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Legacy Theses & Dissertations (2009 - 2024)

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Articles 91 - 120 of 173

Full-Text Articles in Nanoscience and Nanotechnology

First-Principles Study Of The Electric Field Effect On The Water-Adsorbed Rutile Titanium Dioxide Surface, Abraham L. Hmiel Jan 2014

First-Principles Study Of The Electric Field Effect On The Water-Adsorbed Rutile Titanium Dioxide Surface, Abraham L. Hmiel

Legacy Theses & Dissertations (2009 - 2024)

TiO2 is a semiconducting material that has been used extensively in many industrial applications, and recently has become a candidate for photocatalytic water splitting, fuel cell anode support materials, sensors, and other novel nanodevices. The interface of TiO2 with water, historically well-studied but still poorly understood, presents a ubiquitous environmental challenge towards the ultimate practical usefulness of these technologies. Ground-state density functional theory (DFT) calculations studying the characteristics of molecular adsorption on model surfaces have been studied for decades, showing constant improvement in the description of the energetics and electronic structure at interfaces. These simulations are invaluable in the …

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Development Of Novel Technologies To Enhance Performance And Reliability Of Iii-Nitride Avalanche Photodiodes, Puneet Harischandra Suvarna Jan 2014

Development Of Novel Technologies To Enhance Performance And Reliability Of Iii-Nitride Avalanche Photodiodes, Puneet Harischandra Suvarna

Legacy Theses & Dissertations (2009 - 2024)

Solar-blind ultraviolet avalanche photodiodes are an enabling technology for applications in the fields of astronomy, communication, missile warning systems, biological agent detection and particle physics research. Avalanche photodiodes (APDs) are capable of detecting low-intensity light with high quantum efficiency and signal-to-noise ratio without the need for external amplification. The properties of III-N materials (GaN and AlGaN) are promising for UV photodetectors that are highly efficient, radiation-hard and capable of visible-blind or solar-blind operation without the need for external filters. However, the realization of reliable and high performance III-N APDs and imaging arrays has several technological challenges. The high price and …

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Growth And Characterization Of Graphene On Cuni Substrates, Parul Tyagi Jan 2014

Growth And Characterization Of Graphene On Cuni Substrates, Parul Tyagi

Legacy Theses & Dissertations (2009 - 2024)

Graphene is a single layer of sp2 bonded carbon atoms that crystallizes in the honeycomb structure. Because of its true two-dimensional structure, it has very unique electrical properties, including a very high carrier mobility that is symmetric for holes and electrons. To realize these unique properties, it is important to develop a method for growing graphene films with uniform thickness and low defect density. One of the most popular methods of growth is by chemical vapor deposition on Cu substrates, because it is self-limited. However many applications require the growth of graphene films that are more than one atomic layer …

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An Implantable Device For Manipulation Of The In Vivo Tumor Microenvironment, James K. Williams Jan 2014

An Implantable Device For Manipulation Of The In Vivo Tumor Microenvironment, James K. Williams

Legacy Theses & Dissertations (2009 - 2024)

In the past decade, it has become increasingly recognized that interactions between cancer cells and the tumor microenvironment (TME) regulate metastasis. One such interaction is the paracrine loop between macrophages and cancer cells which drives metastatic invasion in mammary tumors. Tumor associated macrophages release epidermal growth factor (EGF), a chemoattractant which induces the migration of cancer cells toward the blood vessels. The cancer cells reciprocate by releasing a macrophage chemoattractant, colony-stimulating factor 1 (CSF-1), resulting in the co-migration of both cell types and subsequent intravasation. In this work, a new technology has been developed for studying the mechanisms by which …

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The Influence Of Impurities And Metallic Capping Layers On The Microstructure Of Copper Interconnects, Michael Rizzolo Jan 2014

The Influence Of Impurities And Metallic Capping Layers On The Microstructure Of Copper Interconnects, Michael Rizzolo

Legacy Theses & Dissertations (2009 - 2024)

As copper interconnects have scaled to ever smaller dimensions on semiconductor devices, the microstructure has become increasingly detrimental for performance and reliability. Small grains persist in interconnects despite annealing at high temperatures, leading to higher line resistance and more frequent electromigration-induced failures. Conventionally, it was believed that impurities from the electrodeposition pinned grain growth, but limitations in analytical techniques meant the effect was inferred rather than observed.

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Characterization Of Extreme Ultraviolet Lithography Photoresists Using Advanced Metrology And Fitting Techniques, Genevieve Kane Jan 2014

Characterization Of Extreme Ultraviolet Lithography Photoresists Using Advanced Metrology And Fitting Techniques, Genevieve Kane

Legacy Theses & Dissertations (2009 - 2024)

As extreme ultraviolet lithography (EUVL) prepares to be incorporated into high volume manufacturing, many challenges must be addressed. Among these challenges, a need for photoresist improvement exists. The work described here will look into some of the problems and challenges facing EUV resists, in particular out-of-band (OOB) wavelengths of light and their interaction with photoresists. Studies have been completed on the effect of out-of-band light on photoresists [1]-[3]. It is imperative that solutions to suppress the deep ultraviolet (DUV) OOB light be incorporated into next generation EUV production tools due to concerns of decreased performance of lithography, and an increase …

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Experimental And Simulation Studies Of Printability Of Buried Euv Mask Defects And Study Of Euv Reflectivity Loss Mechanisms Due To Standard Euv Mask Cleaning Processes, Mihirkant Upadhyaya Jan 2014

Experimental And Simulation Studies Of Printability Of Buried Euv Mask Defects And Study Of Euv Reflectivity Loss Mechanisms Due To Standard Euv Mask Cleaning Processes, Mihirkant Upadhyaya

Legacy Theses & Dissertations (2009 - 2024)

There's a big push for development and commercialization of extreme ultraviolet (EUV) lithography for high-volume semiconductor manufacturing of 14 nm half-pitch patterning and beyond. One of the primary concerns for making this a reality has been the ability to achieve defect-free masks. My study is focused on two aspects related to the performance degradation of the EUV masks namely EUV mask cleaning induced reflectivity loss mechanisms, and the buried multilayer phase defects in EUV masks.

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Radiation Effects In Gate-All-Around Silicon Nanowire Mosfets And Carbon Nanotube P-N Diodes, Everett Steven Comfort Jan 2014

Radiation Effects In Gate-All-Around Silicon Nanowire Mosfets And Carbon Nanotube P-N Diodes, Everett Steven Comfort

Legacy Theses & Dissertations (2009 - 2024)

The scaling of MOSFETs has resulted in short channel effects that increase their power consumption above acceptable levels. In order to lower the power dissipation, new device designs and materials are being considered. For example, multiple-gate MOSFETs, including the gate-all-around silicon nanowire (GAA SiNW) MOSFET, are known to reduce short channel effects. Furthermore, new high-mobility channel materials such as single-walled carbon nanotubes (SWNTs) can be integrated to allow for further scaling of the supply voltage, again aiding in lowering power dissipation.

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Development Of A One-Dimensional Position Sensitive Detector For Tracking Applications, Leigh Kent Lydecker Jan 2014

Development Of A One-Dimensional Position Sensitive Detector For Tracking Applications, Leigh Kent Lydecker

Legacy Theses & Dissertations (2009 - 2024)

Optical Position Sensitive Detectors (PSDs) are a non-contact method of tracking the location of a light spot. Silicon-based versions of such sensors are fabricated with standard CMOS processing, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. Because they are non-contact, they do not degrade over time from surface friction due to repetitive sliding motion associated with standard full contact sliding potentiometers. This results in long, reliable device lifetimes. In this work, an innovative PSD was developed to replace the linear hard contact potentiometer currently being used in a human-computer interface architecture.

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Exposure Assessment And Risk Management Of Engineered Nanoparticles : Investigation In Semiconductor Wafer Processing, Michele Shepard Jan 2014

Exposure Assessment And Risk Management Of Engineered Nanoparticles : Investigation In Semiconductor Wafer Processing, Michele Shepard

Legacy Theses & Dissertations (2009 - 2024)

Engineered nanomaterials (ENMs) are currently used in hundreds of commercial products and industrial processes, with more applications being investigated. Nanomaterials have unique properties that differ from bulk materials. While these properties may enable technological advancements, the potential risks of ENMs to people and the environment are not yet fully understood. Certain low solubility nanoparticles are more toxic than their bulk material, such that existing occupational exposure limits may not be sufficiently protective for workers. Risk assessments are currently challenging due to gaps in data on the numerous emerging materials and applications as well as method uncertainties and limitations.

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Biomacromolecule Conjugated Nanofiber Scaffold For Salivary Gland Tissue Engineering, Kavitha Jayarathanam Jan 2014

Biomacromolecule Conjugated Nanofiber Scaffold For Salivary Gland Tissue Engineering, Kavitha Jayarathanam

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT :

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Properties Of Peg, Ppg And Their Copolymers Influence On The Gap-Fill Characteristics Of Damascene Interconnects, Kevin Ryan Jan 2013

Properties Of Peg, Ppg And Their Copolymers Influence On The Gap-Fill Characteristics Of Damascene Interconnects, Kevin Ryan

Legacy Theses & Dissertations (2009 - 2024)

A laboratory scale plating cell was built that provided reproducible bottom-up fill results for the electrochemical deposition of copper in damascene features. Several techniques used in the full wafer plating tool were incorporated into the setup to accurately control the process conditions. These techniques included but were not limited to a voltage controlled `hot-entry' step, a custom coupon holder to allow sample rotation, a secondary thief electrode and an automatic entry system. The results of qualification experiments are presented to demonstrate that precise control was realized along with repeatable partial fill plating results. The qualified setup was then used to …

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Ion Beam Modification Of Single Crystal Sapphire For High Temperature Optical Waveguiding, William Spratt Jan 2013

Ion Beam Modification Of Single Crystal Sapphire For High Temperature Optical Waveguiding, William Spratt

Legacy Theses & Dissertations (2009 - 2024)

High temperature environments (>1000°C) provide a significant challenge for fiber optic based sensing due to the poor physical properties of silica fiber at elevated temperature. Not only does silica soften above 1000°C, but the dopants that are responsible for the refractive index change between the core and cladding diffuse, reducing the fibers effectiveness as a waveguide. Single-crystal sapphire fiber has the potential to supplement fiber sensing at high temperature however sapphire fiber is unclad and no cladding methods exist that withstand high temperatures. In addition to higher losses the lack of a cladding also leads to decreased sensitivity due …

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Novel Resist Systems For Euv Lithography : Ler, Chain-Scission, Nanoparticle And More, Brian Cardineau Jan 2013

Novel Resist Systems For Euv Lithography : Ler, Chain-Scission, Nanoparticle And More, Brian Cardineau

Legacy Theses & Dissertations (2009 - 2024)

Extreme Ultraviolet (EUV) lithography is currently the best option for replacing 193-nm lithography in future IC fabrication. For EUV to be successful, however, there are a number of challenges that must be overcome. Current resist designs struggle to meet the demands of future lithography nodes. We propose the best way to overcome these obstacles is through the design of novel resist systems.

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Ion Beam Nano-Engineering Of Erbium Doped Silicon For Enhanced Light Emission At 1.54 Microns, Sebastian Naczas Jan 2013

Ion Beam Nano-Engineering Of Erbium Doped Silicon For Enhanced Light Emission At 1.54 Microns, Sebastian Naczas

Legacy Theses & Dissertations (2009 - 2024)

Erbium doped silicon is of great interest as a potential light source in Silicon Photonics research due to its light emission at 1.54 μm, which corresponds to the minimal loss of optical transmission in silica fibers for telecommunications. In this thesis a basic mechanism for excitation and de-excitation of Er in Si is reviewed. Based on such fundamental understanding, an innovative approach is proposed and implemented to improve Er luminescence properties through the formation of metal nanoparticles via impurity gettering in Si nanocavities.

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Study Of Nickel Silicide Formation By Physical Vapor Deposition Techniques, Shanti Pancharatnam Jan 2013

Study Of Nickel Silicide Formation By Physical Vapor Deposition Techniques, Shanti Pancharatnam

Legacy Theses & Dissertations (2009 - 2024)

Metal silicides are used as contacts to the highly n-doped emitter in photovoltaic devices. Thin films of nickel silicide (NiSi) are of particular interest for Si-based solar cells, as they form at lower temperature and consume less silicon. However, interfacial oxide limits the reduction in sheet resistance. Hence, different diffusion barriers were investigated with regard to optimizing the conductivity and thermal stability.

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White-Light And Infrared Emission From Sicxoy-Based Materials, Vasileios Nikas Jan 2013

White-Light And Infrared Emission From Sicxoy-Based Materials, Vasileios Nikas

Legacy Theses & Dissertations (2009 - 2024)

The development of a Si-based light source has attracted a high level of attention due to its potential unique advantages. For one, the monolithic integration of photonics on on-chip level along with the microelectronics devices would enhance the data processing rate. Additionally the cost per transmitted/processed information capacity can be significantly reduced.

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Control Over Variability In Nonvolatile Hafnium-Oxide Resistive-Switching Memory Based On Modeling Of The Switching Processes, Brian Jerad Butcher Jan 2013

Control Over Variability In Nonvolatile Hafnium-Oxide Resistive-Switching Memory Based On Modeling Of The Switching Processes, Brian Jerad Butcher

Legacy Theses & Dissertations (2009 - 2024)

Resistive random access memory (ReRAM) technology presents an attractive option for embedded non-volatile (NV) memory systems if its variability (cycle-to-cycle and device-to-device) can be controlled. This dissertation has focused on investigations to identify key mechanisms and parameters which dominate ReRAM variability, and the development of subsequent experimental and simulation-based tools to address this variability. The first component of these efforts entailed identification of the modern-day non-volatile memory technological gaps that have driven the operational requirements and challenges for resistive memory as an emerging NV memory.

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Mueller Based Scatterometry And Optical Characterization Of Semiconductor Materials, Gangadhara Raja Muthinti Jan 2013

Mueller Based Scatterometry And Optical Characterization Of Semiconductor Materials, Gangadhara Raja Muthinti

Legacy Theses & Dissertations (2009 - 2024)

Scatterometry is one of the most useful metrology methods for the characterization and control of critical dimensions (CD) and the detailed topography of periodic structures found in microelectronics fabrication processes. Spectroscopic ellipsometry (SE) and normal incidence reflectometry (NI) based scatterometry are the most widely used optical methodologies for metrology of these structures. Evolution of better optical hardware and faster computing capabilities led to the development of Mueller Matrix (MM) based Scatterometry (MMS). Dimensional metrology using full Mueller Matrix (16 element) scatterometry in the wavelength range of 245nm-1000nm was discussed in this work. Unlike SE and NI, MM data provides complete …

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Microfluidic-Assisted Atomic Force Microscopy For The Mechanical Characterization Of Soft Biological Materials, Aaron Peter Mosier Jan 2013

Microfluidic-Assisted Atomic Force Microscopy For The Mechanical Characterization Of Soft Biological Materials, Aaron Peter Mosier

Legacy Theses & Dissertations (2009 - 2024)

Viable methods for bacterial biofilm remediation require a fundamental understanding of biofilm mechanical properties and their dependence on dynamic environmental conditions. Mechanical test data, quantifying elasticity or adhesion, may be used to perform physical modeling of biofilm behavior, thus enabling the development of novel remediation strategies. To achieve real-time, dynamic measurements of these properties, a novel analysis platform consisting of a microfluidic flowcell device has been designed and fabricated for in situ analysis using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The flowcell consists of microfluidic channels for biofilm establishment that are then converted into an open …

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Probe Immobilization Strategies And Device Optimization For Novel Transistor-Based Dna Sensors, Nicholas Michael Fahrenkopf Jan 2013

Probe Immobilization Strategies And Device Optimization For Novel Transistor-Based Dna Sensors, Nicholas Michael Fahrenkopf

Legacy Theses & Dissertations (2009 - 2024)

The research presented herein exploits the terminal phosphate group on single stranded DNA molecules for direct immobilization to surfaces utilized in semiconductor device fabrication with the end goal of transistor based DNA sensors. As a demonstration of the feasibility of this immobilization strategy DNA immobilization to a variety of surfaces was evaluated for usefulness in biosensor applications. It was determined that DNA can be directly immobilized to a variety of semiconductor surfaces through the terminal phosphate group. Further, this immobilization allows for the hybridization of the immobilized DNA to complementary target in solution. The immobilization of DNA to hafnium dioxide …

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Charged Particle Imaging Methods For Cd Metrology Of Sub 22nm 3d Device Structures, Aron Joel Cepler Jan 2013

Charged Particle Imaging Methods For Cd Metrology Of Sub 22nm 3d Device Structures, Aron Joel Cepler

Legacy Theses & Dissertations (2009 - 2024)

Critical dimension scanning electron microscopes (CD-SEMs) are used to perform highly accurate dimensional metrology on patterned features. In order to ensure optimal feedback for process control, it is necessary that these tools produce highly reproducible measurements. As the smallest device features continue to shrink, and new challenging high aspect ratio (HAR) structures are being introduced, gaps are appearing between process control measurements that are necessary for high volume manufacturing and the capabilities of the CD-SEM. Two possible routes for solving this problem include improvement of the existing CD-SEM technology or the replacement of the CD-SEM.

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The Localized Manipulation Of The Extracellular Matrix Within 3d Collagen Cell Cultures Using A Biomems Device, Ashley N. Clark Jan 2013

The Localized Manipulation Of The Extracellular Matrix Within 3d Collagen Cell Cultures Using A Biomems Device, Ashley N. Clark

Legacy Theses & Dissertations (2009 - 2024)

Approximately 90% of all cancer related deaths can be attributed to the occurrence of metastasis. There are multiple changes that occur within the tumor microenvironment that have been correlated with the onset of metastasis. Different cell types, extracellular matrices, blood vessels, and soluble factors are some of the various components that make up the complex, heterogeneous microenvironment that exists within a tumor. The dynamic relationship between tumor cells and their surrounding environment makes it an ideal environment to study triggers of metastasis, such as the modification of the extracellular matrix. Changes in the multiple aspects of extracellular matrix composition have …

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Plasmonic-Based High Temperature Chemical Sensing Using Gold Nanoparticles Embedded In Metal Oxide Thin Films, Nicholas Joy Jan 2013

Plasmonic-Based High Temperature Chemical Sensing Using Gold Nanoparticles Embedded In Metal Oxide Thin Films, Nicholas Joy

Legacy Theses & Dissertations (2009 - 2024)

Thin metal oxide films embedded with Au nanoparticles (AuNPs) have been investigated as high temperature localized surface plasmon resonance (LSPR) based sensing materials to monitor H2, CO, and NO2 at a temperature of 500°C. Applications for this technology include turbine engines as well as other combustion environments where it is important to monitor emission gases for both regulatory purposes as well as combustion control. These high temperature applications, which may be oxidizing or reducing in nature, present challenges to sensor reliability and selectivity, and have therefore necessitated the development of novel sensing devices. While there has been …

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Impacts Of Ion Irradiation On Hfo2-Based Resistive Random Access Memory Devices, Xiaoli He Jan 2013

Impacts Of Ion Irradiation On Hfo2-Based Resistive Random Access Memory Devices, Xiaoli He

Legacy Theses & Dissertations (2009 - 2024)

The impacts of ion irradiation on so-called vacancy-change mechanism (VCM) and electrochemical-metallization mechanism (ECM) ReRAM devices based on HfO2 are investigated using various ion sources: H+ (1 MeV), He+ (1 MeV), N+ (1MeV), Ne+ (1.6 MeV) and Ar+ (2.75 MeV) over a range of total doses (105 - 1011 rad(Si)) and fluences (1012 - 1015 cm-2). VCM-ReRAM devices show robust resistive switching function after all irradiation experiments. VCM resistive switching parameters including set voltage (Vset), reset voltage (Vreset), on-state resistance (Ron) and off-state resistance (Roff) exhibited, in most cases, modest changes …

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Understanding Defect Interactions In Si Ultra-Shallow P-N Junctions Formed By Very Low Energy Boron Implantation, Lakshmanan H. Vanamurthy Jan 2013

Understanding Defect Interactions In Si Ultra-Shallow P-N Junctions Formed By Very Low Energy Boron Implantation, Lakshmanan H. Vanamurthy

Legacy Theses & Dissertations (2009 - 2024)

One of the biggest challenges in the scaling of CMOS devices is the formation of a highly activated, abrupt, defect free Source drain extension (SDE) region. This is especially difficult with p-FET's because of the (1) Boron diffusion co-efficient enhancement from Transient enhanced diffusion (TED) and (2) low solid solubility of

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Electrical And Optical Characterization Of Carbon Nanotube Diodes, Argyrios Malapanis Jan 2013

Electrical And Optical Characterization Of Carbon Nanotube Diodes, Argyrios Malapanis

Legacy Theses & Dissertations (2009 - 2024)

Carbon nanotubes are good candidates for future applications, including nanoelectronic and nanophotonic devices. Their quasi-one dimensional (1D) character offers appealing device properties. These include reduced carrier scattering, carrier mobility up to two orders of magnitude higher than that of materials used in state-of-the-art computer chips today, current densities rivaling those of the best semiconductors, enhanced optical absorption, and band gaps tunable with tube diameter and doping. Recent breakthroughs in research point to the possibility of placing nanotubes precisely on substrates with densities approaching that of transistors on today's computer chips in a way that's integratable with existing Si-based technology. Such …

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The Effect Of Energy Deposition On Pattern Resolution In Electron Beam Lithography, Ananthan Raghunathan Jan 2013

The Effect Of Energy Deposition On Pattern Resolution In Electron Beam Lithography, Ananthan Raghunathan

Legacy Theses & Dissertations (2009 - 2024)

Electron beam lithography is one of the most important tools for nanofabrication. Electron beam lithography has consistently been able to offer higher resolution, typically better than 10 nm or so, compared to other techniques. In this work the contribution of electron-substrate interaction to pattern resolution is investigated.

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Local Area Mask Patterning Of Extreme Ultraviolet Lithography Reticles For Native Defect Analysis, Adam Lyons Jan 2013

Local Area Mask Patterning Of Extreme Ultraviolet Lithography Reticles For Native Defect Analysis, Adam Lyons

Legacy Theses & Dissertations (2009 - 2024)

Understanding the nature and behavior of native defects on EUV reticles, particularly their printability, is of critical importance to the successful implementation of EUV lithography for high volume manufacturing, as will be demonstrated in the upcoming chapters. Previous defect characterization work has focused on the examination of programmed defects, native defects on blank reticles, and unaligned native defects on patterned reticles. Each of these approaches has drawbacks, which will be discussed in detail, and the aim of this research is to address these deficiencies by developing a method to pattern features of interest over native defects, enabling the direct observation …

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Defining An Optimal Surface Chemistry For Pluripotent Stem Cell Culture In 2d And 3d, Michael Roy Zonca Jr. Jan 2013

Defining An Optimal Surface Chemistry For Pluripotent Stem Cell Culture In 2d And 3d, Michael Roy Zonca Jr.

Legacy Theses & Dissertations (2009 - 2024)

Surface chemistry is critical for growing pluripotent stem cells in an undifferentiated state. There is great potential to engineer the surface chemistry at the nanoscale level to regulate stem cell adhesion. However, the challenge is to identify the optimal surface chemistry of the substrata for ES cell attachment and maintenance. Using a high-throughput polymerization and screening platform, a chemically defined, synthetic polymer grafted coating that supports strong attachment and high expansion capacity of pluripotent stem cells has been discovered using mouse embryonic stem (ES) cells as a model system. This optimal substrate, N-[3-(Dimethylamino)propyl] methacrylamide (DMAPMA) that is grafted on 2D …

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