Teses / dissertações sobre o tema "Nanoélectronique – Matériaux"
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Rafhay, Quentin. "Modélisation des MOSFET nanométrique de type n aux matériaux de canal alternatifs dans le régime totalement ou quasi balistique". Grenoble INPG, 2008. http://www.theses.fr/2008INPG0167.
Texto completo da fonteMOSFET scaling, building block of integrated circuits, do not allow to improve significantly the device performance anymore. One presently studied solution consists in substituting silicon for high mobility semiconductors (Ge or III-Vs) as channel material. Based on original analytical models, calibrated on advanced simulations (quantum, Monte Carlo), this thesis demonstrate that at nanometric scale, the performances expected from this new technologies are in fact lower than the one of conventional silicon devices. Quantum effects (confinement, tunnelling leakage) have been indeed found to be more penalizing in the case of alternative channel material transistors
Nayak, Goutham. "Amélioration des propriétés physiques de matériaux de basse-dimensionnalité par couplage dans des hétérostructures Van der Waals". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY084/document.
Texto completo da fonteThe extraordinary intrinsic properties of low dimensional materials depend highly on the environment they are subjected to. Hence they need to be prepared, processed and characterized without defects. In this thesis, I discuss about how to control the environment of low dimensional nanomaterials such as graphene, MoS2 and carbon nanotubes to preserve their intrinsic physical properties. Novel solutions for property enhancements are discussed in depth. In the first part, we fabricate state-of-the-art, edge-contacted, graphene Van der Waals(VdW) heterostructuredevices encapsulated in hexagonal-boron nitride(hBN), to obtain ballistic transport. We use a technique based on 1/f-noise measurements to probe bulk and edge transport during integer and fractional Quantum Hall regimes. In the second part, the same fabrication concept of VdW heterostructures has been extended to encapsulate monolayer MoS2 in hBN to improve optical properties. In this regard we present an extensive study about the origin and characterization of intrinsic and extrinsic defects and their affect on optical properties. Further, we describe a technique to probe the interlayer coupling along with the generation of light with spatialresolution below the diffraction limit of light. Finally, we discuss a natural systemic process to enhance the mechanical properties of natural polymer silk using HipCO-made single walled carbon nanotubes as a food for silkworm
Dutta, Tapas. "Modélisation et simulation des composants MOSFETs à matériaux de canal alternatifs". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT122.
Texto completo da fonteAs silicon CMOS technology is approaching fundamental scaling roadblocks, alternative channel materials like Ge and III-V based devices have attracted a lot of attention and have been the subject of active research during the last 10 years. While these new materials have very promising transport properties, studies have shown that they have worse short channel performance than the Si counterparts. Hence there is a strong need to evaluate the impact of change in the channel material on the device performance in terms of the short channel effects. In this work, first some issues with conventional modeling of double gate MOSFETs are dealt with. A new analytical model of the built-in potential is proposed and shown to correct the errors due to wrong boundary conditions. The roles of quantum confinement effects, material parameters and architecture of nanoscale III-V MOSFETs on the electrostatic integrity in terms of SCEs are thoroughly examined. A modified parameter to capture the drain induced barrier lowering is used to predict the performance degradation in the post-threshold region of the MOSFETs. Impact of the source to drain tunneling on the subthreshold behavior and hence the scalability of III-V devices is also analyzed in this thesis
Roumanille, Pierre. "Matériaux d'assemblage basse température pour applications électroniques : de l'intérêt des oxalates et formiates de métaux". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30106/document.
Texto completo da fonteDue to environmental and health concerns, new regulations led to a restriction in the use of lead in electronic equipment. Joining materials (based on tin, silver, copper, bismuth ...) for surface-mount technology are subject to many development work in order to comply with regulatory and technical requirements. The potential of metal carboxylates in electronics has already been demonstrated in the development of metal-organic decomposition processes. The thermal decomposition under controlled atmosphere of such precursors leads to the creation of metal nanoparticles with an increased reactivity compared to that of micron sized particles. The use of nanomaterials is a seriously considered way for developing low temperature joining processes for electronics. It is based on the well-known decrease of melting and sintering temperatures of nanomaterials with particle size. In this context, this work of thesis presents the study of the controlled decomposition of metal-organic precursors intended to be integrated into a low-temperature lead-free joining process. The thermal behavior of several metal-organic precursors of tin and bismuth, as well as the influence of the decomposition atmosphere, were studied. The relationship between the metal particles size and their melting point has been emphasized, as well as the major influence of oxidation on the evolution of particles size and their ability to make reliable joints
François, Terry. "Caractérisation électrique et analyse de mémoires non-volatiles embarquées à base de matériaux ferroélectriques". Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0390.
Texto completo da fonteFerroelectric materials are recently showing, since 2011, a novel appeal for microelectronic applications as it has been shown that, under specific crystal configuration, Hafnium-based dielectrics exhibit a ferroelectric behavior. This opens the way towards highly scalable and CMOS-compatible memory devices. CEA-LETI is currently investigating novel Hafnium-based ferroelectric materials for non-volatile memory applications. One need to evaluate their ferroelectric behavior through dedicated electrical characterization techniques, and in particular, to extract the remanent polarization, which is the direct picture of the memory window for a memory product, the coercive field, the programming speed and the endurance. Moreover, through the analysis of their ferroelectric performances, two materials, Hf0.5Zr0.5O2 and silicon-doped HfO2, are optimized. Furthermore, it is demonstrated that both materials remain ferroelectric after complete integration in the Back-End-Of-Line of a 130nm CMOS technology, with compatible thermal budget. These devices are then integrated in a 16kbit memory array, based on 1T-1C FeRAM architecture. A setup dedicated to this circuit’s characterization is developed and allows the measurement of binary state distributions of the bitcells. Both distributions are demonstrated fully separated, defining an operating memory window which guarantees no bitfails at the 16kbit scale. Finally, by measuring several capacitor surfaces at various programming voltages, one can extrapolate the expected memory window of this kind of 1T-1C architecture in more advanced nodes, following the ongoing trend of densification of industrial microelectronic circuits
Bonvalot, Cyrille. "Contribution à la compréhension du courant d'obscurité dans les détecteurs infrarouges matriciels à base de matériaux III-V". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST016.
Texto completo da fonteLynred is one of the major actors in the high quality cooled infrared detectors market, originally based on II-VI materials (HgCdTe), and more recently on III-V materials (QWIP, InSb, InGaAs). The InSb and InGaAs detectors are composed of photodiode organized in an array, in order to get a two dimension imager. The study reported here aim to enhance our comprehension of the dark current of these photodiodes. The subject is addressed in three steps: a study of the junction profile, an analyze of the phenomenon responsible for the dark current generated in the material’s bulk, and the highlighting of the interfaces role. The junction profile is established from sensibility optimized SIMS measurement. The thicknesses of the absorbing InGaAs layer, and of the space charge region, are obtained from capacity measurement. Because of the non-abrupt junction, the determination of the doping concentration can’t be achieved form the capacity. Diffusion current, which have to be taken into account for the InGaAs diode, is highly dependent upon the double heterojunction. Therefore, vertical and radial diffusion mechanisms have to be considered separately. Additionally, array configuration brings another constraint. Generation current is the witness of the actual technologies progresses, high quality materials with low default concentration and small sized diodes. Bulk material contribution is mostly negligible in comparison of the surface states one, localized at the InSb/SiO or the InGaAs/InP interfaces. Hence, the passivation process, or the epitaxy, is the critical point of those technologies. This thesis made it possible to identify the mechanisms responsible for the dark current of the InSb and InGaAs diodes, allowing us to point out the critical fabrication processes and to propose optimization of design. Characterization means developed during those three years might be used in the production line. It will allow monitoring the stability of the fabrication processes, especially the doping and thickness of the InGaAs absorbing layer. Those methods have the advantages of being simple to use, relatively cheap and above all non-destructives
Lefter, Constantin. "Etudes des propriétés électriques des matériaux à transition de spin : vers des dispositifs pour la nano-électronique". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30003/document.
Texto completo da fonteThe central theme of this thesis is the evaluation of potential interest and applicability of molecular spin crossover (SCO) complexes for nanoelectronic applications. The electrical properties of the [Fe(Htrz)2(trz)](BF4) complex and its Zn substituted analogues were analyzed first in the bulk powder form using broadband dielectric spectroscopy. It has been shown that the ac and dc conductivities as well as the dielectric constant and the dielectric relaxation frequency exhibit an important drop when going from the low spin (LS) to the high spin (HS) state. The iron ions kept their spin transition properties in the Zn diluted samples, but the SCO curves were significantly altered. The Zn substitution of active iron centers led to an important decrease of the electrical conductivity of ca. 6 orders of magnitude (for Zn/Fe = 0.75). We concluded from these results that the ferrous ions directly participate to the charge transport process, which was analyzed in the frame of an activated hopping conductivity model. Micrometric particles of [Fe(Htrz)2(trz)](BF4) were then integrated by dielectrophoresis between interdigitated gold electrodes leading to a device exhibiting bistability in the I-V,T characteristics. The stability of the starting material and the electronic device were carefully controlled and the concomitant effect of temperature changes, light irradiation and voltage bias on the current intensity were analyzed in detail. We showed that the device can be preferentially addressed by light stimulation according to its spin state and the switching from the metastable HS to the stable LS state was also demonstrated by applying an electric field step inside the hysteresis loop. The field effects were discussed in the frame of static and dynamic Ising-like models, while the photo-induced phenomena were tentatively attributed to surface phenomena. The [Fe(bpz)2(phen)] complex was also investigated by dielectric spectroscopy in the bulk powder form and then integrated by high vacuum thermal evaporation into a large-area vertical device with Al (top) and ITO (bottom) electrodes. This approach allowed us to probe the spin-state switching in the SCO layer by optical means while detecting the associated resistance changes both in the tunneling (10 nm junction) and injection-limited (30 and 100 nm junctions) regimes. The tunneling current in the thin SCO junctions showed a drop when going from the LS to the HS state, while the rectifying behavior of the 'thick' junctions did not reveal any significant spin-state dependence. The ensemble of these results provides guidance with new perspectives for the construction of electronic and spintronic devices incorporating SCO molecular materials
Franck, Pierre. "Mesoscopic electromagnetic model of carbon-nanotube arrays and scalable technological processes : Application to the fabrication of novel antennasCo-dirigée par Beng Kang Tay". Limoges, 2013. http://aurore.unilim.fr/theses/nxfile/default/6358938e-2b7f-488e-a1d0-6bd8f7e045e6/blobholder:0/2013LIMO4043.pdf.
Texto completo da fonteNous présentons une étude de faisabilité d’antennes innovantes basées sur les propriétés particulières des nanotubes de carbone (NTC). Celles-ci pourraient permettre une amélioration des performances des antennes électriquement courtes mais aussi le développement de systèmes innovants tels que des réseaux réflecteurs à commande optique. Ce pourrait aussi être une technologie intéressante pour les applications en plein essor dans les domaines des ondes millimétriques et terahertz. Des avancées significatives ont été réalisées suivant les quatre axes interdépendants qui régissent ces antennes : modélisation des NTC, analyse des antennes basées sur les NTC, fabrication à partir de NTC et caractérisation. Ceci nous a permis d’une part de concevoir et de fabriquer les premiers prototypes d’antennes électriquement courtes à base de NTC et d’autre part de mettre en évidence des tendances dans la réponse des NTC sous illumination. En effet, en utilisant une approche mésoscopique, nous avons développé un modèle électromagnétique original pour les ensembles de nano-éléments alignés, en particulier les NTC, permettant leur intégration dans des logiciels de simulation électromagnétique classiques et donc la mise en correspondance des possibilités de fabrication et de simulation. En parallèle nous avons reproduit et développé des méthodes de croissance et de dépôt de NTC et établi des procédés de fabrication pouvant être adaptés à grande échelle. De plus, un modèle analytique des antennes monopôles à base de NTC a été établi à partir d’une approche ligne de transmission. Ces techniques nous ont permis de mettre en avant les compromis nécessaires dans la conception d’antennes de taille réduite à base de NTC et ainsi de concevoir et fabriquer de premiers prototypes. Elles ont aussi été appliquées à la fabrication de structures de test pour une caractérisation des NTC sous illumination. Ceci nous a permis de mettre en évidence les conditions optimales pour générer un courant photoélectrique dans les NTC et d’évaluer les performances pouvant être attendues comme base pour de futurs systèmes
Ottapilakkal, Vishnu. "2D Hexagonal boron nitride epitaxy on epigraphene for electronics". Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0122.
Texto completo da fonteIn this century, the importance of nanoelectronics has grown with the demand for smaller, more efficient devices. Traditional silicon-based technologies face challenges, particularly in scaling down transistors while maintaining performance. Shorter channel lengths improve speed and device density but lead to issues like electromigration, leakage, and thermal load. Graphene, a two-dimensional material, offers a solution due to its high carrier mobility, thermal conductivity, and stability, making it a promising alternative to silicon. Utilizing graphene's properties could overcome silicon's limitations, enabling next-generation nanoelectronics with better performance and scalability. Monolayer graphene is typically produced via exfoliation methods, but these often introduce defects and contaminants, degrading its electrical properties and limiting large-scale production. Chemical vapor deposition (CVD) offers a more scalable solution but can still introduce defects, while reducing graphene oxide leads to too many imperfections for nanoelectronics. Epitaxial graphene (epigraphene) offers superior transport properties for high-performance devices but, like all graphene, is sensitive to environmental factors and requires effective passivation. Hexagonal boron nitride (h-BN) is a promising passivation material due to its structural compatibility with graphene. While conventional methods of h-BN transfer introduce defects, metal-organic vapor phase epitaxy (MOVPE) allows direct growth on epigraphene, solving these issues. This thesis investigates the growth of thin h-BN layers on various epigraphene substrates (monolayer, multilayer, and patterned) using van der Waals epitaxy, with a focus on their potential applications in thin-film transistors (TFTs). The study is divided into three key areas: First, we explored the MOVPE growth of h-BN layers (up to 20 nm) on monolayer and multilayer epigraphene on silicon carbide (SiC), examining the silicon-terminated (Si-face) and carbon-terminated (C-face) faces. Both substrates exhibited similar surface characteristics, and thermal annealing was found to improve crystal quality without compromising the integrity of the h-BN/epigraphene heterostructure up to 1550 degrees. Second, we explored the selective growth of high quality h-BN over patterned epigraphene by etching to retain only the desired graphene patterns prior to h-BN growth. This method helped in reducing particle formation and damage compared to conventional post-deposition patterning techniques. Finally, TFT devices were fabricated from these heterostructures after investigating various etching methods (CF4, XeF2, SF6) to remove h-BN and establish contact with the underlying epigraphene. Preliminary electrical characterizations showed changes in resistance with magnetic fields, although contact resistance was higher than anticipated. This research provides a promising technique for producing high-quality h-BN layers on graphene-based devices, paving the way for further advancements while identifying areas for improvement
Hayes, Maxim. "Intégration de collecteurs de charges avancés dans les cellules solaires bifaciales à haut rendement : vers un procédé générique pour les nouveaux matériaux silicium". Electronic Thesis or Diss., Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0519.
Texto completo da fonteThanks to a relatively simple fabrication process and high conversion efficiency values the PERC structure is well established at the industrial level. Nevertheless, industrial PERC solar cells performances are mostly limited by two charge carrier recombination sources: P thermally diffused emitter on the front side and the Al-Si interfaces at the rear contacts. The main goal of this work aims at limiting both recombination sources. A selective emitter (SE) obtained by plasma immersion ion implantation (PIII) is developed for an integration on the front side; whereas a B-doped polysilicon (poly-Si) on oxide passivated contact (PC) is integrated on the back side. The second goal of this work consists in evaluating the compatibility between these advanced carrier collectors and directionally solidified Si materials. SE featuring good geometrical properties and a well-controlled doping were fabricated thanks to an in situ localized doping process obtained with a specific mask developed for PIII. Besides, several metal deposition technologies were investigated for the poly-Si(B). Fire-through screen-printing appears as the most promising approach so far. Indeed, the deposition of a non-sacrificial hydrogen-rich layer allowed to reach an excellent surface passivation level for solar cell precursors. However, the specific contact resistivity obtained remains too high for an optimal cell integration. Lastly, the fabrication of poly-Si PC showed excellent external gettering efficiencies for multicrystalline Si. Thus, the potential of the developed cell structure to be integrated with low-cost and low carbon footprint materials is encouraging
Schönle, Joachim. "Quantum transport studies for spintronics implementation : from supramolecular carbon nanotube systems to topological crystalline insulator". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY022/document.
Texto completo da fonteMolecular electronics is one of the most intriguing fields of modern research, which could bring forth a modular and scalable building system for nanoscale spintronics applications. A particularly promising example are single-molecule magnets, which have already successfully shown to be suitable for spin valve or spin qubit operations. One of the biggest challenges of the field is the integration of these nanometer-sized objects in complex circuits in order to allow for detection and manipulation of moleculear spin states. As shown in recent years by the NanoSpin group, carbon nanotubes (CNTs) can serve as such type of carrier for the single-molecule magnets, combining features of both constituents.A corner stone of this thesis project was hence the development of a dependable fabrication technique for high-quality CNT devices, controllable by multiple local gate electrodes in order to enable local control of molecular hybrid systems. A process based on conventional one-chip fabrication was developed from scratch, for which optimization of sample design, lithography and deposition techniques as well as material choices had to be carefully incorporated, in order to accomodate the restrictions imposed by the CNT growth conditions on the prevention of leakage currents. We succeeded in producing clean CNT devices, which could support a double dot configuration, tunable from p- to n-type characteristics. The segments created in this way can be stabily controlled over the entire device length and should hence provide a suitable backbone to study molecular physics.Topological matter constitutes an enticing platform to investigate both fundamental principles as well as possible applications from spintronics to quantum computation. Topological crystalline insulators, with tin telluride ( SnTe ) as a prime example, represent a new state of matter within this zoo of 3D topological materials. Soon after first experimental realizations, suggestions were made about the possibility of an unconventional type of superconductivity hosted at the interface between topological matter and conventional superconductors. Possible implications of such systems include Cooper pairing with finite momentum, the FFLO phase, or topological quantum computing, based on peculiar excitations, called Majorana bound states.This thesis project aimed to participate in the investigation of signs of unconventional superconductivity in SnTe . Transport experiments on bare films in Hall bar geometries and superconducting hybrid devices, realized as both Josephson junctions and SQUIDs, are discussed. A surprisingly strong coupling of SnTe to Ta superconductor was found and dependencies of superconductivity on sample geometries, temperature and magnetic field were investigated. The current-phase relation was analyzed in the limit of strong kinetic effects. Electrostatic gating and rf exposure was explored, but predominant physics in such configurations turned out to be of purely conventional type, pointing out the importance of improvements on the material side.In-plane magnetic field measurements gave rise to the manifestation of ϕ0-SQUIDs with tunable 0−π-transitions, providing evidence for possible controlled transitions from trivial superconductivity to unconventional coupling regimes in SnTe
Pigot, Corentin. "Caractérisation électrique et modélisation compacte de mémoires à changement de phase". Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0185.
Texto completo da fontePhase-change memory (PCM) is arguably the most mature emerging nonvolatile memory, foreseen for the replacement of the mainstream NOR-Flash memory for the future embedded applications. To allow the design of new PCM-based products, SPICE simulations, thus compact models, are needed. Those models need to be fast, robust and accurate; nowadays, no published model is able to fill all these requirements.The goal of this thesis is to propose a new compact model of PCM, enabling PCM-based circuit design. The model that we have developed is entirely continuous, and is validated on a wide range of voltage, current, time and temperature. Built on physical insights of the device, a thermal runaway in the Poole-Frenkel mechanism is used to model the threshold switching of the amorphous phase. Besides, the introduction of a new variable representing the melted fraction, depending only on the internal temperature, along with a crystallization speed depending on the amorphous fraction, allow the accurate modeling of all the temporal dynamics of the phase transitions. Moreover, an optimized model card extraction flow is proposed following the model validation, relying on a sensibility analysis of the model card parameters and a simple set of electrical characterizations. It enables the adjustment of the model to any process variation, and thus ensures its accuracy for the design modeling at every step of the technology development
Choukroun, Jean. "Theoretical sStudy of In-plane Heterojunctions of Transition-metal Dichalcogenides and their Applications for Low-power Transistors". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS557/document.
Texto completo da fonteNowadays, microprocessors can contain tens of billions of transistors and as a result, heat dissipation and its impact on device performance has increasingly become a hindrance to further scaling. Due to their working mechanism, the power supply of MOSFETs cannot be reduced without deteriorating overall performance, and Si-MOSFETs scaling therefore seems to be reaching its end. New architectures such as the TFET, which can perform at low supply voltages thanks to its reliance on band-to-band tunneling, and new materials could solve this issue. Transition metal dichalcogenide monolayers (TMDs) are 2D semiconductors with direct band gaps ranging from 1 to 2 eV, and therefore hold potential in electronics and photonics. Moreover, when under appropriate strains, their band alignment can result in broken-gap configurations which can circumvent the traditionally low currents observed in TFETs due to the tunneling mechanism they rely upon. In this work, in-plane TMD heterojunctions are investigated using an atomistic tight-binding approach, two of which lead to a broken-gap configuration (MoTe2/MoS2 and WTe2/MoS2). The potential of these heterojunctions for use in tunnel field-effect transistors (TFETs) is evaluated via quantum transport computations based on an atomistic tight-binding model and the non-equilibrium Green’s function theory. Both p-type and n-type TFETs based on these in-plane TMD heterojunctions are shownto yield high ON currents (ION > 103 µA/µm) and extremely low subthreshold swings (SS < 5 mV/dec) at low supply voltages (VDD = 0.3 V). Innovative device architectures allowed by the 2D nature of these materials are also proposed, and shown to enhance performance even further
Hubert, Quentin. "Optimisation de mémoires PCRAM pour générations sub-40 nm : intégration de matériaux alternatifs et structures innovantes". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01061795.
Texto completo da fonteMazen, Frédéric. "Etude de la nucléation et de la croissance de nanocristaux de silicium élaborés par dépôt chimique en phase vapeur pour dispositifs nanoélectroniques". Lyon, INSA, 2003. http://theses.insa-lyon.fr/publication/2003ISAL0045/these.pdf.
Texto completo da fonteWe have studied the experimental parameters which control the characteristics of silicon nano-crystals (nc-Si) deposited by chemical vapor deposition. The density of ne-Si depends primarily on the partial pressure of the precursor and especially of the chemical properties of the substrate. Very high nc-Si densities (> 1012 nc-Si/cm2) are deposited on Si02, Si3N4 and Al203. Accurate check, between 2 and 30 Nm, of the size from nc-Si is obtained thanks to an original process of deposit in two stages. To control the positioning of the nc-Si, we explored two ways: the nano-manipulation of nc-Si with an AFM probe and the creation of nucleation sites for nc-Si by local modification of the substrate with an electron beam. Control of the development of nc-Si allowed their integration in devices tests which showed promising characteristics of nonvolatile memories
Wang, Lin. "Carrier profiling of ZnO nanowire structures by scanning capacitance microscopy and scanning spreading resistance microscopy". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI031/document.
Texto completo da fonteBased on atomic force microscope (AFM), scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM) have demonstrated high efficiency for two dimensional (2D) electrical characterizations of Si semiconductors at nanoscale and then have been extensively employed in Si-based structures/devices before being extended to the study of some other semiconductor materials. However, ZnO, a representative of the third generation semiconductor material, being considered a promising candidate for future devices in many areas, especially in opto-electronic area, has rarely been addressed. Recently, extensive research interests have been attracted by ZnO NWs for future devices such as LED, UV laser and sensor. Therefore, a good understanding of electrical properties of the NWs is in need. In this context, this thesis work is dedicated to the 2D electrical characterization of ZnO NWs with the focus of carrier profiling on this kind of nanostructure in the effort of their p-type doping. For this purpose, a planarization process has been developed for the NWs structure in order to obtain an appropriate sample surface and perform SCM/SSRM measurements on the top of the NWs. For quantitative analysis, Ga doped ZnO multilayer staircase structures were developed serving as calibration samples. Finally, residual carrier concentrations inside the CBD and MOCVD grown ZnO NWs are determined to be around 3×10^18 cm^-3 and 2×10^18 cm^-3, respectively. The results from SCM/SSRM characterization have been compared with that from macroscopic C-V measurements on collective ZnO NWs and the differences are discussed. In addition to carrier profiling on NWs structure, applications of SCM/SSRM on some other ZnO-based nanostructures are also investigated including ZnO:Sb films, ZnO/ZnO:Sb core-shell NWs structure, ZnO/ZnMgO core-multishell coaxial heterostructures
Bouaziz, Jordan. "Mémoires ferroélectriques non-volatiles à base de (Hf,Zr)O2 pour la nanoélectronique basse consommation". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI057.
Texto completo da fonteSince 2005, the scaling of memory devices, which used to follow Moore's law, slowed down. This lead researchers to conduct multiple approaches in order to keep improving memory devices. Among these approaches, the pathway on ferroelectric components seems very promising. In 2011, a research team from the NamLab in Dresden, Germany, discovered that Si-doped HfO2 could become ferroelectric with an insulating layer of only 10 nm, which resolves the compatibility issue of perovskite-structured materials with CMOS industry. Since then, other dopants have been investigated. However, new issues are now slowing down the emergence of HfO2-based ferroelectric devices on the market. Understanding the mechanisms behind the ferroelectric properties of these materials has, therefore, become a major industrial issue. In this manuscript, we study (Hf,Zr)O2 (HZO), and we perform an under-utilized technique to elaborate this kind of material: magnetron sputtering. The goal of this thesis is to establish connections between the growth conditions of this material and the electrical properties, to understand the mechanisms behind them, as well as to make the memory devices viable. During the fabrication of the capacitors, we demonstrate that the particular cristallochemical properties are essential to obtain ferroelectricity, and that novel HZO properties are discovered. Afterwards, we seek to cross the state of the art. The results we obtain by sputtering are among the best in the world. The industrial endurance and retention tests are pushed beyond what has been done in the literature so far. Particularly, the influence of electrical stress conditions is thoroughly detailed, and we put to evidence the presence of a relaxation during the different tests that could turn out to become problematic for the emergence of industrial applications. It does not seem that this problem has been identified beforehand
Mukhtarova, Anna. "Puits quantiques de composés nitrures InGaN/GaN pour le photovaoltaique". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GRENY008/document.
Texto completo da fonteIn this work we report on epitaxial growth and characterization of InGaN/GaN multiquantumwells (MQWs) heterostructures for application in photovoltaic devices. The sampleswere grown by metal-organic vapor phase epitaxy (MOVPE) on (0001) sapphire substrate.The structural and optical characterization is performed by X-ray diffraction, transmissionelectron microscopy, photoluminescence spectroscopy and transmission measurements. Toinvestigate the presence of photovoltaic effect and estimate the electrical performance of thesamples, they were processed into solar cells by means of the photolithography, inductivelycoupled plasma reactive-ion etching and metallization to manage n and p contacts.We studied the influence of different InGaN/GaN active region designs on thestructural, optical and electrical properties of the samples, i.e. number of InGaN quantumwells, QW and quantum barrier thicknesses and indium composition in the wells. Two mainmechanisms have to be taken into account for an efficient optimization of photovoltaicdevices: photon absorption and carrier collection. We showed that an increase of the MQWsnumber, their thickness and the In-content allows absorption improvement, but causes lossesin the carrier collection efficiency due to: the increase of the active region thickness (lowerelectric field), the difficulty of the carrier to escape from deeper QWs and the strain relaxation(structural defect creation). The decrease of the barrier thickness can solve the first two issues,but the problem with strain relaxation remains. In the best design, we report the value of2.00% of conversion efficiency for 15×In0.18Ga0.82N/GaN samples with spectral responseextending to 465 nm
Lenfant, Stéphane. "Contribution à l'électronique moléculaire : de la jonction au composant". Habilitation à diriger des recherches, Université des Sciences et Technologie de Lille - Lille I, 2013. http://tel.archives-ouvertes.fr/tel-00918954.
Texto completo da fonteDusch, Yannick. "Nano-Système Magnéto-Électro-Mécanique (NMEMS) ultra-basse consommation pour le traitement et le stockage de l'information". Phd thesis, Ecole Centrale de Lille, 2011. http://tel.archives-ouvertes.fr/tel-00697174.
Texto completo da fontePetit-Faivre, Emilie. "Caractérisarion physique par imagerie électronique de défauts dans les technologies mémoires avancées". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4795/document.
Texto completo da fonteNowadays, the microelectronic industry had to take up ambitious challenges to satisfy the strong economic demand because of the mobile electronic products booming like smartphones, tablets, or more recently "phablets". These high added value products requires the growth of data storage capacity and, subsequently, to produce high-performance, dense and reliable components. That implies a great cell memories robustness whose critical dimensions are regularly reduced. In this context, the thesis issue is to better understand the breakdown mechanisms of the thin and ultra-thin oxides embedded in metal/oxide/semiconductor stacks. Actually, epitaxial growth of crystalline silicon hillocks was pinpointed. These hillocks grown under electrical stresses and were associated to DBIE mechanisms (Dielectric Breakdown Induced Epitaxy). Device studies allowed to correlate electrical stress conditions and microstructural defects thanks to a 3-steps methodology : (i) electrical stresses leading to microstructural defects ; (ii) sample preparation including defect localization and extraction ; (iii) identification, observation and characterization of defects by transmission electron microscopy (TEM). Two main electrical parameters were identified with factors responsible for hillocks growth linked to DBIE : the injected charge and the compliance current. These parameters seem to limit the thermal runaway inducing hard breakdown. Consequently, it is possible that delays the irreversible device degradation. In addition, hillocks seem to grow preferentially under polysilicon grain boundaries over the SiO2/Si stacks
Zhang, Wei. "Growth of phosphorene". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS140.
Texto completo da fonteOver the last decade, the research in 2D materials has grown appreciably, due to their new hitherto unknown properties as well as their great promise for application in next generation electronic and optoelectronic devices. In particularly, phosphorene has recently attracted intensive interest because it has several properties that distinguish it from other 2D materials, including an intrinsic direct band gap, that can be tuned from 1.8 eV for a monolayer to 0.35 eV for bulk black phosphorus crystals, and high carrier mobility with high on/off ratio. All these attributes make it suitable for nano-scale devices.Inspired by the investigation of black phosphorene, a new attractive 2D phosphorus allotrope, blue phosphorene, has been predicted theoretically, which shares many excellent characteristics as black phosphorene with the buckled honeycomb lattice. So far, phosphorene is obtained by exfoliation of black phosphorus. The controlled synthesis of phosphorene, based on industrial processes such as MBE and chemical vapor deposition (CVD), is still a major challenge for further applications.In this thesis, we present an experimental investigation of the epitaxial growth of phosphorus on Au(111) and Ag(111) substrates. The experiments were performed using the following ultra-high vacuum surface science techniques: scanning tunneling microscopy and spectroscopy (STM-STS), low energy electron diffraction (LEED), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and angle resolved photoemission spectroscopy (ARPES).In chapter 1, we present the state of the art on the synthesis of phosphorene.In chapter 2, we describe the basis of the experimental setup and techniques used in this thesis.In chapter 3, we present the growth of blue phosphorene Au(111). The STM images show an extended and ordered layer of blue phosphorene while the ARPES measurements show that the blue phosphorene presents a band gap of at least 0.8 eV. The reactivity of phosphorus on Au(111) versus the temperature of the substrate is studied and we highlight a substitution process between phosphorus atoms and the topmost Au atoms.In chapter 4, we present the growth of 2D phosphorus structures on Ag(111). The STM images show self-assembled 2D layer of phosphorus pentamers while the STS measurements give a band gap of 1.20 eV. Deposition of Phosphorus induces also self-assembled black phosphorene nanoribbons with a band gap value of 1.8 eV. Finally, deposition of phosphorus at elevated temperature induces a self-assembled phosphorus monoatomic islands.In the last part we present a conclusion with a perspective of this study
Martin, Luc. "Méthodes de corrections avancées des effets de proximité en lithographie électronique à écriture directe : Application aux technologies sub-32nm". Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0003.
Texto completo da fonteIn electron beam lithography, a new proximity affects correction strategy has been imagined to push the resolution capabilities beyond the limitations of the standard dose modulation. In this work, the proximity affects inherent to e-beam lithography have been studied on the newest e-beam tools available at LETI. First, the limits of the standard dose modulation correction have been evaluated. The influences of each step of the lithographic process have also been analyzed from a theoretical point a view. A simulation approach was built and used to determine the impact of each of these steps on the patterned features. Then, a new writing strategy has been fully developed. It involves sub resolution features known as eRIF (electron Resolution Improvement features) which provide a finer control of the dose profile into the resist. Since the eRIF are exposed a top the nominal features, this new writing strategy is called multiple pass exposure. In this work, the position, the dose and the design of the eRIF have been studied and optimized to get the best of this new strategy. To do so, experiments were led in a clean room environment, and minimization algorithms have been developed. It has been demonstrated that the eRIF provide a significant gain compared to the standard dose modulation. Improvements have been observed even on the most critical levels of the Integrated circuits. By using the multiple pass exposure with optimized eRIF, the resolution capabilities of the e-beam tool have been reduced by 2 technological nodes. The design rules that have been determined to use the eRIF the most efficient way were finally implemented in INSCALE, the new data preparation software developed by ASELTA NANOGRAPHICS. This way, multiple pass exposure can be used in an automated mode to correct full layouts
Feraille, Maxime. "Etude du Transport dans les Transistors MOSFETs Contraints: Modélisation Multi-échelle". Phd thesis, INSA de Lyon, 2009. http://tel.archives-ouvertes.fr/tel-00436049.
Texto completo da fonteRafhay, Quentin. "Modelling of nano nMOSFETs with alternative channel materials in the fully and quasi ballistic regimes". Phd thesis, 2008. http://tel.archives-ouvertes.fr/tel-00398674.
Texto completo da fonteA partir de modèles analytiques originaux, calibrés sur des simulations avancées (quantique, Monte Carlo), cette thèse démontre que, à des dimensions nanométriques, les performances attendues de ces nouvelles technologies sont en fait inférieures à celles des composants silicium conventionnels. En effet, les phénomènes quantiques (confinement, fuites tunnel) pénaliseraient davantage les dispositifs à matériaux de canal alternatifs.