Dans le but d’intégrer des technologies CMOS avec des cellules mémoires, une seule étape de siliciuration de tous les contacts permettrait de diminuer les couts et de faciliter l’intégration. La formation de siliciure simultanément au niveau des sources, drains et grilles avec du NiPt(10 at.%) est nécessaire pour la technologie FD-SOI parce que cette dernière induit des spécifications exigeantes en ce qui concerne la siliciuration. En effet, le siliciure formé avec le procédé Salicide se doit d’être très fin et stable pour contenir le phénomène de diffusion anormale du Ni qui pourrait être à l’origine de fuites de la jonction. De plus, la réduction des dimensions des cellules mémoires nécessite l’incorporation de dopants d’une manière alternative à l’implantation ionique. L’introduction de dopage au phosphore de manière in-situ pendant le dépôt de silicium nécessite la compréhension de l’interaction du siliciure et des dopants. Dans cette étude, différents types de dopage sont étudiés dans des substrats mono et poly-cristallins afin de correspondre aux multiples types de silicium qui sont présents dans les technologies et qui nécessitent une siliciuration. La redistribution du phosphore entraînée par la formation du siliciure est étudiée et discutée à l’aide de caractérisations par sonde atomique tomographique et spectrométrie de masse à ionisation secondaire à temps de vol. De plus, la réaction à l’état solide est étudiée à l’aide de diffraction par rayons-X afin de comprendre l’impact des dopants sur la séquence de phases. Finalement, la redistribution des dopants observée expérimentalement est étayée par des simulations basées sur un modèle par éléments finis / For the purpose of co-integrating the CMOS technology with memory cells, a unique step of silicidation of all the contacts would decrease costs and ease the integration. The simultaneous silicide formation on the source, drain and gate contacts with NiPt(10 at.%) is required for the FD-SOI technology because the latter induces challenging specifications for the silicidation. As a matter of fact, the silicide formed with the Salicide process must be very thin and stable to contain the NiSi piping phenomenon that could lead to junction leakage. Meanwhile, new integration roads and the reduction of the dimensions of the memory cells arise the need of other ways of dopant incorporation as a substitute to ionic implantation. The introduction of phosphorus by in-situ doping during the deposition of silicon requires the understanding of the interaction of silicide and dopants with this configuration. In this study the metallization of phosphorus doped Si is presented. Different doping types are investigated with mono and poly-crystalline substrates in order to match the various silicon layers needing a silicidation and present in the technologies. The phosphorus redistribution occurring during silicide formation is studied and discussed thanks to Atom Probe Tomography and Time-of-Flight Secondary Ion Mass Spectrometry analyses. Moreover, the solid-state reaction is studied thanks to X-Ray diffraction to understand the dopants’ impact on the phase sequence. Finally, the dopant redistribution is analyzed thanks to modeling

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The phenomenon of dopant diffusion as a viable means of coupler fabrication is investigated. It is well known that the diffusion of dopants can improve the uniformity of multimode star couplers manufactured by the fused biconical taper technique. The theoretical basis for the same phenomenon in a single mode coupler is developed, on the basis of the theory of diffusion and the Gaussian approximation for circular fibers. A novel technique to manufacture and design single mode optical fiber couplers with a minimization of the manufacturing complexity is demonstrated. Traditionally fused biconical tapered couplers have been manufactured by twisting, fusing and elongating optical fibers at elevated temperatures. Usually, high temperature oxy-hydrogen flames are used for such purposes and some degree of skill is needed for a human operator. The complexity of control procedures for automation of the process is greatly increased by the fact that the tapering process is an integral part of the feedback loop. This can be eliminated if a constant tension is maintained on the fibers in the heating process while heat is applied uniformly from a source such as a platinum wire furnace. Since the refractive index differentials responsible for the guiding phenomenon at optical frequencies are directly dependent on concentration of dopants like fluorine and germania, radial diffusion of such dopants causes the fiber cores that are heated in a platinum wire furnace to come closer together. Such proximity leads to the phenomenon of evanescent field interaction or coupling of optical power from one arm of the coupler to the other. The time evolution of the coupling process can be predicted in theory. While initial results are promising, the ability to automate the manufacture of couplers will be successful only after greater control over the variables is established. It is the intention of this work to understand the physics behind the mechanism as well as to prove the feasibility of modeling real world phenomena under controlled conditions. / Master of Science

La conductivité électronique de l'éméraldine sel dépend des conditions de sa synthèse (solvant et dopant utilisés) et de son traitement après synthèse. L'objectif principal de cette thèse est de démontrer et d'interpréter les corrélations entre l'environnement et les propriétés de la forme conductrice de la polyaniline. Dans la partie théorique, nous avons examiné l'influence des différents dopants et solvants sur la structure et les propriétés de la polyaniline. Pour atteindre cet objectif, un large dispositif de méthodes de chimie quantique a été testé et une méthode appropriée a été choisie. Dans la partie expérimentale nous avons utilisé une nouvelle approche pour accéder aux propriétés intrinsèques de la polyaniline i.e. sans utiliser ni solvants ni dopants autres que ceux utilisés lors de la synthèse. Les calculs montrent que la description théorique de la polyaniline dépend fortement du choix de la méthode. La modélisation de l'effet de la polarité du solvant grâce à l'utilisation de la méthode PMC semble être cruciale pour une description fiable de l'interaction polyaniline-dopant. Les résultats obtenus démontrent pour la première fois que les interactions, de la polyaniline avec les dopants dépendent de la nature chimique du solvant et pas du dopant lui-même. De plus, nous avons montré que la stabilité de la forme polaronique (conductrice) augmente avec l'augmentation de la polarité du solvant. Ces conclusions correspondent parfaitement à nos résultats expérimentaux qui montrent le rôle crucial du solvant (et pas des dopants) sur les propriétés de la polyaniline.

Hafnium and Zirconium based gate dielectrics are considered potential candidates to replace SiO2 or SiON as the gate dielectric in CMOS processing. Furthermore, the addition of nitrogen into this pseudo-binary alloy has been shown to improve their thermal stability, electrical properties, and reduce dopant penetration. Because CMOS processing requires high temperature anneals (up to 1050 °C), it is important to understand the diffusion properties of any metal associated with the gate dielectric in silicon at these temperatures. In addition, dopant penetration from the doped polysilicon gate into the Si channel at these temperatures must also be studied. Impurity outdiffusion (Hf, Zr) from the dielectric, or dopant (B, As, P) penetration through the dielectric into the channel region would likely result in deleterious effects upon the carrier mobility. In this dissertation extensive thermal stability studies of alternate gate dielectric candidates ZrSixOy and HfSixOy are presented. Dopant penetration studies from doped-polysilicon through HfSixOy and HfSixOyNz are also presented. Rutherford backscattering spectroscopy (RBS), heavy ion RBS (HI-RBS), x-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HR-TEM), and time of flight and dynamic secondary ion mass spectroscopy (ToF-SIMS, D-SIMS) methods were used to characterize these materials. The dopant diffusivity is calculated by modeling of the dopant profiles in the Si substrate. In this disseration is reported that Hf silicate films are more stable than Zr silicate films, from the metal interdiffusion point of view. On the other hand, dopant (B, As, and P) penetration is observed for HfSixOy films. However, the addition of nitrogen to the Hf - Si - O systems improves the dopant penetration properties of the resulting HfSixOyNz films.

La conductivité électronique de l'éméraldine sel dépend des conditions de sa synthèse (solvant et dopant utilisés) et de son traitement après synthèse. L'objectif principal de cette thèse est de démontrer et d'interpréter les corrélations entre l'environnement et les propriétés de la forme conductrice de la polyaniline. Dans la partie théorique, nous avons examiné l'influence des différents dopants et solvants sur la structure et les propriétés de la polyaniline. Pour atteindre cet objectif, un large dispositif de méthodes de chimie quantique a été testé et une méthode appropriée a été choisie. Dans la partie expérimentale nous avons utilisé une nouvelle approche pour accéder aux propriétés intrinsèques de la polyaniline i.e. sans utiliser ni solvants ni dopants autres que ceux utilisés lors de la synthèse. Les calculs montrent que la description théorique de la polyaniline dépend fortement du choix de la méthode. La modélisation de l'effet de la polarité du solvant grâce à l'utilisation de la méthode PMC semble être cruciale pour une description fiable de l'interaction polyaniline-dopant. Les résultats obtenus démontrent pour la première fois que les interactions, de la polyaniline avec les dopants dépendent de la nature chimique du solvant et pas du dopant lui-même. De plus, nous avons montré que la stabilité de la forme polaronique (conductrice) augmente avec l'augmentation de la polarité du solvant. Ces conclusions correspondent parfaitement à nos résultats expérimentaux qui montrent le rôle crucial du solvant (et pas des dopants) sur les propriétés de la polyaniline. / The electric conductivity of the emeraldine salt depends on the conditions of its synthesis (solvents and dopants) and post-synthetic treatment. The main objective of the present thesis is to demonstrate and interpret the correlations between the environment and the properties of the conductive form of polyaniline. In order to achieve this goal a new theoretical approach is developed with reference to the experimental data. In the theoretical section, we examine the influence of different dopants and solvents on the structure and properties of polyaniline. To achieve this, a variety of quantum chemistry methods is tested and a proper method is chosen. In the experimental part we use a new method for tuning of the intrinsic polyaniline properties without using solvents or dopants other than those employed in the synthesis. The calculations show that the theoretical description of polyaniline depends strongly on the choice of the method. Modeling the effect of solvent polarity (in this case by the PCM method) seems to be crucial for the reliable description of the interaction polianiline-dopant. The obtained results demonstrate for the first time that interaction of polyaniline with dopants depends on the chemical nature of the solvent and not on the dopant itself. In addition, the stability of the polaronic form (conducting) grows with the increase of solvent polarity. These findings correspond well to our experimental results that show the crucial role of the solvent (and not of the dopants) for the properties of polyaniline.

abstract: CMOS technology is expected to enter the 10nm regime for future integrated circuits (IC). Such aggressive scaling leads to vastly increased variability, posing a grand challenge to robust IC design. Variations in CMOS are often divided into two types: intrinsic variations and process-induced variations. Intrinsic variations are limited by fundamental physics. They are inherent to CMOS structure, considered as one of the ultimate barriers to the continual scaling of CMOS devices. In this work the three primary intrinsic variations sources are studied, including random dopant fluctuation (RDF), line-edge roughness (LER) and oxide thickness fluctuation (OTF). The research is focused on the modeling and simulation of those variations and their scaling trends. Besides the three variations, a time dependent variation source, Random Telegraph Noise (RTN) is also studied. Different from the other three variations, RTN does not contribute much to the total variation amount, but aggregate the worst case of Vth variations in CMOS. In this work a TCAD based simulation study on RTN is presented, and a new SPICE based simulation method for RTN is proposed for time domain circuit analysis. Process-induced variations arise from the imperfection in silicon fabrication, and vary from foundries to foundries. In this work the layout dependent Vth shift due to Rapid-Thermal Annealing (RTA) are investigated. In this work, we develop joint thermal/TCAD simulation and compact modeling tools to analyze performance variability under various layout pattern densities and RTA conditions. Moreover, we propose a suite of compact models that bridge the underlying RTA process with device parameter change for efficient design optimization. / Dissertation/Thesis / Ph.D. Electrical Engineering 2011

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16396号 / 工博第3477号 / 新制||工||1525(附属図書館) / 29027 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 乾 晴行, 准教授 宇田 哲也 / 学位規則第4条第1項該当

One of two project reports: The other part is designated PART B: OFF-CAMPUS PROJECT. / <p> Ion implantation is investigated as a technique to fabricate solar cells on monocrystalline silicon. The electrical properties of the implanted layer, as determined using the Hall Effect, and solar cell performance have beep studied for varying implant species (As and P), implanted dopant concentration (10^18 - 10^21 cm^-3), implanted substrate temperature (55° to 300°K} and annealing temperature (700° to 900°C). Some progress has been made toward the optimization of the various parameters. </p> / Thesis / Master of Engineering (MEngr)