Artigos
URI permanente para esta coleçãohttps://repositorio.fei.edu.br/handle/FEI/798
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Resultados da Pesquisa
- Modeling of silicon stacked nanowire and nanosheet transistors at high temperatures(2022-07-04) CERDEIRA, A.; ESTRADA, M.; DA SILVA, G. M.; RODRIGUES, J. C.; Marcelo Antonio Pavanello© 2022 IEEE.In this work, we demonstrate that the Symmetric Doped Double-Gate Model (SDDGM), previously validated for modeling FinFETs, stacked nanowire, and nanosheet transistors at room temperature, can be extended for modeling stacked nanowire and nanosheet transistors at high temperatures. The modeled results are validated by comparison with experimental data.
- Pragmatic evaluation of fin height and fin width combined variation impact on the performance of junctionless transistors(2022-01-05) RIBEIRO, T. A.; CERDEIRA, A.; ESTRADA, M.; BARRAUD, S.; Marcelo Antonio PavanelloThis work performs a pragmatic evaluation of the different junctionless devices architectures with channel lengths down to 30 nm on their electrical characteristics. By adopting multiple combinations between the fin height (HFIN) and the fin width (WFIN), chosen from the range of published data in the literature, the devices will operate from double-gate (FinFET like) mode towards to nanowire mode. Additionally, junctionless transistors with and without additional doping at the drain and source extensions were studied. Experimentally calibrated 3D TCAD simulations are used to allow for the study of these several combinations. Results show that for long-channel devices the best performance is obtained for tall and narrow fins, leading to the highest on-to-off current ratio (ION/IOFF) and the smallest values of subthreshold swing and DIBL. On the other hand, for short channel devices, independently of the doping level of the extensions, the best results are found for short HFIN and narrow WFIN, leading to the smaller values of subthreshold swing and DIBL, with a high ION/IOFF ratio. However, the use of doped extensions degrades the overall device performance of short-channel junctionless devices as will be demonstrated.
- On the compact modelling of Si nanowire and Si nanosheet MOSFETs(2022) CERDEIRA, A.; ESTRADA, M.; Marcelo Antonio PavanelloIn this paper, three-dimensional technology computer aided design simulations are used to show that the electron concentration, current density, and electric field distribution from the interface at the lateral channels and from the top channel to the centre of the silicon wire, in nanowire and nanosheet structures, are practically same. This characteristic makes it possible to consider that the total channel width for these structures is equal to the perimeter of the transistor sheet, allowing to extend of the application of the symmetric doped double-gate model (SDDGM) model to nanowires and nanosheets metal-oxide-semiconductor field effect transistors, with no need to include new parameters. The model SDDGM is validated for this application using several measured and simulated structures of nanowires and nanosheets transistors, with different aspect ratios of fin width and fin height, showing very good agreement between measured or simulated characteristics and modelled. SDDGM is encoded in Verilog-A language and implemented in the SmartSPICE circuit simulator.
- Threshold voltages of SOI MuGFETs(2008-12-05) de Andrade M.G.C.; Martino J.A.The multiple-gate field-effect transistor (MuGFET) is a device with a gate folded on different sides of the channel region. They are one of the most promising technological solutions to create high-performance ultra-scaled SOI CMOS. In this work, the behavior of the threshold voltage in double-gate, triple-gate and quadruple-gate SOI transistors with different channel doping concentrations is studied through three-dimensional numerical simulation. The results indicated that for double-gate transistors, one or two threshold voltages can be observed, depending on the channel doping concentration. However, in triple-gate and quadruple-gate it is possible to observe up to four threshold voltages due to the corner effect and the different doping concentration between the top and bottom of the Fin. © 2008 Elsevier Ltd. All rights reserved.
- Influence of fin width and channel length on the performance of buffers implemented with standard and strained triple-gate nFinFETs(2009-09-03) Marcelo Antonio Pavanello; MARTINO, J. A.; SIMOEN, E.; ROOYACKERS, R.; COLLAERT, N.; CLAEYS, C.In this work the application of standard and strained triple-gate FinFETs in unity-gain source-follower configuration is compared. The analysis is performed by evaluating the buffer voltage gain with respect to the fin width and channel length as well as the total harmonic distortion. It is demonstrated that the application of strained material in narrow FinFETs, when the devices are operating in double-gate mode, can be beneficial for the performance of buffers in any channel length. On the other hand, for triple-gate FinFETs or quasi-planar ones the degradation of the output conductance overcomes the transconductance improvements from strained material and the performance of standard buffers is better than of strained ones. Narrow strained buffers also offer better harmonic distortion. © The Electrochemical Society.
- Application of the symmetric doped double-gate model in circuit simulation containing double-gate graded-channel transistors(2009-09-03) CONTRERAS, E.; CERDEIRA, A.; ALVARADO J.; Marcelo Antonio PavanelloThe development of models to simulate circuits containing new devices is an important task to allow for the introduction of these devices in practical applications. In this paper we show the advantages of using the Symmetric Doped Double-Gate Model recently developed and are already introduced in SmartSpice simulator, for modeling circuits containing Double-Gate Graded-Channel (GC) transistors. In this case there is no need to use two different models to represent the graded-channel device, as has been done up to now. A current-mirror circuit using GC devices has been simulated and the results were validated comparing them with those obtained in MIXED-MODE and two-dimensional ATLAS simulation of the GC devices. © The Electrochemical Society.
- Simulation of OTA's with double-gate graded-channel MOSFETS using the symmetric doped double-gate model(2010-01-05) CENTRERAS, E.; CERDEIRA, A.; Marcelo Antonio PavanelloIn this paper Operational Transconductance Amplifiers (OTA's) were simulated in SPICE, using the Symmetric Doped Double-Gate Model which includes the capacitances of Double-Gate (DG) transistors. In this work, all the transistors have been simulated using just one model for lightly doped transistor (TLD) and high doped transistor (THd) N-channel devices and P-channel devices. These OTA's show an improvement in the high open-loop voltage gain which is related mainly to the reduction of the drain output conductance which give higher Early voltages for DG GC transistors. ©The Electrochemical Society.
- Simulation of miller OpAmp analog circuit with FinFET transistors(2012-03-17) CONTRERAS, E.; CERDEIRA, A.; Marcelo Antonio PavanelloIn this paper we present a methodology to use the Symmetric Doped Double-Gate Model implemented in Verilog-A to simulate analog circuits with FinFET Technology. A Miller operational Amplifier was simulated in SPICE simulator and the results were validated comparing them with experimental data published in previous works. © 2012 IEEE.
- An analytical estimation model for the spreading resistance of Double-Gate FinFETs(2012-03-17) MALHEIRO, C. T.; PEREIRA, A. S. N.; Renato GiacominiThe FinFET spreading resistance is the component of the parasitic resistance of FinFETs caused by the curved shape of the current lines in drain and source regions, close to the junctions. This work proposes a very simple analytical model for the spreading resistance of Double-Gate FinFETs that is valid for any fin width from 16nm, without fitting parameters. The model output was compared to data extracted from numeric simulation and it showed accuracy better than 8% for the considered range of devices with three different doping concentrations. © 2012 IEEE.
- Analytical model for potential in double-gate juntionless transistors(2013-09-06) CERDEIRA, A.; ESTRADA, M.; TREVISOLI, R. D.; Rodrido Doria; Michelly De Souza; Marcelo Antonio PavanelloAn analytical model to calculate the potential at the surface and at the center of silicon layer for long-channel Junctionless transistors is derived and explained the basic details. The analytical model is compared with the numerical solution of the fundamental equations showing the validity of the assumptions considered. © 2013 IEEE.