Matching Items (3)
Description
The aging mechanism in devices is prone to uncertainties due to dynamic stress conditions. In AMS circuits these can lead to momentary fluctuations in circuit voltage that may be missed by a compact model and hence cause unpredictable failure. Firstly, multiple aging effects in the devices may have underlying correlations. The generation of new traps during TDDB may significantly accelerate BTI, since these traps are close to the dielectric-Si interface in scaled technology. Secondly, the prevalent reliability analysis lacks a direct validation of the lifetime of devices and circuits. The aging mechanism of BTI causes gradual degradation of the device leading to threshold voltage shift and increasing the failure rate. In the 28nm HKMG technology, contribution of BTI to NMOS degradation has become significant at high temperature as compared to Channel Hot Carrier (CHC). This requires revising the End of Lifetime (EOL) calculation based on contribution from induvial aging effects especially in feedback loops. Conventionally, aging in devices is extrapolated from a short-term measurement, but this practice results in unreliable prediction of EOL caused by variability in initial parameters and stress conditions. To mitigate the extrapolation issues and improve predictability, this work aims at providing a new approach to test the device to EOL in a fast and controllable manner. The contributions of this thesis include: (1) based on stochastic trapping/de-trapping mechanism, new compact BTI models are developed and verified with 14nm FinFET and 28nm HKMG data. Moreover, these models are implemented into circuit simulation, illustrating a significant increase in failure rate due to accelerated BTI, (2) developing a model to predict accelerated aging under special conditions like feedback loops and stacked inverters, (3) introducing a feedback loop based test methodology called Adaptive Accelerated Aging (AAA) that can generate accurate aging data till EOL, (4) presenting simulation and experimental data for the models and providing test setup for multiple stress conditions, including those for achieving EOL in 1 hour device as well as ring oscillator (RO) circuit for validation of the proposed methodology, and (5) scaling these models for finding a guard band for VLSI design circuits that can provide realistic aging impact.
ContributorsPatra, Devyani (Author) / Cao, Yu (Thesis advisor) / Barnaby, Hugh (Thesis advisor) / Seo, Jae-Sun (Committee member) / Arizona State University (Publisher)
Created2017
Description
Spirituality is of paramount importance in end of life care yet this aspect of care is frequently unrecognized. Spiritual and religious needs are often not accurately assessed or understood. This study sought to investigate Christian end of life beliefs and needs. A qualitative study design was used to explore end of life beliefs and needs of members from a non-denominational Christian church who self-declared their Christianity. A 10-item Assessment Tool on end of life needs and beliefs was created by this investigator and used in the study (Appendix 1). A total of 14 participants were interviewed. Notes and audio recordings were taken and later transcribed and analyzed using thematic analysis including an open analysis and an axial analysis of the data. The open analysis identified trends and common concepts which were then categorized into broader themes during the axial analysis. Findings included several major themes that described the Christian population's end of life needs and beliefs. The major themes identified included: trust in God, beliefs about necessity of religious practices, lack of fear of death, similarities in religious rituals and practices, and a desire for quality of life. During a statistical analysis, findings revealed that 86% believed that pain and suffering should be treated and prevented. One hundred percent (100%) of the participants reported that their faith helped with their acceptance of death. An additional 64% stated that they did not fear death. The findings in this study can improve religious and cultural awareness for nurses and others in the healthcare field.
ContributorsStosz, Caroline Kelley (Author) / Rennell, Nathalie (Thesis director) / Stevens, Carol (Committee member) / Murphy, Ana Orrantia (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Solar photovoltaic (PV) deployment has grown at unprecedented rates since the early 2000s. As the global PV market increases, so will the volume of decommissioned PV panels. Growing PV panel waste presents a new environmental challenge, but also unprecedented opportunities to create value and pursue new economic avenues. Currently, in the United States, there are no regulations for governing the recycling of solar panels and the recycling process varies by the manufacturer. To bring in PV specific recycling regulations, whether the PV panels are toxic to the landfills, is to be determined. Per existing EPA regulations, PV panels are categorized as general waste and are subjected to a toxicity characterization leaching procedure (TCLP) to determine if it contains any toxic metals that can possibly leach into the landfill. In this thesis, a standardized procedure is developed for extracting samples from an end of life PV module. A literature review of the existing regulations in Europe and other countries is done. The sample extraction procedure is tested on a crystalline Si module to validate the method. The extracted samples are sent to an independent TCLP testing lab and the results are obtained. Image processing technique developed at ASU PRL is used to detect the particle size in a broken module and the size of samples sent is confirmed to follow the regulation.
ContributorsKrishnamurthy, Raghav (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Kuitche, Joseph (Committee member) / Arizona State University (Publisher)
Created2017