Implications Of Rough Dielectric Surfaces On Charging-Adjusted Actuation Of Rf-Mems, 2014 Purdue University
Implications Of Rough Dielectric Surfaces On Charging-Adjusted Actuation Of Rf-Mems, Sambit Palit, Xin Xu, Arvind Raman, Muhammad Ashraful Alam
Birck and NCN Publications
Actuation voltage shifts due to dielectric charging is a leading reliability concern in Radio-Frequency Micro-Electro-Mechanical Systems (RF-MEMS) capacitive switches. The inability to correlate dielectric surface roughness to charge accumulation makes predictive design difficult. We apply a sophisticated dielectric charging model on representative surfaces based on Atomic Force Microscopy (AFM) data, and show that there are significant, but predictable actuation voltage shifts due to surface roughness. The results suggest that surface roughness should be considered for accurate lifetime predictions, and simple metal-insulator-metal (MIM) capacitors may serve as a useful test structure for this phenomenon.
Health Risks Caused By Wireless Technologies, 2014 Minnesota State University, Mankato
Health Risks Caused By Wireless Technologies, Durreeshahwar Zafarahmed, Qurrat-Ul-Ain Zafarahmed
Journal of Undergraduate Research at Minnesota State University, Mankato
There are many health issues related to the use of cellular phones, wireless local area networks, and other devices that emit electromagnetic radiation (EMR). Some of these systems have become a part of our daily lives and many of us are in direct or indirect contact for extended period of times with these devices. However, the general public is unaware of the health risks associated with the use of these devices. Our research covers studies done by individuals as well as organizations on the harmful effects on the health of people from these devices and their claims. We also present ...
Characterization And Testing Of A 5.8 Kv Sic Pin Diode For Electric Space Propulsion Applications, 2014 University of Nebraska - Lincoln
Characterization And Testing Of A 5.8 Kv Sic Pin Diode For Electric Space Propulsion Applications, Alexandra Toftul
Electrical Engineering Theses and Dissertations
Inductive Pulsed Plasma Thrusters (IPPTs) are a type of in-space propulsion that has multiple advantages over conventional chemical propulsion for long-duration, deep space missions. Existing IPPT prototypes utilize spark gap switches, however these are subject to corrosion problems that make them unreliable for long-term use. Recent advances in solid state switching technology have opened up a variety of switching options that could provide greater reliability, controllability, and increased energy efficiency. Taking advantage of this, a novel thruster drive circuit topology containing a high-power silicon controlled rectifier (SCR) and series fast recovery diode (FRD) is proposed that is expected to increase ...
Low Loss Configuration For Integrated Pin-Schottky Limiters, 2014 SelectedWorks
Low Loss Configuration For Integrated Pin-Schottky Limiters, Chin-Leong Lim
Compared to the PIN diode limiter, the Schottky-PIN limiter improves receiver protection, but has a higher insertion loss. Low cost, plastic packaged diodes can further worsen the loss. Diode stacking, mesa diode construction, and isolating the Schottky diode with a high-impedance quarter wave line or a directional coupler can reduce loss, but detrimentally raises the limiting threshold and/or adds bulk or cost. The PIN-Schottky limiter’s insertion loss can be improved by integrating the diodes’ parasitic capacitances into a low pass ladder network, but this solution requires the PIN diode to have two anode connections. Recently, the PIN-Schottky limiter ...
Electrical Breakdown In Polymers For Beol Applications: Dielectric Heating And Humidity Effects, 2014 Purdue University
Electrical Breakdown In Polymers For Beol Applications: Dielectric Heating And Humidity Effects, Sambit Palit, Muhammad Ashraful Alam
Birck and NCN Publications
Polymer dielectrics may be used as low-k BEOL dielectrics, however, premature electrical breakdown due to high electric fields, high frequencies and ambient humidity conditions have restricted its widespread adoption. In this study, we show that dielectric heating is the primary AC degradation mechanism in polymer dielectrics, and develop an analytical model that is consistent with measured trends in stress tests under both AC and DC electric fields. We also study the effect of exposure to ambient relative humidity on the lifetime of polymer dielectrics.
Rapid Battery Exchange Safety And Sensing, 2014 California Polytechnic State University
Rapid Battery Exchange Safety And Sensing, Ben John Froelich, Isaac Sungjin Kim
The Rapid Battery Exchange system (RBX) swaps batteries in an electric van, allowing almost continuous operation of the vehicle. The RBX system is designed and built by The Cal Poly Electric Vehicle Engineering Club (EVEC). The system includes the exchange ramp, two battery packs, and the electric “G-Van.” While the vehicle drives using one of the battery packs, the other pack charges in the exchange ramp. When the van’s battery depletes, it drives onto the ramp and swaps the dead battery for the charged one, and the process repeats.
The RBX battery pack safety and sensing project divides into ...
Low Voltage Cmos Sar Adc Design, 2014 California Polytechnic State University
Low Voltage Cmos Sar Adc Design, Ryan Hunt
This project centers on the design of a single ended 10-bit successive approximation register analog to digital converter (SAR ADC for short) that easily interfaces to a micro-controller, such as an Arduino. With micro-controller interfacing in mind, the universal data transfer technique of SPI proved an easy way to communicate between the ADC and the micro-controller. The ADC has a range of 1V (highest code value) to 0V (lowest code value) and operates from a single voltage rail value of 1.8V. Typical SPI clock speeds run on the order of 2MHz and with a 10-bit ADC this means a ...
Low Pressure Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films On Silicon, 2014 University of Tennessee, Knoxville
Low Pressure Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films On Silicon, Thomas Gregory Wulz
Boron carbide thin films were grown on the (100) plane of n-type silicon in a low pressure chemical vapor deposition (CVD) system from the thermal decomposition of boron trichloride and methane reactant gases with hydrogen as a carrier gas. Boron trichloride to methane molar ratio was 5, while the boron trichloride to hydrogen molar ratio was 3.5. Thin film deposition was carried out at 900 degrees Celsius at 25 Torr. The thin films were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDS), Laser Induced Breakdown Spectroscopy (LIBS), and current-voltage characteristics. The crystallography ...
Designing High Thermal Conductive Materials Using Artificial Evolution, 2014 Iowa State University
Designing High Thermal Conductive Materials Using Artificial Evolution, Michael Davies
Symposium on Undergraduate Research and Creative Expression
There is a growing need for efficient and effective methods of heat dissipation. One driving force for this need is computer processors. As the processor grows faster and more powerful, it requires more electricity to perform tasks which results in high amounts of heat generated. Designing materials with high thermal-conductivity can enable heat dissipation to allow faster and more powerful computers. Creating such materials is often a trial-and-error process by which several material composites are tested for desirable thermal conductivity. In this research, we employed the use of a genetic algorithm, which mimics the process of evolution through natural selection ...
An Investigation Into The Role Of Energy And Symmetry At Epitaxial Interfaces, 2014 McMaster University
An Investigation Into The Role Of Energy And Symmetry At Epitaxial Interfaces, Gabriel A. Devenyi
Open Access Dissertations and Theses
Epitaxy is a key technological process for the production of thin films and nanostructures for electronic and optoelectronic devices. The epitaxial process has been traditionally studied through the lens of lattice-matched and chemically similar material systems, specifically the III-V quaternary material systems. This work investigates the role energy and symmetry play at epitaxial interfaces for cases far different than those of typical epitaxy. In the realm of energy, the impact of chemically dissimilar epitaxial interfaces was investigated, specifically between semiconductors and oxides, noble metals and oxides, and polar-on-nonpolar epitaxy. For symmetry at epitaxial interfaces, the role of symmetry breaking, through ...
Surface Analysis Of Materials For Direct Wafer Bonding, 2014 McMaster University
Surface Analysis Of Materials For Direct Wafer Bonding, Arif Ul Alam
Open Access Dissertations and Theses
Surface preparation and its exposure to different processing conditions is a key step in heterogeneous integration of electronics, photonics, fluidics and/or mechanical components for More-than-Moore applications. Therefore, it is critical to understand how various processing and environmental conditions affect the surface properties of bonding substrates. In this thesis, the effects of oxygen reactive-ion etching (O2 RIE) plasma followed by storage in ambient and 98% relative humidity on some key surface properties such as roughness, water contact angle, hardness, and the elemental and compositional states of three materials – silicon (Si), silicon dioxide (SiO2) and glass – are investigated to ...
Investigation Of Degradation Effects Due To Gate Stress In Gan-On-Si High Electron Mobility Transistors Through Analysis Of Low Frequency Noise, 2014 California Polytechnic State University
Investigation Of Degradation Effects Due To Gate Stress In Gan-On-Si High Electron Mobility Transistors Through Analysis Of Low Frequency Noise, Michael Curtis Meyer Masuda
Master's Theses and Project Reports
Gallium Nitride (GaN) high electron mobility transistors (HEMT) have superior performance characteristics compared to Silicon (Si) and Gallium Arsenide (GaAs) based transistors. GaN is a wide bandgap semiconductor which allows it to operate at higher breakdown voltages and power. Unlike traditional semiconductor devices, the GaN HEMT channel region is undoped and relies on the piezoelectric effect created at the GaN and Aluminum Gallium Nitride (AlGaN) heterojunction to create a conduction channel in the form of a quantum well known as the two dimensional electron gas (2DEG). Because the GaN HEMTs are undoped, these devices have higher electron mobility crucial for ...
Reactive Magnetron Sputtering As A Growth Alternative For Gallium Nitride Nanowires, 2014 McMaster University
Reactive Magnetron Sputtering As A Growth Alternative For Gallium Nitride Nanowires, Nikolaus A. Jewell
Open Access Dissertations and Theses
Gallium nitride (GaN) nanowires are high-performance materials with wide, direct bandgaps and superior electronic properties. Although their properties make them of great interest for next-generation technologies, widespread adoption has been limited by expensive production processes. Here, the results of growing GaN nanowires via DC magnetron sputtering at different temperatures and using different metal catalysts are reported.
A new substrate heater was designed to minimize contamination from the heater filament and increase the substrate temperature window to in excess of 800°C. Sixteen-mm2 (111) silicon samples had one-to-four nm of a metal catalyst deposited on them using evaporation. This metal ...
An Experimental Investigation Of Hot Switching Contact Damage In Rf Mems Switches, 2014 Northeastern University
An Experimental Investigation Of Hot Switching Contact Damage In Rf Mems Switches, Anirban Basu
Electrical Engineering Dissertations
RF MEMS switches have been shown to have better performance than their solid state counterparts on account of their low insertion loss and high isolation. Despite their superiority, these switches suffer from several reliability issues which limit their lifetime when compared with p-i-n diodes and GaAs FET switches. One of the major reliability issues is the reduction in lifetime of these switches when switched under hot switching conditions i.e. when a DC voltage or RF signal is applied across the contact while it is switching from an off to on position or vice versa. In this work, contact damage ...
A Multi-Physics Computational Approach To Simulating Thz Photoconductive Antennas With Comparison To Measured Data And Fabrication Of Samples, Darren Ray Boyd
Theses and Dissertations--Electrical and Computer Engineering
The frequency demands of radiating systems are moving into the terahertz band with potential applications that include sensing, imaging, and extremely broadband communication. One commonly used method for generating and detecting terahertz waves is to excite a voltage-biased photoconductive antenna with an extremely short laser pulse. The pulsed laser generates charge carriers in a photoconductive substrate which are swept onto the metallic antenna traces to produce an electric current that radiates or detects a terahertz band signal. Therefore, analysis of a photoconductive antenna requires simultaneous solutions of both semiconductor physics equations (including drift-diffusion and continuity relations) and Maxwell’s equations ...
Switched-Capacitor Voltage Doubler Design Using 0.5 Μm Technology, 2014 Rochester Institute of Technology
Switched-Capacitor Voltage Doubler Design Using 0.5 Μm Technology, Hanfeng Wang
While integrated circuit (IC) power management has been an eternal topic for chip designers, inductor based DC-DC converters have been dominant in the field for years. However, because of the natures of inductors: large electro-magnetic interference, high coupling noise, and difficult silicon fabrication process, they are not favorable to on-chip solutions. Switched-capacitor (SC) DC-DC converters, which adopt capacitors for their energy storage components, have become increasingly popular among both the academia and the industry, because, apparently, they avoid the drawbacks of the inductor counterparts, and can be directly implemented on-chip without additional fabrication process.
In this paper, we will investigate ...
Physical Design Of A Smart Camera With Integrated Digital Pixel Sensors Using A 0.13Μm 8-Layer Metal Cmos Process, 2013 University of Nebraska - Lincoln
Physical Design Of A Smart Camera With Integrated Digital Pixel Sensors Using A 0.13Μm 8-Layer Metal Cmos Process, Mahir K. Gharzai
Electrical Engineering Theses and Dissertations
The design of cameras has historically kept imagery and computational circuitry isolated in an attempt to maximize image quality by improving pixel pitch and routing density. Although this technique has worked in creating high density arrays of pixels for large resolution imagers, it has never been able to achieve high framerate computational operations.
A radical approach is introduced to solve this dilemma by creating compact, low- power pixel elements with built-in analog-to-digital converters that directly interface with digital logic. These pixels are capable of integrating alongside logic cells and to create an array of pixels inside the processor that can ...
Max Operation In Statistical Static Timing Analysis On The Non-~Gaussian Variation Sources For Vlsi Circuits, 2013 University of Nevada, Las Vegas
Max Operation In Statistical Static Timing Analysis On The Non-~Gaussian Variation Sources For Vlsi Circuits, Abu M. Baker
UNLV Theses/Dissertations/Professional Papers/Capstones
As CMOS technology continues to scale down, process variation introduces significant uncertainty in power and performance to VLSI circuits and significantly affects their reliability. If this uncertainty is not properly handled, it may become the bottleneck of CMOS technology improvement. As a result, deterministic analysis is no longer conservative and may result in either overestimation or underestimation of the circuit delay. As we know that Static-Timing Analysis (STA) is a deterministic way of computing the delay imposed by the circuits design and layout. It is based on a predetermined set of possible events of process variations, also called corners of ...
In-Phase Coherently-Coupled Optically-Pumped Vecsel Array, 2013 Rose-Hulman Institute of Technology
In-Phase Coherently-Coupled Optically-Pumped Vecsel Array, Alec C. Sills, Gavin N. West, Eryn A. Fennig, Mike P. Grimshaw, Matthew T. Johnson, Manoj Kanskar, Kent D. Choquette, Paul O. Leisher
Faculty Publications - Physics and Optical Engineering
We report on an optically pumped vertical-external-cavity surface-emitting laser array exhibiting coherent coupling. Imaging of the far field shows interference consistent with in-phase coherent coupling, and a majority of total power is present in the central on-axis lobe. The physical mechanism of operation is attributed to diffractive coupling, wherein a small portion of the light emitting from each emitter is shared with adjacent emitters of the array.
Limiting And Transient Performances Of A Low Loss Pin-Schottky Limiter, 2013 SelectedWorks
Limiting And Transient Performances Of A Low Loss Pin-Schottky Limiter, Chin-Leong Lim
The main cause of loss in the PIN-Schottky limiter is the diodes’ parasitic capacitances. Techniques to counter the parasitic capacitances include using bare chip, air cavity packaging, diode stacking, mesa construction, isolating the Schottky diode from the signal path and connecting the diodes to a low impedance node. But the aforementioned techniques either sacrifice cost, manufacturability, size, performances or thermal ruggedness. To reduce loss in the PIN-Schottky limiter, we re-configured its parasitics into a low pass ladder network. This paper reports on the new configuration’s changed large signal and transient performances. We observed improved isolation at 0.9 and ...