Capillary-Driven Reflow of Thin Cu Films with Submicron, High Aspect Ratio Features

Conventional sputtering techniques are no longer sufficient for the fabrication of interconnects as trench widths enter the submicron regime and aspect ratios become greater them 1:1. The goal of this thesis is to investigate Cu as a potential interconnect metal for use in integrated circuit technology. Since sputtering is well established and widely used in the integrated circuit industry, we have used current sputtering technology as our deposition technique of choice. An alternative approach to modify the nonconformal deposition profiles obtained by sputtering is to reflow (planarize by capillary-driven surface diffusion) the metal film during a post-deposition anneal. In particular, reflow is performed for thin Cu films deposited on refractory metal barrier layers (Mo, Ta, and W) at temperatures ≤ 500°C. With a goal of developing and understanding a post-deposition reflow process for Cu, we have studied the following topics. Chapter 1 introduces relevant current concepts in ultra-large scale integration (ULSI) for interconnect technology to motivate the approaches described in this thesis. Chapter 2 investigates several techniques to improve the initial Cu coverage obtained from a magnetron sputtering source. This was found to be necessary since thin Cu films agglomerate on many underlayers, and this constrains the initial Cu thickness requirements for successful reflow. Chapter 3 describes an investigation of the atomic transport mechanism during reflow of Cu films, to understand the kinetics of reflow and measure the appropriate kinetic constants. Extensive transmission electron microscope (TEM) work was done to examine reflowed profiles and to relate the extent of reflow to the morphology, texture, grain size, and orientation of the Cu films. Hot-stage TEM experiments were performed to observe dynamically the reflow of a very low aspect ratio film. Chapter 4 develops a finite-element model to study surface diffusion mediated reflow in high aspect ratio trenches. We have considered (i) reflow of typical continuum, as-deposited profiles from a magnetron sputtering source, (ii) reflow of continuum profiles including an anisotropic surface energy, and (iii) reflow with the inclusion of grain boundaries. We also discuss some limitations of a post-deposition reflow process, and we make recommendations to facilitate the ability to reflow Cu in high aspect ratio trenches. Chapter 5 examines a non-infrared annealing technique to reflow Cu films. In particular, we have examined the possibility of annealing Cu films in a single-mode microwave cavity, which can be advantageous because it is possible to thermally isolate the substrate. Chapter 6 provides a summary of the work in this thesis and suggests some possibilities for future work.</p

Method and apparatus for selectively annealing heterostructures using microwaves

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated

Alesco and Mark Resources: Cross-Border Tax Arbitrage, Economic Reality, and Anti-Avoidance Rules in New Zealand and Canada

This essay compares the role given to the concept of economic reality in New Zealand and Canadian cross-border tax arbitrage decisions, particularly Alesco and Mark Resources. Alesco and Mark Resources both address the problem of drawing the line between acceptable tax mitigation and unacceptable avoidance, and adopt economic substance as a key indicator of where this line lies. This essay considers how the concept of economic reality pervades these cases and evaluates the influence of legislative and judicial context to the significance afforded to the concept of economic reality in the two decisions, as well as reviewing how the economic realities jurisprudence has evolved following these cases

Memory-Relevant Mushroom Body Output Synapses Are Cholinergic

Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses

Cost-effectiveness analysis of an innovative model of care for chronic wounds patients

Current provision of services for the care of chronic wounds in Australia is disjointed and costly. There is large variability in the way that services are provided, and little evidence regarding the cost-effectiveness of a specialist model of care for treatment and management. A decision-analytic model to evaluate the cost-effectiveness of a specialist wound care clinic as compared to usual care for chronic wounds is presented. We use retrospective and prospective data from a cohort of patients as well as information from administrative databases and published literature. Our results show specialist wound clinics are cost-effective for the management of chronic wounds. On average, specialist clinics were $3,947 cheaper than usual clinics and resulted in a quality adjusted life year gain of 0.04 per patient, per year. Specialist clinics were the best option under multiple scenarios including a different cost perspective and when the cost of a hospital admission was reduced. Current models of care are inefficient and represent low value care, and specialist wound clinics represent a good investment compared to current approaches for the management of chronic wounds in Australia

Patient Simulation: A Literary Synthesis of Assessment Tools in Anesthesiology

High-fidelity patient simulation (HFPS) has been hypothesized as a modality for assessing competency of knowledge and skill in patient simulation, but uniform methods for HFPS performance assessment (PA) have not yet been completely achieved. Anesthesiology as a field founded the HFPS discipline and also leads in its PA. This project reviews the types, quality, and designated purpose of HFPS PA tools in anesthesiology. We used the systematic review method and systematically reviewed anesthesiology literature referenced in PubMed to assess the quality and reliability of available PA tools in HFPS. Of 412 articles identified, 50 met our inclusion criteria. Seventy seven percent of studies have been published since 2000; more recent studies demonstrated higher quality. Investigators reported a variety of test construction and validation methods. The most commonly reported test construction methods included "modified Delphi Techniques" for item selection, reliability measurement using inter-rater agreement, and intra-class correlations between test items or subtests. Modern test theory, in particular generalizability theory, was used in nine (18%) of studies. Test score validity has been addressed in multiple investigations and shown a significant improvement in reporting accuracy. However the assessment of predicative has been low across the majority of studies. Usability and practicality of testing occasions and tools was only anecdotally reported. To more completely comply with the gold standards for PA design, both shared experience of experts and recognition of test construction standards, including reliability and validity measurements, instrument piloting, rater training, and explicit identification of the purpose and proposed use of the assessment tool, are required

Multidomain interventions: state-of-the-art and future directions for protocols to implement precision dementia risk reduction. A user manual for Brain Health Services-part 4 of 6.

Although prevention of dementia and late-life cognitive decline is a major public health priority, there are currently no generally established prevention strategies or operational models for implementing such strategies into practice. This article is a narrative review of available evidence from multidomain dementia prevention trials targeting several risk factors and disease mechanisms simultaneously, in individuals without dementia at baseline. Based on the findings, we formulate recommendations for implementing precision risk reduction strategies into new services called Brain Health Services. A literature search was conducted using medical databases (MEDLINE via PubMed and SCOPUS) to select relevant studies: non-pharmacological multidomain interventions (i.e., combining two or more intervention domains), target population including individuals without dementia, and primary outcomes including cognitive/functional performance changes and/or incident cognitive impairment or dementia. Further literature searches covered the following topics: sub-group analyses assessing potential modifiers for the intervention effect on cognition in the multidomain prevention trials, dementia risk scores used as surrogate outcomes in multidomain prevention trials, dementia risk scores in relation to brain pathology markers, and cardiovascular risk scores in relation to dementia. Multidomain intervention studies conducted so far appear to have mixed results and substantial variability in target populations, format and intensity of interventions, choice of control conditions, and outcome measures. Most trials were conducted in high-income countries. The differences in design between the larger, longer-term trials that met vs. did not meet their primary outcomes suggest that multidomain intervention effectiveness may be dependent on a precision prevention approach, i.e., successfully identifying the at-risk groups who are most likely to benefit. One such successful trial has already developed an operational model for implementing the intervention into practice. Evidence on the efficacy of risk reduction interventions is promising, but not yet conclusive. More long-term multidomain randomized controlled trials are needed to fill the current evidence gaps, especially concerning low- and middle-income countries and integration of dementia prevention with existing cerebrovascular prevention programs. A precision risk reduction approach may be most effective for dementia prevention. Such an approach could be implemented in Brain Health Services

Increasing awareness of gynaecological cancer symptoms: a GP perspective.

In the UK there has been an effort, through the National Awareness and Early Diagnosis Initiative (NAEDI), to increase early stage diagnoses and ultimately cancer survival. Encouraging early symptom presentation through awareness-raising activities in primary care is one method to achieve this goal. Understanding GPs' views about this type of activity, however, is crucial prior to implementation

Development of an intervention to expedite cancer diagnosis through primary care: a protocol.

BACKGROUND: GPs can play an important role in achieving earlier cancer diagnosis to improve patient outcomes, for example through prompt use of the urgent suspected cancer referral pathway. Barriers to early diagnosis include individual practitioner variation in knowledge, attitudes, beliefs, professional expectations, and norms. AIM: This programme of work (Wales Interventions and Cancer Knowledge about Early Diagnosis [WICKED]) will develop a behaviour change intervention to expedite diagnosis through primary care and contribute to improved cancer outcomes. DESIGN & SETTING: Non-experimental mixed-method study with GPs and primary care practice teams from Wales. METHOD: Four work packages will inform the development of the behaviour change intervention. Work package 1 will identify relevant evidence-based interventions (systematic review of reviews) and will determine why interventions do or do not work, for whom, and in what circumstances (realist review). Work package 2 will assess cancer knowledge, attitudes, and behaviour of GPs, as well as primary care teams' perspectives on cancer referral and investigation (GP survey, discrete choice experiment [DCE], interviews, and focus groups). Work package 3 will synthesise findings from earlier work packages using the behaviour change wheel as an overarching theoretical framework to guide intervention development. Work package 4 will test the feasibility and acceptability of the intervention, and determine methods for measuring costs and effects of subsequent behaviour change in a randomised feasibility trial. RESULTS: The findings will inform the design of a future effectiveness trial, with concurrent economic evaluation, aimed at earlier diagnosis. CONCLUSION: This comprehensive, evidence-based programme will develop a complex GP behaviour change intervention to expedite the diagnosis of symptomatic cancer, and may be applicable to countries with similar healthcare systems

4th symposium on primary breast cancer in older women. Theme: putting personalized care into practice (held: 3 March 2017)

Following the inception in 2010, the University of Nottingham hosted the 4th Symposium on Primary Breast Cancer in Older Women, under the auspices of the International Society of Geriatric Oncology, in March 2017, at East Midlands Conference Centre. This is the only meeting of its kind in the UK, now held biennially, aiming at a multidisciplinary audience, including patients, their carers and advocates. With a theme on ’Putting personalising care into practice’, this Symposium included sessions on ’local and systemic therapies’, ’new ideas’, ’patients and carers’, and ’challenging areas’, covered by an international and local faculty, interviewing patients and carers, and abstract presentations. Topics covered were practical and wide-ranging, including selecting for chemotherapy, radiotherapy and breast reconstruction, treating HER2-positive disease, and the roles of the geriatrician and geriatric oncology nurse