Engineering Commons^™

Secondary Electron Interactions In Exposures Of Euv Photoresists, Steven Grzeskowiak

Legacy Theses & Dissertations (2009 - 2024)

The microelectronic industry’s movement toward smaller feature sizes has necessitated a shift to extreme ultraviolet (EUV) lithography to enable cost-effective patterning of sub 20-nm features. However, this shift from 193-nm lithography (6.4 eV) to EUV (13.5 nm, 92 eV) poses significant obstacles, such that photolithography is now operating in an energy range above the electron binding energies of common atomic species in photoresists. This significant energy increase means the chemical reactions happening within operate in the realm of radiation chemistry instead of photochemistry since the observed reactions are due almost entirely to the action of photoelectrons as they dissipate their …

Synthesis Of Cadmium Arsenide Semiconductor Nanoparticles, Superatomic Silver Clusters, And Silver Coordination Polymers, Sarthak Jashubhai Patel

Legacy Theses & Dissertations (2009 - 2024)

Nanomaterials have chemical, electronic, optical, and other properties distinct from their bulk counterparts. However, the atom-precise synthesis of these materials remains a challenge, leaving open many scientific questions regarding the size regime between nanoparticulate (quantum confined) and bulk character. In this work, efforts toward the synthesis of nanoparticulate and atom-precise metal and semimetal materials are described. The synthesis of II-V semiconductor Cd3As2 having a near-zero bandgap is discussed. Analysis by UV-Vis absorption spectroscopy and powder X-ray diffraction indicate the formation of material with unexpected crystallinity and absorption properties The interaction between the molecular source of As and the solvent was …

Investigation Of Optical Second Harmonic Generation From Si (100) With Process Tailored Surface & Embedded Ag Nanostructures For Advanced Si Nonlinear Nanophotonics, Gourav Bhowmik

Legacy Theses & Dissertations (2009 - 2024)

The challenge of current microelectronic architecture in transmission bandwidth and power consumption can be potentially solved by using silicon photonics technologies that are compatible with modern CMOS fabrication. One of the critical active photonic devices for Si photonics is a Si based optical modulator. Most of the reported silicon modulators rely on the free carrier plasma dispersion effect. In those cases, a weak change of the refractive index obtained by carrier accumulation, injection or depletion is utilized in a Mach-Zehnder interferometer or a microring resonator to achieve intensity modulation, rendering them difficult for chip-level implementation due to a large footprint …

Development And Demonstration Of A Processing And Assembly Pathway For A 3d-Synchronous Field Programmable Gate Array, Robert Carroll

Legacy Theses & Dissertations (2009 - 2024)

Field Programmable Gate Arrays (FPGA) are integrated circuits which can implement virtually any digital function and can be configured by a designer after manufacturing. This is beneficial when dedicated application specific runs are not time or cost effective; however, this flexibility comes at the cost of a substantially higher interconnect overhead. Three-dimensional (3D) integration can offer significant improvements in the FPGA architecture by stacking multiple device layers and interconnecting them in the third or vertical dimension, through the substrate, where path lengths are greatly reduced. This will allow for a higher density of devices and improvements in power consumption, signal …

Cvd Molybdenum Disulfide : Material And Device Engineering, Eui Sang Song

Legacy Theses & Dissertations (2009 - 2024)

Molybdenum disulfide (MoS2) is a semiconducting 2D layered material that has attracted a lot of attention due to its material properties for electronics and optoelectronics device applications. These include a layer-dependent band gap, an indirect to direct energy transition at monolayer state, and strong light-matter interaction. A large majority of 2D materials and devices have been studied through micromechanical exfoliation for extraction and electron beam lithography for device fabrication. These methodologies while able to generate high quality materials and precisely fabricated devices, are not suitable for large scale production. Efforts have been made to make MoS2 and other 2D materials …

Tetradymite Topological Insulators : Towards High Performance Broadband Photodetection, Asish Parbatani

Legacy Theses & Dissertations (2009 - 2024)

Topological insulators are characterized by the presence of a finite energy gap in the bulk state and a conducting metallic surface state consisting of odd number of Dirac cones. The conducting surface states are along the edge boundaries, free from disorders and are protected by time reversal symmetry. The presence of Dirac cone leads to universal optical absorption phenomenon like graphene. This phenomenon of universal optical absorption leads to frequency independent photoexcitation of carriers. Bi2Te3, Sb2Te3 and Bi2Se3 belong to tetradymite topological insulators (TTI) family and are often referred to as 3D layered materials. Theoretical predictions characterize TTIs by low …

Design And Simulation Of A Voltage Controlled Current Source For Electrical Impedance Tomography Applications, Farial Nur Maysha

Legacy Theses & Dissertations (2009 - 2024)

Electrical impedance tomography (EIT) is a simple, non-invasive and ionizing radiation-free imaging technology with potential application to medical diagnostics such as lung function, cardiac output, breast cancer, and cysts. Of the above imaging techniques, lung imaging has developed into the prime application for EIT. Because it presents an ill-posed inverse problem, EIT requires high-precision instrumentation and this thesis studies a new method for obtaining a high-precision current source and voltmeter for EIT. This thesis describes various simulation studies performed on the voltage-controlled current source (VCCS). The output impedance (Zo) of various types of Howland current source (HCS) including the basic …

Low Energy Electron Interactions With Aliphatic And Aromatic Self-Assembled Monolayers On Au(111), Jodi Marie Grzeskowiak

Legacy Theses & Dissertations (2009 - 2024)

Understanding the interaction of low energy electrons with organic thin films is important for the development of many technological applications, one of which is extreme ultra-violet (EUV, 92 eV) lithography. At this energy, the photon will produce an electron cascade that induces most of the chemical changes within the photoresist. In order to better understand these interactions, electron scattering experiments have been performed on self-assembled monolayers (SAMs) of the aliphatic molecule 1-decanethiol and the aromatic molecule 1,1’-biphenyl-4-thiol grown on Au(111) via vapor phase deposition. The molecules take on either a lying down (LD) or standing up (SU) geometry depending on …

Stem Education : A Programmatic And Economic Analysis, Rebecca Kate Laforest

Legacy Theses & Dissertations (2009 - 2024)

Innovations of the 21st century have created a need for a highly skilled and adaptable workforce. In this search, industry representatives are having a difficult time finding highly qualified US candidates. From private firms to public officials and economic analysts to educators, many acknowledge the need to update training and education to better prepare our future workforce. This work will examine the performance of students in the United States, the current employment landscape, the evolution of education in the US, and trends in education to support college and career preparation. This work will then analyze specific facets of new educational …

Autonomous Spectrum Enforcement : A Blockchain Approach, Maqsood Ahamed Abdul Careem

Legacy Theses & Dissertations (2009 - 2024)

A core limitation in existing wireless technologies is the scarcity of spectrum, to support the exponential increase in Internet-connected and multimedia-capable mobile devices and the increasing demand for bandwidth-intensive services. As a solution, Dynamic Spectrum Access policies are being ratified to promote spectrum sharing for various spectrum bands and to improve the spectrum utilization. This poses an equally challenging problem of enforcing these spectrum policies. The distributed and dynamic nature of policy violations necessitates the use of autonomous agents to implement efficient and agile enforcement systems. The design of such a fully autonomous enforcement system is complicated due to the …

Emotion Forecasting In Dyadic Conversation : Characterizing And Predicting Future Emotion With Audio-Visual Information Using Deep Learning, Sadat Shahriar

Legacy Theses & Dissertations (2009 - 2024)

Emotion forecasting is the task of predicting the future emotion of a speaker, i.e., the emotion label of the future speaking turn–based on the speaker’s past and current audio-visual cues. Emotion forecasting systems require new problem formulations that differ from traditional emotion recognition systems. In this thesis, we first explore two types of forecasting windows(i.e., analysis windows for which the speaker’s emotion is being forecasted): utterance forecasting and time forecasting. Utterance forecasting is based on speaking turns and forecasts what the speaker’s emotion will be after one, two, or three speaking turns. Time forecasting forecasts what the speaker’s emotion will …

Synthesis And Adsorption Experiments With Metal-Organic Frameworks For High School And Undergraduate Laboratory Settings, Kate Holley

Legacy Theses & Dissertations (2009 - 2024)

Seven experiments are described and outlined here that introduce high school and undergraduate students to metal–organic frameworks (MOFs) and their applications. The experiments were designed to be completed with basic laboratory equipment and supplies and without the use of expensive characterization instruments, simulating typical high school chemistry laboratory conditions. Students synthesized two well-known MOFs, HKUST-1 and aluminum fumarate, using simple, safe, and rapid methods (fast enough to be performed within the time constrains of a typical high school class). Students then use their synthesized MOFs to explore their inherent sorption properties. In one set of experiments, the synthesized MOFs are …

Partitioning Of Defect Sources And Defects Reduction In Euv Mask Blank Multilayer Deposition, Alin O. Antohe

Legacy Theses & Dissertations (2009 - 2024)

Extreme ultraviolet lithography (EUVL) is the next-generation lithography technology and is slated to replace 193-nanometer argon fluoride (ArF) lithography. EUVL uses 13.5-nanometer wavelength light to expose the photoresist. In doing so it enables the technological achievement of 20-nanometer half-pitch circuits which cannot be achieved with conventional 193-nanometer optical lithography.

Mechanistic Investigation Of Antimony Carboxylate Photoresists For Euv Lithography, Michael Murphy

Legacy Theses & Dissertations (2009 - 2024)

In 2019, Extreme Ultraviolet (EUV) lithography begins its integration into high volume manufacturing to replace 193-nm lithography at key steps in the fabrication of integrated circuits. To achieve the requirements of the 7- and 5-nm nodes, a new photoresist technology is required to replace traditional chemically-amplified photoresists (CAR). One novel technology incorporates metal atoms with high EUV absorptivity into the photoresist. In this work, we describe the development, evaluation and mechanistic investigation of triorganoantimony(V) dicarboxylate complexes as novel photoresists for EUV lithography.

Communications Using Deep Learning Techniques, Priti Gopal Pachpande

Legacy Theses & Dissertations (2009 - 2024)

Deep learning (DL) techniques have the potential of making communication systems

Exploring Gated Nanoelectronic Devices Fabricated From 1d And 2d Materials, Prathamesh A. Dhakras

Legacy Theses & Dissertations (2009 - 2024)

One and two dimensional materials are being extensively researched toward potential application as ultra-thin body channel materials. The difficulty of implementing physical doping methods in these materials has necessitated various alternative doping schemes, the most promising of which is the electrostatic gating technique due to its reconfigurability. This dissertation explores the different fundamental devices that can be fabricated and characterized by taking advantage of the electrostatic gating of individual single-walled carbon nanotubes (SWNTs), dense SWNT networks and exfoliated 2D tungsten diselenide (WSe2) flakes.

Application Of Sensor Fusion For Si Engine Diagnostics And Combustion Feedback, Fnu Muralidhar Nischal

Dissertations, Master's Theses and Master's Reports

Shifting consumer mindsets and evolving government norms are forcing automotive manufacturers the world over to improve vehicle performance and also reduce greenhouse gas emissions. A critical aspect of achieving future fuel economy and emission targets is improved powertrain control and diagnostics.

This study focuses on using a sensor fusion based approach to improving control and diagnostics in a gasoline engine. A four cylinder turbocharged engine was instrumented with a suite of sensors including ion sensors, exhaust pressure sensors, crank position sensors and accelerometers. The diagnostic potential of these sensors was studied in detail. The ability of these sensors to detect …

Optimization And Comparison Of Over-Expanded And Other High Efficiency Four-Stroke Spark-Ignited Boosted Engines, Zhuyong Yang

Dissertations, Master's Theses and Master's Reports

Recent fuel economy and emission regulations are the major concern of the research and development of modern internal combustion engine. Such technologies include variable valve timing (VVT), direct injection (DI), turbocharging, downsizing, and over-expanded cycle are used by many manufacturers to improve engine fuel economy or increase power density.

Current Atkinson cycle technology in the production engine is mainly realized by an advanced valvetrain system to reduce the effective compression ratio while maintaining the same expansion ratio. Another approach to realize over-expanded cycle engine is to utilize a multi-link cranktrain mechanism. Although the Atkinson cycle was originally patented in the …

Test 2209a: New Holland Wormaster 70, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

A Compact Single-Element Pattern Reconfigurable Antenna With Wide-Angle Scanning Tuned By A Single Varactor, Haozhan Tian, Lijun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we propose a convenient fixed-frequency beam steering method, using a single patch antenna controlled by only one electronically tunable component. The antenna is based on coupled-mode patch antenna (CMPA) [1] that is capable to scan the beam as the function of frequency. A ground-etched slot loaded with one varactor diode is tuned to be capacitive, resonant, or inductive. In order to test broader tuning range, two kinds of varactors with the ranges of 9.24 pF-1.77 pF and 2.67 pF-0.63 pF are implemented respectively. By analyzing how the loaded slot affects the cavity modes and fields, we demonstrate …

Applying Deep Learning Approach To The Far-Field Subwavelength Imaging Based On Near-Field Resonant Metalens At Microwave Frequencies, He Ming Yao, Min Li, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we utilize the deep learning approach for the subwavelength imaging in far-field, which is realized by the near-field resonant metalens at microwave frequencies. The resonating metalens consisting of split-ring resonators (SRRs) are equipped with the strong magnetic coupling ability and can convert evanescent waves into propagating waves using the localized resonant modes. The propagating waves in the far-field are utilized as the input of a trained deep convolutional neural network (CNN) to realize the imaging. The training data for establishing the deep CNN are obtained by the EM simulation tool. Besides, the white Gaussian noise is added …

Real-Time Path Planning In Constrained, Uncertain Environments, Randall Christensen, Robert C. Leishman

Faculty Publications

A key enabler of autonomous vehicles is the ability to plan the path of the vehicle to accomplish mission objectives. To be robust to realistic environments, path planners must account for uncertainty in the trajectory of the vehicle as well as uncertainty in the location of obstacles. The uncertainty in the trajectory of the vehicle is a difficult quantity to estimate, and is influenced by coupling between the vehicle dynamics, guidance, navigation, and control system as well as any disturbances acting on the vehicle. Monte Carlo analysis is the conventional approach to determine vehicle dispersion, while accounting for the coupled …

Machine-Learning-Based Pml For The Fdtd Method, He Ming Yao, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, a novel absorbing boundary condition (ABC) computation method for finite-difference time-domain (FDTD) is proposed based on the machine learning approach. The hyperbolic tangent basis function (HTBF) neural network is introduced to replace traditional perfectly matched layer (PML) ABC during the FDTD solving process. The field data on the interface of conventional PML are employed to train HTBF-based PML model. Compared to the conventional approach, the novel method greatly decreases the size of a computation domain and the computation complexity of FDTD because the new model only involves the one-cell boundary layer. Numerical examples are provided to benchmark …

A Case For Open Mission Systems In Dod Aircraft Avionics, Michael J. Brown, R. David Fass, Jonathan D. Ritschel

Faculty Publications

The DOD is adopting open mission systems (OMS) as the future in the military aviation environment. OMS proponents promise reduced costs and truncated schedules through increased competition in the marketplace and reduced coding efforts. To the best of our knowledge, no studies have examined the success of these open architectures in the DOD. Therefore, we investigate costs and schedule for a recent DOD avionics OMS demonstration platform in comparison to 13 historically analogous programs.

Reliability Estimation Of Reciprocating Seals Based On Multivariate Dependence Analysis And It's Experimental Validation, Chao Zhang, Rentong Chen, Shaoping Wang, Yujie Qian, Mileta M. Tomovic

Engineering Technology Faculty Publications

Accurate reliability estimation for reciprocating seals is of great significance due to their wide use in numerous engineering applications. This work proposes a reliability estimation method for reciprocating seals based on multivariate dependence analysis of different performance indicators. Degradation behavior corresponding to each performance indicator is first described by the Wiener process. Dependence among different performance indicators is then captured using D-vine copula, and a weight-based copula selection method is utilized to determine the optimal bivariate copula for each dependence relationship. A two-stage Bayesian method is used to estimate the parameters in the proposed model. Finally, a reciprocating seal degradation …

Improving Stem Recruitment Through A Theme-Based Summer Residential Camp Focused On Sea Level Rise, Vukica M. Jovanović, Balša Terzić, Mujde Erten-Unal, Victoria Hill, George Mcleod, Michelle Covi, David Burdige, Jenifer Alonzo, Justin Mason, Tysha Batts, Cynthia Tomovic

Engineering Technology Faculty Publications

In this paper, the authors present an enrichment program that focuses on Science, Technology, Engineering, and Math (STEM) concepts. The program is named Building Leaders to Advance Science and Technology (BLAST) and is held each summer at three universities across the Commonwealth of Virginia: Old Dominion University, the University of Virginia, and the Virginia Polytechnic Institute. BLAST is sponsored in partnership among these three universities and the Virginia Space Grant Consortium (VSGC), and is funded by the General Assembly of Commonwealth of Virginia. Its main purpose is to expose high school students to topics related to different STEM fields through …

Doctoral Engineering Grant Writing Experience To Prepare Future Professionals And Faculty, Katherine Smith, Nathapon Siangchokyoo, Erika Gamarra, Ashish Tamhane, Anthony W. Dean

Engineering Technology Faculty Publications

While there have been many efforts to broaden opportunities for all STEM students by engaging in interdisciplinary endeavors and education focusing on professional development, there are particular problems facing students pursuing doctoral degrees in engineering disciplines. Doctoral programs of the future need to become better equipped to prepare students for future careers as engineering professionals or faculty. It has been noted recently that many doctoral degree recipients are turning to jobs outside of academia but increases in undergraduate enrollment and the average age of the professoriate indicate an increase in demand for new faculty. Both future faculty and professionals can …

Experimental Verification Of Transparent Spin Mode In Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang

Engineering Technology Faculty Publications

High electron and ion polarizations are some of the key design requirements of a future Electron Ion Collider (EIC). The transparent spin mode, a concept inspired by the figure 8 ring design of JLEIC, is a novel technique for preservation and control of electron and ion spin polarizations in a collider or storage ring. It makes the ring lattice "invisible" to the spin and allows for polarization control by small quasi-static magnetic fields with practically no effect on the beam’s orbital characteristics. It offers unique opportunities for polarization maintenance and control in Jefferson Lab’s JLEIC and in BNL’s eRHIC. The …

Sustainability In Higher Education: Perceptions Of Social Responsibility Among University Students, Younghan Jung, Kayoung Park, Junyong Ahn

Engineering Technology Faculty Publications

Many construction-related training and education programs in the United States have now embraced the concept of sustainability, offering sustainable construction courses that highlight sustainable design and construction practices. These courses have mainly focused on green building strategies for the design and construction of built environments and indoor environmental quality necessary for students’ knowledge enhancement and career development. This study examined the effect of sustainability course on students’ knowledge as well as their perceptions of social responsibility and sustainable behaviors. Data were collected by conducting a survey from construction related programs in U.S. universities. Students were categorized based on their experience …

A Blockchain-Enabled Peer-To-Peer Energy Trading Platform For Managing Complex Exchange Of Kilowatt-Hours And Negawatts, Murat Kuzlu, Rasheq Rahman, Jason Lin

Engineering Technology Faculty Publications

Under the Department of Energy’s STTR funding, BEM Controls LLC performed research from July 2, 2018 to April 1, 2019. The purpose of this research was to design, develop and demonstrate the technical feasibility of the blockchain enabled energy trading platform for managing complex exchange of kilowatt hours and negawatts. The energy trading platform was developed in the open-source HyperLedger Fabric blockchain framework and the performance of the blockchain network was evaluated. Key research findings and results include (1) the successful design and development of an open-architecture blockchain-based energy trading platform able to execute smart contract transactions across eight use …