Download or read book DISCUSSIONS ET MISES EN OEUVRE DES METHODES DE CARACTERISATION DES DEFAUTS DE SEMICONDUCTEURS written by ABDELLATIF.. MENKASSI and published by . This book was released on 1993 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOUS METTONS EN UVRE LES METHODES DE CARACTERISATION DES DEFAUTS DES SEMICONDUCTEURS A NIVEAUX D'ENERGIE DISCRETS OU A DENSITE D'ETATS G(E). CES METHODES ANALYSENT LE TRANSITOIRE DE CAPACITE D'UNE DIODE A JONCTION SILICIUM POLYCRISTALLIN-SILICIUM MONOCRISTALLIN OU D'UNE DIODE MOS DONT LA COUCHE DE SILICIUM POLYCRISTALLIN EST SITUEE ENTRE L'OXYDE ET LE SUBSTRAT DE SILICIUM MONOCRISTALLIN. NOUS RAPPELONS ET EXPOSONS LA MISE EN UVRE DES METHODES FTDLTS (FOURIER TRANSFORM DEEP LEVEL TRANSIENT SPECTROSCOPY) ET DE PROVENCHER POUR LA CARACTERISATION DES DEUX TYPES DE DEFAUTS PRECEDENTS. L'ANALYSE D'UN SIGNAL BI-EXPONENTIEL SYNTHETISE ET L'ANALYSE DE TRANSITOIRES DE CAPACITE D'UNE DIODE SCHOTTKY FAITE SUR DU GAAS IMPLANTE EN OXYGENE, MONTRE LA SUPERIORITE DE LA METHODE DE PROVENCHER SUR LA FTDLTS POUR CARACTERISER LES DEFAUTS A NIVEAUX D'ENERGIE DISCRETS. CETTE SUPERIORITE EST ENCORE VRAIE POUR DES SIGNAUX PRODUITS PAR UNE DENSITE D'ETATS REPARTIE DANS UN FAIBLE DOMAINE D'ENERGIE. MAIS C'EST LE CONTRAIRE DANS LE CAS D'UNE LARGE REPARTITION. A PARTIR DES TRANSITOIRES DE CAPACITE D'UNE JONCTION SILICIUM POLYCRISTALLIN-SILICIUM MONOCRISTALLIN, NOUS OBTENONS UNE DENSITE D'ETATS AYANT UN MAXIMUM A 0,34 EV ET UN MINIMUM A 0,26 EV AU-DESSOUS DE LA BANDE DE CONDUCTION. LA DENSITE D'ETATS G(E) DU SILICIUM POLYCRISTALLIN DE LA DIODE MOS EST DETERMINEE PAR LES METHODES FTDLTS, DE LANG ET EGALEMENT PAR LA METHODE C(V) DE DETERMINATION DE DENSITE DES ETATS D'INTERFACE QUE NOUS AVONS DEVELOPPEE. LES DENSITES OBTENUES PAR LES TROIS METHODES SONT SENSIBLEMENT LES MEMES, MAIS DIFFERENT DE LA VALEUR OBTENUE POUR LA DIODE A JONCTION. NOUS AVONS AUTOMATISE LA METHODE DE FORTUNATO POUR LA DETERMINATION DE G(E) DU SILICIUM POLYCRISTALLIN DU CANAL D'UN TRANSISTOR A EFFET DE CHAMP. DANS L'INTERVALLE 70-130 NM. LES VALEURS DE G(E) OBTENUES SONT INDEPENDANTES DE L'EPAISSEUR ET VARIENT PEU AVEC LE DOPAGE QUE DU SILICIUM POLYCRISTALLIN DU CANAL
Download or read book tude des d fauts dans les alliages de semi conducteurs grand gap B AlGa N et de leur r le dans les propri t s de transport written by Sarrah Amor and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le nitrure de gallium (GaN) et ses alliages ternaires et quaternaires suscitent de plus en plus d'intérêt dans les communautés scientifiques et industrielles pour leur potentiel d'utilisation dans des dispositifs électroniques haute fréquence, dans les transistors à forte mobilité électroniques, dans la photo-détection UV et les cellules solaires de nouvelles générations. L'aboutissement de ces nouveaux composants reste entravé à l'heure actuelle, entre autre, par la non maîtrise des techniques d'établissement de contacts électriques. C'est dans ce cadre général que s'inscrivent les travaux de cette thèse. Même si l'objectif principal de cette thèse concerne l'étude des défauts électriquement actifs dans les alliages de semiconducteurs à grand gap B(AlGa)N et de leur rôle dans les propriétés de transport, la réalisation des contacts ohmiques et des contacts Schottky constitue une étape essentielle dans la réalisation des dispositifs à étudier. Pour les contacts ohmiques, nous avons déposé des couches de type Ti/Al/Ti/Au (15/200/15/200) par évaporation thermique. Des résistances spécifiques des contacts de l'ordre de 3x10-4Wcm2 ont été déterminées par les méthodes des TLM linéaires et confirmées par les TLM circulaires. Une modélisation théorique a été entreprise dans ce sens pour analyser les mesures expérimentales. Ensuite on a réalisé des diodes Schottky en déposant des contacts métalliques de Platine (Pt) d'épaisseur 150 nm. Des facteurs d'idéalité de 1.3 et une hauteur de barrière de 0.76 eV ont été obtenus et d'une manière reproductible. Une fois ces dispositifs réalisés, une étude des mécanismes de transport a été entreprise et nous a permis de mettre en évidence l'existence des effets tunnel direct et assisté par le champ, en plus de l'effet thermoïonique classique. Ceci a été mis en évidence par des mesures de courant et de capacité en fonction de la température. Pour les photodétecteurs, nous avons réalisés les mêmes mesures de courant et de capacité à l'obscurité et sous illumination à des longueurs d'ondes adaptées. Ces mesures nous ont permis de comprendre les phénomènes de gain qu'on a observés sur ces échantillons et aussi de mettre en évidence des mécanismes thermiquement actifs, dont les énergies d'activation ont été déterminées par la technique de l'Arrhenius. L'étude des défauts électriquement actifs a été menée par la technique transitoire de capacité de niveaux profonds, la (DLTS). Cette technique a été récemment mise en oeuvre au laboratoire et nous a permis d'effectuer des mesures sous différentes conditions incluant diverses polarisations de repos, différentes fréquences, et différentes hauteurs et largeurs d'impulsion de polarisation. Un des résultats importants est la possibilité de caractérisation à la fois des pièges à majoritaires et des pièges à minoritaire en changeant simplement les conditions de polarisation et contrairement aux procédures habituelles où une excitation optique supplémentaire est souvent nécessaire pour augmenter la concentration des porteurs minoritaires. Il a ainsi été mis en évidence, en accord avec la plupart des résultats de la littérature, l'existence de 6 pièges à électrons, tous situés en dessous de 0.9 eV de la bande de conduction, de trois pièges à trous dans l'intervalle 0.6 - 0 .7 eV au dessus de la bande de valence et un piège à trous distribué à l'interface. Une procédure rigoureuse de fit a été mise au point et a permis de confirmer nos résultats obtenus par la procédure classique de l'Arrhenius.
Download or read book Contribution l tude et la mise en oeuvre de diverses m thodes de caract risation lectrique et thermique des dispositifs semi conducteurs written by Abdelaziz Naamane and published by . This book was released on 1986 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA REALISATION DES COMPOSANTS SEMI-CONDUCTEURS ET L'EVOLUTION RAPIDE DE LEURS APPLICATIONS EXIGENT UNE BONNE CONNAISSANCE DES PARAMETRES QUI REGISSENT LEUR COMPORTEMENT STATIQUE ET DYNAMIQUE. LE PROBLEME DE LEUR CARACTERISATION SE POSE DONC A CHAQUE ETAPE DE LA FABRICATION DE CES COMPOSANTS. DIVERSES METHODES DE DETERMINATION ET DIVERS APPAREILS SONT COURAMMENT EMPLOYES. ILS PEUVENT ETRE CLASSES EN DEUX GROUPES : METHODE ET APPAREILLAGES A CONTACTS DU TYPE MICROSONDAGE RESISTIF OU RELEVE DE POTENTIEL. METHODES ET APPAREILLAGES SANS CONTACT, DU TYPE MICROSONDAGE OPTIQUE. CE TRAVAIL A CONSISTE EN LA REALISATION ET LA MISE EN OEUVRE DE DIVERS APPAREILLAGES DE CARACTERISATION METTANT EN JEU PLUSIEURS TECHNIQUES D'EVALUATION APPLICABLES AUX SEMI-CONDUCTEURS A SAVOIR : CARTOGRAPHIE DE POTENTIEL ET DE DENSITE DE COURANT, MICROSONDAGE RESISTIF "SPREADING RESISTANCE", CARTOGRAPHIE DE TEMPERATURE (MICROSCOPIE OU THERMOGRAPHIE I.R.), DETERMINATION D'EPAISSEURS DE COUCHES EPITAXIEES OU TRIPLE DIFFUSEES
Download or read book Fabrication of GaAs Devices written by Albert G. Baca and published by IET. This book was released on 2005-09 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides fundamental and practical information on all aspects of GaAs processing and gives pragmatic advice on cleaning and passivation, wet and dry etching and photolithography. Other topics covered include device performance for HBTs (Heterojunction Bipolar Transistors) and FETs (Field Effect Transistors), how these relate to processing choices, and special processing issues such as wet oxidation, which are especially important in optoelectronic devices. This book is suitable for both new and practising engineers.
Download or read book Basic Concepts for Simple and Complex Liquids written by Jean-Louis Barrat and published by Cambridge University Press. This book was released on 2003-03-27 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a unified approach, this book focusses on the concepts and theoretical methods that are necessary for an understanding of the physics and chemistry of the fluid state. The authors do not attempt to cover the whole field in an encyclopedic manner. Instead, important ideas are presented in a concise and rigorous style, and illustrated with examples from both simple molecular liquids and more complex soft condensed matter systems such as polymers, colloids, and liquid crystals.
Download or read book On the Continuity of the Gaseous and Liquid States written by J. D. Van Der Waals and published by Courier Corporation. This book was released on 2004-01-01 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This much-cited thesis by J. D. van der Waals, the recipient of the 1910 Nobel Prize in physics, is accompanied by an introductory essay by J. S. Rowlinson and another work by van der Waals on the theory of liquid mixtures. 1988 edition.
Download or read book Polymers on the Crime Scene written by Valerio Causin and published by Springer. This book was released on 2015-04-20 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book approaches the analysis of forensic contact traces from a polymer science perspective. The development of characterization methods of new or unusual traces and the improvement of existing protocols is described. The book starts with a general introduction to polymers and the issues related to transfer, persistence and recovery of polymeric traces. The chapters present a distinctive feature of polymers, discussing how it can be measured, what the practical difficulties which can be encountered in the analysis, and how useful that information is for comparison or identification purposes. Practical tips for the realization of the forensic analyses are included.
Download or read book Acta electronica written by and published by . This book was released on 1983 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annales des t l communications written by and published by . This book was released on 1998 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Download or read book Properties of UO2 written by J. Belle and published by . This book was released on 1957 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cracks in superalloys written by Jonas Saarimäki and published by Linköping University Electronic Press. This book was released on 2018-01-18 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines are widely used in industry for power generation and as a power source at hard to reach locations where other possibilities for electrical power supplies are insufficient. New ways of producing greener energy is needed to reduce emission levels. This can be achieved by increasing the combustion temperature of gas turbines. High combustion temperatures can be detrimental and degrade critical components. This raises the demands on the high temperature performance of the superalloys used in gas turbine components. These components are frequently subjected to different cyclic loads combined with for example dwell-times and overloads at elevated temperatures, which can influence the crack growth. Dwell-times have been shown to accelerate crack growth and change cracking behaviour in both Inconel 718, Haynes 282 and Hastelloy X. On the other hand, overloads at the beginning of a dwell-time cycle have been shown to retard the dwell-time effect on crack growth in Inconel 718. More experiments and microstructural investigations are needed to better understand these effects. The work presented in this thesis was conducted under the umbrella of the research program Turbo Power; "High temperature fatigue crack propagation in nickel-based superalloys", where I have mainly looked at fatigue crack growth mechanisms in superalloys subjected to dwell-fatigue, which can have a devastating effect on crack propagation behaviour. Mechanical testing was performed under operation-like cycles in order to achieve representative microstructures and material data for the subsequent microstructural work. Microstructures were investigated using light optical microscopy and scanning electron microscopy (SEM) techniques such as electron channeling contrast imaging (ECCI) and electron backscatter diffraction (EBSD). The outcome of this work has shown that there is a significant increase in crack growth rate when dwell-times are introduced at maximum load (0 % overload) in the fatigue cycle. With the introduction of a dwell-time there is also a shift from transgranular to intergranular crack growth for both Inconel 718 and Haynes 282. The crack growth rate decreases with increasing overload levels in Inconel 718 when an overload is applied prior to the dwell-time. At high temperature, intergranular crack growth was observed in Inconel 718 as a result of oxidation and the creation of nanometric voids. Another observed growth mechanism was crack advance along ?-phase boundaries with subsequent oxidation of the ?-phase. This thesis comprises two parts. Part I gives an introduction to the field of superalloys and the acting microstructural mechanisms related to fatigue and crack propagation. Part II consists of five appended papers, which report the work completed as part of the project.
Download or read book An Introduction To Plasmonics written by Olivier Pluchery and published by World Scientific. This book was released on 2023-08-28 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is a plasmon? Is it a particle, like a photon or a wave? Plasmonics stands at the frontier of condensed matter physics, which is the world of electrons, optics and of photons. Plasmonics is one of the most active fields in nanophotonics. This book begins by exploring the concepts behind waves, and the electromagnetic description of light when it interacts with metals; it dedicates every chapter thereafter to all aspects of plasmonics. In particular, the surface plasmon polariton wave is explained in full detail, as well as the localized surface plasmon resonance of metallic nanoparticles. The active research area opened by plasmonics, as well as its applications, are also briefly explained, such as advanced biosensing, subwavelength waveguiding, quantum plasmonics, nanoparticle-based cancer therapies, optical nano-antenna and high-efficiency photovoltaic cells.The book is adapted for graduate students and places a special emphasis on providing complete explanations of the fundamental concepts of plasmonics. Further, each of these concepts is illustrated with examples drawn from the most recent scientific literature. Each chapter ends with a set of exercises that will help the reader revise the concepts and go deeper into the world of plasmonics. More than 70 exercises are included.
Download or read book Molecular Beam Epitaxy written by John Wilfred Orton and published by . This book was released on 2015 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a history of Molecular Beam Epitaxy (MBE) as applied to the growth of semiconductor thin films (note that it does not cover the subject of metal thin films). It begins by examining the origins of MBE, first of all looking at the nature of molecular beams and considering their application to fundamental physics, to the development of nuclear magnetic resonance and to the invention of the microwave MASER. It shows how molecular beams of silane (SiH4) were used to study the nucleation of silicon films on a silicon substrate and how such studies were extended to compound semiconductors such as GaAs. From such surface studies in ultra-high vacuum the technique developed into a method of growing high quality single crystal films of a wide range of semiconductors. Comparing this with earlier evaporation methods of deposition and with other epitaxial deposition methods such as liquid phase and vapour phase epitaxy (LPE and VPE). The text describes the development of MBE machines from the early 'home-made' variety to that of commercial equipment and show how MBE was gradually refined to produce high quality films with atomic dimensions. This was much aided by the use of various in-situ surface analysis techniques, such as reflection high energy electron diffraction (RHEED) and mass spectrometry, a feature unique to MBE. It looks at various modified versions of the basic MBE process, then proceed to describe their application to the growth of so-called 'low-dimensional structures' (LDS) based on ultra-thin heterostructure films with thickness of order a few molecular monolayers. Further chapters cover the growth of a wide range of different compounds and describe their application to fundamental physics and to the fabrication of electronic and opto-electronic devices. The authors study the historical development of all these aspects and emphasise both the (often unexpected) manner of their discovery and development and the unique features which MBE brings to the growth of extremely complex structures with monolayer accuracy.
Download or read book INIS Atomindeks written by and published by . This book was released on 1979 with total page 1462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Fatigue Behaviour of Austenitic Stainless Steel written by Hugo Wärner and published by Linköping University Electronic Press. This book was released on 2018-12-20 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global energy consumption is increasing and together with global warming from greenhouse gas emission, create the need for more environmental friendly energy production processes. Higher efficiency of biomass power plants can be achieved by increasing temperature and pressure in the boiler section and this would increase the generation of electricity along with the reduction in emission of greenhouse gases e.g. CO2. The power generation must also be flexible to be able to follow the demands of the energy market, this results in a need for cyclic operating conditions with alternating output and multiple start-ups and shut-downs. Because of the demands of flexibility, higher temperature and higher pressure in the boiler section of future biomass power plants, the demands on improved mechanical properties of the materials of these components are also increased. Properties like creep strength, thermomechanical fatigue resistance and high temperature corrosion resistance are critical for materials used in the next generation biomass power plants. Austenitic stainless steels are known to possess such good high temperature properties and are relatively cheap compared to the nickel-base alloys, which are already operating at high temperature cyclic conditions in other applications. The behaviour of austenitic stainless steels during these widened operating conditions are not yet fully understood. The aim of this licentiate thesis is to increase the knowledge of the mechanical behaviour at high temperature cyclic conditions for austenitic stainless steels. This is done by the use of thermomechanical fatigue- and creepfatigue testing at elevated temperatures. For safety reasons, the effect of prolonged service degradation is investigated by pre-ageing before mechanical testing. Microscopy is used to investigate the microstructural development and resulting damage behaviour of the austenitic stainless steels after testing. The results show that creep-fatigue interaction damage, creep damage and oxidation assisted cracking are present at high temperature cyclic conditions. In addition, simulated service degradation resulted in a detrimental embrittling effect due to the deterioration by the microstructural evolution.
