Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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12 resultados
Resultados da Pesquisa
- 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.
- Comparison between SOI nMOSFET's under uniaxial and biaxial mechanical stress in analog applications(2011-09-02) DE SOUZA, M. A. S.; SOUZA, F. N.; Michelly De Souza; Marcelo Antonio PavanelloThis work presents a study comparing the analog performance of uniaxially and biaxially strained planar Silicon-on-Insulator nMOSFETs for a wide range of channel lengths. The study is performed via two-dimensional numerical and process simulation and supported by experimental measurements. The comparison between devices from the same technology with these two strained techniques demonstrated that higher intrinsic voltage gain is obtained for biaxial mechanical stress. However, the transconductance is higher for uniaxial mechanical stress for shorter devices (below 550 nm) leading to larger unity gain frequency. On the other hand, despite both strain techniques degrades the output conductance, this degradation with channel length shortening is less pronounced for devices under biaxial mechanical stress. © The Electrochemical Society.
- Comparative study of biaxial and uniaxial mechanical stress influence on the low frequency noise of fully depleted SOI nMOSFETs operating in triode and saturation regime(2012-09-02) DE SOUZA, M. A. S.; Rodrido Doria; Michelly De Souza; MARTINO, J. A.; Marcelo Antonio PavanelloThis paper presents an experimental comparative study of uniaxial and biaxial strain techniques influence on the low frequency noise of planar fully depleted SOI nMOSFETs operating in linear and saturation regimes. The comparison between devices from the same technology with these two strained techniques demonstrated a reduction of low frequency noise for devices with both strain technologies in linear regime for shorter devices (below 410 nm). In saturation regime the reduction of low frequency noise for uniaxial and biaxial strain also occurs, but does not depend on the channel length, and the reduction of low frequency noise in favor of both strain technologies is more pronounced for channel length of 160 nm. © The Electrochemical Society.
- Analog performance of submicron GC SOI MOSFETs(2012-03-17) NEMER J. P.; Michelly De Souza; Marcelo Antonio Pavanello; FLANDRE, D.This paper aims to demonstrate the performance of GC SOI MOSFET devices in comparison to standard SOI MOS transistors, comparing the improvements achieved by the adoption of the GC architecture in a submicron fully depleted SOI technology varying the channel length. The results obtained by two-dimensional numerical simulations show that the best improvement is obtained when the length of lightly doped region length is approximately 100 nm, independently of the total channel length. © 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.
- Low frequency noise in submicron Graded-Channel SOI MOSFETs(2013-09-06) NEMER, J. P.; Michelly De Souza; FLANDRE, D.; Marcelo Antonio PavanelloThe origin of the low-frequency noise in submicron fully depleted Graded-Channel (GC) SOI MOSFET is investigated in terms of the channel length comparing two different technologies, OKI semiconductors and UCL. © 2013 IEEE.
- Analog behavior of submicron graded-Channel SOI MOSFETs varying the channel length, doping concentration and temperature(2013-05-16) NEMER, J. P.; Michelly De Souza; FLANDRE, D.; Marcelo Antonio PavanelloIn this paper the analog performance of Graded-Channel (GC) SOI nMOSFETs with deep submicrometer channel length is presented. Experimental data of GC transistors fabricated in an industrial 150 nm fully-depleted SOI technology from OKI Semiconductors were used to adjust the two-dimensional numerical simulations, in order to analyze the devices analog behavior by extrapolating their physical parameters. The obtained results show that the larger intrinsic voltage gain improvement occurs when the length of the lightly doped region is approximately 100 nm regardless the total channel length, doping concentration and temperature. © The Electrochemical Society.
- Effect of high temperature on analog parameters of Asymmetric Self-Cascode SOI nMOSFETs(2014-10-29) D'OLIVEIRA, L. M.; FLANDRE, D.; Marcelo Antonio Pavanello; Michelly De SouzaThis paper presents an analysis on the high temperature operation of Silicon-on-Insulator (SOI) nMOSFETs in Asymmetric Self-Cascode (A-SC) configuration. For this analysis, experimental results in the range of 300K to 500K of A-SC structures with different channel lengths for both the drain side transistor (MD) and source side transistor (MS) are used. The effect of varying channel length under high temperatures on the A-SC association is evaluated using as figure of merit important analog parameters, such as the intrinsic voltage gain and transconductance over drain current ratio.
- On the origin of low-frequency noise of submicron Graded-Channel fully depleted SOI nMOSFETs(2015-08-31) MOLTO, A. R.; Rodrigo Doria; Michelly De Souza; Marcelo Antonio PavanelloThis paper deals with the Low-Frequency Noise (LFN) behavior of submicron Graded-Channel SOI nMOSFETs, fabricated in a 150 nm Technology from Oki Semiconductors as a continuation from previous works, looking at the noise sources of these devices. The effects of channel length reduction and gate bias dependence on the LFN of devices biased in linear regime are investigated. The effective trap density and the KF constant, which can be used in BSIM SPICE-like models, are determined.
- 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.