A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering 25 May 2017 / Two of the main contributors to high voltage insulation failure are thermal and electrical stresses. The failures may be mitigated by using nanodielectrics. The enhanced effect of nanoparticles in nanodielectrics is attributed to an interaction zone/interphase around each individual nanoparticle between the nanoparticle and host polymer. However, particle clumping or agglomerates are a major challenge in nanodielectric technology. In this work mitigation of the clumping challenges was explored through Rheology in determining optimal particle loading levels. The nanodielectrics studies were Boron Nitride and Carbon Nanospheres in Araldite Epoxy. The rheology results indicated an optimal loading level of 1.09 vol % to 1.35 vol% for Boron Nitride in Epoxy and 0.33 vol% for Carbon Nanospheres in Epoxy. Microscopy, dielectric spectroscopy, electrical tree characterisation, thermal expansion and laser flash analysis were used to validate the efficacy of the rheology results. The results indicated improved properties of the resultant dielectric such as; increased mechanical stiffness, increased electrical resistance and the percolation threshold, partial discharge suppression and increased thermal conductivity at the glass transition temperature. This study has established a rheology-based technique incorporated in the manufacturing process to determine the optimal filler loading of C/Epoxy and BN/Epoxy nanodielectrics. Future work is recommended as investigating either new particle types such as Sulphur hexafluoride in Carbon Nanospheres or mixtures of Carbon Nanospheres and Boron Nitiride. / MT 2017

This thesis aims to provide insights into two challenging problems in the field of molecular electronics: Understanding the role of the electronic and the mechanical properties of electrodes in determining the charge transport dynamics of molecular devices and achieving the optical control of charge transport through single-molecule junctions by exploiting the optical properties of electrodes. We start by investigating the impact of electrode band structure on the charge transport characteristics of molecular devices. To this end, we conduct two independent, yet highly related studies. In the first study, we demonstrate how the metallic band structure dictates the molecular orbital coupling at metal-molecule interfaces by studying charge transport through pyridine-based single-molecule junctions with Au and Ag electrodes using a newly developed scanning tunneling microscope-based spectroscopy technique and performing density functional theory calculations. We find that pyridine derivatives couple well to Au electrodes compared with Ag electrodes. The density functional theory calculations show that the increase in the molecular orbital coupling to Au compared with Ag is due to an enhanced density of d-states near the Fermi level resulting from relativistic effects. Second, we study the interfacial charge transport properties of molecular devices with metal, semimetal and semiconductor electrodes using X-ray photoemission based spectroscopy techniques. In particular, we probe the hot electron dynamics of 4,4'-bipyrdine on Au (metal), epitaxial graphene (semimetal) and graphene nanoribbon (semiconductor) surfaces. We find that charge transfer from the molecule to the substrate is fastest on the metal surface and slowest on the semiconductor surface. We attribute this trend to a reduced electronic interaction between the molecule and the surface as a results of a decrease in the density of electronic states near the Fermi level as the metallic character of the substrate is reduced. Furthermore, we provide evidence for fast phase decoherence of hot electrons via an interaction with the substrate in these systems. Third, we shed light onto the origin of flicker noise in single-molecule junctions, tunnel junctions and gold point-contacts at room temperature. We find that the switching of gold atoms between metastable sites in the electrodes due to the thermal energy leads to conductance fluctuations in these systems. We further demonstrate how the flicker noise characteristics of single-molecule junctions can be used to infer the nature of the electronic interaction at metal-molecule interfaces. Specifically, we find that flicker noise exhibits a power dependence on junction conductance that can distinguish between through-space and through-bond charge transport. This work demonstrates how the mechanical properties of electrodes affect charge transport through single-molecule junctions and how noise can be used to understand the electronic properties of metal-molecule interfaces. Lastly, we explore the possibility of driving currents through single-molecule junctions using electromagnetic radiation. To this end, we perform photocurrent measurements on single-molecule junctions, tunnel junctions and gold point-contacts obtained using the scanning tunneling microscope-based break-junction technique. We find that the primary source of photocurrents in these systems is the laser induced local heating and the subsequent thermal expansion when probed using a lock-in type technique in which the light intensity is being modulated. We further develop an experimental method that differentiates between the photocurrents due to thermal expansion and the optical currents in single-molecule junctions, and provide evidence for optical currents due to electron-photon interaction during charge transport through single-molecule junctions. By using this method we estimate the plasmonic electric field enhancement factor in single-molecule junctions formed by 4,4'-bipyridine. Our estimate is in very good agreement with values inferred from tip enhanced Raman spectroscopy measurements and field emission measurements. We believe that the results presented in this thesis provide original insights into the fundamentals of the physics that govern charge transport across metal-molecule interfaces. Furthermore, the new experimental techniques introduced in this thesis offer new ways for investigating the rich physics present in nanoscale systems.

This thesis presents architectures and integrated circuits for the implementation of energy-efficient, high-power "digital'' transmitters to realize high-speed long-haul links at millimeter-wave frequencies in nano-scale silicon-based processes.

Single-molecule electronics is an emerging subfield of nanoelectronics where the ultimate goal is to use individual molecules as the active components in electronic circuitry. Over the past century, chemists have developed a rich understanding of how a molecule’s structure determines its electronic properties; transposing the paradigms of chemistry into the design and understanding of single-molecule electronic devices can thus provide a tremendous impetus for growth in the field. This dissertation describes how we can harness the principles of organosilicon and organogermanium chemistry to control charge transport and function in single-molecule devices. We use a scanning tunneling microscope-based break-junction (STM-BJ) technique to probe structure-conductivity relationships in silicon- and germanium-based wires. Our studies ultimately demonstrate that charge transport in these systems is dictated by the conformation, conjugation, and bond polarity of the σ-backbone. Furthermore, we exploit principles from reaction chemistry such as strain-induced Lewis acidity and σ-bond stereoelectronics to create new types of digital conductance switches. These studies highlight the vast opportunities that exist at the intersection between chemical principles and single-molecule electronics. Chapter 1 introduces the fields of single-molecule electronics, silicon microelectronics, and physical organosilane chemistry and our motivation for bridging these three worlds. Chapters 2-6 elaborate on the specific approach taken in this dissertation work, which is to deconstruct the molecular wire into three structural modules – the linker, backbone, and substituent – then synthetically manipulate each component to elucidate fundamental conductance properties and create new types of molecular conductance switches. Chapter 2 describes the first single-molecule switch that operates through a stereoelectronic effect. We demonstrate this behavior in permethyloligosilanes with methylthiomethyl electrode linkers; the strong σ-conjugation in the oligosilane backbone couples the stereoelectronic properties of the sulfur-methylene σ-bonds that terminate the molecule. Chapter 3 describes the electric field breakdown properties of C-C, Si-Si, Ge-Ge, Si-O, and Si-C bonds. The robust covalent linkage that the methylthiol endgroup forms with the electrodes enables us to study molecular junctions under high voltage biases. Chapter 4 unveils a new approach for synthesizing atomically discrete wires of germanium and presents the first conductance measurements of molecular germanium. Our findings show that germanium and silicon wires are nearly identical in conductivity at the molecular scale, and that both are much more conductive than aliphatic carbon. Chapter 5 describes a series of molecular wires with π–σ–π backbone structures, where the π–moiety is an electrode–binding thioanisole ring and the σ–moiety is a triatomic α–β–α chain composed of C, Si, or Ge atoms. We find that placing heavy atoms at the α–position decreases conductance, whereas placing them at the β–position increases conductance. Chapter 6 demonstrates that silanes with strained substituent groups can couple directly to gold electrodes. We can switch off the high conducting Au-silacycle interaction by altering the environment of the electrode surface. These chapters outline new molecular design concepts for tuning conductance and incorporating switching functions in single–molecule electrical devices.

Modern computing and mobile device technologies are now based on semiconductor technology with nanoscale components, i.e., nanoelectronics, and are used in an increasing variety of consumer, scientific, and space-based applications. This rise to global prevalence has been accompanied by a similarly precipitous rise in fabrication cost, toxicity, and technicality; and the vast majority of modern nanotechnology cannot be repaired in whole or in part. In combination with looming scaling limits, it is clear that there is a critical need for fabrication technologies that rely upon clean, inexpensive, and portable means; and the ideal nanoelectronics manufacturing facility would harness micro- and nanoscale fabrication and self-assembly techniques. The field of molecular electronics has promised for the past two decades to fill fundamental gaps in modern, silicon-based, micro- and nanoelectronics; yet molecular electronic devices, in turn, have suffered from problems of size, dispersion and reproducibility. In parallel, advances in DNA nanotechnology over the past several decades have allowed for the design and assembly of nanoscale architectures with single-molecule precision, and indeed have been used as a basis for heteromaterial scaffolds, mechanically-active delivery mechanisms, and network assembly. The field has, however, suffered for lack of meaningful modularity in function: few designs to date interact with their surroundings in more than a mechanical manner. As a material, DNA offers the promise of nanometer resolution, self-assembly, linear shape, and connectivity into branched architectures; while its biological origin offers information storage, enzyme-compatibility and the promise of biologically-inspired fabrication through synthetic biological means. Recent advances in DNA chemistry have isolated and characterized an orthogonal DNA base pair using standard nucleobases: by bridging the gap between mismatched cytosine nucleotides, silver(I) ions can be selectively incorporated into the DNA helix with atomic resolution. The goal of this thesis is to explore how this approach to “metallize” DNA can be combined with structural DNA nanotechnology as a step toward creating electronically-functional DNA networks. This work begins with a survey of applications for such a transformative technology, including nanoelectronic component fabrication for low-resource and space-based applications. We then investigate the assembly of linear Ag+-functionalized DNA species using biochemical and structural analyses to gain an understanding of the kinetics, yield, morphology, and behavior of this orthogonal DNA base pair. After establishing a protocol for high yield assembly in the presence of varying Ag+ functionalization, we investigate these linear DNA species using electrical means. First a method of coupling orthogonal DNA to single-walled carbon nanotubes (SWCNTs) is explored for self-assembly into nanopatterned transistor devices. Then we carry out scanning tunneling microscope (STM) break junction experiments on short polycytosine, polycationic DNA duplexes and find increased molecular conductance of at least an order of magnitude relative to the most conductive DNA analog. With an understanding of linear species from both a biochemical and nanoelectronic perspective, we investigate the assembly of nonlinear Ag+-functionalized DNA species. Using rational design principles gathered from the analysis of linear species, a de novo mathematical framework for understanding generalized DNA networks is developed. This provides the basis for a computational model built in Matlab that is able to design DNA networks and nanostructures using arbitrary base parity. In this way, DNA nanostructures are able to be designed using the dC:Ag+:dC base pair, as well as any similar nucleobase or DNA-inspired system (dT:Hg2+:dT, rA:rU, G4, XNA, LNA, PNA, etc.). With this foundation, three general classes of DNA tiles are designed with embedded nanowire elements: single crossover Holliday junction (HJ) tiles, T-junction (TJ) units, and double crossover (DX) tile pairs and structures. A library of orthogonal chemistry DNA nanotechnology is described, and future applications to nanomaterials and circuit architectures are discussed.

Thesis (Ph. D.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Dr. Andrei G. Fedorov; Committee Member: Dr. Azad Naeemi; Committee Member: Dr. Suresh Sitaraman; Committee Member: Dr. Vladimir V. Tsukruk; Committee Member: Dr. Yogendra Joshi. Part of the SMARTech Electronic Thesis and Dissertation Collection.

L'intérêt porté au domaine Terahertz (THz) ayant beau être en pleine expansion depuis les années 1990, un gros effort de recherche doit encore être effectué pour tirer la quintessence des applications actuelles ou potentielles que représente cette gamme du spectre électromagnétique dans des domaines aussi variés que la spectroscopie, la cosmologie, l'imagerie médicale, la sécurité ou les télécommunications. En effet les sources, les détecteurs mais également les outils qui permettent d'amplifier ou de moduler un signal – dispositifs très présents dans les régions voisines du spectre électromagnétique que sont l'infrarouge et les micro-ondes - sont encore particulièrement limités par des facteurs tels que la compacité, la température de fonctionnement, l'intégrabilité mais également la puissance, la sensibilité ou encore le coût.Cette thèse porte sur l'étude expérimentale de divers composants en nitrure de gallium (GaN) contenant un puits quantique avec pour objectif de déterminer leurs capacités d'émission, d'amplification ou de détection d'une radiation THz.Pour ce faire, trois différents dispositifs expérimentaux ont été utilisés, améliorés ou même créés dans le but de pouvoir faire varier des paramètres tels que la polarisation électrique, leur température de fonctionnement, les fréquences THz sondées et bien sûr les différentes géométries des échantillons.De plus amples détails sur le monde des THz, sur les dispositifs électroniques GaN utilisés ainsi que sur les montages expérimentaux mis en places sont développés dans ce manuscrit de thèse. Les principaux résultats expérimentaux obtenus montrent :- une émission vers 3 THz avec une fréquence accordable en fonction du champ électrique appliqué au puits quantique GaN,- un coefficient de transmission variable en fonction de la tension appliquée aux contacts en doigts interdigités de différentes structures GaN,- la détection hétérodyne de radiations avec une fréquence RF de 0,3 THz et IF pouvant monter jusqu'à 40 GHz. De plus, chaque type de résultats expérimentaux a été expliqué théoriquement à l'aide de modèles analytiques développés en collaboration avec des équipes internationales au cours de ces trois dernières années. / Even if the interest upon the Terahertz (THz) domain is increasing since the 1990s, a strong research effort still needs to be done to get the most of the current and potential applications that this area of the electromagnetic spectrum has to offer in the various domains of spectroscopy, cosmology, medical imaging, security and telecommunications. Indeed, sources, detectors and even the tools that permits to amplify or modulate a signal – these devices are well developed in the neighboring regions of infrared and microwaves – are still particularly limited by characteristics like compactness, operating temperature, integrability but also power, sensitivity or cost.This thesis focuses on the experimental study of different gallium nitride (GaN) devices containing a quantum well. The main objective was to determine their capacities in emission, amplification or detection of a THz radiation.To do so, three different experimental setups where used, improved or even created in order to be able to change parameters like the electric bias, their working temperature, the probed THz frequencies and of course the different geometries of the samples.More details about the THz domain, the studied GaN electronic devices and the used experimental setups are developed in this PhD thesis.The main obtained experimental results show:- an emission of radiation near 3 THz with a tunable frequency versus electric field applied to the GaN quantum well,- a transmission coefficient variable as a function of the voltage applied to the contacts of different GaN interdigitated fingers structures,- heterodyne detection of radiation with a RF frequency of 0.3 THz and an IF that can reach up 40 GHz.In addition, each type of experimental results has been investigated theoretically using analytical models developed in collaboration with international teams during the past three years.

Cette thèse est consacrée à l'étude expérimentale des excitons dans des puitsquantiques polaires fabriqués à partir de semi-conducteurs à large bande interdite. En raison de la structure de ces matériaux à cristaux wurtzite, les électrons et les trous sont séparés le long de l'axe de croissance du puits quantique, de sorte que les excitons peuvent être considérés comme des excitons indirects (IX) : ils forment une famille de quasi-particules bosoniques à longue durée de vie, dont le moment dipolaire est orienté selon l'axe de croissance du puits. Les IX sont considérés comme un système modéle pour l'étude des états collectifs dans les gaz quantiques bosoniques. Ils sont aussi prometteurs pour le développement de dispositifs excitoniques. Leur longue durée de vie, leur répulsion dipolaire, permettent aux IXs de se déplacer sur de grandes distances avant de se recombiner, ce qui offre la possibilité d'étudier le transport d'exciton par imagerie optique. Dans cette thèse, nous abordons le transport des IXs dans des puits quantiques de GaN/(Al,Ga)N et de ZnO/(Mg,Zn)O. Ce choix de matériau est motivé par l'énergie de liaison élevée des IXs ainsi obtenue. Elle est suffisamment élevée pour, en thèorie, stabiliser les IXs jusqu'à la température ambiante. Mais ce choix poseaussi un certain nombre de défis expérimentaux, car (i) le temps de vie radiatifdépend fortement de la densité d'excitons, ce qui rend la mesure de la densitéexcitonique très complexe ; (ii) la recombinaison non radiative activée thermiquement supprime le signal de photoluminescence excitonique à température ambiante ; (iii) la propagation excitonique coexiste avec une propagation photonique le long du plan du puit quantique, ce qui complique l'analyse ; (iv) il existe un fort champ électrique le long de l'axe de croissance, et aussi desuctuations dans l'épaisseur du puits quantique, ce qui crée un fort élargissement inhomogène de l'émission excitonique. Nous avons abordé toutes ces questions et nous démontrons dans ce travail que les excitons se propagent effectivement dans le plan du puits quantique. Nous arrivons à cette conclusion en combinant des expériences de micro-photoluminescence en régime continu avec des mesures de spectroscopie résolues en temps, et en comparant nos données expérimentales avec divers modèles numériques basés sur les équations dedérive et de diffusion. Dans du matériau de qualité, des puits GaN/(Al,Ga)N obtenus sur substrats GaN, nous avons observé une propagation à temprature ambiante sur plus de 10 µm, et sur plus de 20 µm à 4 K. Nos résultats suggérent que la propagation des excitons sous excitation à onde continue est facilitée par l'écrantage du désordre par les excitons. Néanmoins, la propagation excitonique est encore limitée par la diffusion des excitons sur les défautsiii plutôt que par la diffusion exciton-exciton. Ainsi, l'amélioration de la qualité des interfaces du puits quantique pourrait encore permettre une propagation excitonique sur de plus grandes distances. / This thesis is devoted to experimental study of excitons in polar quantum wells(QWs) based on wide band-gap semiconductors. Due to wurtzite crystal structureof these materials, electron and hole are separated in the QW growth axis, sothat excitons can be considered as indirect excitons (IX), a family of long-living bosonic quasi-particles with dipole moment oriented along the QW growth axis. IX are considered as a model system for studies of collective states in quantum gases of bosons, and are also promising for the development of excitonic circuit devices. Long lifetimes and dipole repulsion allow IXs to travel over large distances before recombination providing the opportunity to study exciton transport by optical imaging. In this thesis we address IX transport in a set of GaN/(Al,Ga)N and ZnO/(Mg,Zn)O QWs. This choice of IX is motivated by high binding energy, and potential stability up to room temperature, but present a number of experimental challenges, including (i) dramatic dependence of the exciton radiative lifetime on the exciton density that makes exciton density measurement very complex, (ii) thermally activated nonradiative recombination that quenches exciton PL at room temperature,(iii) coexistence of photon propagation with exciton propagation along the QW plane, and strong inhomogeneous broadening of the exciton emission due to strong built-in electric field and the presence of both monolayeructuations of the QW thickness and the fluctuations of alloy composition in the barriers. We have addressed all these issues and demonstrated exciton propagation by combining continuous wave µ-photoluminescence and time-resolved spectroscopy measurements, supplemented by modelling of the exciton transport within drift-diffusion formalism. In the best quality GaN/(Al,Ga)N QWs grown on free-standing GaN substrates we achieved room-temperature propagation over ~10 µm and up to 20 µm at 4 K. Our results suggest that propagation of excitons under continuous-wave excitation is assisted by effcient screening of the in-plane disorder. Nevertheless, exciton propagation is still limited by the exciton scattering on defects rather than by exciton-exciton scatteringso that improving interface quality can boost exciton transport further.

Orientador: José Alexandre Diniz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T05:49:16Z (GMT). No. of bitstreams: 1 Santos_MarcosViniciusPuydingerdos_M.pdf: 6478260 bytes, checksum: 702c164c26bda0f3d93109290d6f74a1 (MD5) Previous issue date: 2013 / Resumo: Neste trabalho é apresentado o desenvolvimento do processo de obtenção de nanofios de silício (SiNW) para aplicações em dispositivos MOS tridimensionais utilizando as técnicas de Feixe Íons Focalizados com íons de Gálio (GaFIB) e Litografia por Feixe de Elétrons (EBL). O processo completo de fabricação foi desenvolvido para a obtenção de transistores sem junção baseados em nanofios (junctionless nanowire transistors, JNT), escolhidos devido à facilidade de processamento ¿ comparativamente a outros dispositivos, como FinFETs ¿ e à ausência de efeitos de canal curto e perfuração MOS (punchthrough). Lâminas de tecnologia SOI (Silicon on Insulator) foram utilizadas como substrato. GaFIB/SEM ¿ um sistema de duplo feixe acoplado a um microscópio eletrônico de varredura -, com resolução nominal de feixe iônico de 20 nm, foi utilizado para a definição dos nanofios de silício com dopagem local por íons de Gálio (p+ - SiNW) e deposição de dielétrico de porta de SiO2 e eletrodos de fonte, dreno e porta de Platina. Para deposição dos eletrodos metálicos e do dielétrico de porta foi utilizado feixe de elétrons disponível no SEM de modo a evitar implantação iônica extra e evitar o processo de sputtering dos nanofios de silício. As dimensões do comprimento (LFin) e altura (HFin) do nanofio, comprimento (LPorta) e largura (WPorta) da porta foram, respectivamente, 6 ?m, 15 nm, 1 ?m e 35 nm. O estudo da condução de corrente elétrica no p+-SiNW foi feito por medidas elétricas em dispositivos pseudo-MOS utilizando o dióxido de silício enterrado (BOX) da lâmina SOI como dielétrico de porta para controlar a corrente através do p+-SiNW. Curvas de corrente entre fonte e dreno (IDS) versus tensão entre a porta das costas da lâmina e fonte (VBGS) indicam regime de acumulação para o p+-SiNW. Curvas IDS versus VDS indicam que o dispositivo JNT opera como um resistor controlado pela porta. Por outro lado, a técnica EBL ¿ com resolução nominal do feixe eletrônico 2 nm ¿ foi utilizada para a fabricação de dispositivos JNT do tipo nMOS - com dopagem de Arsênio (n+-SiNW) por implantação iônica -, juntamente com o sistema de deposição a partir de fase química, ECR-CVV (Electron Cyclotron Ressonance) para a definição dos nanofios utilizando o sistema de corrosão por plasma RF e formação de dielétrico de porta. Eletrodos de fonte, dreno e porta de Titânio e Alumínio foram depositados pela técnica de sputtering. As dimensões de largura (W) e comprimento (L), assim como o número de nanofios dos transistores foram variados para permitir uma excursão de até 3 ordens de grandeza da corrente elétrica do dispositivo. As dimensões mínimas obtidas para o comprimento (LFin) e altura (HFin) do nanofio, comprimento (LPorta) e largura (WPorta) da porta foram, respectivamente, 10 ?m, 15 nm, 100 nm e 50 nm O tempo médio para fabricação de um dispositivo JNT utilizando o sistema FIB é de aproxi-madamente 2 dias e seu custo médio é estimado em US$ 4,000.00. Por outro lado, a fabricação do dispositivo utilizando a técnica EBL demanda maior tempo ¿ aproximadamente 10 dias ¿, contudo custando menos de uma ordem de grandeza do valor do FIB (aproximadamente US$ 150.00). Os resultados obtidos revelam que os métodos desenvolvidos nos sistemas FIB e EBL para fa-bricação de nanofios de silício para aplicações em nanoeletrônica são inovadores no Brasil e permitem avanços consistentes em nanofabricação. Esses processos, já calibrados, contribuirão para o desenvolvimento de novos processos, como, por exemplo, transistores do tipo FinFET ou dispositivos baseados em nanofios / Abstract: This work presents the development for obtaining silicon nanowires (SiNW) for applications in 3D MOS devices using Focused Ion Beam with gallium ions (GaFIB) and Electron Beam Lithography (EBL) techniques. The complete fabrication process was developed for obtaining junctionless nanowire-based transistors, chosen due to the simplicity of processing and to the absence of short channel and punchthrough effects. Silicon on Insulator (SOI) wafers were used as substrate. GaFIB/SEM - a dual beam system coupled to a scanning electron microscope -, with nominal resolution for the ionic beam of 20 nm, was used to define silicon nanowires and dope them locally by gallium ions (p+-SiNW), in addition to deposit SiO2 dielectric gate and Pt source, drain and gate electrodes. Metal electrodes and gate dielectric deposition were taken place with the electron beam available in the SEM to avoid extra ion implantation and prevent sputtering process of silicon nanowires. The dimensions obtained for the nanowire length (LFin) and high (HFin), gate length (LGate) and width (WGate) were, respectively, 6 ?m, 15 nm, 1 ?m e 35 nm. The study of the driving electric current through p+-SiNW was achieved by electrical measurements in the pseudo-MOS devices using the buried silicon dioxide (BOX) of the SOI wafer as gate dielectric to control the current through the p+-SiNW. Electrical current between source and drain (IDS) versus gate voltage between the back-gate and source (VBGS) curves indicate accumulation regime for the p+-SiNW. IDS versus VDS curves indicate that the JNT device operates as a gated resistor gate. Still, the EBL technique ¿ with nominal resolution for the electronic beam of 2 nm ¿ was used to fabricate nMOS JNT devices - with arsenic dopant (n+-SiNW) - along with ECR-CVC (Electron Cyclotron Resonance) chemical phase deposition plasma system, for defining the nanowires using RF plasma etching and formation of the gate dielectric. Titanium and aluminum source, drain and gate electrodes were deposited by sputtering. The dimensions of width (W) and length (L), as well as the number of nanowire transistors were varied to allow a range of up to 3 orders of the electrical current magnitude through the device. The minimum dimensions obtained for the nanowire length (LFin) and high (HFin), gate length (LGate) and width (WGate) were, respectively, 10 ?m, 15 nm, 100 nm e 50 nm. The average time for the fabrication of one single JNT device using FIB system is 2 days, with the average cost of US$ 4,000.00. Still, the device fabrication using EBL technique is longer ¿ approximately 10 days ¿, however it costs less than one order of magnitude compared to FIB (approximately US$ 150.00). These results show that the methods developed for FIB and EBL systems for fabrication of silicon nanowires for applications in nanoelectronics are innovative in Brazil and allow consistent advances in nanofabrication. These processes, now calibrated, will contribute to the development of new processes, for example, FinFET transistors based on nanowires / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica