoemission and scanning tunneling microscopy), is the basis of further discussions on the carbon supply mechanisms and on the kinetics effects. The entire work underlines the important role of hydrogen during growth and its effects on the final graphene structure. © 2013 AIP Publishing LLC.


Michaud J.F.,University Pierre and Marie Curie | Portail M.,French National Center for Scientific Research | Chassagne T.,NOVASiC | Zielinski M.,NOVASiC | Alquier D.,University Pierre and Marie Curie
Microelectronic Engineering | Year: 2013

Among the different silicon carbide polytypes, 3C-SiC is very interesting for Micro-Electro-Mechanical-Systems (MEMS) applications. This interest could benefit from the development of multi stacked Si/SiC heterostructures as illustrated by the achievement of a continuous silicon monocrystalline thin film on 3C-SiC epilayers deposited on (1 0 0) silicon substrates. Based on this recent result, an original monocrystalline 3C-SiC/Si/3C-SiC/Si hetero-structure has been developed by Low Pressure Chemical Vapor Deposition with a two-step process. This kind of structure allows the selective etching of the silicon epilayer in order to define an original 3C-SiC micro-structure. By wet etching, the remaining silicon film, used as a sacrificial layer, can be then etched, resulting in a monocrystalline 3C-SiC membrane on a 3C-SiC pseudo-substrate. This new and original approach opens the field for future MEMS devices. © 2013 Elsevier B.V. All rights reserved.


Jiao S.,University Pierre and Marie Curie | Jiao S.,French National Center for Scientific Research | Michaud J.F.,University Pierre and Marie Curie | Portail M.,French National Center for Scientific Research | And 4 more authors.
Materials Letters | Year: 2012

The recent achievement of a continuous silicon monocrystalline thin film on 3C-SiC epilayers deposited on silicon substrates has opened the field for new microstructures. In this work, this original hetero-structure is the basis for the elaboration of an entire cantilever for atomic force microscopy. The hetero-epitaxially grown silicon layer is used to define the tip of the cantilever fabricated from the 3C-SiC epilayer deposited on silicon. The complete cantilever is elaborated by plasma etching using a nickel mask. The use of a full dry etching process is very promising as it is independent of the crystalline orientation of the silicon epilayer contrary to process based on wet etching solutions. Moreover, based on such hetero-structure, new MEMS devices can be considered. © 2012 Elsevier B.V. All rights reserved.


Jiao S.,University Pierre and Marie Curie | Jiao S.,French National Center for Scientific Research | Portail M.,French National Center for Scientific Research | Michaud J.-F.,University Pierre and Marie Curie | And 3 more authors.
Materials Science Forum | Year: 2012

The growth of continuous silicon monocrystalline thin films on 3C-SiC epilayers deposited on silicon substrates is presented in this study. Such heterostructures can be beneficial for the fabrication of Micro Electro Mechanical Systems or electronic applications. The elaboration of these heterostructures was carried out using Low Pressure Chemical Vapor Deposition. X-ray Diffraction, Fourier Transformed Infra-Red spectroscopy and Scanning Electron Microscopy have been used to investigate the structural properties of Si epilayers and their dependence on growth conditions. Monocrystalline Si(110) films are obtained on 3C-SiC(100)/Si(100) substrates, only when using growth temperatures close to 850° C. The strong influence of the underlying 3C-SiC film on the final structural properties of Si epilayer is evidenced. © (2012) Trans Tech Publications.

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