Silicon has been the mainstay of the microelectroncs industry for over four decades. There is no material which can match the balance it affords between cost-benefit, mass consumability, process versatility, and nano-scale electron device performance. It is, therefore, the logical (and perhaps inevitable) platform for the development of integrated opto-electronics - a technology that is being aggressively developed to meet the next generation of bandwidth demands that are already beginning to strain interconnect architectures all the way down to the intra-chip level. While silicon-based materials already provide a variety of passive optical functionalities, the success of a genuine silicon-based optoelectronics will depend upon the ability of engineers to overcome those limitations in the optical properties of bulk silicon that occur at critical junctions in device requirements (eg. modulator and laser). Such solutions must not render the device processing incompatible with CMOS, for then the "silicon advantage" is lost. Achieving reliable and efficient electroluminescence in silicon remains the most intractable of these problems to date. Reliability problems in recently developed light emitting devices operating near a wavelength of 1.54 f..Lm, based on the thermally induced formation of silicon nano-clusters in erbium-doped silicon rich silicon oxide thin films, has reinforced the need for a further understanding of the luminescence mechanisms in this material. Indeed, the efficient and stable sensitized photoluminescence from Er3+ ions (near the telecom wavelength), embedded in an oxide matrix, based on a quasi-resonant energy transfer from nanostructured silicon, has the potential to make possible compact waveguide amplifiers and thin film electroluminescence. This thesis represents a study into the luminescence mechanisms in erbium-doped silicon oxide (SiOx, x~2) thin films grown by electron cyclotron resonance plasma enhanced chemical vapour deposition. Importantly, the film growth relies on in-situ erbium doping through the cracking of a volatile organalanthanide Er(tmhd)3 source. Rutherford backscattering spectroscopy has been used to map the film composition space generated from an ECR-PECVD parameter subspace consisting of precursor gas flow rates and the erbium precursor temperature. The response of the film photoluminescence spectra in both visible and infrared bands consistenly reveals three classes of luminescence centres, whose relative ability to emit light is shown in this study to exhibit a considerable degree of variability through the control of the film composition, subsequent thermal anneal temperature, duration, and process ambient. These three classes consist of optically active Er3 + ions, silicon nano-clusters phase separated during thermal annealing, and oxide-based defects (which may additionally include organic chromophores). The latter two of these species show the ability to sensitize the Er3 + luminescence. In fact, sensitization by intrinsically luminescent defects is a rarely studied phenomenon, which seems to be an important phenomenon in the present films owing to a potentially unique Er incorporation complex. To further investigate the ability of the oxide defects in this regard, an optimally luminescent film has been subject to a damaging ion irradiation to induce a photoluminescence quenching. The subsequent recovery of this luminescence with stepwise isochronous annealing has been correlated with Doppler broadening positron annihilation spectroscopy measurements made with a slow positron beam. Irradiation to a sufficiently high fluence has demonstrated a unique ability to de-couple luminescent sensitizers and Er3+ ions, producing enhanced blue and violet emissions. / Thesis / Master of Science (MS)

The corrosion protection performance of epoxy-coated reinforcing steel (ECR) was evaluated in 18 concrete bridge decks in Virginia in 1997. The decks were 2 to 20 years old at the time of the investigation. The concrete bridge deck inspections included crack survey and cover depth determination in the right traffic lane. Maximum of 12 cores with the top reinforcement randomly located in the lowest 12th percentile cover depth and 3 cores with the truss bars were drilled from each bridge deck. The concrete core evaluation included visual examination and determination of carbonation depth, moisture content, absorption, percent saturation and chloride content at 13 mm depth. Rapid chloride permeability test was also performed for the surface and base concrete on samples obtained from cores containing truss bars. The ECR inspection consisted of visual examination and damage evaluation, coating thickness and adhesion determination. The condition of the steel underneath the epoxy coating was also evaluated. Adhesion loss of the epoxy coating to the steel surface was detected for 4 years old bridge decks. The epoxy coating had debonded from the reinforcing bar before the chloride arrival. Visible signs of a possibility of a corrosion process underneath the coating suggest that ECR will not provide any or little additional service life for concrete bridge decks in comparison to black steel. Other systems, which will provide longer protection with a higher degree of reliability against chloride induced corrosion of steel in concrete, should be considered. / Ph. D.

Les films à base de Si, C et N sont des matériaux multifonctionnels aux propriétés optiques, électroniques et mécaniques attractives pour des applications dans le domaine du photovoltaïque et de la microélectronique entre autres. Il existe une forte dépendance de ces propriétés par rapport à la structure. Ce travail de thèse a plusieurs objectifs. Le premier objectif est la mise au point d’un procédé de dépôt de films minces de SiCxNy:H dans un réacteur CVD assistée par plasma micro-ondes ECR avec les précurseurs organosiliciés héxaméthyldisilazane (HMDSN) et tétraméthylsilane (TMS). Le second objectif est la caractérisation des dépôts synthétisés dans ce nouveau réacteur et le développement d’outils de diagnostic afin d’étudier le dépôt en cours de croissance. Deux techniques de caractérisation in situ ont été développées. Un procédé d’extraction de la ligne de base interférentielle des spectres FT-IR permet la détermination des paramètres optiques dans l’infrarouge (indice de réfraction et épaisseur) du film sondé. Ce diagnostic est adapté aussi bien à une analyse post-dépôt qu’au contrôle de procédé in situ en temps réel. De plus, la mise au point de la technique de réflectométrie a permis le suivi et le contrôle des dépôts lors de leur croissance dans le domaine visible. L’influence de la température de dépôt, du flux de précurseur et de la puissance injectée dans le plasma ainsi que le vieillissement des films à l’air ont été étudiés dans un premier temps. Ces études ont permis l’établissement des paramètres de dépôts optimaux et la détermination des conditions menant aux dépôts les plus denses avec la meilleure résistance à l’oxydation. Dans un second temps, l’étude de l’influence du taux d’azote dans le mélange gazeux a permis la synthèse de films avec une composition variée allant d’un type SiC:H à un type SiN:H et ainsi d’obtenir une large gamme d’indices de réfraction. Enfin, l’utilisation d’un procédé de dépôt hybride couplant le plasma ECR micro-ondes dans un mélange gazeux contenant TMS à la pulvérisation d’une cible de Si, a mené à la synthèse de films plus riches en silicium améliorant la densité de liaisons Si-C et entraînant la hausse de l’indice de réfraction des films / Si, C and N based thin films are multifunctional materials with optical, electronical and mechanical properties showing great potential for photovoltaic and microelectronic applications and more. Those properties exhibit a strong dependency upon the structure of the thin film. Several goals were set for this thesis work: the development of a ECR microwave plasma assisted CVD deposition reactor using organosilicon precursors (hexamethyldisilazane or HMDSN and tetramethylsilane or TMS), the characterization of SiCN thin films deposited in this reactor, and the development of diagnosis tools suited for the analysis of the growing film. Two in situ characterization techniques have been developed. The interferential baseline extraction from FT-IR spectra enables the determination of thin film optical parameters (refractive index and thickness) in the infrared range. This diagnosis is applied as well with post-deposition analysis as with real time in situ control of the deposition process. Moreover, the development of a reflectometry diagnosis has allowed to monitor and control the deposition process in the visible range. Influence of substrate temperature, precursor flow and plasma power as well as thin film ageing has been studied. Those analyses have enabled the derivation of optimal deposition conditions leading to denser films with better oxidation resistance. Then, the variation of nitrogen concentration in the gaseous mixture has led to the synthesis of a wide variety of thin film compositions ranging from SiC to SiN like thin films with a large range of refractive index. Finally, using an innovative hybrid system coupling an ECR microwave plasma with the pulverization of a Si target, Si-richer thin films have been synthesized allowing for denser thin films with higher refractive indices owing to an increase in Si-C bonding.

The broad theme of the present research investigation is Ion Assisted Deposition of thin films and its effect on the properties of thin films. Though this activity has been of interest to researchers for more than a decade, the development of different types of ion sources with control over the ion flux and energy, makes it a current topic of interest. Ion assisted deposition was successful in depositing thin films of many material with desired qualities, however, there are certain class of materials whose deposition has been rather difficult. This has mainly been attributed to higher energies and low ion flux of conventional ion sources. The advent of ECR ion sources for thin film deposition has given impetus to the deposition of such materials. This is due to the low energy high-density plasma generated in this type of sources. Hitherto, these sources were widely used in PECVD techniques and only recently the importance of ECR sources in PVD techniques has been realized. This thesis is on the development of ECR plasma source for ion assisted deposition of thin films using PVD techniques. This thesis is organized into six chapters. The first chapter gives an introduction on the ion assisted growth of thin films and the importance of ECR plasma. A detailed discussion on various aspects of ECR sources has been included. The design details on the development of ECR source have been discussed in the second chapter. The performance of ECR source as analyzed by the Langmuir probe are also discussed. Variation of plasma parameters like ion density, electron temperature, plasma potential and floating potential as a function of pressure and microwave power have been studied using Langmuir probe analysis. An ion density of the order of 1011/cm3 was measured at a distance of 8 cm from the plasma source with a microwave power of 400 watts. This was comparable to the ion density reported in downstream plasma of ECR sources. The behavior of plasma parameters with variation in microwave power and pressure was explained on the basis of microwave transmission above critical ion density and the microwave power absorption. The uniformity of the plasma parameters at the substrate position (29 cm from the ECR source) was found to be ± 2% over a diameter of 12 cm, which makes the ion source suitable for ion assisted deposition. The third chapter deals with the simulation and experimental study of the ECR sputtering process. ECR sputter type sources are equipped with cylindrical targets. The sputtered flux distribution on the substrate depends on target geometry, sputtering pressure and target-substrate distance. The effect of cylindrical geometry on the distribution of sputtered flux has been simulated by Monte Carlo methods. It is found that the sputtered flux distribution at different pressures and target-substrate distances in ECR sputter type source differs from the conventional glow discharge sputtering system equipped with planar targets. The simulated results are compared with the experimental results. The simulated data agree very well with the experimental data. The deposition and characterization of the TiN thin films for diffusion barrier applications in copper metallization have been discussed in the fourth chapter. Titanium nitride films are prepared by ECR sputtering. The effect of high density ion bombardment on the morphology, orientation and resistivity of the films was studied. It was observed that films with atomic smoothness could be prepared by ECR sputtering. Also the high density ion bombardment has been found to be effective for the film growth in (100) orientation. The behavior of TiN films deposited by this method as a diffusion barrier in copper metallization has been investigated. The resistivity measurements and RBS depth profile studies showed that up to 700°C there is no diffusion of copper into silicon. This shows that ECR sputtered TiN can be used as an effective diffusion barrier in copper metallization. The fifth chapter contains investigations on the ECR assisted growth of silicon nitride films. The films are characterized for composition, morphology and chemical bonding using AES, RBS, AFM, XPS and FTIR. AFM studies revealed that ion bombardment results in the reduction of surface roughness, which indicates dense film growth. The effect of ion assistance on the optical and electrical properties is studied in detail. Films prepared with microwave power ranging from 100 to 200 watts are having bandgap and refractive index of 4.9 eV and 1.92 respectively. Interface state density of silicon nitride films prepared in the above mentioned range was found to be 5x10 10 eVcm2. These films exhibited a resistivity of 10 13 Ω, cm and critical field of 4 MV/cm. The electrical conductivity in these films has been explained on the basis of Poole and Frenkel conduction. The low value of interface state density, higher resistivity, and critical field show that good quality SiN4 films can be deposited with low energy high density ECR plasma. A detailed summary of this research investigation has been discussed in the last chapter. The thesis is concluded with a discussion on the need of focused ECR source to establish ECR assisted deposition as a versatile technique for the growth of thin films.

Zugl.: Göttingen, Univ., Diss., 2009

No description available.

This thesis explores the influence of mother's mental disorder, specifically schizophrenia, on child's attachment in adulthood. In the theoretic part, basic terms of attachment theory are introduced. I describe selected methods of attachment assessment and the associated attachment types or states of mind with respect to attachment. Further on, key information on schizophrenia is presented with an emphasis on impact of schizophrenia on mother - child relationship. The following empiric part explores the form and type of attachment of children with mothers who suffer from schizophrenia and its evolution in time. I was also interested in different strategies the children employ to cope with their mother's illness. Adult Attachment Interview (AAI) is the primary method used in the research, complemented by Experiences in Close Relationships Scale (ECR) and Thematic Apperception Test (TAT). The research results show that attachment of children with schizophrenic mothers tend to be anxious, specifically anxious-avoidant and disoriented-disorganized, more often than in the general population. Mother's illness thus has negative effects on child's attachment.

Syftet med denna uppsats är att beskriva vilka strategier översättaren Carl G. Martinsson använt sig av vid översättningen av kulturspecifika fenomen (Extralinguistic Cultural References, ECR) från persiska till svenska i novellsamlingen Getingboet och nitton andra noveller från Iran (Martinsson, 1983), samt redogöra för huruvida Martinssons översättningar varit källspråksorienterade eller målspråksorienterade. Klassificeringen av översättningsstrategier har baserats på Jan Pedersens modell (2007). Analysen visar att strategierna bevarande och generalisering använts i en majoritet av fallen, och att de kulturspecifika fenomenen varken översatts särskilt källspråks- eller målspråksorienterat. / The aim of this thesis is to describe the strategies used by the translator Carl G. Martinsson when translating Extralinguistic Cultural References (ECRs) from Persian to Swedish in the short story collection Getingboet och nitton andra noveller från Iran (Martinsson, 1983), as well as to present whether Martinsson’s translations are source language oriented or target language oriented. The classification of the translation strategies is based on Jan Pedersen’s model (2007). The analysis shows that the strategies retention and generalization were employed for a majority of the cases, and that the translation of the ECRs was neither source language oriented nor target language oriented.

La première partie de la thèse est consacrée à la caractérisation de la source d'ions ECR SIMPA, nous avons d'abord exploré les performances de la source d'ions, en terme des courants extraits pour trois éléments, que sont l'argon, le krypton et le néon. En analysant les spectres Bremsstrahlung, nous avons déterminé la température électronique dans la plasma ainsi que la densité électronique et la densité ionique au sein du plasma. Dans un deuxième temps, nous avons enregistré des spectres haute résolution du plasma d'argon et du plasma de krypton. En prenant en compte les principaux mécanismes de production d'une lacune en couche K des ions dans le plasma, nous avons pu déterminer la densité ionique des états de charges élevés de l'argon. Enfin, nous avons mis en évidence, une corrélation entre la densité des états de charges avec les intensités de courants extraits.<br /><br />La seconde partie de la thèse est consacrée à la collision des ions Ne9+ avec des agrégats d'argon. Dans un premier temps, nous avons présenté des modèles théoriques simples mais efficaces dans l'interprétation des phénomènes survenant au cours de la collision, du point de vue du projectile, nous avons effectué une application théorique simple pour une collision d'un ion Ne9+ avec un agrégat d'argon d'une certaine taille, dans le but de connaître les niveaux énergétiques peuplés lors de la capture électronique et de suivre l'évolution du nombre d'électrons dans chaque couche du projectile. Enfin, nous avons présenté les premiers résultats de collision entre un faisceau d'ion Ne9+ et des agrégats d'argon. Ces résultats, nous ont permis de mettre en évidence par les photons X emis lors de la collision ions-agrégats, un fort taux d'agrégation des atomes, ainsi que la multi-capture électronique faite par les projectiles.

Bibliographische Beschreibung und Referat Dani, Ines "ECR-Plasmadiagnostik im System Ar-H2-N2-TMS und Charakterisierung der entstehenden SiCxNy:H-Schichten" Technische Universität Chemnitz, Institut für Physik, Dissertation, 2002 (102 Seiten, 62 Abbildungen, 17 Tabellen, 74 Literaturstellen) In den letzten Jahren wurde im Rahmen der Entwicklung neuartiger Hartstoffschichten verstärkt das System Si-C-N untersucht. Das am häufigsten zur Herstellung genutzte Verfahren ist die chemische Gasphasenabscheidung (CVD). Plasmagestützte CVD-Verfahren bieten die Möglichkeit, auch bei geringen Substrattemperaturen Schichten mit guten mechanischen Eigenschaften herzustellen. Der Abscheideprozess ist jedoch sehr komplex und bis heute nicht vollständig verstanden. Eine Optimierung erfolgt daher meist nach dem trial-and-error-Prinzip, was aber durch die Vielzahl an frei wählbaren Parametern sehr zeitaufwendig ist. Der Zusammenhang zwischen äußeren, regelbaren Parametern und inneren Entladungsparametern ist die Grundlage für ein besseres Verständnis der Plasmachemie und der Schichtwachstumsprozesse in einem molekularem Nichtgleichgewichtsplasma. Da beschichtende Plasmen besonders hohe Anforderungen an die verwendeten Diagnostikverfahren stellen, ist es in den meisten Fällen nicht möglich, die primär für die Schichtbildung interessanten Teilchen zu beobachten. Nur aus der Kombination sich ergänzender Verfahren können elementare Prozesse der Schichtbildung bestimmt werden. Aus ihrer Kenntnis ergibt sich die Möglichkeit einer gezielten Beeinflussung von Schichteigenschaften auf der Basis physikalisch relevanter Größen. In dieser Arbeit wird die Herstellung von amorphen SiCxNy:H-Schichten mit einem ECR-plasmagestützten CVD-Verfahren untersucht. Als Precursor wird dabei Tetramethylsilan (TMS) genutzt. Das vorrangig zur Bestimmung von Teilchenzahldichten eingesetzte Verfahren ist die optische Emissionsspektroskopie. Eine Weiterentwicklung der Aktinometrie ermöglicht die Bestimmung absoluter Teilchenzahldichten unter Beschichtungsbedingungen. Unter Zugrundelegung des Korona-Modells und der Nutzung publizierter Ratenkoeffizienten werden die Grundzustandsdichten von atomarem Wasserstoff, CH und Silicium berechnet. Die Überprüfung der Methode anhand von Argon zeigt eine ausgezeichnete Übereinstimmung zwischen den optisch bestimmten und den gaskinetisch berechneten Teilchenzahldichten. Die Verfälschung der berechneten Teilchenzahldichten durch dissoziative Anregung von H durch H2 ist in einem Plasma mit H2-Zugabe nicht zu vernachlässigen. Dagegen ist der Einfluss dissoziativer Anregung aus TMS auf H, CH und Si sehr gering. Die Teilchenzahldichten von Si und CH sind bei konstantem TMS-Fluss von der Elektronendichte abhängig, bei steigendem TMS-Fluss kommt es in Abhängigkeit von der jeweiligen Elektronendichte zu einer Sättigung. Die Teilchenzahldichte von atomarem Wasserstoff steigt linear mit dem TMS-Fluss. Eine Abscheidung mit hoher Rate ist nur durch Si-haltige Precursorfragmente mit kleinen Massenzahlen möglich. Als Maß für die Entstehung dieser Fragmente können die Teilchenzahldichten von Si bzw. CH genutzt werden.