The Experts below are selected from a list of 10080 Experts worldwide ranked by ideXlab platform
W I Milne - One of the best experts on this subject based on the ideXlab platform.
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highly electron transparent graphene for field emission triode Gates
Advanced Functional Materials, 2014Co-Authors: Matthew T Cole, Jamie H Warner, Wei Lei, Xiaobing Zhang, Baoping Wang, Kai Ying, Yan Zhang, Alex R Robertson, Shuyi Ding, W I MilneAbstract:The enhanced emission performance of a graphene/Mo hybrid Gate Electrode integrated into a nanocarbon field emission micro-triode electron source is presented. Highly electron transparent Gate Electrodes are fabricated from chemical vapor deposited bilayer graphene transferred to Mo grids with experimental and simulated data, showing that liberated electrons efficiently traverse multi-layer graphene membranes with transparencies in excess of 50-68%. The graphene hybrid Gates are shown to reduce the Gate driving voltage by 1.1 kV, whilst increasing the electron transmission efficiency of the Gate Electrode significantly. Integrated intensity maps show that the electron beam angular dispersion is dramatically improved (87.9°) coupled with a 63% reduction in beam diameter. Impressive temporal stability is noted ( < 1.0%) with surprising negligible long-term damage to the graphene. A 34% increase in triode perveance and an amplification factor 7.6 times that of conventional refractory metal grid Gate Electrode-based triodes are noted, thus demonstrating the excellent stability and suitability of graphene Gates in micro-triode electron sources. A nanocarbon field emission triode with a hybrid Gate Electrode is developed. The graphene/Mo Gate shows a high electron transparency (50-68%) which results in a reduced turn-on potential, increased beam collimation, reduced beam diameter (63%), enhanced stability ( < 1% variation), a 34% increase in perveance, and an amplification 7.6 times that of equivalent conventional refractory metal Gate triodes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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fabrication and electrical characteristics of carbon nanotube field emission microcathodes with an integrated Gate Electrode
Nanotechnology, 2002Co-Authors: G Pirio, G A J Amaratunga, Pierre Legagneux, Didier Pribat, K B K Teo, Manish Chhowalla, W I MilneAbstract:We report on the fabrication of field emission microcathodes which use carbon nanotubes as the field emission source. The devices incorporated an integrated Gate Electrode in order to achieve truly low-voltage field emission. A single-mask, self-aligned technique was used to pattern the Gate, insulator and catalyst for nanotube growth. Vertically-aligned carbon nanotubes were then grown inside the Gated structure by plasma-enhanced chemical vapour deposition. Our self-aligned fabrication process ensured that the nanotubes were always centred with respect to the Gate apertures (2 µm diameter) over the entire device. In order to obtain reproducible emission characteristics and to avoid degradation of the device, it was necessary to operate the Gate in a pulsed voltage mode with a low duty cycle. The field emission device exhibited an initial turn-on voltage of 9 V. After the first measurements, the turn-on voltage shifted to 15 V, and a peak current density of 0.6 mA cm-2 at 40 V was achieved, using a duty cycle of 0.5%.
Jamie H Warner - One of the best experts on this subject based on the ideXlab platform.
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three terminal graphene single electron transistor fabricated using feedback controlled electroburning
Applied Physics Letters, 2015Co-Authors: Pawel Puczkarski, Pascal Gehring, Chit Siong Lau, Junjie Liu, Arzhang Ardavan, Jamie H Warner, Andrew G D Briggs, Jan A MolAbstract:We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor fabricated using feedback-controlled electroburning. The small separation between the side Gate Electrode and the graphene quantum dot results in a Gate coupling up to 3 times larger compared to the value found for the back Gate Electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side Gate voltage of about 1 V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced Gate coupling.
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three terminal graphene single electron transistor fabricated using feedback controlled electroburning
arXiv: Mesoscale and Nanoscale Physics, 2015Co-Authors: Pawel Puczkarski, Pascal Gehring, Chit Siong Lau, Junjie Liu, Arzhang Ardavan, Jamie H Warner, Andrew G D Briggs, Jan A MolAbstract:We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor (SET) fabricated using feedback-controlled electroburning. The small separation between the side Gate Electrode and the graphene quantum dot results in a Gate coupling up to 3 times larger compared to the value found for the back Gate Electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side Gate voltage of about 1V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced Gate coupling.
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highly electron transparent graphene for field emission triode Gates
Advanced Functional Materials, 2014Co-Authors: Matthew T Cole, Jamie H Warner, Wei Lei, Xiaobing Zhang, Baoping Wang, Kai Ying, Yan Zhang, Alex R Robertson, Shuyi Ding, W I MilneAbstract:The enhanced emission performance of a graphene/Mo hybrid Gate Electrode integrated into a nanocarbon field emission micro-triode electron source is presented. Highly electron transparent Gate Electrodes are fabricated from chemical vapor deposited bilayer graphene transferred to Mo grids with experimental and simulated data, showing that liberated electrons efficiently traverse multi-layer graphene membranes with transparencies in excess of 50-68%. The graphene hybrid Gates are shown to reduce the Gate driving voltage by 1.1 kV, whilst increasing the electron transmission efficiency of the Gate Electrode significantly. Integrated intensity maps show that the electron beam angular dispersion is dramatically improved (87.9°) coupled with a 63% reduction in beam diameter. Impressive temporal stability is noted ( < 1.0%) with surprising negligible long-term damage to the graphene. A 34% increase in triode perveance and an amplification factor 7.6 times that of conventional refractory metal grid Gate Electrode-based triodes are noted, thus demonstrating the excellent stability and suitability of graphene Gates in micro-triode electron sources. A nanocarbon field emission triode with a hybrid Gate Electrode is developed. The graphene/Mo Gate shows a high electron transparency (50-68%) which results in a reduced turn-on potential, increased beam collimation, reduced beam diameter (63%), enhanced stability ( < 1% variation), a 34% increase in perveance, and an amplification 7.6 times that of equivalent conventional refractory metal Gate triodes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Anil Kottantharayil - One of the best experts on this subject based on the ideXlab platform.
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work function tuning and improved Gate dielectric reliability with multilayer graphene as a Gate Electrode for metal oxide semiconductor field effect device applications
Applied Physics Letters, 2012Co-Authors: Abhishek Kumar Misra, Mayur Waikar, Amit Gour, Hemen Kalita, Manali Khare, M Aslam, Anil KottantharayilAbstract:Graphene with varying number of layers is explored as metal Gate Electrode in metal oxide semiconductor structure by inserting it between the dielectric (SiO2) and contact metal (TiN) and results are compared with TiN Gate Electrode. We demonstrate an effective work function tuning of Gate Electrode upto 0.5 eV by varying the number of graphene layers. Inclusion of even 1-3 layers of graphene results in significantly improved dielectric reliability as measured by breakdown characteristics, charge to breakdown, and interface state density. These improvements are attributed to the impermeability of graphene for TiN and hence reduced metallic contamination in the dielectric.
Jan A Mol - One of the best experts on this subject based on the ideXlab platform.
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three terminal graphene single electron transistor fabricated using feedback controlled electroburning
Applied Physics Letters, 2015Co-Authors: Pawel Puczkarski, Pascal Gehring, Chit Siong Lau, Junjie Liu, Arzhang Ardavan, Jamie H Warner, Andrew G D Briggs, Jan A MolAbstract:We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor fabricated using feedback-controlled electroburning. The small separation between the side Gate Electrode and the graphene quantum dot results in a Gate coupling up to 3 times larger compared to the value found for the back Gate Electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side Gate voltage of about 1 V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced Gate coupling.
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three terminal graphene single electron transistor fabricated using feedback controlled electroburning
arXiv: Mesoscale and Nanoscale Physics, 2015Co-Authors: Pawel Puczkarski, Pascal Gehring, Chit Siong Lau, Junjie Liu, Arzhang Ardavan, Jamie H Warner, Andrew G D Briggs, Jan A MolAbstract:We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor (SET) fabricated using feedback-controlled electroburning. The small separation between the side Gate Electrode and the graphene quantum dot results in a Gate coupling up to 3 times larger compared to the value found for the back Gate Electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side Gate voltage of about 1V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced Gate coupling.
Veena Misra - One of the best experts on this subject based on the ideXlab platform.
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electrical and physical analysis of mota alloy for Gate Electrode applications
Journal of The Electrochemical Society, 2006Co-Authors: Bei Chen, Nivedita Biswas, Veena MisraAbstract:This article presents Mo x Ta v as a potential candidate for dual metal complementary metal oxide semiconductor (CMOS) applications. The electrical characterization results of MoTa alloy indicates that the effective work function can be controlled to around 4.3 eV on SiO 2 and is suitable for n-type MOS Gate Electrode application. The MoTa alloy forms a solid solution instead of an intermetallic compound. We report that the MoTa solid solution can achieve low work function values and is stable up to 900°C. X-ray diffraction results indicated only a single MoTa alloy phase. X-ray photoelectron spectroscopy analysis confirmed that no Mo-Ta compound bonding formed within the MoTa alloy. Moreover, from Auger electron spectroscopy and Rutherford backscattering spectroscopy analysis, MoTa was found to be stable on SiO 2 under high-temperature anneals and no metal diffusion into substrate Si channel was detected. This indicates that Mo x Ta y is a good candidate for CMOS metal Gate applications.
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investigation of work function tuning using multiple layer metal Gate Electrodes stacks for complementary metal oxide semiconductor applications
Applied Physics Letters, 2005Co-Authors: Rashmi Jha, Jaehoon Lee, P Majhi, Veena MisraAbstract:Metal Gate Electrodes consisting of three layered stacks of metals are investiGated for complementary metal-oxide-semiconductor device applications. It was observed that the effective work function of the entire Gate Electrode stack was dominated by the work function of the first metal layer (50A of tantalum nitride) contacting the Gate dielectric. No significant difference in the effective oxide thickness was observed in devices with and without the initial tantalum nitride layer. The potential reasons for this, based on the penetration of an electron wave function from the Gate Electrode to the Gate dielectric and Gate depletion due to longer Debye length of electrons in tantalum nitride, will be discussed.
