Electrical conduction in thin aggregated metal films

Electrical conduction in thin aggregated metal films PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Electrical conduction in thin aggregated metal films

Electrical conduction in thin aggregated metal films PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Proceedings

Proceedings PDF Author:
Publisher:
ISBN:
Category : Microelectronics
Languages : en
Pages : 298

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Nanobiotechnology and Nanobiosciences

Nanobiotechnology and Nanobiosciences PDF Author: Claudio Nicolini
Publisher: CRC Press
ISBN: 9814241393
Category : Medical
Languages : en
Pages : 367

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Book Description
This volume introduces, in a coherent and comprehensive fashion, the Pan Stanford Series on Nanobiotechnology by defining and reviewing the major sectors of nanobiotechnology and nanobiosciences with respect to the most recent developments. It covers the basic principles and main applications of nanobiotechnology as an emerging field at the frontiers of biotechnology and nanotechnology, with contributions from leading scientists active in their respective specialties.

Electrical Times

Electrical Times PDF Author:
Publisher:
ISBN:
Category : Electric engineering
Languages : en
Pages : 876

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Aggregation and Flow of Solids

Aggregation and Flow of Solids PDF Author: Sir George Thomas Beilby
Publisher:
ISBN:
Category : Solids
Languages : en
Pages : 416

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Thin metal films on weakly-interacting substrates

Thin metal films on weakly-interacting substrates PDF Author: Andreas Jamnig
Publisher: Linköping University Electronic Press
ISBN: 9179298206
Category :
Languages : en
Pages : 108

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Vapor-based growth of thin metal films with controlled morphology on weakly-interacting substrates (WIS), including oxides and van der Waals materials, is essential for the fabrication of multifunctional metal contacts in a wide array of optoelectronic devices. Achieving this entails a great challenge, since weak film/substrate interactions yield a pronounced and uncontrolled 3D morphology. Moreover, the far-from-equilibrium nature of vapor-based film growth often leads to generation of mechanical stress, which may further compromise device reliability and functionality. The objectives of this thesis are related to metal film growth on WIS and seek to: (i) contribute to the understanding of atomic-scale processes that control film morphological evolution; (ii) elucidate the dynamic competition between nanoscale processes that govern film stress generation and evolution; and (iii) develop methodologies for manipulating and controlling nanoscale film morphology between 2D and 3D. Investigations focus on magnetron sputter-deposited Ag and Cu films on SiO2 and amorphous carbon (a-C) substrates. Research is conducted by strategically combining of in situ and real-time film growth monitoring, ex situ chemical and (micro)-structural analysis, optical modelling, and deterministic growth simulations. In the first part, the scaling behavior of characteristic morphological transition thicknesses (i.e., percolation and continuous film formation thickness) during growth of Ag and Cu films on a-C are established as function of deposition rate and temperature. These data are interpreted using a theoretical framework based on the droplet growth theory and the kinetic freezing model for island coalescence, from which the diffusion rates of film forming species during Ag and Cu growth are estimated. By combining experimental data with ab initio molecular dynamics simulations, diffusion of multiatomic clusters, rather than monomers, is identified as the rate-limiting structure-forming process. In the second part, the effect of minority metallic or gaseous species (Cu, N2, O2) on Ag film morphological evolution on SiO2 is studied. By employing in situ spectroscopic ellipsometry, it is found that addition of minority species at the film growth front promotes 2D morphology, but also yields an increased continuous-layer resistivity. Ex situ analyses show that 2D morphology is favored because minority species hinder the rate of coalescence completion. Hence, a novel growth manipulation strategy is compiled in which minority species are deployed with high temporal precision to selectively target specific film growth stages and achieve 2D morphology, while retaining opto-electronic properties of pure Ag films. In the third part, the evolution of stress during Ag and Cu film growth on a-C and its dependence on growth kinetics (as determined by deposition rate, substrate temperature) is systematically investigated. A general trend toward smaller compressive stress magnitudes with increasing temperature/deposition rate is found, related to increasing grain size/decreasing adatom diffusion length. Exception to this trend is found for Cu films, in which oxygen incorporation from the residual growth atmosphere at low deposition rates inhibits adatom diffusivity and decreases the magnitude of compressive stress. The effect of N2 on stress type and magnitude in Ag films is also studied. While Ag grown in N2-free atmosphere exhibits a typical compressive-tensile-compressive stress evolution as function of thickness, addition of a few percent of N2 yields to a stress turnaround from compressive to tensile stress after film continuity which is attributed to giant grain growth and film roughening. The overall results of the thesis provide the foundation to: (i) determine diffusion rates over a wide range of WIS film/substrates systems; (ii) design non-invasive strategies for multifunctional contacts in optoelectronic devices; (iii) complete important missing pieces in the fundamental understanding of stress, which can be used to expand theoretical descriptions for predicting and tuning stress magnitude. La morphologie de films minces métalliques polycristallins élaborés par condensation d’une phase vapeur sur des substrats à faible interaction (SFI) possède un caractère 3D intrinsèque. De plus, la nature hors équilibre de la croissance du film depuis une phase vapeur conduit souvent à la génération de contraintes mécaniques, ce qui peut compromettre davantage la fiabilité et la fonctionnalité des dispositifs optoélectroniques. Les objectifs de cette thèse sont liés à la croissance de films métalliques sur SFI et visent à: (i) contribuer à une meilleure compréhension des processus à l'échelle atomique qui contrôlent l'évolution morphologique des films; (ii) élucider les processus dynamiques qui régissent la génération et l'évolution des contraintes en cours de croissance; et (iii) développer des méthodologies pour manipuler et contrôler la morphologie des films à l'échelle nanométrique. L’originalité de l’approche mise en œuvre consiste à suivre la croissance des films in situ et en temps réel par couplage de plusieurs diagnostics, complété par des analyses microstructurales ex situ. Les grandeurs mesurées sont confrontées à des modèles optiques et des simulations atomistiques. La première partie est consacrée à une étude de comportement d’échelonnement des épaisseurs de transition morphologiques caractéristiques, à savoir la percolation et la continuité du film, lors de la croissance de films polycristallins d'Ag et de Cu sur carbone amorphe (a-C). Ces grandeurs sont examinées de façon systématique en fonction de la vitesse de dépôt et de la température du substrat, et interprétées dans le cadre de la théorie de la croissance de gouttelettes suivant un modèle cinétique décrivant la coalescence d’îlots, à partir duquel les coefficients de diffusion des espèces métalliques sont estimés. En confrontant les données expérimentales à des simulations par dynamique moléculaire ab initio, la diffusion de clusters multiatomiques est identifiée comme l’étape limitante le processus de croissance. Dans la seconde partie, l’incorporation, et l’impact sur la morphologie, d’espèces métalliques ou gazeuses minoritaires (Cu, N2, O2) lors de la croissance de film Ag sur SiO2 est étudié. A partir de mesures ellipsométriques in situ, on constate que l'addition d'espèces minoritaires favorise une morphologie 2D, entravant le taux d'achèvement de la coalescence, mais donne également une résistivité accrue de la couche continue. Par conséquent, une stratégie de manipulation de la croissance est proposée dans laquelle des espèces minoritaires sont déployées avec une grande précision temporelle pour cibler sélectivement des stades de croissance de film spécifiques et obtenir une morphologie 2D, tout en conservant les propriétés optoélectroniques des films d’Ag pur. Dans la troisième partie, l'évolution des contraintes résiduelles lors de la croissance des films d'Ag et de Cu sur a-C et leur dépendance à la cinétique de croissance est systématiquement étudiée. On observe une tendance générale vers des amplitudes de contrainte de compression plus faibles avec une augmentation de la température/vitesse de dépôt, liée à l'augmentation de la taille des grains/à la diminution de la longueur de diffusion des adatomes. Également, l’ajout dans le plasma de N2 sur le type et l'amplitude des contraintes dans les films d'Ag est étudié. L'ajout de quelques pourcents de N2 en phase gaz donne lieu à un renversement de la contrainte de compression et une évolution en tension au-delà de la continuité du film. Cet effet est attribué à une croissance anormale des grains géants et le développement de rugosité de surface. L’ensemble des résultats obtenus dans cette thèse fournissent les bases pour: (i) déterminer les coefficients de diffusion sur une large gamme de systèmes films/SFI; (ii) concevoir des stratégies non invasives pour les contacts multifonctionnels dans les dispositifs optoélectroniques; (iii) apporter des éléments de compréhension à l’origine du développement de contrainte, qui permettent de prédire et contrôler le niveau de contrainte intrinsèque à la croissance de films minces polycristallins.

Current Technical Papers

Current Technical Papers PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 500

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Methods for Film Synthesis and Coating Procedures

Methods for Film Synthesis and Coating Procedures PDF Author: Laszlo Nanai
Publisher:
ISBN: 1789855667
Category :
Languages : en
Pages : 174

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Photoenergy and Thin Film Materials

Photoenergy and Thin Film Materials PDF Author: Xiao-Yu Yang
Publisher: John Wiley & Sons
ISBN: 1119580552
Category : Science
Languages : en
Pages : 762

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Book Description
This book provides the latest research & developments and future trends in photoenergy and thin film materials—two important areas that have the potential to spearhead the future of the industry. Photoenergy materials are expected to be a next generation class of materials to provide secure, safe, sustainable and affordable energy. Photoenergy devices are known to convert the sunlight into electricity. These types of devices are simple in design with a major advantage as they are stand-alone systems able to provide megawatts of power. They have been applied as a power source for solar home systems, remote buildings, water pumping, megawatt scale power plants, satellites, communications, and space vehicles. With such a list of enormous applications, the demand for photoenergy devices is growing every year. On the other hand, thin films coating, which can be defined as the barriers of surface science, the fields of materials science and applied physics are progressing as a unified discipline of scientific industry. A thin film can be termed as a very fine, or thin layer of material coated on a particular surface, that can be in the range of a nanometer in thickness to several micrometers in size. Thin films are applied in numerous areas ranging from protection purposes to electronic semiconductor devices. The 16 chapters in this volume, all written by subject matter experts, demonstrate the claim that both photoenergy and thin film materials have the potential to be the future of industry.

1965 Transactions of the Third International Vacuum Congress

1965 Transactions of the Third International Vacuum Congress PDF Author: H. Adam
Publisher: Elsevier
ISBN: 1483164896
Category : Technology & Engineering
Languages : en
Pages : 182

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Book Description
1965 Transactions of the Third International Vacuum Congress, Volume 1: Invited Papers is the first of two-volumes that review the state of knowledge in vacuum technology. The present volume comprises the opening address by Prof Auwárter and the twelve comprehensive main lectures. In keeping with the purpose of an international congress, the organizers took great pains to ensure that the choice of topics for the main lectures not only covered the scientific fundamentals as a whole, but also gave appropriate consideration to the technical applications. An analysis of the submitted topics shows that the strong points of research and development lie in the fields of ""Coating and Thin Layers"", ""Adsorption and Desorption,"" and ""Pressure Measurement and Leak Detection"". In the fields of application, ""Vacuum Metallurgy"" ranks highly. The papers published in the transactions originate from many European and overseas countries, proof that vacuum science is not only keenly pursued in all major industrial countries, but also that the new organizational form of the IUVSTA is capable of winning the services of all these countries for fruitful international cooperation in the vacuum field.