Block copolymers are an ideal solution for a wide variety of nanolithographic opportunities due to their tendency to self-assemble on nanoscopic length scales. High etch selectivity and thin-film orientation are crucial to the success of this technology. Most conventional block copolymers have poor etch selectivity; however, incorporating silicon into one block produces the desired etch selectivity. A positive side effect of the silicon addition is that the χ value (a block-to-block interaction parameter) of the block copolymer increases. This decreases the critical dimension of potential features. Unfortunately, one negative side effect is the increase in the surface energy difference between the blocks. Incorporating silicon decreases the surface energy of that block. Typically, annealing is used to induce the chain mobility that is required for the block copolymer to reach its minimum thermodynamic energy state. Thermal annealing is the easiest annealing technique; however, if the glass transition temperature (Tg) of one block is above the thermal decomposition temperature of the other block, the latter will degrade before the former can reorient. In addition, annealing silicon-containing block copolymers usually results in a wetting layer and parallel orientation since the lower surface energy block favors the air interface, minimizing the free energy. Solvent annealing replaces the air interface with a solvent, thereby changing the surface energy. The solvent plasticizes the block copolymer, effectively decreasing the Tgs of both blocks. Another benefit is the ability to reversibly alter the orientation by changing the solvent or solvent concentration. The challenge with solvent annealing is that it depends on a number of parameters including: solvent selection, annealing time, and vapor concentration, which generate a very large variable space that must be searched to find optimum screening conditions. / text

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There are three implemented algorithms in this work: lessons permutation, lessons permutation with simulated annealing adjustment, lessons permutation using Bayesian approach theory to optimize SA parameters algorithms. Algorithms and graphical user interface are programmed with JSP which is based on Java object programming language. To evaluate schedule goodness algorithms are computing every penalty points which are given for some inconvenieces. User is able to define how much penalty points will be given if some inconveniece is satisfied. Also he is able to assign stochastic algorithm parameters. There was accomplished theory, where was observed using of simulated annealing and Bayesian approch methods in other stochastic algorithms and their different combination. There is a description of profiled school schedule optimization algorithm, which is based on SA searching methodology: searching for the optima through lower quality solutions, using temperature function which convergence, difference in quality. Algorythm which is using BA was created in case to improve SA searching methodology. User by changing systems temperature or annealing speed througth parameters can make big influence to SA behaviour. Passing parameters then using algorithm with BA meaner influence is made to behaviour because this method prognosticates, acording to him, better parameters with which SA should work effectively and changing them. Researches with three stochastic algorithms were made... [to full text]

An optimal stochastic multi-crop irrigation scheduling algorithm was developed which was able to incorporate complex farm system models, and constraints on daily and seasonal water use, with the objective of maximising farm profit. This scheduling method included a complex farm simulation model in the objective function, used decision variables to describe general management decisions, and used a custom heuristic method for optimisation. Existing optimal schedulers generally use stochastic dynamic programming which relies on time independence of all parameters except state variables, thereby requiring over-simplistic crop models. An alternative scheduling method was therefore proposed which allows for the inclusion of complex farm system models. Climate stochastic properties are modelled within the objective function through the simulation of several years of historical data. The decoupling of the optimiser from the objective function allows easy interchanging of farm model components. The custom heuristic method, definition of decision variables, and use of the Markov chain equation (relating an irrigation management strategy to mean water use) considerably increases optimisation efficiency. The custom heuristic method used simulated annealing with continuous variables. Two extensions to this method were the efficient incorporation of equality constraints and utilisation of population information. A case study comparison between the simulated annealing scheduler and scheduling using stochastic dynamic programming, using a simplistic crop model, showed that the two methods resulted in similar performance. This demonstrates the ability of the simulated annealing scheduler to produce close to optimal schedules. A second case study demonstrates the ability of the simulated annealing scheduler to incorporate complex farm system models by including the FarmWi$e model by CSIRO in the objective function. This case study indicates that under conditions of limited seasonal water, the simulated annealing scheduler increases pasture yield returns by an average of 10%, compared with scheduling irrigation using best management practice. Alternatively expressed, this corresponds to a 20-25% reduction in seasonal water use (given no change in yield return).

Many areas in which computational optimisation may be applied are multi-objective optimisation problems; those where multiple objectives must be minimised (for minimisation problems) or maximised (for maximisation problems). Where (as is usually the case) these are competing objectives, the optimisation involves the discovery of a set of solutions the quality of which cannot be distinguished without further preference information regarding the objectives. A large body of literature exists documenting the study and application of evolutionary algorithms to multi-objective optimisation, with particular focus being given to evolutionary strategy techniques which demonstrate the ability to converge to desired solutions rapidly on many problems. Simulated annealing is a single-objective optimisation technique which is provably convergent, making it a tempting technique for extension to multi-objective optimisation. Previous proposals for extending simulated annealing to the multi-objective case have mostly taken the form of a traditional single-objective simulated annealer optimising a composite (often summed) function of the objectives. The first part of this thesis deals with introducing an alternate method for multiobjective simulated annealing, dealing with the dominance relation which operates without assigning preference information to the objectives. Non-generic improvements to this algorithm are presented, providing methods for generating more desirable suggestions for new solutions. This new method is shown to exhibit rapid convergence to the desired set, dependent upon the properties of the problem, with empirical results on a range of popular test problems with comparison to the popular NSGA-II genetic algorithm and a leading multi-objective simulated annealer from the literature. The new algorithm is applied to the commercial optimisation of CDMA mobile telecommunication networks and is shown to perform well upon this problem. The second section of this thesis contains an investigation into the effects upon convergence of a range of optimiser properties. New algorithms are proposed with the properties desired to investigate. The relationship between evolutionary strategies and the simulated annealing techniques is illustrated, and explanation of the differing performance of the previously proposed algorithms across a standard test suite is given. The properties of problems on which simulated annealer approaches are desirable are investigated and new problems proposed to best provide comparisons between different simulated annealing techniques.

This Masters thesis investigates the effects of post growth rapid thermal annealing on colloidal CdTe nanoparticles. This novel process has not previously been applied to colloidal nanoparticles. It is found that rapid thermally annealing with temperatures up to 400°C, the number of defect bonds in the semiconductor core will decrease and the zincblende structural phase will prevail. These findings are identified using Raman spectroscopy enhanced in a liquid core waveguide and corroborated using a variety of other analysis techniques. What is also important is that while the semiconductor core is changing, the optical characteristics of the material remain nominally unchanged. Additionally, a circulatory peristaltic pump system that is suitable for future in situ monitoring was developed and used to investigate the length effects of Teflon capillary tubes as a liquid core waveguide for Raman spectroscopy.

This Masters thesis investigates the effects of post growth rapid thermal annealing on colloidal CdTe nanoparticles. This novel process has not previously been applied to colloidal nanoparticles. It is found that rapid thermally annealing with temperatures up to 400°C, the number of defect bonds in the semiconductor core will decrease and the zincblende structural phase will prevail. These findings are identified using Raman spectroscopy enhanced in a liquid core waveguide and corroborated using a variety of other analysis techniques. What is also important is that while the semiconductor core is changing, the optical characteristics of the material remain nominally unchanged. Additionally, a circulatory peristaltic pump system that is suitable for future in situ monitoring was developed and used to investigate the length effects of Teflon capillary tubes as a liquid core waveguide for Raman spectroscopy.

High energy particle irradiation inevitably generates defects in solids in the form of collision cascades. The ballistic formation and thermalization of cascades occur rapidly and are believed to be reasonably well understood. However, knowledge of the evolution of defects after damage cascade thermalization, referred to as dynamic annealing, is quite limited. Unraveling the mechanisms associated with dynamic annealing is crucial since such processes play an important role in the formation of stable post-irradiation disorder in ion-beam-processed semiconductors and determines the “radiation tolerance” of many nuclear materials. The purpose of this dissertation is to further our understanding of the processes involved in dynamic annealing. In order to achieve this, two main tasks are undertaken. First, the effects of dynamic annealing are investigated in ZnO, a technologically relevant material that exhibits very high dynamic defect annealing at room temperature. Such high dynamic annealing leads to unusual defect accumulation in heavy ion bombarded ZnO. Through this work, the puzzling features that were observed more than a decade ago in ion-channeling spectra have finally been explained. We show that the presence of a polar surface substantially alters damage accumulation. Non-polar surface terminations of ZnO are shown to exhibit enhanced dynamic annealing compared to polar surface terminated ZnO. Additionally, we demonstrate one method to reduce radiation damage in polar surface terminated ZnO by means of a surface modification. These results advance our efforts in the long-sought-after goal of understanding complex radiation damage processes in ceramics. Second, a pulsed-ion-beam method is developed and demonstrated in the case of Si as a prototypical non-metallic target. Such a method is shown to be a novel experimental technique for direct extraction of dynamic annealing parameters. The relaxation times and effective diffusion lengths of mobile defects during the dynamic annealing process play a vital role in damage accumulation. We demonstrate that these parameters dominate the formation of stable post-irradiation disorder. In Si, a defect lifetime of ∼ 6 ms and a characteristic defect diffusion length of ∼ 30 nm are measured. These results should nucleate future pulsed-beam studies of dynamic defect interaction processes in technologically relevant materials. In particular, understanding length- and time-scales of defect interactions are essential for extending laboratory findings to nuclear material lifetimes and to the time-scales of geological storage of nuclear waste.

Thermische Ausheilprozesse werden bei der Transistorformation im Wesentlichen eingesetzt, um die durch die Ionenimplantation entstandenen Kristallschäden auszuheilen und die eingebrachten Dotanden zu aktivieren. Besonders kritisch sind dabei die finalen Aktivierungsprozesse, bei denen die Source/Drain-Gebiete der Transistoren gebildet werden. Im Zuge der kontinuierlichen Skalierung der CMOSFET-Technologie ist es außerdem erforderlich, möglichst flache, abrupte Dotierungsprofile mit maximaler elektrischer Aktivierung zu erhalten, um die bei diesen Bauelementeabmessungen immer stärker auftretenden Kurzkanaleffekte zu unterdrücken und gleichzeitig eine höhere Leistungsfähigkeit der Transistoren zu gewährleisten. Zur maximalen Aktivierung bei minimaler Diffusion der eingebrachten Dotanden müssen dazu während der finalen Ausheilung extrem kurze Ausheilzeiten bei sehr hohen Temperaturen bewerkstelligt werden. Mit dem derzeitig angewandten Ausheilverfahren, der schnellen thermischen Ausheilung (RTA), bei der die minimale Ausheilzeit im Bereich von 1 s liegt, sind diese Vorgaben nicht mehr realisierbar. Nur durch den Einsatz von neuartigen thermischen Ausheilprozessen mit Ausheilzeiten im Millisekundenbereich können diese Forderungen erreicht werden. Das Thema der vorliegenden Arbeit ist die wissenschaftliche Untersuchung der neuartigen Ausheilprozesse und die experimentelle Realisierung von Integrationsmöglichkeiten in die planare Hochleistungs-SOI-CMOSFET-Technologie. Dazu wird zunächst die Notwendigkeit der Einführung der neuartigen Ausheilprozesse erläutert. Anschließend wird basierend auf experimentellen Untersuchungen der Einfluss der Kurzzeitausheilung auf die Diffusion und Aktivierung der Dotierstoffe für eine p- und n-Dotierung analysiert. Des Weiteren werden zwei unterschiedliche Technologien der Kurzzeitausheilung, die Blitzlampen- und Laser-Ausheilung, und deren Einfluss auf das Transistorverhalten sowohl auf Wafer- als auch auf Mikroprozessorebene untersucht. Der Schwerpunkt der vorliegenden Arbeit liegt auf der experimentellen Untersuchung zur Integration der Kurzzeitausheilung in den Herstellungsprozess von Hochleistungs-SOI-CMOSFETs. Zwei verschiedene Ansätze werden dabei näher betrachtet. Zum Einen wird der Einfluss der Kurzzeitausheilung als zusätzlicher Ausheilschritt im Anschluss an die herkömmliche RTA und zum Anderen als alleiniger Ausheilschritt ohne RTA untersucht. Die Ergebnisse der durchgeführten Experimente zeigen, dass durch die zusätzliche Kurzzeitausheilung nach Ansatz 1 ohne eine Veränderung des Herstellungsprozesses ein verbessertes Transistorverhalten erreicht werden kann. Demgegenüber ist die Integration der Kurzzeitausheilung nach Ansatz 2 nur durch eine Anpassung der Transistorarchitektur und eine Optimierung der Implantationsparameter für die Halo-, Source/Drain-Erweiterungs- und Source/Drain-Gebiete möglich. Ein Hauptaugenmerk bei der Herstellung diffusionsarmer p-MOSFETs nach Ansatz 2 liegt in der Implementierung von Si1-xGex-Source/Drain-Gebieten, um die Erhöhung der Leistungsfähigkeit durch diese Verspannungsquelle auch bei diesen Transistortypen zu gewährleisten. Die dazu durchgeführten experimentellen Untersuchungen zeigen, dass bei diffusionsarmen p-MOSFETs mit Si1-xGex in den Source/Drain-Gebieten des Transistors, die Wahl der richtigen Implantationsspezies von entscheidender Bedeutung ist. Abschließend erfolgt eine Gegenüberstellung der Ergebnisse von optimierten, diffusionsarmen n- und p-MOSFETs mit Transistoren der 45 nm-Technologie. Letztere basieren auf einem Prozess mit einer kombinierten Ausheilung von RTA und Kurzzeitausheilung. Dabei wird gezeigt, dass im Gegensatz zur herkömmlichen RTA-Ausheilung eine weitere Miniaturisierung der planaren Transistorstruktur mit Hilfe der Kurzzeitausheilung möglich ist.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Accompanied by CD-ROM: Appendix 1: Electronic copy of source code and input data. Includes bibliographical references (leaves 173-179). Also available via the World Wide Web.