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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.
1

A Novel device consisting of MOSFET with Resonance Inter-band Tunneling Diode

Hou, Chao-yu 27 August 2007 (has links)
This thesis focuses on combination of RITD (Resonant Inter-band Tunneling Diode) in MOS (Metal Oxide Semiconductor). Such new device gives architecture, applying to a latch theory and produces a stable, robust output working voltage. This output voltage can induce electric field to control drive current of said MOS. This design can guarantee high noise-defense, reduce power consumption, high speed switch and save space occupation. When gate voltage has longer slew time, the generated current working point may shift seriously due to noise interference. Importing this new architecture can form latch-phenomenon to keep working point into two stable states robustly, so this design can improve noise-defense ability of MOS. Because the announced device has lower working point voltage, it can reduce power consumption. During switch phase, said RITD can provide high current density to bring low slew rate of a conventional MOS up, thus the high speed switch is reached. Finally, this design of proposed device in this thesis is stack-like shape, then it can cut down space occupation efficiently to match futuristic trend of product profile.
2

SIMULATION AND DESIGN OF GERMANIUM-BASED MOSFETs FOR CHANNEL LENGTHS OF 100 nm AND BELOW

ARNOLD, MARTIN KEITH, JR. 02 July 2007 (has links)
No description available.
3

Metal-oxide-semiconductor capacitor for diamond transistor : simulation, fabrication and electrical analysis / Capacité métal-oxyde-semiconducteur pour le transistor en diamant : simulation, fabrication et caractérisation électrique

Maréchal, Aurélien 27 November 2015 (has links)
Plus de deux décennies de progrès technologiques dans le contrôle de la qualité de la croissance, du dopage et dans la conception de composants ont conduit à l'émergence de nouvelles potentialités pour des applications d'électronique de puissance. Comme le diamant représente le semi-conducteur ultime en raison de ses propriétés physiques supérieures, des efforts ont été réalisés pour développer divers dispositifs électroniques, tels que des diodes Schottky, des transistors à effet de champ (MOSFET), transistor bipolaire, jonctions pin ...Le développement d'outils de simulation capables d'anticiper les propriétés électriques des dispositifs électroniques ainsi que leur architecture pour profiter pleinement des propriétés physiques du diamant est une condition préalable à la mise au point de nouveaux composants de puissance. D'autre part, l'étude expérimentale du contact de grille, la deuxième brique élémentaire du transistor, est fondamentale en vue de développer des dispositifs de haute performance. À cet égard, on peut considérer plusieurs questions ouvertes: (i) Les outils de simulation sont-ils capables de prendre en compte les spécificités du diamant pour modéliser les composants électroniques? (ii) L'oxyde d'aluminium est-il approprié pour développer un contact de grille de transistor? (iii) Si oui, l'interface oxyde/diamant est-elle d'assez bonne qualité? (iv) La fabrication d'un MOSFET en diamant est-elle un obstacle technologique?Ce projet de doctorat, vise à répondre à ces questions et à ouvrir la voie vers la réalisation du MOSFET à canal d'inversion.Les propriétés physiques du diamant seront soulignées et aideront à comprendre pourquoi ce matériau est le semi-conducteur ultime. L'état de l'art des dispositifs en diamant sera présenté en se concentrant sur des transistors à effet de champ. L'anticipation des propriétés électriques et de l'architecture grâce à des logiciels de simulation basés sur la méthode des éléments finis constitue un sujet complémentaire. Ainsi, le besoin d'outils de simulation fiables sera présenté.D'une part, les principaux modèles mis en œuvre dans les outils de simulation seront présentés en insistant sur les propriétés électriques du diamant. Pour la simulation du MOSFET diamant, l'étude de deux briques élémentaires est nécessaire: la jonction pn et le contact de grille. Les propriétés idéales de la grille seront présentées tandis que la jonction pn servira de base pour le calibrage des paramètres physiques mises en œuvre dans le logiciel de simulation. L'influence des modèles de génération-recombinaison sur les propriétés électriques simulée de jonction pn sera discutée. Enfin, la simulation des propriétés électriques d'un MOSFET en diamant sera présentée.D'autre part, l'accent sera mis sur la fabrication et la caractérisation électrique du condensateur diamant métal-oxyde-semi-conducteur (MOSCAP). Plus précisément, le raccordement des bandes à l'interface Al2O3/diamant à terminaison oxygène (O-diamant) a été étudiée en utilisant la méthode de spectroscopie photoélectronique à rayons X. Les résultats ont permis l'établissement du diagramme de bande de l'hétérostructure Al2O3/O-diamant et démontre que l'Al2O3 est utilisable en tant qu'oxyde de grille. Ensuite, l'étude de la densité des états d'interface a révélé l'ancrage du niveau de Fermi à l'interface entre l'Al2O3 et le diamant. En outre, les courants de fuite à travers la couche d'Al2O3 seront discutés en termes d'effet tunnel assisté par pièges de trous de la couche de diamant au contact de grille. Enfin, la caractérisation électrique du premier MOSFET en diamant, effectuée au National Institute for Advanced Industrial Science and Technology (AIST) au Japon, sera présentée. Cette première tentative s'est révélée infructueuse. Néanmoins, les résultats sont très prometteurs pour le développement de diamant MOSFET étant donné que la démonstration de la réalisation du composant est clairement établie. / Over two decades of technological progresses in growth quality, doping control and device processing have led to the emergence of new potentialities for power electronic applications. As diamond represents the ultimate semiconductor owing to its superior physical properties, efforts have been conducted to develop various electronic devices, such as Schottky diodes, field effect transistors, bipolar transistor, p-i-n junctions...As a prerequisite to the development of new generation diamond power devices, on one side, is the development of simulation tools able to anticipate the device electrical properties as well as its architecture in order to take full advantage of the material physical properties. On the other hand, experimental study of the gate contact, the second building block of the transistor, is fundamental in order to develop high performance devices. In this regard, one can consider several open questions: (i) Are the simulation tools able to take into account the specificities of diamond to model electrical devices? (ii) Is the aluminum oxide suitable to develop a MOSFET gate contact? (iii) If so, is the oxide/diamond interface of good enough quality? (iv) Is the fabrication of a diamond MOSFET a technological issue?This PhD project, attend to answer these questions and pave the way towards the inversion mode MOSFET.Emphasize on the diamond physical properties will help to understand why this material is the ultimate WBG semiconductor. State of the art diamond devices will be presented focusing on field effect transistors. A complementary topic for the development of new generation diamond power device is the anticipation of device electrical properties and architecture through finite element base simulation software. Thus the need for reliable simulation tools will be presented.On one hand, the main models implemented in the simulation tools will be presented and emphasize on the diamond electrical properties will be given. For the simulation of diamond metal-oxide-semiconductor field effect transistor (MOSFET), the study of two building blocks is required: the p-n junction and the gate contact. The later ideal properties will be presented while the former will serve as a basis for the calibration of the physical parameters implemented in the finite element based software. Generation-recombination models influence on the simulated p-n junction electrical properties will be discussed. Finally, the simulation of the electrical properties of a diamond metal-oxide-semiconductor field effect transistor (MOSFET) will be shown.On the other hand, focus will be made on diamond metal-oxide-semiconductor capacitor (MOSCAP) fabrication and electrical characterization. Specifically, the interfacial band configuration of the Al2O3/oxygen-terminated diamond (O-diamond) has been investigated using X-ray photoelectron spectroscopy. The results allowed establishing the band diagram of the Al2O3/O-diamond heterostructure. Then, the electrical properties of the diamond MOSCAP will be shown. Specifically, investigation of the interface states density revealed the pinning of the Fermi level at the interface between the Al2O3 and the O-diamond. Moreover, the leakage currents through the Al2O3 layer will be discussed in terms of temperature dependent trap assisted tunneling of holes from the diamond layer to the top gate contact. Finally, the electrical characterization of the first diamond MOSFET, performed at the National Institute for Advanced Industrial Science and Technology (AIST) in Japan, will be presented. Even if this first attempt was unsuccessful, it is promising for the development of diamond MOSFET since the demonstration of the actual realization of the device is clearly established.
4

SiC oxidation processing technology for MOSFETs fabrication / Technologie d'oxydation pour la fabrication de composants MOSFETs en SiC

Constant, Aurore 25 July 2011 (has links)
De nos jours, les dispositifs d'électroniques de puissance sont principalement basés sur la technologie silicium qui est mature et très bien établie. Toutefois, le silicium présente quelques limitations importantes concernant les pertes de puissance, le fonctionnement à haute température et la vitesse de commutation. Par ailleurs, la technologie silicium a presque atteint ses limites physiques. Ainsi, une nouvelle génération de dispositifs de puissance à base de nouveaux matériaux doit être développée pour faire face aux futurs défis énergiques. Aujourd'hui, le matériau semi-conducteur le plus prometteur est le carbure de silicium (SiC). SiC est considéré de plus en plus comme le meilleur candidat pour surmonter les limites intrinsèques du silicium pour l'élaboration de dispositifs de haute puissance et haute température. Il montre le meilleur compromis entre les caractéristiques théoriques et les réelles disponibilités commerciales de la matière première et de la maturité de ses procédés technologiques.Cette thèse est axée sur les dispositifs d'alimentation à base de SiC, en particulier, sur l'un des enjeux majeurs de la technologie SiC: le procédé d'oxydation. En effet, le SiC peut être facilement oxydé comme le silicium pour former une fine couche de dioxyde de silicium (SiO2). Ceci fournit une occasion unique de développer des dispositifs Métal-Oxyde-Semiconducteur (MOS), comme en technologie silicium. Malheureusement, la qualité de l'interface oxyde/SiC et la fiabilité de l'oxyde sont des obstacles majeurs à la fabrication de dispositifs MOSFET avancés en SiC. Des solutions alternatives ont été développées pour surmonter ces problèmes. Toutefois, les MOSFETs en SiC ont seulement été récemment commercialisés, principalement en raison des problèmes de fiabilité. Le procédé de fabrication de MOSFETs adapté à la production de masse est encore un défi.Les principaux efforts réalisés dans le cadre de cette thèse concernent le développement des MOSFETs en SiC par l'amélioration du procédé d'oxydation pour la fabrication de l'oxyde de grille. Un nouveau procédé basé sur l'oxydation par Rapid Thermal Processing (RTP) est démontré. De plus, les mécanismes physiques associés à la formation de l'oxyde et des propriétés de l'interface SiO2/SiC sont proposés. Ce procédé d'oxydation a été testé sur le SiC hexagonal (4H-SiC) et le SiC cubique (3C-SiC). En outre, la technologie d'oxydation étudiée a été intégrée dans la fabrication de MOSFETs en 4H-SiC. La fiabilité des composants a été aussi évaluée pour des stress en tension jusqu'à des températures de fonctionnement de 300°C. / Power electronic devices are mainly based on the mature and very well established silicon technology. However, silicon exhibits some important limitations regarding power losses, operation temperature and speed of switching. Furthermore, unfortunately the successful silicon technology has almost reached its physical limits. Hence, a new generation of power devices based on new materials must be developed to face the future global energetic challenges. Nowadays, the most promising semiconductor material is silicon carbide (SiC). SiC is increasingly considered as the best candidate to overcome the intrinsic limitations of silicon in developing high-power and high-temperature electronic devices. It shows the best trade-off between theoretical characteristics and real commercial availability of the starting material and maturity of its technological processes.This thesis is focused on SiC-based power devices, particularly, on one of the major issues in SiC technology: the gate oxidation process. Indeed, SiC can be easily oxidized to form a thin silicon dioxide (SiO2) layer. This provides a unique opportunity to develop power Metal Oxide Semiconductor (MOS) devices, as in the Si-based technology. SiC-based power MOSFETs are expected to have great potential for high-speed and low-loss switching devices. Unfortunately, the oxide/SiC interface quality and oxide reliability are major barriers to the fabrication of advanced SiC power MOSFET devices. Alternative solutions have been developed to overcome these problems. However, SiC MOSFETs have only been recently commercially available, mainly due to reliability concerns. The MOSFET process suitable for mass production is still a challenge. The main efforts carried out in the framework of this thesis are addressed towards the development of SiC MOSFETs by improving the current gate oxide process state-of-the-art. A newly gate oxidation process based on rapid thermal processing is demonstrated, and the physical mechanisms associated with oxide formation and the SiO2/SiC interface properties are proposed. This oxidation process has been tested on hexagonal SiC (4H-SiC) and cubic SiC (3C-SiC). Furthermore, the investigated oxidation processing technology is integrated into the fabrication of reliable 4H-SiC MOSFETs, and the bias-stress instability has been evaluated up to operating temperatures of 300 ºC.
5

Framtagning av testutrustning för transistorer vid induktiv last.

Gunnarsson, Mathias January 2015 (has links)
When a transistor is used as a switch in a conversion of electrical energy, the switching losses are decisive in the choice of the transistor. In order to compare these losses, a test equipment has been developed, which can be used to perform measurements on different IGBT-transistors when switching an inductive load. The objective of this work was to develop a test equipment, and to use it to take measurements of a number of transistors. The equipment has been designed in such a way that the components that affect the switching losses can be replaced in a simple manner. Parameters like switched voltage and pulse duration of the gate signal can be adjusted as well. In this way, different components influence can be examined and measurements can be adjusted to mimic different net-voltages. Developed test equipment has been used to perform measurements of four different IGBT-transistors when turned off, and a comparison between fall times, energy consumption and switching losses have been made. Measurements have only been done on IGBT-transistors as fluctuations occurred during the measurements of the MOSFET. This is believed to be due to that the fall time of the MOSFET is significantly less than for the IGBT, which leads to an increase of the impact of the parasitic components. For measurement of the MOSFET the components needs to be placed closer to each other, to thereby reduce parasitic components. Such equipment means that the components can not be replaced in a simple manner, which was the purpose of the test equipment. Measurements and comparison has been carried out on four different IGBT-transistor. They show an opportunity to reduce switching losses through the replacement of the current transistor.
6

Investigation of the interaction between acoustic phonons and the 2DEG of a silicon MOSFET

Newton, M. I. N. January 1987 (has links)
No description available.
7

Conception de convertisseurs de puissance pour applications contraignantes

Onambélé Essono Ela, Charles 30 May 2018 (has links)
L'utilisation de systèmes multiphasés de conversion électromécanique connaît une croissance continue dans divers domaines comme l'énergie et l'électrification des transports. Cette thèse vise à proposer des solutions technologiquement viables permettant de concevoir des convertisseurs de puissance adaptés à des applications contraignantes tant vis-à-vis des performances qu'à l'environnement physique: haut rendement, haute température ambiante, volume réduit, modularité, etc. Les technologies de composants semi - conducteurs à large bande interdite sont étudiées (carbure de silicium et nitrure de gallium) afin de les intégrer dans des modèles de co-simulation avec des machines électriques hexaphasées. D'autre part, une analyse thermique en trois dimensions de systèmes d'électronique de puissance pour ce type d'application est proposée, le calcul numérique par éléments finis permettant de modéliser au mieux le système en tenant compte des diverses contraintes de l'application. Enfin, une validation expérimentale de la technologie du semi - conducteur est menée à bien / The use of multiphase electromechanical conversion systems is increasing steadily in different fields like energy and transportation. This thesis aims to propose solutions which are technologically viable, allowing to design power converters for severe applications: both in terms of performances (high efficiency, modularity, etc.) and physical environment (high ambient temperature, reduced volume...). Wide band gap semiconductor technologies are studied (silicon carbide and gallium nitride) in order to integrate them in co-simulation models with hexaphase machines. Besides, a 3D thermal analysis of power electronic systems for such applications is proposed, knowing that the finite element model considers different severe requirements of the system. An experimental validation of the semiconductor technology is carried out successfully
8

Characterization of Silicon and Indium Phosphide MOS Structures with Titanium Oxide as Gate Oxides

Huang, Jung-Jie 29 July 2005 (has links)
The dielectric constant of poly-crystalline titanium oxide (TiO2) films grown on silicon (Si) by metal organic chemical vapor deposition (MOCVD) is high. The leakage current is also high, which is dominated by the grain boundary and lower barrier height. Silicon oxide (SiO2) film is used as an interfacial layer for the structure of MOCVD-TiO2/SiO2/Si. The leakage current is much improved due to the high quality and high barrier height of SiO2/Si, but the total capacitance is lost due to the series of low-dielectric constant SiO2 films and amorphous low dielectric constant of TiO2 film grown on SiO2. Liquid-phase-deposited SiO2 is used as a cap layer for the structure of LPD-SiO2/MOCVD-TiO2/Si, the high dielectric constant of MOCVD-TiO2/Si is preserved. The leakage current is much improved due to the high barrier height SiO2 and the passivation of the dangling bonds of the grain boundary of poly-crystalline MOCVD-TiO2 films by the F from LPD-SiO2 films. Therefore, high dielectric constant and low leakage current LPD-SiO2/MOCVD-TiO2/Si films were obtained. Therefore, MOSFET with LPD-SiO2/MOCVD-TiO2 gate oxide can have lower off state leakage current, smaller subthreshold swing, higher transconductance, and higher field effect mobility. On the other hand, LPD-SiO2/MOCVD-TiO2 film on (NH4)2Sx-treated InP not only can lower leakage current but can lower interface state density. The leakage current densities are 1.37¡Ñ10-7 A/cm2 and 1.45¡Ñ10-7A/cm2 under positive and negative electric fields at 1.5 MV/cm, respectively. The lowest interface state density is 4.7¡Ñ1011 cm-2eV-1 in the band gap. Moreover, the dielectric constant can reach 61.2. Therefore, LPD-SiO2/MOCVD-TiO2 structure is a high dielectric constant and low leakage current film.
9

Characterization of Silicon and Gallium Arsenide MOS Structures with Titanium Oxide as dielectric layer

Lin, Shih-Hao 26 July 2006 (has links)
For MOCVD-TiO2/Si MOS structure, oxygen vacancy and grain boundary are the main defects of polycrystalline TiO2 films. They are the main mechanisms for the leakage current. In order to improve the problems, oxygen annealing treatment is often used for filling oxygen vacancies. The electrical characteristics of as-grown MOCVD-TiO2 films can be improved. However, it is from the lattice mismatch between the TiO2 film and Si substrate. In order to release the stress, the TiO2 film will produce a lot of defects and degrade its stoichiometry. Besides, the thermal ionic emission is due to lower conduction band offset between TiO2/Si than that of SiO2/Si. These problems need further improvement. In order to solve the above mentioned problems, fluorinated liquid phase deposition (LPD) SiO2 deposited upon polycrystalline MOCVD-TiO2/Si. Higher barrier height (Eg = 9 eV) of fluorinated LPD-SiO2 could avoid the thermal ionic emission from lower conduction band offset of TiO2/Si. Moreover, the LPD-SiO2 film can provide fluorine (F-) from the hydrofluosilicic acid (H2SiF6) aqueous solution. Fluorine could passivate grain boundaries of poly-crystalline MOCVD-TiO2 films and interface state density (Dit) of the MOCVD-TiO2/Si interface. The main leakage current of polycrystalline MOCVD-TiO2 films could be .effective to reduce. Furthermore, nitrogen (N2) annealing was used to enhance fluorine passivation of LPD-SiO2/O2-annealed MOCVD-TiO2 films. Therefore, it can be expected that higher dielectric constant and lower leakage current density will be obtained from LPD-SiO2/O2-annealed MOCVD-TiO2/Si MOS structure. Therefore, MOSFET with fluorinated MOCVD-TiO2 gate oxide can have lower off state leakage current, smaller subthreshold swing, higher transconductance, and higher field effect mobility. On the other hand, LPD-SiO2/MOCVD-TiO2 film on (NH4)2Sx-treated GaAs not only can lower leakage current but can lower interface state density. The leakage current densities are 2.3¡Ñ10-7 A/cm2 and 3.6¡Ñ10-7A/cm2 under positive and negative electric fields at 10V, respectively. The lowest interface state density is 4.7¡Ñ1011 cm-2eV-1 in the band gap. Moreover, the dielectric constant can reach 62. Therefore, LPD-SiO2/MOCVD-TiO2/(NH4)2Sx-treated GaAs structure is a high dielectric constant and low leakage current film. This structure has high potential for the further development of GaAs MOSFETs.
10

Digital Airsoftstyrning : DAC Mark.I

Bengtsson, Petter January 2014 (has links)
The Airsoft Community always search for realism and optimal performance.When the performance and/or the realism in your AEG1 aren’t enough you turn to modifications toimprove the weapon. But to manufacture such modifications isn’t that easy, hence you turn tocompanies that are specialized in creating such devices.The goal with this project is to create a prototype of a modification called “Programmable MOSFET”and targets optimization of the electrical components within the AEG. This means that you digitalizethe control of your AEG thus entails new functions and more stability to the system that isn’t possiblewith its mechanical predecessor.A prototype has been manufactured and programmed with functions according to requirementspecificationsthen it was tested on an airsoft-gearbox with rewarding results. The resulting prototypeis used as the basis for a final product that it is possible to base a business on.

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