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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Metodologia determinística para simulação elétrica do impacto de BTI em circuitos MOS

Furtado, Gabriela Firpo January 2017 (has links)
Aborda-se, nesse trabalho, o fenômeno de envelhecimento de transistores MOS por bias temperature instability (BTI), relevante fator de degradação da confiabilidade e de redução do tempo de vida de circuitos integrados CMOS. Uma nova modelagem matemática determinística para BTI é introduzida, proporcionando, rapidamente, informação acerca do desvio na tensão de limiar de um transistor em decorrência da ação de BTI. O modelo é, então, implementado em uma ferramenta comercial SPICE, com o intuito de se verificarem, através de simulações transientes, os efeitos de BTI em circuitos CMOS; nesse sentido, a abordagem determinística representa um enorme avanço em relação à modelagem estocástica tradicional, que, muitas vezes, não pode ser aplicada em simulações transientes de circuitos complexos, devido ao seu vultoso custo computacional. O fenômeno de alargamento de pulso induzido pela propagação (PIPB) de single event transients (SETs), verificado experimentalmente na literatura, é estudado e tido como resultado da ação de BTI nas bordas de subida e descida do pulso transiente. À vista disso, simula-se a propagação de um pulso SET injetado na entrada de uma cadeia de 10000 inversores lógicos de tecnologia PTM bulk 90nm, verificando a dependência do alargamento de pulso com a tensão de alimentação, com o tempo de estresse DC anterior à aplicação do pulso e com a frequência do sinal de entrada. O aumento do atraso de portas lógicas em decorrência da ação de bias temperature instability é abordado, também, através da simulação da aplicação de um pulso nas entradas de uma porta NAND, medindo-se a variação do tempo de atraso de propagação devido à inserção da modelagem matemática para BTI. Utiliza-se novamente o modelo de transistores PTM bulk 90nm, e apuram-se os efeitos da variação da tensão de alimentação e do tempo de estresse DC no tempo de atraso de propagação. Por fim, as disparidades na variação do atraso para as bordas de subida e descida de pulsos lógicos de nível alto-baixo-alto (“101”) e baixo-alto-baixo (“010”) são verificadas, sendo explicadas em termos do diferente impacto de BTI para os períodos de estresse e de relaxação e, também, para transistores PMOS e NMOS. / This work addresses the aging of MOS transistors by bias temperature instability (BTI), which is a key factor to the degradation of the reliability and of the lifetime of CMOS integrated circuits. A novel deterministic mathematical model is presented, providing fast information about the impact of BTI in the transistors threshold voltage shifts. The model is implemented in a commercial SPICE tool, in order to verify the effects of BTI in CMOS circuits through transient simulations; in this sense, the deterministic approach represents a great advance compared to the traditional stochastic modelling, that may result in prohibitively long transient simulations for complex circuits, due to its huge computation cost. The phenomenon of propagation induced pulse broadening (PIPB) of single event transients (SETs), verified experimentally in the literature, is studied and understood as the result of the BTI effect on the rising and falling edges of the transient pulse. Therefore, the propagation of a SET injected in the input of a 10,000-inverters chain is simulated, using the PTM bulk 90nm technology model, verifying the dependence of the pulse broadening on the supply voltage, on the DC stress time previous to the application of the pulse and on the input signal frequency. The increase of the propagation delay of logic gates due the action of bias temperature instability is also studied through the simulation of the injection of a pulse in the inputs of a NAND gate, and the variation of the propagation delay time due to the BTI effect is evaluated. The PTM bulk 90nm model is used once again, and the outcome of variations on the supply voltage and on the DC stress time on the propagation delay is measured. Finally, the disparities on the delay variation for the rising and falling edges of high-low-high (“101”) and low-high-low (“010”) input logic pulses are verified, and they are explained as the result of the different impact of BTI for the stress and recovery periods and also for PMOS and NMOS transistors.
12

Redundant Skewed Clocking of Pulse-Clocked Latches for Low Power Soft-Error Mitigation

January 2015 (has links)
abstract: An integrated methodology combining redundant clock tree synthesis and pulse clocked latches mitigates both single event upsets (SEU) and single event transients (SET) with reduced power consumption. This methodology helps to change the hardness of the design on the fly. This approach, with minimal additional overhead circuitry, has the ability to work in three different modes of operation depending on the speed, hardness and power consumption required by design. This was designed on 90nm low-standby power (LSP) process and utilized commercial CAD tools for testing. Spatial separation of critical nodes in the physical design of this approach mitigates multi-node charge collection (MNCC) upsets. An advanced encryption system implemented with the proposed design, compared to a previous design with non-redundant clock trees and local delay generation. The proposed approach reduces energy per operation up to 18% over an improved version of the prior approach, with negligible area impact. It can save up to 2/3rd of the power consumption and reach maximum possible frequency, when used in non-redundant mode of operation. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015
13

Radiation Effects Measurement Test Structure using GF 32-nm SOI process

January 2017 (has links)
abstract: This thesis describes the design of a Single Event Transient (SET) duration measurement test-structure on the Global Foundries (previously IBM) 32-nm silicon-on insulator (SOI) process. The test structure is designed for portability and allows quick design and implementation on a new process node. Such a test structure is critical in analyzing the effects of radiation on complementary metal oxide semi-conductor (CMOS) circuits. The focus of this thesis is the change in pulse width during propagation of SET pulse and build a test structure to measure the duration of a SET pulse generated in real time. This test structure can estimate the SET pulse duration with 10ps resolution. It receives the input SET propagated through a SET capture structure made using a chain of combinational gates. The impact of propagation of the SET in a >200 deep collection structure is studied. A novel methodology of deploying Thick Gate TID structure is proposed and analyzed to build multi-stage chain of combinational gates. Upon using long chain of combinational gates, the most critical issue of pulse width broadening and shortening is analyzed across critical process corners. The impact of using regular standard cells on pulse width modification is compared with NMOS and/or PMOS skewed gates for the chain of combinational gates. A possible resolution to pulse width change is demonstrated using circuit and layout design of chain of inverters, two and three inputs NOR gates. The SET capture circuit is also tested in simulation by introducing a glitch signal that mimics an individual ion strike that could lead to perturbation in SET propagation. Design techniques and skewed gates are deployed to dampen the glitch that occurs under the effect of radiation. Simulation results, layout structures of SET capture circuit and chain of combinational gates are presented. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2017
14

Metodologia determinística para simulação elétrica do impacto de BTI em circuitos MOS

Furtado, Gabriela Firpo January 2017 (has links)
Aborda-se, nesse trabalho, o fenômeno de envelhecimento de transistores MOS por bias temperature instability (BTI), relevante fator de degradação da confiabilidade e de redução do tempo de vida de circuitos integrados CMOS. Uma nova modelagem matemática determinística para BTI é introduzida, proporcionando, rapidamente, informação acerca do desvio na tensão de limiar de um transistor em decorrência da ação de BTI. O modelo é, então, implementado em uma ferramenta comercial SPICE, com o intuito de se verificarem, através de simulações transientes, os efeitos de BTI em circuitos CMOS; nesse sentido, a abordagem determinística representa um enorme avanço em relação à modelagem estocástica tradicional, que, muitas vezes, não pode ser aplicada em simulações transientes de circuitos complexos, devido ao seu vultoso custo computacional. O fenômeno de alargamento de pulso induzido pela propagação (PIPB) de single event transients (SETs), verificado experimentalmente na literatura, é estudado e tido como resultado da ação de BTI nas bordas de subida e descida do pulso transiente. À vista disso, simula-se a propagação de um pulso SET injetado na entrada de uma cadeia de 10000 inversores lógicos de tecnologia PTM bulk 90nm, verificando a dependência do alargamento de pulso com a tensão de alimentação, com o tempo de estresse DC anterior à aplicação do pulso e com a frequência do sinal de entrada. O aumento do atraso de portas lógicas em decorrência da ação de bias temperature instability é abordado, também, através da simulação da aplicação de um pulso nas entradas de uma porta NAND, medindo-se a variação do tempo de atraso de propagação devido à inserção da modelagem matemática para BTI. Utiliza-se novamente o modelo de transistores PTM bulk 90nm, e apuram-se os efeitos da variação da tensão de alimentação e do tempo de estresse DC no tempo de atraso de propagação. Por fim, as disparidades na variação do atraso para as bordas de subida e descida de pulsos lógicos de nível alto-baixo-alto (“101”) e baixo-alto-baixo (“010”) são verificadas, sendo explicadas em termos do diferente impacto de BTI para os períodos de estresse e de relaxação e, também, para transistores PMOS e NMOS. / This work addresses the aging of MOS transistors by bias temperature instability (BTI), which is a key factor to the degradation of the reliability and of the lifetime of CMOS integrated circuits. A novel deterministic mathematical model is presented, providing fast information about the impact of BTI in the transistors threshold voltage shifts. The model is implemented in a commercial SPICE tool, in order to verify the effects of BTI in CMOS circuits through transient simulations; in this sense, the deterministic approach represents a great advance compared to the traditional stochastic modelling, that may result in prohibitively long transient simulations for complex circuits, due to its huge computation cost. The phenomenon of propagation induced pulse broadening (PIPB) of single event transients (SETs), verified experimentally in the literature, is studied and understood as the result of the BTI effect on the rising and falling edges of the transient pulse. Therefore, the propagation of a SET injected in the input of a 10,000-inverters chain is simulated, using the PTM bulk 90nm technology model, verifying the dependence of the pulse broadening on the supply voltage, on the DC stress time previous to the application of the pulse and on the input signal frequency. The increase of the propagation delay of logic gates due the action of bias temperature instability is also studied through the simulation of the injection of a pulse in the inputs of a NAND gate, and the variation of the propagation delay time due to the BTI effect is evaluated. The PTM bulk 90nm model is used once again, and the outcome of variations on the supply voltage and on the DC stress time on the propagation delay is measured. Finally, the disparities on the delay variation for the rising and falling edges of high-low-high (“101”) and low-high-low (“010”) input logic pulses are verified, and they are explained as the result of the different impact of BTI for the stress and recovery periods and also for PMOS and NMOS transistors.
15

Modelamento do single-Event effiects em circuitos de memória FDSOI / Single event effects modeling in FDSOI memory circuits

Bartra, Walter Enrique Calienes January 2016 (has links)
Este trabalho mostra a comparação dos efeitos das falhas provocadas pelos Single-Event Effects em dispositivos 28nm FDSOI, 28nm FDSOI High-K e 32nm Bulk CMOS e células de memória 6T SRAM feitas com estes dispositivos. Para conseguir isso, foram usadas ferramentas TCAD para simular falhas transientes devido a impacto de íons pesados a nível dispositivo e nível circuito. As simulações neste ambiente tem como vantagem a simulação dos fatos e mecanismos que produz as falhas transientes e seus efeitos nos dispositivos, além de também servir para projetar virtualmente estes dispositivos e caraterizar eles para estas simulações. Neste caso, foram projetados três dispositivos para simulação: um transistor NMOS de 32nm Bulk, um transistor NMOS de 28nm FDSOI e um transistor NMOS de 28nm FDSOI High-K para fazer comparações entre eles. Estes dispositivos foram projetados, caraterizados e testados contra o impacto de íons pesados a níveis dispositivo e circuito. Como resultado obtido, transistor Bulk de 32nm teve, no pior caso, uma carga coletada de 7.57 e 7.19 vezes maior que a carga coletada pelo dispositivo FDSOI de 28nm e FDSOI High-K de 28nm respectivamente atingido pelo mesmo íon pesado de 100MeV-cm2/mg. Com estes dados foi possível modelar o comportamento da carga coletada de ambos dispositivos usando este íon pesado, atingindo os terminais de Fonte e Dreno em distintos lugares e ângulos. Usando a mesma ferramenta e os dados obtidos de carga coletada pelos testes anteriores, foram projetadas células de memória SRAM de 6 transistores. Isso foi para testar elas contra os efeitos do impacto de íons pesados nos transistores NMOS de armazenagem da dados. Neste caso, a Transferência Linear de Energia (LET) do íon necessária para fazer que o dado armazenado na SRAM Bulk mude é 12.8 vezes maior que no caso da SRAM FDSOI e 10 maior no caso da SRAM FDSOI High-K, embora a quantidade de carga coletada necessária para que o dado mude em ambas células seja quase a mesma. Com estes dados foi possível modelar os efeitos dos íons pesados em ambos circuitos, descobrir a Carga Crítica destes e qual é o mínimo LET necessário para que o dado armazenado nestas SRAMs mude. / This work shows a comparison of faults due to Single-Event Effects in 28nm Fully Depleted SOI (FDSOI), 28nm FDSOI High-K and 32nm Bulk CMOS devices, and in 6T SRAM memory cells made with these devices. To provide this, was used TCAD tools to simulate transient faults due to heavy ion impacts on device and circuit levels. The simulations in that environment have the advantage to simulate the facts and mechanisms which produce the transient faults and this effects on the electronic devices, it also allow to simulate the virtual device fabrication and to characterize them. In this case, two devices were created for the simulations: a 32nm Bulk NMOS transistor and a 28nm FDSOI NMOS transistor for compare them. These devices were created, characterized and tested against heavy ion impacts at device and circuit levels. The results show that 32nm Bulk transistor has, in the worst case, a collected charge 7.57 and 7.19 times greater than the 28nm FDSOI and 28nm FDSOI High-K respectively collected charge with the same 100MeV-cm2/mg heavy ion. With these data it was possible to model the behavior of the collected charge in both devices with the same heavy-ion, reach the Source and Drain Terminal in different places and angles. Using the same tools and the obtained collected charge data of previous simulations, it was designed 6 transistors SRAM Memory Cells. That is done to test these circuits against the heavy ion effects on the data-storage NMOS transistor. In this case, the necessary Ion Linear Energy Transfer (LET) to flip the Bulk SRAM is 12.8 greater than the FDSOI SRAM and 10 times greater than the FDSOI High- K SRAM case, although the amount of charge to flip the cells is almost the same in both cases. With these data it was possible to model the heavy-ion effects in both circuits, discover the Critical Charge of them and the minimum LET to flips these SRAMs.
16

Etude et modélisation des effets de synergie issus de l’environnement radiatif spatial naturel et intentionnel sur les technologies bipolaires intégrées / Investigation and Modeling of Synergistic Effects in Integrated Bipolar Technologies Exposed to Natural Space Environment or Nuclear Detonation

Roig, Fabien 11 December 2014 (has links)
L'environnement spatial constitue une contrainte radiative susceptible d'altérer le bon fonctionnement des dispositifs électroniques embarqués à bord des engins spatiaux, engendrant ainsi des défaillances. Dans le cadre de ces travaux, deux types de dysfonctionnements sont répertoriés : les effets cumulatifs dus à une accumulation continue d'énergie déposée tout au long d'une mission et les effets transitoires dus au passage d'une particule unique dans une zone sensible d'un composant ou à un dépôt d'énergie en un temps très court dans le cadre spécifique d'une explosion nucléaire exoatmosphérique. Lors des procédures de qualification des composants électroniques, ces deux effets sont traités séparément et ce, malgré une probabilité non négligeable qu'ils se produisent simultanément en vol. Ces travaux sont dédiés à l'étude de la synergie entre effets cumulatifs et effets transitoires sur différentes technologies bipolaires intégrées. Les résultats obtenus permettent de fournir des éléments de réponse sur l'éventualité d'une évolution des normes de test pour prendre en compte la menace que pourrait représenter ce phénomène. Ces travaux s'attachent également à étendre une méthodologie de simulation, basée sur une analyse circuit approfondie, dans l'optique de reproduire les perturbations transitoires « pire-cas » sur un amplificateur opérationnel à trois étages de plusieurs fabricants, survenues lors des tests sous faisceau laser, ions lourds et flash X. L'influence des effets cumulatifs sur la sensibilité des perturbations transitoires est prise en compte en faisant varier les paramètres internes du modèle en fonction de la dégradation de certains paramètres électriques issue des essais radiatifs des équipementiers. / The space environment is a radiative concern that affects on board electronic systems, leading to failures. It is possible to distinguish two types of effects: the cumulative effects due to continuous deposition of energy throughout the space mission and the transient effects due to the single energetic particle crossing a sensitive area of the component or deposition of energy in a very short time in the specific context of an exo-atmospheric nuclear explosion. During qualification procedures for space mission, these effects are studied separately. However, the probability that they occur simultaneously in flight is significant. As a consequence, this work is about the study of the synergy between both cumulative and transient effects on various integrated bipolar technologies. The present results are used to provide some answers about potential changes of test methods. This work also evaluates the predictive capability of the previously developed model to reproduce accurately both the fast and the long lasting components of transients in circuitry and so to model transients' effects. This simulation methodology is extended to an operational amplifier from different manufacturers and for three different synergistic effects. The comparison between transients obtained experimentally during heavy ions, pulse laser and flash X experiments and the predicted transients validates the investigated methodology. The cumulative effects are taken into account by injecting the internal electrical parameters variations using irradiation exposure.
17

Modelamento do single-Event effiects em circuitos de memória FDSOI / Single event effects modeling in FDSOI memory circuits

Bartra, Walter Enrique Calienes January 2016 (has links)
Este trabalho mostra a comparação dos efeitos das falhas provocadas pelos Single-Event Effects em dispositivos 28nm FDSOI, 28nm FDSOI High-K e 32nm Bulk CMOS e células de memória 6T SRAM feitas com estes dispositivos. Para conseguir isso, foram usadas ferramentas TCAD para simular falhas transientes devido a impacto de íons pesados a nível dispositivo e nível circuito. As simulações neste ambiente tem como vantagem a simulação dos fatos e mecanismos que produz as falhas transientes e seus efeitos nos dispositivos, além de também servir para projetar virtualmente estes dispositivos e caraterizar eles para estas simulações. Neste caso, foram projetados três dispositivos para simulação: um transistor NMOS de 32nm Bulk, um transistor NMOS de 28nm FDSOI e um transistor NMOS de 28nm FDSOI High-K para fazer comparações entre eles. Estes dispositivos foram projetados, caraterizados e testados contra o impacto de íons pesados a níveis dispositivo e circuito. Como resultado obtido, transistor Bulk de 32nm teve, no pior caso, uma carga coletada de 7.57 e 7.19 vezes maior que a carga coletada pelo dispositivo FDSOI de 28nm e FDSOI High-K de 28nm respectivamente atingido pelo mesmo íon pesado de 100MeV-cm2/mg. Com estes dados foi possível modelar o comportamento da carga coletada de ambos dispositivos usando este íon pesado, atingindo os terminais de Fonte e Dreno em distintos lugares e ângulos. Usando a mesma ferramenta e os dados obtidos de carga coletada pelos testes anteriores, foram projetadas células de memória SRAM de 6 transistores. Isso foi para testar elas contra os efeitos do impacto de íons pesados nos transistores NMOS de armazenagem da dados. Neste caso, a Transferência Linear de Energia (LET) do íon necessária para fazer que o dado armazenado na SRAM Bulk mude é 12.8 vezes maior que no caso da SRAM FDSOI e 10 maior no caso da SRAM FDSOI High-K, embora a quantidade de carga coletada necessária para que o dado mude em ambas células seja quase a mesma. Com estes dados foi possível modelar os efeitos dos íons pesados em ambos circuitos, descobrir a Carga Crítica destes e qual é o mínimo LET necessário para que o dado armazenado nestas SRAMs mude. / This work shows a comparison of faults due to Single-Event Effects in 28nm Fully Depleted SOI (FDSOI), 28nm FDSOI High-K and 32nm Bulk CMOS devices, and in 6T SRAM memory cells made with these devices. To provide this, was used TCAD tools to simulate transient faults due to heavy ion impacts on device and circuit levels. The simulations in that environment have the advantage to simulate the facts and mechanisms which produce the transient faults and this effects on the electronic devices, it also allow to simulate the virtual device fabrication and to characterize them. In this case, two devices were created for the simulations: a 32nm Bulk NMOS transistor and a 28nm FDSOI NMOS transistor for compare them. These devices were created, characterized and tested against heavy ion impacts at device and circuit levels. The results show that 32nm Bulk transistor has, in the worst case, a collected charge 7.57 and 7.19 times greater than the 28nm FDSOI and 28nm FDSOI High-K respectively collected charge with the same 100MeV-cm2/mg heavy ion. With these data it was possible to model the behavior of the collected charge in both devices with the same heavy-ion, reach the Source and Drain Terminal in different places and angles. Using the same tools and the obtained collected charge data of previous simulations, it was designed 6 transistors SRAM Memory Cells. That is done to test these circuits against the heavy ion effects on the data-storage NMOS transistor. In this case, the necessary Ion Linear Energy Transfer (LET) to flip the Bulk SRAM is 12.8 greater than the FDSOI SRAM and 10 times greater than the FDSOI High- K SRAM case, although the amount of charge to flip the cells is almost the same in both cases. With these data it was possible to model the heavy-ion effects in both circuits, discover the Critical Charge of them and the minimum LET to flips these SRAMs.
18

Methodical Design Approaches to Multiple Node Collection Robustness for Flip-Flop Soft Error MItigation

January 2015 (has links)
abstract: The space environment comprises cosmic ray particles, heavy ions and high energy electrons and protons. Microelectronic circuits used in space applications such as satellites and space stations are prone to upsets induced by these particles. With transistor dimensions shrinking due to continued scaling, terrestrial integrated circuits are also increasingly susceptible to radiation upsets. Hence radiation hardening is a requirement for microelectronic circuits used in both space and terrestrial applications. This work begins by exploring the different radiation hardened flip-flops that have been proposed in the literature and classifies them based on the different hardening techniques. A reduced power delay element for the temporal hardening of sequential digital circuits is presented. The delay element single event transient tolerance is demonstrated by simulations using it in a radiation hardened by design master slave flip-flop (FF). Using the proposed delay element saves up to 25% total FF power at 50% activity factor. The delay element is used in the implementation of an 8-bit, 8051 designed in the TSMC 130 nm bulk CMOS. A single impinging ionizing radiation particle is increasingly likely to upset multiple circuit nodes and produce logic transients that contribute to the soft error rate in most modern scaled process technologies. The design of flip-flops is made more difficult with increasing multi-node charge collection, which requires that charge storage and other sensitive nodes be separated so that one impinging radiation particle does not affect redundant nodes simultaneously. We describe a correct-by-construction design methodology to determine a-priori which hardened FF nodes must be separated, as well as a general interleaving scheme to achieve this separation. We apply the methodology to radiation hardened flip-flops and demonstrate optimal circuit physical organization for protection against multi-node charge collection. Finally, the methodology is utilized to provide critical node separation for a new hardened flip-flop design that reduces the power and area by 31% and 35% respectively compared to a temporal FF with similar hardness. The hardness is verified and compared to other published designs via the proposed systematic simulation approach that comprehends multiple node charge collection and tests resiliency to upsets at all internal and input nodes. Comparison of the hardness, as measured by estimated upset cross-section, is made to other published designs. Additionally, the importance of specific circuit design aspects to achieving hardness is shown. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2015
19

Modelamento do single-Event effiects em circuitos de memória FDSOI / Single event effects modeling in FDSOI memory circuits

Bartra, Walter Enrique Calienes January 2016 (has links)
Este trabalho mostra a comparação dos efeitos das falhas provocadas pelos Single-Event Effects em dispositivos 28nm FDSOI, 28nm FDSOI High-K e 32nm Bulk CMOS e células de memória 6T SRAM feitas com estes dispositivos. Para conseguir isso, foram usadas ferramentas TCAD para simular falhas transientes devido a impacto de íons pesados a nível dispositivo e nível circuito. As simulações neste ambiente tem como vantagem a simulação dos fatos e mecanismos que produz as falhas transientes e seus efeitos nos dispositivos, além de também servir para projetar virtualmente estes dispositivos e caraterizar eles para estas simulações. Neste caso, foram projetados três dispositivos para simulação: um transistor NMOS de 32nm Bulk, um transistor NMOS de 28nm FDSOI e um transistor NMOS de 28nm FDSOI High-K para fazer comparações entre eles. Estes dispositivos foram projetados, caraterizados e testados contra o impacto de íons pesados a níveis dispositivo e circuito. Como resultado obtido, transistor Bulk de 32nm teve, no pior caso, uma carga coletada de 7.57 e 7.19 vezes maior que a carga coletada pelo dispositivo FDSOI de 28nm e FDSOI High-K de 28nm respectivamente atingido pelo mesmo íon pesado de 100MeV-cm2/mg. Com estes dados foi possível modelar o comportamento da carga coletada de ambos dispositivos usando este íon pesado, atingindo os terminais de Fonte e Dreno em distintos lugares e ângulos. Usando a mesma ferramenta e os dados obtidos de carga coletada pelos testes anteriores, foram projetadas células de memória SRAM de 6 transistores. Isso foi para testar elas contra os efeitos do impacto de íons pesados nos transistores NMOS de armazenagem da dados. Neste caso, a Transferência Linear de Energia (LET) do íon necessária para fazer que o dado armazenado na SRAM Bulk mude é 12.8 vezes maior que no caso da SRAM FDSOI e 10 maior no caso da SRAM FDSOI High-K, embora a quantidade de carga coletada necessária para que o dado mude em ambas células seja quase a mesma. Com estes dados foi possível modelar os efeitos dos íons pesados em ambos circuitos, descobrir a Carga Crítica destes e qual é o mínimo LET necessário para que o dado armazenado nestas SRAMs mude. / This work shows a comparison of faults due to Single-Event Effects in 28nm Fully Depleted SOI (FDSOI), 28nm FDSOI High-K and 32nm Bulk CMOS devices, and in 6T SRAM memory cells made with these devices. To provide this, was used TCAD tools to simulate transient faults due to heavy ion impacts on device and circuit levels. The simulations in that environment have the advantage to simulate the facts and mechanisms which produce the transient faults and this effects on the electronic devices, it also allow to simulate the virtual device fabrication and to characterize them. In this case, two devices were created for the simulations: a 32nm Bulk NMOS transistor and a 28nm FDSOI NMOS transistor for compare them. These devices were created, characterized and tested against heavy ion impacts at device and circuit levels. The results show that 32nm Bulk transistor has, in the worst case, a collected charge 7.57 and 7.19 times greater than the 28nm FDSOI and 28nm FDSOI High-K respectively collected charge with the same 100MeV-cm2/mg heavy ion. With these data it was possible to model the behavior of the collected charge in both devices with the same heavy-ion, reach the Source and Drain Terminal in different places and angles. Using the same tools and the obtained collected charge data of previous simulations, it was designed 6 transistors SRAM Memory Cells. That is done to test these circuits against the heavy ion effects on the data-storage NMOS transistor. In this case, the necessary Ion Linear Energy Transfer (LET) to flip the Bulk SRAM is 12.8 greater than the FDSOI SRAM and 10 times greater than the FDSOI High- K SRAM case, although the amount of charge to flip the cells is almost the same in both cases. With these data it was possible to model the heavy-ion effects in both circuits, discover the Critical Charge of them and the minimum LET to flips these SRAMs.
20

An Automated Approach to a 90-nm CMOS DRFM DSSM Circuit Design

Hopkins, Thomas A. 18 October 2010 (has links)
No description available.

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