Engenharia Elétrica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/21
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17 resultados
Resultados da Pesquisa
- Comparative of analog performance of transcapacitances in asymmetric self-cascode and graded-channel SOI nMOSFETs(2023-01-04) ALVES, C. R.; Michelly De Souza© 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.This work presents a comparative study of the transcapacitances of an asymmetric self-cascode (A-SC) and graded-channel (GC) silicon-on-insulator (SOI) nMOSFETs with different gate lengths. This analysis was done by means of two-dimensional numerical simulations. Simulated results show the influence of others transcapacitances on the gate-to-gate capacitance for the ASC SOI device and the GC SOI device.
- 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.
- 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.
- Asymmetric self-cascode configuration to improve the analog performance of SOI nMOS transistors(2011-10-11) Michelly De Souza; FLANDRE, D.; Marcelo Antonio PavanelloIn this work an asymmetric self-cascode (SC) structure implemented in a 150nm technology have been studied as a function of the threshold voltage and length of both transistors in the structure, aiming to improve the analog characteristics of FD SOI transistors. Experimal results indicate that this structure provided improvement in comparison to single and symmetric (SC) transistors, and that it depends on the saturation voltage of both transistors. The effect of threshold voltage and length variation of both transistors have been analyzed through 2D numerical simulations. The obtained results showed that the analog characteristics of the A-SC is improved both by reducing V T,2 and increasing L 1 and/or L 2, although there would be a maximum M 2 length in which no significant g D reduction is observed. By properly choosing these parameters, a g D reduction of more than one order of magnitude can be achieved. The A-SC has shown to provide an intrinsic voltage gain improvement of more than 20dB in comparison to single devices with similar effective channel length. © 2011 IEEE.
- Application of junctionless nanowire transistor in the self-cascode configuration to improve the analog performance(2012-09-02) Rodrido Doria; TREVISOLI, R. D.; Michelly De Souza; Marcelo Antonio PavanelloThe self-cascode (SC) configuration consists in a series association of two transistors with tied gates usually applied to improve the analog performance of MOS devices. This paper compares the analog parameters of single Junctionless transistors with the ones presented by self-cascode associations composed by two Junctionless devices with identical or different fin widths (symmetric and asymmetric, respectively). The transconductance to the drain current ratio, the Early voltage (VEA) and the intrinsic voltage gain (AV) have been evaluated for both single devices and SC structures. It has been shown that the SC configurations, specially the asymmetric ones, present a strong reduction of the drain conductance (gD) with respect to single devices, resulting in an increase of VEA and AV, which can be higher than 30 dB depending on the bias conditions. © The Electrochemical Society.
- Analog performance of asymmetric self-cascode p-channel fully depleted SOI transistors(2012-03-17) Michelly De Souza; Marcelo Antonio Pavanello; FLANDRE, D.This work presents an analysis of the analog performance of asymmetric threshold voltage self-cascode fully depleted (FD) p-type SOI transistors. The experimental results showed that this structure is able to improve the devices transconductance and output conductance, resulting in increased intrinsic voltage gain and breakdown voltage in comparison to single transistors and the conventional symmetric self-cascode. © 2012 IEEE.
- 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.
- 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.