Digital Commons Network^™

Strains In Si-Onsio2 Structures Formed By Oxygen Implantation: Raman Scattering Characterization, D.J. Olego, H. Baumgart, G.K. Celler

Electrical & Computer Engineering Faculty Publications

Low-temperature Raman scattering measurements were carried out to characterize Si-on-SiO₂ structures formed by oxygen implantation and subsequent furnace or lamp annealing. The experiments were conducted with 413.1 nm laser light to probe only the thin Si layers at the top of the structures. The Raman spectra of the furnace-annealed samples are red shifted and broadened when compared with a virgin Si surface. The shifts and broadenings decrease with increasing annealing temperatures but they are still present in samples annealed above 1250°C for 3 h. No shifts or broadenings affect the Raman peaks of the layers, which were lamp annealed …

Raman Scattering Characterization Of The Microscopic Structure Of Semi-Insulating Polycrystalline Si Thin Films, D.J. Olego, H. Baumgart

Electrical & Computer Engineering Faculty Publications

Raman scattering experiments were carried out to study the microscopic structure of semi-insulating polycrystalline Si (SIPOS) thin films prepared by low-pressure chemical vapor deposition. The samples contain 18, 25, and 30 at. % of oxygen and after growth they were annealed at 900 and 1000°C for 30 min. The Raman spectra show in the vibrational region of the optical frequencies of Si two bands, which arise from scattering in crystalline grains and disordered forms of Si. The behavior of these bands as a function of oxygen content and annealing temperatures was established in detail. The crystallinelike band peaks below the …

Microprocessor Controller For A Multi-Targets System, Shoeineng Lin

Theses

This thesis presents a microprocessor controller for a multi-targets system, which is designed by a direct digital control in the modern computer-aided manufacture system. It is made up of digital control theory, computer hardware configuration and software algorithm. An example is illustrated by IBM PC/XT computer. In this example, the control laws of three simple targets are developed and implemented by C-language. Simultaneously, the computer self-test routines, such as CPU, ROM etc, are developed by intel-8088 assembly language.

Interfacing Of The Digital Spyghnomanometer [Sic] Ds-165 To The Intel 8052ah Basic Based Single Board Computer, Rakesh P. Patel

Theses

The aim of this thesis is to collect the measured data from the blood pressure measurement unit to the single board computer and to store the data for the analysis purposes.

Two-Dimensionat Studies Of Streamers Fn Gases, S. K. Dhali, P. F. Williams

P. F. (Paul Frazer) Williams Publications

We present the results of two-dimensional computer simulations of streamer initiation and propagation in atmospheric pressure N₂. The simulation algorithm makes use of flux-corrected transport techniques and was used as a tool to study the solutions of the transport equations under conditions suitable for streamers, for which realistic analytic solutions are not known. We present and discuss conclusions about streamer transport based on the results of these studies. Finally, we present a novel method of checking on the numerical accuracy with which the algorithm solves the transport equations.

Constraint On The Optical Constants Of A Transparent Film On An Absorbing Substrate For Inversion Of The Ratio Of Complex P And S Reflection Coefficients At A Given Angle Of Incidence, R. M.A. Azzam, M. A. Habli

Electrical Engineering Faculty Publications

An absorbing substrate of complex refractive index n₂-jk₂ can be coated by a transparent thin film of refractive index n₁ and normalized thickness ζ so that the ratio of complex reflection coefficients for the pand s polarizations of the film-covered substrate ρ is the inverse of that of the film-free substrate ρ¯ at a given angle of incidence φ. A pair of parallel (metallic) mirrors, one uncoated and the other coated with a ρ-inverting layer, causes a beam displacement without change of polarization and with a certain net reflectance (insertion loss) ℜ. In this …

Surface-To-Surface Transition Via Electromagnetic Coupling Of Coplanar Waveguides, Robert W. Jackson, David W. Matolak

Faculty Publications

A transition is investigated which couples coplanar waveguide on one substrate surface (a motherboard) to coplanar waveguide on another substrate surface (a semiconductor chip or subarray) placed above the first. No wire bonds are necessary. A full-wave analysis using coupled line theory is presented and verified experimentally. The use of this transition for coupling to millimeter-wave integrated circuits is discussed.

Pulse-Train Instabilities In A Mode-Locked Argon Laser: Experimental Studies, Duncan Leo Macfarlane, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The output train of pulses from an acousto-optically mode-locked argon-ion laser was studied as a function of the loss modulation frequency for small detunings from the optimum c/2L modulation. A shift away from the optimum frequency by as little as 1 part in 10⁴ was found to produce several strong lower-frequency components that amplitude modulate the mode-locked pulse train. Notably, the strongest subharmonic is a frequency near ƒopt/4. Further detuning results in an irregular, slow (of the order of 10⁵ Hz) amplitude envelope on the pulse train. The homodyne spectrum of this phase of operation represents a progressive filling-in behavior …

Testing Of Ultrasonic Bonding In Microcircuits, Ioannis Andrea Phiniotis

Theses

A model for the ultrasonic bond as used in making microcircuit interconnections was studied. This model was based on Bowden & Tabor's dry friction theory and Mindlin's analysis of Hertz's model for elastic deformation under compressive and shear stresses. To develop a well-controlled bonding system, the critical bonding machine parameters were determined, and a high-frequency capacitor microphone was fitted to the bonding machine to monitor the tool tip oscillation. Application of these techniques made it possible to control the parameters of the machine to ±5%. Flip-chip bond studies were made using this machine. The data obtained were consistent with the …

Model Of Hot-Film Sensor With Substrate Effects, David Mcalpine Judge

Electrical & Computer Engineering Theses & Dissertations

A detailed mathematical model is constructed to investigate the frequency response of a hot-film anemometer system. Since several diverse factors affect the frequency response, the analysis is broken down into three main parts. Each part is a detailed mathematical model. The first model consists of the ordinary differential equations which govern the electronics of the feedback system and heat transfer of the sensor. An important simplification in this model is that the rate of heat conduction from the sensor to its substrate is constant.

In the second model the unsteady state heat transfer properties of the substrate are examined by …

Moment Method Analysis Of The Electric Field Under Ehv Transmission Lines, T. L. Simpson, Charles W. Brice

Faculty Publications

The charge moment method is applied to the analysis of electric fields under EHV transmission lines over irregular terrain.

A Dsp Toolkit For The Unix/C Environment Of The Pc 7300 Compute, Suwutchai Jesdanun

Theses

The Digital Signal Processing (DSP) TOOLKIT is a package of programs designed to use the fast Fourier transform (FFT) and display its output responses in graphics form. This tool provides three different window functions and five data modifiers for filter designing and spectrum analysis. Flexible features for modifying the plottings, such as y-axis auto-scaling, xy-axis scaling and center line adjusting of the graphics display, are included.

All programs are written in C programming language for the UNIX System Environment of the UNIX PC 7300 computer. The program structure of DSP TOOLKIT is designed so that modules can be added or …

Photodetector Arrangement For Measuring The State Of Polarization Of, Rasheed M.A. Azzam

University of New Orleans Patents

A photopolarimeter for the simultaneous measurement of all four Stokes parameters of light. The light beam, the state of polarization of which is to be determined, strikes, at oblique angles of incidence, three photodetector surfaces in succession, each of which is partially specularly reflecting and each of which generates an electrical signal proportional to the fraction of the radiation it absorbs. A fourth photodetector is substantially totally light absorbtive and detects the remainder of the light. The four outputs thus developed form a 4x1 signal vector I which is linearly related, I=A S, to the input Stokes vector S. Consequently, …

The Relationship Between Linguistic And Image Based Learning Approaches For Complex Problem Solving: A Case For Computer Generated Animation In Instructional Presentation Of Complex Technical Processes, Stanley T. Bissinger

Graduate Research Papers

The purpose of this study is to provide a rationale for development of new approaches to educating students about complex technical processes. This study may also prove helpful for determining what type of technical content is better suited for computer animated presentation.

An Investigation Of The Uses Of Scanning Electron Microscopy In The Analysis Of The Substructure Morphology Of Semiconducting Devices, Michael E. Courbat

Graduate Research Papers

The purpose of this study is to determine the technical requirements of SEM failure analysis in regard to its' inclusion in the Energy and Power curriculum of the Department of Industrial Technology, University of Northern Iowa.

The Influence Of Transverse Magnetic Fields On The Current-Voltage Characteristics Of Glow Discharges, Thomas J. Powers

Electrical & Computer Engineering Theses & Dissertations

In low pressure discharges, operated in electronegative gas mixtures to the right of the Paschen curve minimum, the discharge resistance can be increased by application of transverse magnetic fields. In this range of operation, both the mean free path and the larmor radius are small compared to the discharge dimensions. The relationship between the electric field and the magnetic field is therefore controlled by electron- molecule collisional processes. Specifically, the magnetically induced increase in the discharge resistance is caused by a downward shift of the electron energy distribution which leads to an increase in attachment and a reduction in ionization. …

Image Analyzing Instrumentation System For The Activity Measurement Of Rats, Yun-Kang Li

Theses

A microcomputer based instrumentation system has been developed to measure the activity of rats in 12 metabolic chambers. The instrumentation system monitors the rats' behaviors and estimates their activity continuously in an automatic manner. The activity information of the rats are expressed by a quantitative index which describes the intensity of the activity level.

An Apple II microcomputer system is used to manage the activity measurement which consists of an image recording operation and an image analyzing operation. During the measurement, the microcomputer controls Optic RAM digital cameras to record the rats' image. The camera can take a digital picture …

Mizer : A Ruled Based Cad Tool For Logic Optimization, Sandip Mukerjee

Theses

This objective of this research was to develop a knowledge based CAD tool, to address the problems of Logic Design. MIZER is an expert system, that accepts functional specifications of a logic circuit and connectivity description of its implementation to generate an optimal design. This information is then used to develop a hazard free circuit that brings about an optimization in area and timing. It stores the newly created design into its knowledge base with the approval of the designer, for future use.

Hardware Based Data Compression System Using Sliding Dictionary Algorithm, Hemant L. Nerurkar

Theses

Popular data compression schemes found in the literature are software based and present innumerable difficulties in hardware implementation. A data compression scheme, which can be directly implemented in hardware using systolic arrays, has been described. The scheme has a remarkable ability to 'adapt' itself to the changing statistics of the source file. Results generated after a comprehensive study and simulations of the algorithm have been presented. The scheme is inherently suitable for parallel processing. It can be incorporated in transmitting devices since it can be fabricated on a single VLSI chip. Comparison has been made with the LZW scheme. A …

Analysis Of An Inertial Navigation System On A Silicon Wafer, Ashok K. Parida

Theses

This thesis describes a self-contained inertial navigation system for commercial vehicles. It is low cost miniature system employing some of the newest techniques in micromechanical and microelectronic hardware.

The system employes an array of vibrating tuning fork gyros, a number of feedback force-balance accelerometers, and a central processing unit, all fabricated on a silicon wafer using integrated circuit fabrication technology. A miniature platform (size of a golf ball) driven by gearless torque motors is used to provide a quiet environment for the gyros and accelerometers. There are radio links between components that are on and off the platform (eliminating need …

Investigation Of The Size Of Gallium Clusters Formed Using A Modified Ion Cluster Beam Source With A Crucible Temperature Of 1250 Degrees C, Sujit M. Shah

Theses

Energy analysis of the ionized gallium clusters was done by retarding field method. The objective of this research was to investigate the possibility of gallium cluster formation during nozzle jet expansion and to estimate the probability of ionization of clusters. The measurements at a crucible temperature of 1250°C corresponding to gallium vapor pressure of 0.23 torr (inside the crucible) showed that no large cluster sizes could be obtained. The relationship between mass deposition rate (atoms/cm2-sec) and cluster size (atoms/cluster) showed that there were two distinct peaks. One with a cluster size of 1 atom/cluster and the other with about 13 …

Reliability Studies On Microcircuit, Salim Shehadeh

Theses

The primary objective of this thesis is to determine and analyze the failure mechanisms of Low Power Schottky microcircuit device (2-Input NAND Gate). Pinpoint the causes, and suggest the precautionary measures that prevent the occurrence of these failures. To achieve this goal, the study went in two directions, theoretical and experimental. The theoretical part is a comprehensive review of the work done on Low Power Schottky 2-Input NAND Gates since 1960 up to date.

The experimental part of the study is a life test ( 1000 hours ) of 2-Input NAND Gates under humidity and high temperature.

For each unit, …

Life Testing Of Solid Dielectric Materials, Muhammad Irfan Soomro

Theses

The main objective of this thesis was to find correlation between the electrical noise generated within the body of the solid dielectric material with the failure (puncture), under simultaneously applied thermal and electrical stresses.

The term 'Corona' is commonly used to describe any partial discharges occurring in voids (defects) in the material. Precisely corona is a flow of electrons and ions which occur in a void in air or other gasses. This event emits acoustic, optical and radio frequency energy, and can be detected by measuring any of these radiations. In the present thesis, Radio Interference Voltage (RIV) technique was …

Method Of Moments Analysis Of Very Thin Wires Using The Mini-Numerical Electromagnetics Code, Douglas F. Stolarz

Theses

The analysis of thin wire antenna systems in the presence of a conducting ground plane is an important engineering problem. This thesis presents an analysis of wire radiators using the method of moments as implemented in the Mini-Numerical Electromagnetics Code (MININEC). Due to singularities in the formulation, MININEC yields inaccurate results for very thin wires. This code was modified by introducing filament currents for very thin wire structures thereby eliminating inaccuracy due to the treatment of singularities.

The modified code was tested on a monopole over a perfect ground, symmetrical and asymmetrical dipoles in free space, and inverted L and …

A Cad Tool For Edif Model Generation, Sri Nagesh Valluri

Theses

This thesis describes a new CAD tool designed to create models proposed by Electronic Design Interchange Format steering committee. In its present form the system can generate models for standard SSI and MSI devices. The menu driven window based fillup the form features of the tool allows a novice user to provide structural and timing informations of the device from any manufacture's data book. The software performs online checking of the user data and guides them to generate the correct model.

Time Series Analysis Of Respiration Component In Heart Rate Variability, Anuradha Ramaswamy Iyengar

Theses

Time series signal processing techniques (Fourier based) were applied to analyze the relationship between heart rate and respiration. This analysis takes advantage of the different timing charecteristics of the autonomic nervous system inputs to analyze their influence on the heart rate.

Data from three experiments were analyzed. The first set of data was from helicopter pilots of the US Army. They injected atropine into themselves on certain days. The effect of atropine on the heart rate spectrum and the relationship between heart rate and respiration was studied. It was found that atropine abolishes the respiration peak in the heart rate …

An Investigation Of Electrical And Optical Properties Of Sputtered Amorphous Silicon Nitride And Germanium Thin Films, Rajendra S. Khandelwal

Theses

Low temperature preparation of thin amorphous Silicon Nitride and Germanium Films by direct RF sputter deposition was investigated. Influence of various sputtering parameters on film properties was studied. Infrared transmission spectrophotometry was used to evaluate optical properties of the films whereas electrical characteristics of the films were determined from current-voltage measurements of MIS structures. For Silicon Nitride films it was observed that the stoichiometry, as indicated by the IR transmission, dielectric constant and current density versus square root of electric field measurements, was a strong function of the sputtering gas composition and particularly the Ar/N ratio in the sputtering gas. …

Properties Of Sputtered A-Ge And A-Ge : H Thin Films, Hanjin Cho

Theses

The effect of the amorphous and glassy structure of amorphous germanium films on their electrical characteristics was investigated experimentally. The films were deposited onto silicon substrates using a modified MRC 8800 triode sputtering system. The Poole-Frenkel and Schottky mechanisms are discussed in detail and the shortcomings of the accepted picture of the former in amorphous materials are dealt with. It was concluded on the basis available evidence that the current flow in amorphous germanium favors the Poole-Frenkel mechanism at high fields.

Amorphous hydrogenated germanium films which were deposited by bias sputtering were characterized by measuring the infrared absorption. The films …

Study Of Reliability And Failure Mechanism Of Solid Tantalum Capacitor, Rajan N. Bhatt

Theses

Today, reliability is acknowledged as an important item in design and operation of the electronic systems.

This thesis provides some theory, and experiments are instituted to evaluate the reliability of SOLID TANTALUM CAPACITORS made by reputed manufacturers. The experiment was conducted on four batches of tantalum capacitors at different temperatures at different humidity levels. One chapter is on different manufacturing techniques presently applied.

Literature study concentrates on the reliability in solid tantalum capacitors developed between 1961 and 1986.

Several failure mechanism with figure are illustrated to point out how higher reliability of solid tantalum capacitor may be developed.

The bibliography …

Microcomputer-Based Automated System To Monitor Flow And Respiratory Quotient, Chung C. Chien

Theses

An instrument system has been designed to monitor Respiratory Quotient experiments on rats which are living within whole-body calorimeters. By using multiplexing techniques, this system is capable of monitoring Respiratory Quotients in six calorimeters (animal chambers). It exhibits some features that make it more versatile than the previous system. One of the features of this instrument is that it uses a more accurate method of determining rapid changes in gas exchange between subject and environment. The value of this method is its ability to assess the rapid change in metabolic rate which occurs as a result of change in activity, …