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Full-Text Articles in Engineering

Exploring Gated Nanoelectronic Devices Fabricated From 1d And 2d Materials, Prathamesh A. Dhakras Jan 2019

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.


Electron Transport In One And Two Dimensional Materials, Samuel William Lagasse Jan 2019

Electron Transport In One And Two Dimensional Materials, Samuel William Lagasse

Legacy Theses & Dissertations (2009 - 2024)

This dissertation presents theoretical and experimental studies in carbon nanotubes (CNTs), graphene, and van der Waals heterostructures. The first half of the dissertation focuses on cutting edge tight-binding-based quantum transport models which are used to study proton irradiation-induced single-event effects in carbon nanotubes [1], total ionizing dose effects in graphene [2], quantum hall effect in graded graphene p-n junctions [3], and ballistic electron focusing in graphene p-n junctions [4]. In each study, tight-binding models are developed, with heavy emphasis on tying to experimental data. Once benchmarked against experiment, properties of each system which are difficult to access in the laboratory, …


Synthesis Of Cadmium Arsenide Semiconductor Nanoparticles, Superatomic Silver Clusters, And Silver Coordination Polymers, Sarthak Jashubhai Patel Jan 2019

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 Contact Properties At Metal Graphene Junctions, Their Degradation And Intrinsic Limitations, Zhenjun Zhang Jan 2016

Investigation Of Contact Properties At Metal Graphene Junctions, Their Degradation And Intrinsic Limitations, Zhenjun Zhang

Legacy Theses & Dissertations (2009 - 2024)

Graphene is a two-dimensional material, comprised of a monolayer of carbon in a hexagonal lattice. Since 2004, the most promising applications of this material are high frequency devices (such as mixers and power amplifiers), as well as flexible and transparent electronics. However, these applications can’t be realized without a proper contact metal. With more understanding of the contact properties, the range of prospects for graphene’s applications can be better defined.


Optical Metrology For Directed Self-Assembly Patterning Using Mueller Matrix Spectroscopic Ellipsometry Based Scatterometry, Dhairya J. Dixit Jan 2015

Optical Metrology For Directed Self-Assembly Patterning Using Mueller Matrix Spectroscopic Ellipsometry Based Scatterometry, Dhairya J. Dixit

Legacy Theses & Dissertations (2009 - 2024)

The semiconductor industry continues to drive patterning solutions that enable devices with higher memory storage capacity, faster computing performance, lower cost per transistors, and higher transistor density. These developments in the field of semiconductor manufacturing along with the overall minimization of the size of transistors require cutting-edge metrology tools for characterization.


Nanoparticle Generation And Interactions With Surfaces In Vacuum Systems, Yashdeep Khopkar Jan 2015

Nanoparticle Generation And Interactions With Surfaces In Vacuum Systems, Yashdeep Khopkar

Legacy Theses & Dissertations (2009 - 2024)

Extreme ultraviolet lithography (EUVL) is the most likely candidate as the next generation technology beyond immersion lithography to be used in high volume manufacturing in the semiconductor industry. One of the most problematic areas in the development process is the fabrication of mask blanks used in EUVL. As the masks are reflective, there is a chance that any surface aberrations in the form of bumps or pits could be printed on the silicon wafers. There is a strict tolerance to the number density of such defects on the mask that can be used in the final printing process. Bumps on …


Design And Development Of Stress Engineering Techniques For Iii-Nitride Epitaxy On Si, Jeff Leathersich Jan 2015

Design And Development Of Stress Engineering Techniques For Iii-Nitride Epitaxy On Si, Jeff Leathersich

Legacy Theses & Dissertations (2009 - 2024)

III-Nitrides have been a heavily researched material system for decades. Their material properties are favorable for a number of applications, most commonly in the optoelectronic and power device industry. Currently a majority of commercialized devices are fabricated on sapphire and SiC substrates but these are expensive and limit the widespread commercialization of the technology. There is substantial ongoing research geared toward the development of GaN on Si substrates because of the significant cost saving that would be realized through the inexpensive, large wafer and maturity of Si fabrication. Significant challenges with the deposition of GaN on Si have, thus far, …


An Assessment Of Critical Dimension Small Angle X-Ray Scattering Metrology For Advanced Semiconductor Manufacturing, Charles Michael Settens Jan 2015

An Assessment Of Critical Dimension Small Angle X-Ray Scattering Metrology For Advanced Semiconductor Manufacturing, Charles Michael Settens

Legacy Theses & Dissertations (2009 - 2024)

Simultaneous migration of planar transistors to FinFET architectures, the introduction of a plurality of materials to ensure suitable electrical characteristics, and the establishment of reliable multiple patterning lithography schemes to pattern sub-10 nm feature sizes imposes formidable challenges to current in-line dimensional metrologies. Because the shape of a FinFET channel cross-section immediately influences the electrical characteristics, the evaluation of 3D device structures requires measurement of parameters beyond traditional critical dimension (CD), including their sidewall angles, top corner rounding and footing, roughness, recesses and undercuts at single nanometer dimensions; thus, metrologies require sub-nm and approaching atomic level measurement uncertainty.


Fundamental Studies Of Supported Graphene Interfaces : Defect Density Of States In Graphene Field Effect Transistors (Fets) And Ideal Graphene - Silicon Schottky Diodes, Dhiraj Sinha Jan 2014

Fundamental Studies Of Supported Graphene Interfaces : Defect Density Of States In Graphene Field Effect Transistors (Fets) And Ideal Graphene - Silicon Schottky Diodes, Dhiraj Sinha

Legacy Theses & Dissertations (2009 - 2024)

The physics of transport in atomically thin 2D materials is an active area of research, important for understanding fundamental properties of reduced dimensional materials and for applications. New phenomena based on graphene may include properties of topologically protected insulators. Applications of these materials are envisioned in electronics, optoelectronics and spintronics.


Oxide Defect Engineering Methods For Valence Change (Vcm) Resistive Random Access Memories, Jihan Ocampo Capulong Jan 2014

Oxide Defect Engineering Methods For Valence Change (Vcm) Resistive Random Access Memories, Jihan Ocampo Capulong

Legacy Theses & Dissertations (2009 - 2024)

Electrical switching requirements for resistive random access memory (ReRAM) devices are multifaceted, based on device application. Thus, it is important to obtain an understanding of these switching properties and how they relate to the oxygen vacancy concentration and oxygen vacancy defects. Oxygen vacancy defects in the switching oxide of valence-change-based ReRAM (VCM ReRAM) play a significant role in device switching properties. Oxygen vacancies facilitate resistive switching as they form the conductive filament that changes the resistance state of the device. This dissertation will present two methods of modulating the defect concentration in VCM ReRAM composed of Pt/HfOx/Ti stack: …


Towards A Fundamental Understanding Of Inhomogeneous Interfaces Utilizing Ballistic Electron Emission Microscopy, Robert John Balsano Jan 2014

Towards A Fundamental Understanding Of Inhomogeneous Interfaces Utilizing Ballistic Electron Emission Microscopy, Robert John Balsano

Legacy Theses & Dissertations (2009 - 2024)

A fundamental understanding of charge transport across metal/semiconductor interfaces is of great technological and scientific importance. Metal/semiconductor, or Schottky barrier devices are widely utilized in sensing applications and power electronics. Additionally, Schottky barriers appear in resistive memory technology and current transistor technology. Although Schottky interfaces are ubiquitous, the effects of spatially variant interfaces on the measured Schottky barrier height (SBH) are not entirely understood. For these reasons it is necessary to explore the spatial variation at Schottky interfaces at the nanoscale. Ballistic electron emission microscopy (BEEM) is a three terminal scanning tunneling microscopy (STM) technique used to measure hot carrier …


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 …


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


Modified Statistical Dynamical Diffraction Theory : A Novel Metrological Analysis Method For Partially Relaxed And Defective C Doped Si And Sige Heterostructures, Paul Kenneth Shreeman Jan 2012

Modified Statistical Dynamical Diffraction Theory : A Novel Metrological Analysis Method For Partially Relaxed And Defective C Doped Si And Sige Heterostructures, Paul Kenneth Shreeman

Legacy Theses & Dissertations (2009 - 2024)

The statistical dynamical diffraction theory, which has been initially developed by late Kato remained in obscurity for many years due to intense and difficult mathematical treatment that proved to be quite challenging to implement and apply. With assistance of many authors in past (including Bushuev, Pavlov, Pungeov, and among the others), it became possible to implement this unique x-ray diffraction theory that combines the kinematical (ideally imperfect) and dynamical (the characteristically perfect diffraction) into a single system of equations controlled by two factors determined by long range order and correlation function within the structure. The first stage is completed by …


Surface Potential Measurements Of Reconfigurable P-N Junctions In Graphene, Yunfei Wang Jan 2012

Surface Potential Measurements Of Reconfigurable P-N Junctions In Graphene, Yunfei Wang

Legacy Theses & Dissertations (2009 - 2024)

Manipulation and control of electron current in a graphene p-n junction (e.g. electron waveguiding, reflection, focusing) is directly determined by the spatial gradient of the Fermi level across the junction. Sharp Fermi level gradients are associated with negative index `lensing' of electrons in graphene while broader gradients are predicted to form reflective boundaries. Quantitative metrology of the Fermi level gradient at p-n junctions is thus essential to determine device performance, validate models for device design and switch architectures, and quantitatively determine the impact of defects on device function and leakage.


Cost-Effective Imprint Template Fabrication For Step And Flash Imprint Lithography, Adam Marc Munder Jan 2011

Cost-Effective Imprint Template Fabrication For Step And Flash Imprint Lithography, Adam Marc Munder

Legacy Theses & Dissertations (2009 - 2024)

The College of Nanoscale Science and Engineering (CNSE) is studying imprint template fabrication with the 100kV Vistec VB300 Gaussian E-Beam writer. The major goal is to develop and advance imprint template fabrication technology using low cost quartz wafers for proof-of-concept demonstrations.


Optimization And Development Of Silicon-Based Semiconductor Devices Using Tcad, Changwoo Lee Jan 2011

Optimization And Development Of Silicon-Based Semiconductor Devices Using Tcad, Changwoo Lee

Legacy Theses & Dissertations (2009 - 2024)

Computer simulation of the electrical and optical properties of semiconductor devices has been became as an essential tool for developing new device as well as for improving existing device. This presentation describes applications of physical device simulation: (1) design optimization of power MOSFET, which is single crystalline based silicon semiconductor device, for cryogenic temperature application and (2) two-dimensional device simulation of amorphous silicon based solar cell to develop novel photovoltaic device with high efficiency.