Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Influence of Deposition Time on Bonding and Morphology of Amorphous Carbon Nitride Thin Films
Author: Influence of Deposition Parameters on Morphology, Growth and Structure of Crystalline and Amorphous Organic Thin Films
Author: Phenwisa NiyamakomTetrahedrally Bonded Amorphous Carbon Films I
Author: Bernd SchultrichPublisher: Springer
ISBN: 3662559277
Category : Technology & Engineering
Languages : en
Pages : 769
Book Description
This book presents the status quo of the structure, preparation, properties and applications of tetrahedrally bonded amorphous carbon (ta-C) films and compares them with related film systems. Tetrahedrally bonded amorphous carbon films (ta-C) combine some of the outstanding properties of diamond with the versatility of amorphous materials. The book compares experimental results with the predictions of theoretical analyses, condensing them to practicable rules. It is strictly application oriented, emphasizing the exceptional potential of ta-C for tribological coatings of tools and components.
Deposition of Carbon Nitrides Using Pulsed Laser Ablation and Microwave-assisted Chemical Vapor Deposition Techniques
Author: Jacob Anthony HernandezPublisher:
ISBN:
Category :
Languages : en
Pages : 146
Book Description
Properties and Characterization of Amorphous Carbon Films
Author: John J. PouchPublisher: Trans Tech Publications
ISBN:
Category : Amorphous substances
Languages : en
Pages : 720
Book Description
Amorphous, hydrogenated carbon (AHC) films can be deposited on various substrates using several techniques, e.g. plasma deposition and ion beam deposition. The resulting films can be hard, wear resistant and transparent.
Amorphous Carbon: State Of The Art - Proceedings Of The 1st International Specialist Meeting On Amorphous Carbon (Smac '97)
Author: S R P SilvaPublisher: World Scientific
ISBN: 9814544973
Category :
Languages : en
Pages : 374
Book Description
Diamond-like carbon is amorphous carbon with a high degree of sp3 bonding, and is widely used for hard coatings and field emission cathodes. This book contains reviews by leading workers in the field, covering the topics of deposition methods, deposition mechanisms, atomic structure, surface atomic structure, electronic structure calculations, Raman, doping, luminescence, electron field emission, mechanical properties and tribology.
Composition and Bonding in Amorphous Carbon Films Grown by Ion Beam Assisted Deposition
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Amorphous carbon films have been grown by evaporation of graphite with concurrent Ar+ ions bombardment assistance. The ion energy has been varied between 0-800 V while keeping a constant ion to carbon atom arrival ratio. Film composition and density were determined by ion scattering techniques (RBS and ERDA), indicating a negligible hydrogen content and a density dependence with the assistance voltage. The bonding structure of the films has been studied by Raman and X-ray Absorption Near-Edge (XANES) spectroscopy. Different qualitative effects have been found depending on the ion energy range. For ion energies below 300 eV, there is a densification of the carbon layer due to the increase in the sp3 content. For ion energies above 300 eV sputtering phenomena dominate over densification, and thinner films are found with increasing assistance voltage until no film is grown over 600 V. The films with the highest SP3 content are grown with intermediate energies between 200-300 V.
Thin metal films on weakly-interacting substrates
Author: Andreas JamnigPublisher: Linköping University Electronic Press
ISBN: 9179298206
Category :
Languages : en
Pages : 108
Book Description
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.
Sputter Deposition Synthesis and Characterization of Thin Films
Author: Dujiang WanProperties of Carbon Nitride Films Deposited With and Without Electron Cyclotron Resonance Plasma Assistance
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Research on carbon nitride has received considerable attention since BETA-C3N4 offers high technological potential for protective, wear, and optical applications. Deposition of carbon nitride by various techniques has mostly resulted in nitrogen deficient amorphous CNx; films. In this research, reactive magnetron sputtering with and without the assistance of an electron cyclotron resonance (ECR) source was used to deposit CNx thin films at ambient temperature. The process variables include power level, nitrogen partial pressure, and substrate bias. X-ray photoelectron spectroscopy and Auger analysis were used to determine the composition and chemical bonding of the films. Ball-on-disc experiments were performed between 440C stainless steel balls and CNx -coated 440C substrates at 0.1 m/s sliding velocity and 1 N load. The effects of process variables and interface modification on friction and wear rate were examined. Mechanical properties including hardness, modulus, and elastic response were obtained form nanoindentation. CNx films with hardness in the range of 12-16 GPa demonstrated better wear performance than the hardest diamond-like carbon (24 GPa) deposited by the same technique. ECR assisted magnetron sputtering provided films with the lowest wear rates.