Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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46 resultados
Resultados da Pesquisa
- Junctionless nanowire transistors effective channel length extraction through capacitance characteristics(2023-10-05) SILVA, E. M.; TREVISOLI, R.; Rodrigo Doria© 2023 Elsevier LtdThis work aims to extract the effective channel length (LEFF) of Junctionless Nanowire Transistors (JNT) through the maximum gate capacitance of the devices. The LEFF extraction has been done by extrapolating the maximum gate capacitance as a function of the devices’ channel length (LMASK) and has shown that LEFF is around 10–15 nm longer than LMASK for devices of different channel doping concentrations.
- 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.
- Interface traps density extraction through transient measurements in junctionless transistors(2022-08-05) TEICEIRA DA FONTE, E.; TREVISOLI, R.; BARRAUD S.; Rodrigo Doria© 2022 Elsevier LtdThis paper presents an extraction method for the interface traps density on Junctionless Transistors (JNTs) using an adapted charge pumping technique. To the best of our knowledge, this is the first work to apply this method in JNTs. Initially, it was stated through numerical simulations that a transient current, which increases with the trap density, is observed in the devices when the charge pumping method is applied. Then, a measurement setup was proposed to extract the pumping current resultant from a gate pulse and a mathematical expression was proposed to extract the density of trapped charges in the Oxide/Silicon interface (Nit). Aiming to demonstrate the method applicability for determining the JNTs interface quality, it was applied to simulations considering different trap densities as well as to experimental data of Junctionless Nanowire Transistors. It was observed that the method accuracy increases for larger trap densities and presents agreement to theoretical data for Nit > 1 × 1011 cm−2.
- Cross-coupling effects in common-source current mirrors composed by UTBB transistors(2022) JOSÉ DA COSTA, F.; TREVISOLI, R.; Rodrigo Doria© 2022 Elsevier LtdThis work performs an analysis of the cross-coupling effects influence on the performance of current mirrors composed by advanced UTBB SOI MOSFETs through 3D numerical simulations validated to experimental data of single devices. It is shown the presence of a capacitive coupling acting in the system, which can be demonstrated through the threshold voltage reduction at small distances between devices. Additionally, the temperature rise in the system due to the thermal coupling provokes a decrease in the input current as the devices become closer to each other. This is responsible for an increase of 3 % on ID2/ID1 ratio when the devices are biased at the same time and when the distance between them is lowered to 100 nm.
- Electrical characteristics of n-type vertically stacked nanowires operating up to 600 K(2022-08-05) MARINIELLO, G.; BARRAUD, S.; VINET, M.; CASSE, M.; FAYNOT, O.; CALCADE, J.; Marcelo Antonio Pavanello© 2022 Elsevier LtdThis paper aims at analyzing the electrical characteristics of n-type vertically stacked nanowires with variable fin width, operating in the temperature range of 300–600 K. Basic electrical parameters, such as threshold voltage, subthreshold slope, and carrier mobility are extracted in the linear region, whereas the transconductance, output conductance, and intrinsic voltage gain are extracted in saturation, to access some of device's analog figures of merit. Also, it has been analyzed the DIBL, GIDL, Ion, and Ioff. currents.
- Electrical characterization of stacked SOI nanowires at low temperatures(2022-05-05) RODRIGUES, J. C.; MARINIELLO, G.; CASSE, M.; BARRAUD, S.; VINET, M.; FAYNOT, O.; Marcelo Antonio PavanelloThis work presents the electrical characterization of 2-level vertically stacked nanowire MOSFETs with variable fin widths in the temperature range from 93 K to 400 K. The basic electrical properties, such as threshold voltage, subthreshold slope, and carrier mobility are examined in the linear region with low VDS. In sequence, certain analog figures of merit such as the transconductance, the output conductance, and the voltage gain are assessed in saturation. The threshold voltage variation with temperature is linear and slightly increases for wider devices, which was satisfactorily validated by an analytical model for 3D devices. Additionally, the subthreshold slope remains close to the theoretical limit in the whole range of temperatures. The intrinsic voltage gain is weakly temperature-sensitive in the studied range regardless of the fin width. On the other hand, it increases for narrow devices in all temperatures.
- Electron valence-band tunnelling excess noise in twin-gate silicon-on-insulator MOSFETs(2006-01-05) SIMOEN, E.; CLAEYS. C.; LUKYANCHIKOVA, N.; GARBER, N.; SMOLANKA, A.; DER AGOPIAN, P. G.; MARTINO, J. A.The impact of using a twin-gate (TG) configuration on the Electron Valence-Band (EVB) tunnelling-related floating-body effects has been studied in partially depleted (PD) SOI MOSFETs belonging to a 0.13 μm CMOS technology. In particular, the influence on the so-called linear kink effects (LKEs), including the second peak in the linear transconductance (gm) and the associated Lorentzian noise overshoot was investigated. It is shown that while there is a modest reduction of the second gm peak, the noise overshoot may be reduced by a factor of 2. At the same time, little asymmetry is observed when switching the role of the slave and the master transistor, in contrast to the case of the impact ionization related kink effects. Two-dimensional numerical simulations support the observations and show that both the gm, the second gm peak and the body potential are changed in the TG structure compared with a single transistor. © 2005 Elsevier Ltd. All rights reserved.
- Temperature influence on the gate-induced floating body effect parameters in fully depleted SOI nMOSFETs(2008) AGOPIAN P. G. D.; MARTINO, J, A.; SIMOEN, E.; CLAEYS, C.The temperature influence on the gate-induced floating body effect (GIFBE) in fully depleted (FD) silicon-on-insulator (SOI) nMOSFETs is investigated, based on experimental results and two-dimensional numerical simulations. The GIFBE behavior will be evaluated taking into account the impact of carrier recombination and of the effective electric field mobility degradation on the second peak in the transconductance (gm). This floating body effect is also analyzed as a function of temperature. It is shown that the variation of the studied parameters with temperature results in a "C" shape of the threshold voltage corresponding with the second peak in the gm curve. © 2008 Elsevier Ltd. All rights reserved.
- 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.
- Impact of SEG on uniaxially strained MuGFET performance(2011-05-05) Paula Agopian; PACHECO, V. H.; MARTINO J. A.; SIMOEN, E.; CLAEYS, C.This work focuses on the impact of the source and drain Selective Epitaxial Growth (SEG) on the performance of uniaxially strained MuGFETs. With the channel length reduction, the normalized transconductance (gm.L/W) of unstressed MuGFETs decreases due to the series resistance and short channel effects (SCE), while the presence of uniaxial strain improves the gm. The competition between the series resistance (Rs) and the uniaxial strain results in a normalized gm maximum point for a specific channel length. Since the SEG structure influences both Rs and the strain in the channel, this work studies from room down to low temperature how these effects influence the performance of the triple-gate FETs. For lower temperatures, the strain-induced mobility enhancement increases and leads to a shift in the maximum point towards shorter channel lengths for devices without SEG. This shift is not observed for devices with SEG where the strain level is much lower. At 150 K the gm behavior of short channel strained devices with SEG is similar to the non SEG ones due to the better gm temperature enhancement for devices without SEG caused by the strain. For lower temperatures SEG structure is not useful anymore. © 2011 Elsevier Ltd. All rights reserved.