Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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6 resultados
Resultados da Pesquisa
- 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.
- Junctionless nanowire transistors parameters extraction based on drain current measurements(2019) Trevisoli R.; Doria R.T.; de Souza M.; Barraud S.; Pavanello M.A.© 2019 Elsevier LtdThe aim of this work is to propose and qualify a systematic method for parameters extraction of Junctionless Nanowire Transistors (JNTs) based on drain current measurements and compact modeling. As junctionless devices present a different conduction mechanism than inversion-mode transistors, the methods developed for the latter devices either are not compatible or cannot be directly applied to JNTs before a deep analysis on their applicability. The current work analyzes the extraction of the series resistance, including a discussion about the influence of the first and second order mobility degradation factors, flatband voltage and low field mobility in junctionless transistors based only on static drain current curves. An analysis of the method accuracy considering the influence of the channel length, nanowire width and height, gate oxide thickness and doping concentration is also presented for devices with different characteristics through three-dimensional numerical simulations. The inclusion of the second order effects in a drain current model is also shown, considering the extracted values. The method applicability is also successfully demonstrated in experimental devices.
- Charge-based compact analytical model for triple-gate junctionless nanowire transistors(2016) Avila-Herrera F.; Paz B.C.; Cerdeira A.; Estrada M.; Pavanello M.A.© 2016 Elsevier Ltd.A new compact analytical model for short channel triple gate junctionless transistors is proposed. Based on a previous model for double-gate transistors which neglected the fin height effects, a new 3-D continuous model has been developed, including the dependence of the fin height and the short channel effects. An expression for threshold voltage is presented. The model defines a one-dimensional semiconductor effective capacitance due to the width and the height of the fin, which in turn redefines the potentials and charges, without altering the general modeling procedure. Threshold voltage roll-off, subthreshold slope, DIBL and channel length modulation, as well as, the mobility degradation and the velocity saturation have been introduced into the model. The validation was done by 3-D numerical simulations for different fin heights and channel lengths, as well as, by experimental measurements in nanowire transistors with doping concentrations of 5 × 1018 and 1 × 1019 cm-3. The developed model is suitable for describing the current-voltage characteristics in all operating regions from double-gate to nanowire transistor with only 8 adjusting parameters.
- Compact model for short-channel symmetric double-gate junctionless transistors(2015) Avila-Herrera F.; Cerdeira A.; Paz B.C.; Estrada M.; Iniguez B.; Pavanello M.A.© 2015 Elsevier Ltd.Abstract In this work a compact analytical model for short-channel double-gate junctionless transistor is presented, considering variable mobility and the main short-channel effects as threshold voltage roll-off, series resistance, drain saturation voltage, channel shortening and saturation velocity. The threshold voltage shift and subthreshold slope variation is determined through the minimum value of the potential in the channel. Only eight model parameters are used. The model is physically-based, considers the total charge in the Si layer and the operating conditions in both depletion and accumulation. Model is validated by 2D simulations in ATLAS for channel lengths from 25 nm to 500 nm and for doping concentrations of 5 × 1018 and 1 × 1019 cm-3, as well as for Si layer thickness of 10 and 15 nm, in order to guarantee normally-off operation of the transistors. The model provides an accurate continuous description of the transistor behavior in all operating regions.
- Compact core model for Symmetric Double-Gate Junctionless Transistors(2014) Cerdeira A.; Avila F.; Iniguez B.; De Souza M.; Pavanello M.A.; Estrada M.A new charge-based compact analytical model for Symmetric Double-Gate Junctionless Transistors is presented. The model is physically-based and considers both the depletion and accumulation operating conditions including the series resistance effects. Most model parameters are related to physical magnitudes and the extraction procedure for each of them is well established. The model provides an accurate continuous description of the transistor behavior in all operating conditions. Among important advantages with respect to previous models are the inclusion of the effect of the series resistance and the fulfilment of being symmetrical with respect to drain voltage equal to zero. It is validated with simulations for doping concentrations of 5 × 10 18 and 1 × 1019 cm-3, as well as for layer thickness of 10 and 15 nm, allowing normally-off operation. © 2014 Elsevier B.V.
- Charge-based continuous model for long-channel Symmetric Double-Gate Junctionless Transistors(2013) Cerdeira A.; Estrada M.; Iniguez B.; Trevisoli R.D.; Doria R.T.; De Souza M.; Pavanello M.A.A new charge-based continuous model for long-channel Symmetric Double-Gate Junctionless Transistors (SDGJLTM) is proposed and validated with simulations for doping concentrations of 5 × 1018 and 1 × 10 19 cm-3, as well as for layer thicknesses of 10, 15 and 20 nm. The model is physically-based, considering both the depletion and accumulation operating conditions. Most model parameters are related to physical magnitudes, and the extraction procedure for each of them is well established. The model provides an accurate description of the transistor behavior in all operating conditions. Among important advantages with respect to previous models are the inclusion of the effect of the series resistance and the fulfilment of the requirement of being symmetrical with respect to Vd = 0 V. © 2013 Elsevier Ltd. All rights reserved.