Artigos
URI permanente para esta coleçãohttps://repositorio.fei.edu.br/handle/FEI/798
Navegar
51 resultados
Resultados da Pesquisa
- Impact of series resistance on the drain current variability in inversion mode and junctionless nanowire transistors(2023-10-05) SILVA, L. M. B. DA; Marcelo Antonio Pavanello; CASSÉ, M.; BARRAUD, S.; VINET, M.; FAYNOT, O.; Michelly De Souza© 2023 Elsevier LtdThis work analyzes the influence of source-drain series resistance variability over the drain current in junctionless and inversion mode nanowire transistors. A comparison between drain current and Y-function variability is presented using experimental data of nanowires with different widths and channel lengths. The source-drain series resistance variability is also presented. The results indicates that source-drain series resistance influence is higher on drain current variability for junctionless than inversion mode nanowire transistors.
- Analysis of the scattering mechanisms in the accumulation layer of junctionless nanowire transistors at high temperature(2019-08-05) RIBEIRO, T. A.; Marcelo Antonio Pavanello© 2019 IEEE.This work studies the effects of high temperature on the scattering mechanisms of Junctionless Nanowire Transistors with several fin width from nanowire to quasi-planar devices. With the variation of the temperature it was possible to analyze the impact of the scattering mechanisms on the devices. For nanowire devices at room temperature a degradation of up to 19% was seen from the maximum mobility to the mobility at higher gate bias to around 15% at 500K, while quasi-planar devices show a degradation of around 12% for all temperatures. Further analysis shows that the impact of the surface roughness for nanowires increase the degradation of these devices, where a reduction of its degradation at higher temperature shows the phonon scattering as the main scattering mechanism.
- Modeling Quantum Confinement in Multi-Gate Transistors with Effective Potential(2022) SOARES, C. S.; BAIKADI, P. K. R.; ROSSETO, A. C. J.; Marcelo Antonio Pavanello; VASILESKA, D.; WIRTH, G. I.© 2022 IEEE.Particle-based Monte Carlo device simulators are an efficient tool to investigate the performance and reliability of transistors. The semiclassical theoretical model employed in the Monte Carlo device simulator is unsuccessful to describe some aspects of the multi-gate transistors that come from the quantum behavior of charge carriers. To take into consideration the space-quantization effects in these simulators, a quantum correction is necessary. We propose to include an effective potential in the Monte Carlo device simulator to address the wave-like behavior of electrons in n-type silicon FinFET and n-type silicon nanowire transistors. The effective potential has a unique parameter, which can be adjusted to find a line density using an Effective Potential-Poisson solver that matches with the line density calculated using a Schrodinger-Poisson solver. We demonstrated that using the effective potential model, the effect of the electron confinement is well described.
- An Experimental Evaluation of Fin Width and Low-Temperature Influence on GIDL in Stacked SOI Nanowires(2022) Michelly De Souza; RODRIGUES, J. C.; MARINIELLO, G.; CASSE, M.; BARRAUD, S.; VINET, M.; FAYNOT, O.; Marcelo Antonio Pavanello© 2022 IEEE.In this work, an experimental evaluation of the gate-induced drain leakage (GIDL) of vertically stacked SOI nanowire (NW) FETs is carried out, as a function of temperature for the first time. It is shown that at room temperature, NW width decrease improves gate coupling favoring longitudinal band-to-band-tunneling, which increases normalized GIDL current. The increase of GIDL current with fin narrowing becomes more pronounced with temperature reduction. The influence of fin width has been evaluated, showing that GIDL variation with temperature depends on the device geometry.
- Analysis of Variability in Transconductance and Mobility of Nanowire Transistors(2022-08-22) SILVA, L. M. B. DA; Marcelo Antonio Pavanello; CASSE, M.; BARRAUD, S.; VINET, M.; FAYNOT, O.; Michelly De Souza© 2022 IEEE.This work presents a comparison between the variability in junctionless nanowire transistors and inversion-mode nanowire transistors, looking at the transconductance, low-field mobility, linear and quadratic mobility degradation coefficients. To extract these parameters, the Y-Function method has been used. The obtained results shows differences in mobility and transconductance matching coefficients, indicating that mobility influence is not the only source of transconductance variation.
- Variability Modeling in Triple-Gate Junctionless Nanowire Transistors(2022-01-05) TREVISOLI, R.; Marcelo Antonio Pavanello; Rodrigo Doria; CAPOVILLA, C.E.; BARRAUD, S.; Michelly De SouzaIEEEThis work aims at proposing an analytical model for the variability of the threshold voltage and drain current in junctionless nanowire transistors. The model is continuous in all operation regions and has been validated through Monte Carlo simulations using a physically based drain current model and 3-D numerical simulations. A discussion about the influences of each variability source based on the proposed model is carried out. Finally, the modeled results are compared to the experimental data for a fully physical validation.
- Experimental Assessment of Variability in Junctionless Nanowire nMOS Transistors(2021-09-06) Michelly De Souza; BARRAUD, S.; CASSE, M.; VINET, M.; FAYNOR, O.; Marcelo Antonio PavanelloIn this work, experimental assessment of the variability of threshold voltage and drain current in junctionless nanowire n MOS transistors is presented. Die-to-die variability of threshold voltage and drain current is presented and compared to inversion mode nanowire with the same dimensions. Although the junctionless nanowires have shown larger threshold voltage matching coefficients than inversion mode devices, the variability obtained experimentally has shown to be smaller than predicted by some simulations reported in the literature. Also, it has been shown that as the channel length of junctionless nanowire transistors is reduced, the current variability becomes smaller than in inversion mode nanowires, at the same current level and dimensions.
- The roles of the electric field and the density of carriers in the improved output conductance of junctionless nanowire transistors(2011-01-05) Rodrigo Doria; Marcelo Antonio Pavanello; TREVISOLI, R. D.; Michelly De Souza; LEE, C. W.; FERAIN, I.; DEHDASHTI AKHAVAN, N.; YAN, R.; RAZAVI, P.; YU, R.; KRANTI, A.; COLINGE, J. P.This paper evaluates the roles of the electric field (E) and the density of carries (n) in the drain conductance of Junctionless Nanowire Transistors (JNTs). The behavior of E and n presented by JNTs with the variation of the gate and the drain voltages has been compared to the one presented by Inversion Mode (M) Trigate devices of similar dimensions. It has been shown that the lower drain output conductance exhibited by Junctionless transistors with respect to the IM ones is correlated not only to the differences in the mobility and its degradation but also to the electric field, the density of carries and the first order derivative of these variables with respect the drain voltage. ©The Electrochemical Society.
- Analytical model for the threshold voltage in junctionless nanowire transistors of different geometries(2011-09-02) TREVISOLI, R. D.; Rodrigo Doria; Marcelo Antonio PavanelloJunctionless nanowire transistors (JNTs) are considered promising for the sub-20 nm era. As these devices have a constant doping profile from source to drain, they have a great scalability without the need for rigorously controlled doping and activation techniques. These devices also present a flexible threshold voltage, which strongly depends on the device cross section. This work proposes an analytical model for JNTs. The model is derived from the solution of the Poisson equation with the appropriate boundary conditions. The quantum confinement for devices of reduced dimensions has also been accounted. The threshold voltage in cylindrical and trigate JNTs are analyzed. Tridimensional numerical simulations were performed to validate the model. ©The Electrochemical Society.
- Impact of the series resistance in the I-V characteristics of nMOS junctionless nanowire transistors(2011-09-02) Rodrigo Doria; TREVISOLI, D. T.; Marcelo Antonio PavanelloThe series resistance (Rs) of Junctionless Nanowire Transistors (JNTs) with different doping concentrations was extracted from 473 K down to 100 K. The source/drain parasitic resistance presented by JNTs was compared to the one presented by classical inversion mode (IM) triple gate devices and the impact of the series resistance on the drain current of the devices was evaluated. The R S analysis was carried out through experimental results and devices tridimensional numerical simulations. According to the study, R S presents opposite behavior with the temperature variation in EVI triple transistors and JNTs. In the latter, a reduction on R S is noted with the temperature increase, whereas a resistance decrease is obtained with the temperature lowering in IM devices. The parasitic resistance in JNTs affects the drain current in such a way that there may not be a Zero Temperature Coefficient (ZTC) operation point. © The Electrochemical Society.