Engineering Commons^™

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …

Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

This Thesis is concerned with the design, layout, and testing of avalanche photodiodes (APDs). APDs are a type of photodetector and, thus, convert light signals into electrical signals (current or voltage). APDs can be fabricated using silicon (Si). In this Thesis, however, three integrated circuit (IC) chips containing various silicon-germanium (SiGe) APDs with different sizes, structures, and geometries were designed, laid out, and fabricated using the Austriamicrosystems (AMS) 0.35μm SiGe BiCMOS (S35) process. This was done in order to compare SiGe APDs to Si only APDs and investigate the hypothesis that SiGe APDs are capable of detecting longer wavelengths than …

Comparison Of Organic And Inorganic Solar Photovoltaic Systems, Khulan Orgil

Electrical Engineering

This senior project report addresses the consumer’s need for accurate and easily accessible information when making a solar panel purchasing decision. Thus, the project analyzes and compares the costs and benefits of organic and inorganic photovoltaic systems during their life cycle. The cost comparison includes analysis of the environmental and economic costs of materials, production, installation, and disposal. The benefit comparison includes analysis of the economic, environmental, and social benefits accrued during the system’s lifetime. With the project’s data, consumers can make more informed decisions to fit their specific needs.

Application Of Silicon Nanohair Textured P-N Junctions In A Photovoltaic Device, Michael Small

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for a silicon photovoltaic device which incorporates a nanohair textured p-n junction. The silicon nanowires are etched into a silicon wafer, comprising an epitaxial p-layer on n-substrate, via metal-assisted chemical etching (MACE). The resulting nanowires contain p-n junctions that lie along the length of the vertical nanowires. This construct has the potential to increase the optical bandwidth of a silicon photovoltaic device by allowing a greater amount of short wavelength light to reach the junction. In addition, the MACE method of nanofabrication has the potential for decreasing …

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

Thermoreflectance Technique For Thermal Properties Measurement Of Micro/Nanoscale Cantilever Beams, Mirza M. Elahi

Electrical and Computer Engineering ETDs

Thermal property analysis of thin film materials on a semi-infinite substrate is a very important area of research in last few decades due to the deviation of their properties from its bulk values and measurement technique plays very important role to be free from the effect of interface conductance, surface impurities, convective and radiative losses and fabrication tolerances. Non-contact optical measurement technique drew attention to be applicable to measure thermal properties using pump-probe thermoreflectance where short pulse Laser beam applied to the film to avoid heat loss with the inclusion of the interfacial conductance and extract thermal diffusivity which is …

Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young

Graduate Theses and Dissertations

The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type …

Laser Direct Written Silicon Nanowires For Electronic And Sensing Applications, Woongsik Nam

Open Access Dissertations

Silicon nanowires are promising building blocks for high-performance electronics and chemical/biological sensing devices due to their ultra-small body and high surface-to-volume ratios. However, the lack of the ability to assemble and position nanowires in a highly controlled manner still remains an obstacle to fully exploiting the substantial potential of nanowires. Here we demonstrate a one-step method to synthesize intrinsic and doped silicon nanowires for device applications. Sub-diffraction limited nanowires as thin as 60 nm are synthesized using laser direct writing in combination with chemical vapor deposition, which has the advantages of in-situ doping, catalyst-free growth, and precise control of position, …

Transfer Printed Semiconductor Nanomembranes For Heterogeneously Integrated Multi-Band Imager Arrays, Laxmy Menon

Electrical Engineering Dissertations

The electronics industry is ruled by silicon which is realized as the solution to meet the requirements of higher bandwidth and low cost high density monolithic integration. However, silicon has its limitations when it comes to high frequency or optoelectronic applications. Fusion of several functionalities on one chip can be obtained by heterogeneous integration of materials that have optimized performance for a specific application. The ability to tailor heterogeneous materials to be able to integrate them with each other, in rigid or flexible form, can lead to novel and superior functionalities, with impact in multitude of areas like electronics, optoelectronics, …

Performance Optimization Of Lateral-Mode Thin-Film Piezoelectric-On-Substrate Resonant Systems, Hedy Fatemi

Electronic Theses and Dissertations

The main focus of this dissertation is to characterize and improve the performance of thin-film piezoelectric-on-substrate (TPoS) lateral-mode resonators and filters. TPoS is a class of piezoelectric MEMS devices which benefits from the high coupling coefficient of the piezoelectric transduction mechanism while taking advantage of superior acoustic properties of a substrate. The use of lateral-mode TPoS designs allows for fabrication of dispersed-frequency filters on a single substrate, thus significantly reducing the size and manufacturing cost of devices. TPoS filters also offer a lower temperature coefficient of frequency, and better power handling capability compared to rival technologies all in a very …

Study Of Millisecond Laser Annealing On Ion Implanted Soi And Application To Scaled Finfet Technology, Tyler J. Michalak

Legacy Theses & Dissertations (2009 - 2024)

The fabrication of metal-oxide-semiconductor field effect transistors (MOSFET) requires the engineering of low resistance, low leakage, and extremely precise p-n junctions. The introduction of finFET technology has introduced new challenges for traditional ion implantation and annealing techniques in junction design as the fin widths continue to decrease for improved short channel control. This work investigates the use of millisecond scanning laser annealing in the formation of n-type source/drain junctions in next generation MOSFET.

Fabrication And Characterization Of Compact High Resolution Radiation Detectors Based On 4h-Sic N-Type Epilayer And Cdznte, Kelvin Juvenal Zavalla Mendoza

Theses and Dissertations

The need of room-temperature, compact, and high resolution radiation detectors has opened the path for the development of new materials with suitable properties. Silicon carbide (SiC) and CdZnTe (CZT) are semiconductor materials with wide band gap that can operate efficiently at room temperatures (RT) and above. CZT has a high average atomic number (Z) which offers a high photoelectric absorption coefficient for x-/gamma rays. SiC allows high energy heavy ion detection due to its high radiation hardness even at temperatures much higher than room temperatures (RT). This thesis focuses on the fabrication and characterization of semiconductor based radiation detectors for …

Fabrication Of Horizontal Silicon Nanowires Using A Thin Aluminum Film As A Catalyst, Khaja Hafeezuddin Mohammed

Graduate Theses and Dissertations

Silicon nanowires have been the topic of research in recent years for their significant attention from the electronics industry to grow even smaller electronic devices. The semiconductor industry is built on silicon. Silicon nanowires can be the building blocks for future nanoelectronic devices. Various techniques have also been reported in fabricating the silicon nanowires. But most of the techniques reported, grow vertical silicon nanowires. In the semiconductor industry, integrated circuits are designed and fabricated in a horizontal architecture i.e. the device layout is flat compared to the substrate. When vertical silicon nanowires are introduced in the semiconductor industry, a whole …

Size Dependent Melting And Diffusion Of Silicon For Microsystem Applications, Noel Felipe Marquez

Open Access Theses & Dissertations

The size dependent reduced melting point and hydrogen enhanced surface diffusion effect on silicon nanostructures was explored experimentally. SOI and silicon wafers were patterned using nanimprint lithography and dry etching to explore the reduced melting point effect; and patterned with photolithography and dry etching to explore the hydrogen enhanced surface diffusion. The nanotextured samples were annealed in a wide variety of furnaces with nitrogen, forming gas, and argon atmospheres. Nitrogen was found to block the reshaping effect while argon was found to cause extensive pitting damage in the setup used. Micropatterned samples were annealed in a low pressure hydrogen enabled …

Growth And Characterization Of Non-Polar Gan Materials And Investigation Of Efficiency Droop In Ingan Light Emitting Diodes, Xianfeng Ni

Theses and Dissertations

General lighting with InGaN light emitting diodes (LEDs) as light sources is of particular interest in terms of energy savings and related environmental benefits due to high lighting efficiency, long lifetime, and Hg-free nature. Incandescent and fluorescent light sources are used for general lighting almost everywhere. But their lighting efficiency is very limited: only 20-30 lm/W for incandescent lighting bulb, approximately 100 lm/W for fluorescent lighting. State-of-the-art InGaN LEDs with a luminous efficacy of over 200 lm/W at room temperature have been reported. However, the goal of replacing the incandescent and fluorescent lights with InGaN LEDs is still elusive since …

Optically Powered Logic Transistor, Hanho Cho

Theses and Dissertations

This thesis presents the modeling and fabrication of a new solid-state device meant to be used for digital logic circuits. Most current logic circuits are based on MOSFETs. The new logic device uses some of the same operating principles, but also relies on optical illumination to provide input power. In order to obtain the desired current-voltage behavior of the new device, the Silvaco (Atlas) device simulation was used to give some insight into the correct doping levels in the semiconductor and device geometries. Prototypes were fabricated on p-type silicon wafers using CMOS fabrication processes including oxide growth, photolithography, precise plasma …

Reflection High-Energy Electron Diffraction Studies Of Indium Phosphide (100) And Growth On Indium And Indium Nitride On Silicon (100), Mohamed Abd-Elsattar Hafez

Electrical & Computer Engineering Theses & Dissertations

Study of the effects of atomic hydrogen exposure on structure and morphology of semiconductor surfaces is important for fundamental properties and applications. In this dissertation, the electron yield of a hydrogen-cleaned indium phosphide (InP) surface was measured and correlated to the development of the surface morphology, which was monitored by in situ reflection high-energy electron diffraction (RHEED). Atomic hydrogen treatment produced a clean, well-ordered, and (2x4)-reconstructed InP(100) surface. The quantum efficiency, after activation to negative electron affinity, and the secondary electron emission were shown to increase with hydrogen cleaning time. RHEED patterns of low-index InP(100) surface were modified by the …

Design And Development Of Microcantilever As A Platform For Moisture Sensing, Qi Chen

Doctoral Dissertations

Ultra-sensitive and selective moisture sensors are needed in various industries for processing control or environmental monitoring. As an outstanding sensor platform, microcantilevers have potential application in moisture detection due to their advantages, such as low-level moisture detection limits, high accuracy, quick response time, high reproducibility, good recovery rate and low in cost. Our research results will lead to the first of its kind for the commercialization of a microcantilever-based moisture sensor used for industrial and household applications. The novelty of the present work is the development of SiO2 and Si cantilevers, which were fabricated using developed processes and modified with …

Study Of Si/Sio2 Interface Passivation And Sio2 Reliability On Deuterium Implanted Silicon, Tias Kundu

Dissertations

One of the major defects that contribute to the interface states in the silicon band gap is the dangling bond, which degrades performance of MOS devices. Passivation of these bonds with hydrogen had been found to diminish their effect but the improvement degrades the operation due to hot electron effect. Passivation with deuterium annealing has proven to improve the lifetime of the metal oxide semiconductor devices but this technique is not very effective for a multi-level metal-dielectric structure. This work investigates and optimizes incorporation of deuterium by ion implantation into the silicon substrate before the growth of 6.5 nm thin …

Bulk Micromachining Of Silicon For Moems Prototype, Sung-Dong Suh

Doctoral Dissertations

In this dissertation, the optical application of silicon micromachining technology was investigated in order to create the three-dimensional microstructures that can be used as the components for the MOEMS prototype. These microstructures were designed and fabricated by utilizing corner compensation techniques and silicon bulk micromachining technologies. The fabricated microstructures are silicon mirror arrays that have a 1250 μm etch depth and through-holes across the OE-MCM substrate that has sixteen-fan-out OCDN on front side and a 1mm thickness.

Guided-wave OCDN on MCMs are designed and fabricated to meet the high-speed clocking requirements of next-generation digital systems through a realization of superior …

Compensation And Characterization Of Gallium Arsenide, Randy A. Roush

Electrical & Computer Engineering Theses & Dissertations

The properties of transition metals in gallium arsenide have been previously investigated extensively with respect to activation energies, but little effort has been made to correlate processing parameters with electronic characteristics. Diffusion of copper in gallium arsenide is of technological importance due to the development of GaAs:Cu bistable photoconductive devices. Several techniques are demonstrated in this work to develop and characterize compensated gallium arsenide wafers. The material is created by the thermal diffusion of copper into silicon-doped GaAs. Transition metals generally form deep and shallow acceptors in GaAs, and therefore compensation is possible by material processing such that the shallow …

Aluminum Epitaxy On Silicon, Samuel Cruz Ramac

Theses

The purpose of this work was to study the effect of 4° miscut and chem¬ical pretreatment of Si(111) wafers on the epitaxial growth of Al by thermal evaporation in a UHV environment (~ 10^-9 Torr). Two chemical pretreatments of the wafers were used. One included HF only and the other included NH₄F after an initial HF treatment. The substrates were not heated dur¬ing deposition. XRD measurements of the films were done before and after annealing in a high vacuum oven for one hour at temperatures between 200 and 350°C.

The A1(200) films deposited on wafers pretreated with …

Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan

Theses

This thesis presents the damage effects to the Si ? SiO₂ structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO₂ MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which …