Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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9 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.
- Experimental Demonstration of Ω-Gate SOI Nanowire MOS Transistors' Mobility Variation Induced by Substrate Bias(2022) BERMAMASCHI, F. E.; RIBEIRO, T. A.; PAZ, B. C.; Michelly De Souza; BARRAUD, S.; CASSE, M.; VINET, M.; FAYNOT, O.; Marcelo Antonio Pavanello© 1963-2012 IEEE.This work investigates the carrier mobility variation in Ω-gate silicon-on-insulator (SOI) nanowire MOS transistors induced by substrate (or back) biasing. The analysis is carried out through experimental measurements and 3-D TCAD simulation, performed in n-type devices with variable fin width. Mobility enhancement is observed for lower back bias levels, due to the initial conduction through the Si-BOX interface, which presents higher mobility, prior to the activation of the front channel. As back bias is increased, however, the strong substrate-induced electric field in the back channel (BC) is responsible for worsening scattering mechanisms in the BC, such as surface roughness and acoustic phonon scattering, inducing mobility degradation. The effect is amplified as the fin width increases. For short-channel devices, the use of back bias was more beneficial for mobility due to a stronger mobility enhancement and lower mobility degradation.
- High Temperature and Width Influence on the GIDL of Nanowire and Nanosheet SOI nMOSFETs(2023-01-05) Michelly De Souza; CERDEIRA, A.; ESTRADA, M.; BARRAUD, S.; CASSE, M.; VINET, M.; FAYNOT, O.; Pavanello M. A.AuthorIn this work, an experimental evaluation of Gate-Induce Drain Leakage (GIDL) current is presented for nanowire and nanosheet-based SOI transistors. The effects of fin width and temperature increase are studied. Obtained results indicate that the increase in device width makes the GIDL current more sensitive to temperature increase. Three-dimensional numerical simulations have shown that despite the reverse junction leakage increase with temperature, leakage current in nanosheet and nanowire transistors is composed predominantly of GIDL current. The change in valence and conduction bands caused by temperature increase favors the band-to-band tunneling, which is responsible for the worsening of GIDL at high temperatures.
- Analysis of the Gate-Induced Drain Leakage of SOI Nanowire and Nanosheet MOS Transistors at High Temperatures(2022-07-04) Michelly De Souza; CERDEIRA, A.; ESTRADA, M.; BARRAUD, S.; CASSE, M.; VINET, M.; FAYNOT, O.; Marcelo Antonio Pavanello© 2022 IEEE.This work presents a comparison between the Gate-Induced Drain Leakage (GIDL) current of the nanowire (tri-gate MOSFET with narrow fin width) and nanosheet (tri-gate MOSFET with wide fin width) SOI MOSFETs at high temperatures, in the range between 300 K and 580 K. The study is conducted using experimental data, corroborated with 3D TCAD simulations. It is demonstrated that the GIDL current normalized by the total fin width is larger in nanosheet MOSFET than for the nanowire at high temperatures. Additionally, the nanosheet device presents a larger variation of the normalized GIDL current with the temperature than the nanowire one.
- Comparative Analysis of Transcapacitances in Asymmetric Self-Cascode and Graded-Channel SOI nMOSFETs(2022-07-04) ALVES, C. R.; D'OLIVEIRA, L. M.; Michelly De Souza© 2022 IEEE.This work presents a comparative study of the transcapacitances of asymmetric self-cascode (A-SC) and graded-channel (GC) silicon-on-insulator (SOI) nMOSFETs, by means of two-dimensional numerical simulations. Simulated results show that the gate-to-drain capacitance is smaller for the ASC SOI device if compared to the GC SOI device, despite of the applied VDS.
- Analysis of Capacitances in Asymmetric SelfCascode SOI nMOSFETs(2021-08-27) ALVES, C.R.; D' OLIVEIRA, L. M.; Michelly De Souza©2021 IEEE.This work presents a study of the capacitance of asymmetric self-cascode silicon-on-insulator (ASC SOI) MOSFETs with similar gate areas and different gate lengths. Experimental results of total gate capacitance of different ASC are presented and complemented with the results of twodimensional simulations. The transcapacitances are explored through two-dimensional simulations. Results show that different channel lengths of the composite transistors have more influence in the depletion region of the capacitance curves for low VDS. The gate-source and gate-drain capacitances show opposite trends with the change in the lengths of source and drain transistors, despite of the VDS applied.
- Analysis of gate capacitance of n-type junctionless transistors using three-dimensional device simulations(2012-03/17) MARINIELLO, G.; Rodrido Doria; Michelly De Souza; Marcelo Antonio Pavanello; TREVISOLI, R. D. G.Junctionless transistors can be an excellent alternative for extremely scaled MOSFETs as they present a good behavior with no doping gradients between channel and source/drain regions. This paper aims at analyzing the gate capacitance (C gg) of junctionless transistors dependence with the three most important technological parameters for these devices: doping concentration (N D), fin width (W fin) and fin height (H fin). © 2012 IEEE.
- Liquid helium temperature analog operation of asymmetric self-cascode FD SOI MOSFETs(2012-10-04) Michelly De Souza; KILCHTYSKA, V.; FLANDRE, D.; Marcelo Antonio PavanelloFully Depleted (FD) SOI technology is well known to provide improved analog performance of CMOS transistors [1, 2]. However, FD SOI transistors may suffer from parasitic bipolar effects (PBE) that cause the degradation of the output conductance [3]. The use of cascode transistors with common gate (making a self-cascode-SC topology) has been shown to reduce the output conductance of MOSFETs, while keeping some advantages of long-channel transistors [4]. Fig. 1 represents the self-cascode transistor, composed by transistors MS and MD, with channel lengths LS and LD, and threshold voltages VT, S and VT, D, respectively (with VT, S = VT, D in the symmetric SC-S-SC). Recent works [5, 6] showed that the use of different threshold voltages (VT) for MS and MD (so-called asymmetric self-cascode-A-SC) is able to further enhance the analog properties of SC n-and pMOS transistors, in comparison to the S-SC, at room temperature (RT). In this paper the enhanced analog performance of asymmetric SC structure is experimentally demonstrated at deep cryogenic environments emphasizing its capability to minimize (or even suppress) PBE in FD SOI n-and p-type MOSFETs at liquid helium temperature (LHT), where this effect is more pronounced [7]. © 2012 IEEE.
- A New Method for Series Resistance Extraction of Nanometer MOSFETs(2017-07-05) TREVISOLI, R.; Rodrido Doria; Michelly De Souza; BARRAUD, S.; VINET, M.; CASSE, M.; REIMBOLD, G.; FAYNOT, O.; GHIBAUDO, G.; Marcelo Antonio PavanelloThis paper presents a new method for the series resistance extraction in ultimate MOSFETs using a single drain current versus gate voltage characteristic curve. The method is based on the Y-function curve, such that the series resistance is obtained through the curve of the total resistance as a function of the inverse of the Y-function. It includes both first-and second-order mobility degradation factors. To validate the proposed method, numerical simulations have been performed for devices of different characteristics. Besides, the method applicability has been demonstrated for experimental silicon nanowires and FinFETs. Apart from that, devices with different channel lengths can be used to estimate the mobility degradation factor influence.