Engineering Commons^™

Nanowire-Based Frequency-Selective Capacitive Photodetector For Resonant Detection Of Infrared Radiation At Room Temperature, Saumil Bandyopadhyay

Electrical and Computer Engineering Publications

Characteristics of a capacitive infrared photodetector that works at room temperature by registering a change in capacitance upon illumination are reported. If used in an ideal resonant inductor-resistor-capacitor circuit, it can exhibit zero dark current, zero standby power dissipation, infinite detectivity, and infinite light-to-dark contrast ratio. It is also made frequency-selective by employing semiconductor nanowires that selectively absorb photons of energies close to the nanowire's bandgap. Based on measured parameters, the normalized detectivity is estimated to be ∼3 × 10⁷ Jones for 1.6 μm IR wavelength at room temperature.

Excitonic Recombination Dynamics In Non-Polar Gan/Algan Quantum Wells, D. Rosales, B. Gil, T. Bretagnon, B. Guizal, F. Zhang, S. Okur, M. Monavarian, N. Izyumskaya, V. Avrutin, Ü Özgür, H. Morkoç, J. H. Leach

Electrical and Computer Engineering Publications

The optical properties of GaN/Al0.15Ga0.85N multiple quantum wells are examined in 8 K–300 K temperature range. Both polarized CW and time resolved temperature-dependent photoluminescence experiment are performed so that we can deduce the relative contributions of the non-radiative and radiative recombination processes. From the calculation of the proportion of the excitonic population having wave vector in the light cone, we can deduce the variation of the radiative decay time with temperature. We find part of the excitonic population to be localized in concert with the report of Corfdir et al. (Jpn. J. Appl. Phys., Part 2 52, 08JC01 (2013)) in …

Properties Of The Main Mg-Related Acceptors In Gan From Optical And Structural Studies, B. Monemar, P. P. Paskov, G. Pozina, C. Hemmingsson, J. P. Bergman, S. Khromov, V. N. Izyumskaya, V. Avrutin, X. Li, H. Morkoç, H. Amano, M. Iwaya, I. Akasaki

Electrical and Computer Engineering Publications

The luminescent properties of Mg-doped GaN have recently received particular attention, e.g., in the light of new theoretical calculations, where the deep 2.9 eV luminescence band was suggested to be the main optical signature of the substitutional Mg Ga acceptor, thus, having a rather large binding energy and a strong phonon coupling in optical transitions. We present new experimental data on homoepitaxial Mg-doped layers, which together with the previous collection of data give an improved experimental picture of the various luminescence features in Mg-doped GaN. In n-type GaN with moderate Mg doping (<10¹⁸ cm⁻³), the 3.466 eV …

Spectroscopy Studies Of Straincompensated Mid-Infrared Qcl Active Regions On Misoriented Substrates, Gregory Edward Triplett, Justin Grayer, Charles Meyer, Emily Cheng, Denzil Roberts

Electrical and Computer Engineering Publications

In this work, we perform spectroscopic studies of AlGaAs/InGaAs quantum cascade laser structures that demonstrate frequency mixing using strain-compensated active regions. Using a three-quantum well design based on diagonal transitions, we incorporate strain in the active region using single and double well configurations on various surface planes (100) and (111). We observe the influence of piezoelectric properties in molecular beam epitaxy grown structures, where the addition of indium in the GaAs matrix increases the band bending in between injector regions and demonstrates a strong dependence on process conditions that include sample preparation, deposition rates, mole fraction, and enhanced surface diffusion …

Orientation-Dependent Pseudomorphic Growth Of Inas For Use In Lattice-Mismatched Mid-Infrared Photonic Structures, Gregory Edward Triplett, Charles Meyer, Emily Cheng

Electrical and Computer Engineering Publications

In this study, InAs was deposited on GaAs (100) and GaAs (111)B 2 degrees towardssubstrates for the purpose of differentiating the InAs growth mode stemming from strain and then analyzed using in-situ reflection high energy electron diffraction, scanning electron microscopy, Raman spectroscopy, reflectance spectroscopy, and atomic force microscopy. The procession of InAs deposition throughout a range of deposition conditions results in assorted forms of strain relief revealing that, despite lattice mismatch for InAs on GaAs (approximately 7%), InAs does not necessarily result in typical quantum dot/wire formation on (111) surfaces, but instead proceeds two-dimensionally due primarily to the surface orientation.

Investigating Engineering Practice Is Valuable For Mathematics Learning, Eileen Goold Dr

Conference Papers

While engineering mathematics curricula often prescribe a fixed body of mathematical knowledge, this study takes a different approach; second-year engineering students are additionally required to investigate and document an aspect of mathematics used in engineering practice. A qualitative approach is used to evaluate the impact that students’ investigations have on their mathematics learning and whether this approach creates greater value for students compared to curriculum mathematics learning. This article contains an account of students’ engagement with and their emotional responses to their investigations of professional engineers’mathematics usage.The study illustrates the positive changes in students’ mathematics attitudes arising from their insights …

Magnetic Battery Feasibility Study Using Flux Switching Topology, Andrew W. Janzen, John R. Natzke

Faculty Publications - Department of Electrical Engineering and Computer Science

Permanent magnets have long been known to store magnetic energy in the alignment of the magnetic domains within the material. This paper investigates the possibility of constructing a magnetic device which can effectively extract the stored potential energy from permanent magnets and convert that energy into electrical energy. The concept stemmed from a number of patents which claimed to effectively extract energy from strong neodymium or samarium cobalt magnets on a macroscopic scale using specially designed magnetic flux paths. Their method uses one of several different techniques to switch permanent magnet flux between alternating paths and electrical energy is extracted …

An Active Learning Module For An Introduction To Software Engineering Course, A. Frank Ackerman, Ph.D.

Computer Science & Software Engineering

Many schools do not begin to introduce college students to software engineering until they have had at least one semester of programming. Since software engineering is a large, complex, and abstract subject it is difficult to construct active learning exercises that build on the students’ elementary knowledge of programming and still teach basic software engineering principles. It is also the case that beginning students typically know how to construct small programs, but they have little experience with the techniques necessary to produce reliable and long-term maintainable modules. I have addressed these two concerns by defining a local standard (Montana Tech …

Analytical Parametric Model Used To Study The Influence Of Electrostatic Force On Surface Coverage During Electrospinning Of Polymer Fibers, Joshua Beisel, Jerry Kyeremateng, Lance Purkett, Jessica Andriolo, Jack L. Skinner

Electrical Engineering

Electrospinning (ES) can readily produce polymer fibers with cross-sectional dimensions ranging from tens of nanometers to tens of microns. Qualitative estimates of surface area coverage are rather intuitive. However, quantitative analytical and numerical methods for predicting surface coverage during ES have not been covered in sufficient depth to be applied in the design of novel materials, surfaces, and devices from ES fibers. This article presents a modeling approach to ES surface coverage where an analytical model is derived for use in quantitative prediction of surface coverage of ES fibers. The analytical model is used to predict the diameter of circular …

Engineering At San Jose State University, Winter 2014, San Jose State University, Charles W. Davidson College Of Engineering

Engineering at San Jose State University

No abstract provided.

The Literature Of Political Things And Places: Reading And Writing Design, Susan Yelavich

Articles

No abstract provided.

An Ontology Pattern For Oceanographic Cruises: Towards An Oceanographer's Dream Of Integrated Knowledge Discovery, Adila Krisnadhi, Robert Arko, Suzanne Carbotte, Cynthia Chandler, Michelle Cheatham, Timothy Finin, Pascal Hitzler, Krzysztof Janowicz, Thomas Narock, Lisa Raymond, Adam Shepherd, Peter Wiebe

Computer Science and Engineering Faculty Publications

EarthCube is a major effort of the National Science Foundation to establish a next-generation knowledge architecture for the broader geosciences. Data storage, retrieval, access, and reuse are central parts of this new effort. Currently, EarthCube is organized around several building blocks and research coordination networks. OceanLink is a semantics enabled building block that aims at improving data retrieval and reuse via ontologies, Semantic Web technologies, and Linked Data for the ocean sciences. Cruises, in the sense of research expeditions, are central events for ocean scientists. Consequently, information about these cruises and the involved vessels has to be shared and made …

From Cardiac Optical Imaging Data To Body Surface Ecg: A Three Dimensional Ventricle Model, Yihua Zhao

Theses and Dissertations--Biomedical Engineering

Understanding the mechanisms behind unexplained abnormal heart rhythms is important for diagnosis and prevention of arrhythmias. Many studies have investigated the mechanisms at organ, tissue, cellular and molecular levels. There is considerable information available from tissue level experiments that investigate local action potential properties and from optical imaging to observe activity propagation properties at an organ level. By combining those electrophysiological properties together, in the present study we developed a simulation model that can help in estimation of the resulting body surface potentials from a specific electrical activity pattern within the myocardium. Some of the potential uses of our model …

Enhancing Ocean Research Data Access, Cyndy Chandler, Robert Groman, Adam Shepherd, Molly Allison, Robert Arko, Yu Chen, Peter Fox, David Glover, Pascal Hitzler, Adam Leadbetter, Thomas Narock, Patrick West, Peter Wiebe

Computer Science and Engineering Faculty Publications

No abstract provided.

Optimization Of Ald High-K Dielectrics Via C-V Analysis, William Abisalih

Journal of the Microelectronic Engineering Conference

As device scaling is an ever present concern in semiconductor manufacturing, the need for thin, conformal films with which to fabricate these devices is paramount. One technology that appears prominently placed to fill this need is Atomic Layer Deposition. This work presents a study on atomic layer deposited alumina (Al₂O₃), hafnia (HfO₂), and silicon dioxide (SiO₂) as dielectric materials characterized using capacitance-voltage (CV) analysis. MOS capacitors were fabricated utilizing various combinations of alumina or hafnia and silicon dioxide as an interfacial layer. Each dielectric film was characterized optically to determine the thickness, …

Investigation Of A Self-Assembled Monolayer As A Cu Diffusion Barrier For Solar Cell Metallization, Anthony F. Aiello

Journal of the Microelectronic Engineering Conference

Copper diffusion into the silicon bulk is a detrimental obstacle to advanced-CMOS and photovoltaic processes that seek to incorporate copper into the metallization steps because of its deep-level trap nature to carriers. Recent studies have hinted that an organic porphyrin or silane-based self-assembled monolayer (SAM) could be a method of prevention to copper diffusion. Inorganic alternatives using TiO₂ or Ni may also present a solution. The self-assembly of 5,10,15,20- Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (OHTPP) over SiO₂ has been examined using atomic-force microscopy (AFM), contact angle measurements, and variable angle spectroscopic ellipsometry (VASE). Results indicate that this particular OHTPP chemistry fails to …

Investigation Of Electrical Characteristics Of Sputtered Igzo Tfts, Nicholas Edwards

Journal of the Microelectronic Engineering Conference

A study on the gas ambient (varying percent 02 flow) and gap spacing (distance between the target and wafer) during the sputter deposition of indium-gallium-zinc-oxide (IGZO) for a TFT channel material was executed. The effect these parameters have on electrical characteristics was investigated to better understand the role 02 vacancies play on device performance. This experiment was performed to enable investigations on IGZO TFTs without the use of external resources. Devices fabricated exhibited differences between treatment combinations, however results show a lower on-off current ratio, larger subthreshold swing (SS) and higher threshold voltage (Vth) than observed from devices fabricated with …

Dry Etching For High Aspect Ratio Silicon Fins, Michal Kucer

Journal of the Microelectronic Engineering Conference

The aim of this project is to develop a dry etching process that could be utilized to realize high aspect ratio fins. The traditional planar silicon transistor has seen amazing development ever since it became the workhorse of the semi conductor industry and the dominant way of realizing logic and analog circuits. However as its gate channels length is scaled down, the transistor encounters issues termed short channel effects and which has sprouted an extensive research into future replacements for the planar MOSFET. One of such devices is the Fin Field Effect Transistor or FinFET. Most of the FinFET fabrication …

"Black Silicon" By Rie For Photovoltaics, Jacob D. Lana

Journal of the Microelectronic Engineering Conference

Silicon-based solar cell technology continues to dominate the solar cell market making efficiency improvements to this class of devices sought after. A RIE process for creating “Black Silicon (BS)” was developed and integrated into a monocrystalline- Si solar cell process. Solar cells with BS exhibited an R_avg of 3.8% compared to 38.4% for solar cells with no antireflection apparatus (λ = 360-750 nm). BS solar cells were also found to have an EQE 16.4% higher than that of the control (λ = 360-1100 nm). On average J_sc and FF was higher for the BS solar cells …

Surface Cleaning Of Iii-V Pin Diodes To Reduce I0 For Tfet Applications, Ian R.T Manwaring

Journal of the Microelectronic Engineering Conference

The effect of surface cleaning and passivation techniques on the reverse bias saturation current Jo of In_0.53Ga_0.47As PIN diodes was investigated. The primary surface clean and passivation chemistries used were an HCI/D.I. H₂O solution, and an (NH₄)₂S solution, respectively. The effect of a Benzocyclobutene (BCB) capping layer, along with the influence of the BCB adhesion promoter was also investigated. It was found that the use of the surface clean and sulfide passivation reduced I₀ by over an order of magnitude, while also drastically tightening the overall distribution of I …

Mems Hall Effect Sensor, Michell Graciani Melo Espitia

Journal of the Microelectronic Engineering Conference

This paper presents a Hall effect sensor fabricated at the Semiconductor & Microsystems Fabrication Laboratory (SMFL) at the Rochester Institute of Technology. The Device was fabricated to have the maximum sensitivity possible with the available fabrication toolset and processes at the SMFL. The obtained resistivity of the fabricated devices was higher than expected and this affected the sensitivity of the devices. Results are shown where the devices are capable of sensing 100's of Gauss instead of the intended sensitivity of under 1 Gauss.

Design, Fabrication, And Testing Of A Mems Peltier Cooler (Tec- Thermoelectric Cooler), Brendan Merna

Journal of the Microelectronic Engineering Conference

In this paper, a MEMS Peltier Cooler was designed, fabricated, and tested to prove TEC (Thermoelectric Coolers) can be created with a fabrication process. Design was done using Mentor Graphics IC Station software, fabrication was done using a custom process, and testing was done using built in temperature sensors to observe the temperature difference between each side.

Self-Aligned Crossbar For Memristive Device Fabrication (May 2014), E Pethybridge

Journal of the Microelectronic Engineering Conference

Shadow Evaporation is demonstrated as a means of producing self-aligned crossbar structures with potential memristive applications. This serves as a solution to difficult metal oxide etching processes by substituting them with a single liftoff to form both electrodes. SEM and STEM analysis confirm the proper formation of the device and highlight opportunities for process optimization. The most significant improvement area is the replacement of the tantalum with aluminum for electrode material to prevent oxidation. The shadow evaporation process and device formation are the focus of this exercise.

Characterization Of Conductive Tin Oxide For Mems Chemical Gas Sensors, Alycia N. Roux

Journal of the Microelectronic Engineering Conference

Conductive tin oxide films were deposited through reactive sputtering on glass substrates under different preparation conditions sch as substrate temperature, substrate type, and total chamber pressure. The films were characterized viz X-ray diffraction (XRD), thickness, and sheet resistance. The thicknesses of the films were found to be around 0.5 microns for the oxide films which is half the thickness of the metal control films. The thickness of the heated oxide film was measured to be 0.4 microns. The sheet resistances of the oxide films ranged from values of 98 Ω/sq. to an unreadable value due to the entire film being …

A Method For Clustering High-Dimensional Data Using 1d Random Projections, Sangchun Han

Open Access Dissertations

Clustering high-dimensional data is more difficult than clustering low-dimensional data. The problem is twofold. First, there is an efficiency problem related to the data size, which increases with the dimensionality. Second, there is an effectiveness problem related to the fact that the mere existence of clusters in sample sets of high dimensions is questionable, as empirical samples hardly tend to cluster together in a meaningful fashion. The current approach to addressing this issue is to seek clusters in embedded subspaces of the original space. However, as dimensionality increases, a naive exhaustive search among all subspaces becomes exponentially more complex, which …

Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde

STAR Program Research Presentations

This project explores the stability analysis of a given flow field. Specifically, where the peak disturbance occurs in a flow as this is the disturbance that is most likely to occur. In rocket combustion, it is important to understand where the maximum disturbance occurs so that the mixing of fuel can be stabilized. The instabilities are the results of frequencies in the area surrounding the flow field. The linear stability governing equations are employed to better understand the disturbance. The governing equations for continuity and momentum in the x and y directions are used to form an equation for the …

The Influence Of Partial And Full Thickness Tears On Infraspinatus Tendon Strain Patterns, Kayt E. Frisch, David Marcu, Geoffrey S. Baer, Darryl G. Thelen, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Tears on the bursal and articular sides of the rotator cuff tendons are known to behave differently and strain is thought to play a role in this difference. This study investigates the effect of tear location on the changes in three strain measurements (grip-to-grip, insertion, and mid-substance tissue) in a sheep infraspinatus tendon model during axial loading. We introduced a 14mm wide defect near the insertion from either the articular or bursal side of the tendon to three depths (3 mm, 7mm & full) progressively. For each condition, tendons were sinusoidally stretched (4% at 0.5 Hz) while insertion and midsubstance …

Combining Monte Carlo Transport And Level Set Surface Evolution For Modeling Vapor Phase Deposition Of Thin Films Over Sub-Micron Features, John Lewis Smith

Graduate Theses - Chemical Engineering

A hybrid scheme is used to model the vapor phase deposition of thin films at the feature scale. The transport of the chemical species to the substrate surface is modeled with a Collisionless Direct Simulation Monte Carlo (DSMC) method. The Level Set Method is used to model the growth of the thin-film on the substrate. The convergence criteria for these methods were not found in literature.

The governing equations for the Level Set Method are, in general, non-linear partial differential equations. The coupling of the DSMC Method with the Level Set Method results in a set of non-Gaussian stochastic non-linear …

New Sensor Technology Integration For Safe And Efficient E-Navigation, Michael Baldauf, R. Glenn Wright

Conference Papers

This paper discusses the relation of new sensor technology on bridge resource management as pertaining to the integration of new information sources and types for ship navigation in a future e-Navigation environment. An overview of several new technologies will be provided showing how systems and devices currently available in the commercial marketplace are being adapted and used to aid ship navigation planning and decision making. Examples include live Doppler radar useful for coastal navigation available from land-based sources through broadband Internet connections, imagery from unmanned aerial vehicles to aid in ice-navigation in, and forward-looking sonar for navigating in poorly charted, …

Null Convention Logic Asynchronous Register Full Path Completion Feedback Loop Using Two Stage Voltage Divider, Christopher P. Taylor

Browse all Theses and Dissertations

As fabrication technologies improve logic densities increase. It becomes harder to mitigate clock skew and jitter. Higher clock rates combined with increased numbers of sinks increase mixed-system substrate noise. An increasingly popular approach to address these problems is clockless logic. One technique is Null Convention Logic (NCL). However, traditional NCL feedback loops have large area overhead and require many gate delays. This makes NCL impractical in many applications. In this paper we propose to replace the feedback logic with a two-stage voltage divider. Using our technique we show up to 50% area reduction and require only one unit gate delay.