Printing of Contact Holes for the 45nm Generation using Immersion Interference Lithography

Interference lithography is a valuable tool for evaluating photoresist performance at the resolutions unattainable with conventional exposure tools. interference lithography is most commonly used to generate one dimensional patterns such as lines and spaces. however two dimensional patterns are of much greater interest to both the resist developers and the device manufacturers in microlithography. This paper presents a technique to produce two dimensional images of contact holes at the resolution of 45nm half pitch. To our knowledge this is the highest resolution contacts printed to date using 193nm radiation. Photoresist patterns with a half-pitch of 45 nm were formed with an effective NA of 1.05 utilizing the JUT Immersion Interference system [4]. The wafer was subsequently rotated and the same pattern was printed at an angle relative to the original pattern. This double exposure technique allowed the formation of the two dimensional features. The images formed were processed, and the scanning electron micrograph (SEM) images and analysis of the data will be presented

Development and Characterization of a GaAs nipi Superlattice Solar Cell

The development of photovoltaics as an energy source has been propelled by numerous technological advancements over the past 60 years to now enable the conversion of sunlight into power at an efficiency of 46%. This enables power production that is cleaner, and more transferrable to locations off the grid than ever before, however new technologies are required to further increase efficiency while driving down costs. Currently a large effort is being made to achieve intermediate band solar cells (IBSC) that more efficiently convert energy from the entire solar spectrum. This is enabled through multiple techniques, including quantum dots (QDs), and potentially through doping superlattice solar cells. Doping superlattices have been explored theoretically and some historic work has used these superlattices to form nipi solar cells with alternating n-type, intrinsic, p-type, intrinsic layers. Multiple purposes exist for evaluating nipi solar cells, which include radiation hardness, an electronically adjustable absorption edge, use with nanostructures, and the possibility of an IBSC. The primary motivation for this work is to develop the nipi solar cell for evaluation as an IBSC, while also evaluating the radiation tolerance of the design for potential use in space applications. This has been completed through a theoretical and experimental analysis of nipi superlattice layers, and an extensive evaluation of the fabrication and growth processes required to achieve a high efficiency solar cell. Additionally an improved model for nipi diodes and solar cells has been developed. Also a novel process for fabricating nipi solar cells through epitaxial regrowth and diffused junctions has been developed, where record efficiencies for nipi solar cells have been measured for devices fabricated via epitaxial regrowth at 12.5%. An understanding of the effect of adding QD into a nipi superlattice has been obtained. Finally a greater understanding of the intrinsic radiation hardness of the nipi design has been achieved and possible methods to improve it have been evaluated. The techniques and processes developed here have the possibility to be used to further the understanding of nipi devices, and lead to the potential development of an IBSC with a QD-nipi design

An Empirical Assessment of Corporate Environmental Crime-Control Strategies

Corporate illegality is often attributed to greed by corporate managers and insufficient legal safeguards. Underlying this argument is an explicit critique of corporate crime regulatory systems. Yet there is little systematic investigation of the relative merits of different types or components of crime-control strategies; research comparing more punitive command-and-control strategies with self-regulatory approaches is particularly lacking. In this Article, we assess these crime prevention-and-control mechanisms in the context of individual and situational risk factors that may increase the likelihood of illegal behavior in the environmental arena. We use data drawn from two groups of business managers who participated in a factorial survey (using vignettes) measuring their intentions to participate in two types of environmental offenses. Generally, results show that the most effective regulatory levers are (1) credible legal sanctions and (2) the certainty and severity of informal discovery by significant others in the firm. We conclude by discussing the implications of our findings for regulatory policy and strategy, and for efforts to account for the role of social norms in corporate environmental compliance

Longitudinal Effects of a 2-Year Meditation and Buddhism Program on Well-being, Quality of Life, and Valued Living

Objectives: Most research on mindfulness and meditation has focused on structured therapeutic interventions, such as mindfulness-based stress reduction, or meditation retreats. Such programs have received moderate empirical support for improving psychological outcomes in clinical and nonclinical populations, but there remains a paucity of research on intensive or long-term mindfulness or meditation programs for experienced practitioners, especially those that incorporate Buddhist teachings. The purpose of the current study was to investigate the effects of a long-term integrated mindfulness/meditation and Buddhism program, Dharma in Daily Life (DIDL). Methods: Well-being, quality of life, valued living, and theorized processes of change were measured using a naturalistic, quasi-experimental design over the course of the 2-year program and 6-month follow-up. Participants included 17 individuals enrolled in the program and 14 individuals recruited from community meditation groups. Results: Participation in the program predicted increases in subjective well-being and mindfulness over time compared to the control group. Regardless of condition, frequency of meditation predicted lower psychological inflexibility and higher mindfulness, well-being, and progress toward values. Length of meditation session predicted a greater ability to observe experience, and prior meditation experience predicted greater non-reactivity to experience. Conclusions: Although preliminary, results suggest that participation in a long-term integrated mindfulness/meditation and Buddhism program may positively impact mindfulness and general well-being. Frequency of meditation sessions appears to be a particularly important variable. These findings warrant further investigation of such programs and practice parameters, as well as how each may affect key outcomes

Which Exercise Interventions Can Most Effectively Improve Reactive Balance in Older Adults? A Systematic Review and Network Meta-Analysis

Background: Reactive balance is the last line of defense to prevent a fall when the body loses stability, and beneficial effects of various exercise-based interventions on reactive balance in older adults have been reported. However, their pooled evidence on the relative effects has yet to be described. Objective: To review and evaluate the comparative effectiveness of various exercise-based interventions on reactive balance in older adults. Methods: Nine electronic databases and reference lists were searched from inception to August 2021. Eligibility criteria according to PICOS criteria were as follows: (1) population: older adults with the mean age of 65 years or above; (2) intervention and comparison: at least two distinct exercise interventions or one exercise intervention with no-exercise controlled intervention (NE) compared in each trial; (3) outcome: at least one measure of reactive balance; (4) study: randomized controlled trial. The main network meta-analysis was performed on data from the entire older adult population, involving all clinical conditions as well as healthy older adults. Subgroup analyses stratified by characteristics of participants (healthy only) and reactive balance outcomes (simulated slip or trip while walking, simulated forward falls, being pushed or pulled, and moveable platform) were also conducted. Results: Thirty-nine RCTs (n = 1388) investigating 17 different types of exercise interventions were included in the network meta-analysis. Reactive balance training as a single intervention presented the highest probability (surface under the cumulative ranking (SUCRA) score) of being the best intervention for improving reactive balance and the greatest relative effects vs. NE in the entire sample involving all clinical conditions [SUCRA = 0.9; mean difference (95% Credible Interval): 2.7 (1.0 to 4.3)]. The results were not affected by characteristics of participants (i.e., healthy older adults only) or reactive balance outcomes. Summary/Conclusion: The findings from the NMA suggest that a task-specific reactive balance exercise could be the optimal intervention for improving reactive balance in older adults, and power training can be considered as a secondary training exercise

Kassiopeia: A Modern, Extensible C++ Particle Tracking Package

The Kassiopeia particle tracking framework is an object-oriented software package using modern C++ techniques, written originally to meet the needs of the KATRIN collaboration. Kassiopeia features a new algorithmic paradigm for particle tracking simulations which targets experiments containing complex geometries and electromagnetic fields, with high priority put on calculation efficiency, customizability, extensibility, and ease of use for novice programmers. To solve Kassiopeia's target physics problem the software is capable of simulating particle trajectories governed by arbitrarily complex differential equations of motion, continuous physics processes that may in part be modeled as terms perturbing that equation of motion, stochastic processes that occur in flight such as bulk scattering and decay, and stochastic surface processes occuring at interfaces, including transmission and reflection effects. This entire set of computations takes place against the backdrop of a rich geometry package which serves a variety of roles, including initialization of electromagnetic field simulations and the support of state-dependent algorithm-swapping and behavioral changes as a particle's state evolves. Thanks to the very general approach taken by Kassiopeia it can be used by other experiments facing similar challenges when calculating particle trajectories in electromagnetic fields. It is publicly available at https://github.com/KATRIN-Experiment/Kassiopei

GaSb solar cells grown on GaAs via interfacial misfit arrays for use in the III-Sb multi-junction cell

Growth of GaSb with low threading dislocation density directly on GaAs may be possible with the strategic strain relaxation of interfacial misfit arrays. This creates an opportunity for a multi-junction solar cell with access to a wide range of well-developed direct bandgap materials. Multi-junction cells with a single layer of GaSb/GaAs interfacial misfit arrays could achieve higher efficiency than state-of-the-art inverted metamorphic multi-junction cells while forgoing the need for costly compositionally graded buffer layers. To develop this technology, GaSb single junction cells were grown via molecular beam epitaxy on both GaSb and GaAs substrates to compare homoepitaxial and heteroepitaxial GaSb device results. The GaSb-on-GaSb cell had an AM1.5g efficiency of 5.5% and a 44-sun AM1.5d efficiency of 8.9%. The GaSb-on-GaAs cell was 1.0% efficient under AM1.5g and 4.5% at 44 suns. The lower performance of the heteroepitaxial cell was due to low minority carrier Shockley-Read-Hall lifetimes and bulk shunting caused by defects related to the mismatched growth. A physics-based device simulator was used to create an inverted triple-junction GaInP/GaAs/GaSb model. The model predicted that, with current GaSb-on-GaAs material quality, the not-current-matched, proof-of-concept cell would provide 0.5% absolute efficiency gain over a tandem GaInP/GaAs cell at 1 sun and 2.5% gain at 44 suns, indicating that the effectiveness of the GaSb junction was a function of concentration

The Journal of Microelectronic Research 2005

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