Engineering Commons^™

Modeling All Spin Logic: Multi-Magnet Networks Interacting Via Spin Currents, Srikant Srinivasan

Srikant Srinivasan

All-spin logic (ASL) represents a new approach to information processing where the roles of charges and capacitors in CMOS are played by spins and magnets. This paper (1) summarizes our earlier work on the input-output isolation and intrinsic directivity of ASL devices, (2) uses an experimentally benchmarked simulator for multimagnet networks coupled by spin transport channels to demonstrate a combinational NAND gate, and (3) describes the natural mapping of such ASL networks into neuromorphic circuits suitable for hybrid analog/digital information processing.

An Rf Cmos Implementation Of An Adaptive Filter For Narrow-Band Interferer Suppression In Uwb Systems, Markus Both

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Ultra-wideband (UWB) technology is a new type of technology for wireless communication that is based on the transmission of low power sub-nanosecond pulses. UWB communication utilizes a large bandwidth that overlaps and is coexistent with other wireless communication standards that can be also considered as narrow-band interferers. Because UWB systems are highly susceptible to narrow-band interferers, there is a demand for interferer suppression. An adaptive filter consisting of a two-element diversity receiver that performs minimum mean square error combining (MMSE) by the LMS algorithm is proposed. Thereby the elements of the LMS algorithm as well as the receiver LNA were …

Reliability Analysis Of Nanocrystal Embedded High-K Nonvolatile Memories, Chia-Han Yang

Doctoral Dissertations

The evolution of the MOSFET technology has been driven by the aggressive shrinkage of the device size to improve the device performance and to increase the circuit density. Currently, many research demonstrated that the continuous polycrystalline silicon film in the floating-gate dielectric could be replaced with nanocrystal (nc) embedded high-k thin film to minimize the charge loss due to the defective thin tunnel dielectric layer.

This research deals with both the statistical aspect of reliability and electrical aspect of reliability characterization as well. In this study, the Zr-doped HfO₂ (ZrHfO) high-k MOS capacitors, which separately contain the nanocrystalline zinc …

Design Of Wireless Power Transfer And Data Telemetry System For Biomedical Applications, Ashraf Bin Islam

Doctoral Dissertations

With the advancement of biomedical instrumentation technologies sensor based remote healthcare monitoring system is gaining more attention day by day. In this system wearable and implantable sensors are placed outside or inside of the human body. Certain sensors are needed to be placed inside the human body to acquire the information on the vital physiological phenomena such as glucose, lactate, pH, oxygen, etc. These implantable sensors have associated circuits for sensor signal processing and data transmission. Powering the circuit is always a crucial design issue. Batteries cannot be used in implantable sensors which can come in contact with the blood …

Modeling And Characterization Of P-Type Silicon Carbide Gate Turn Off Thyristors, Osama Shihadeh Saadeh

Graduate Theses and Dissertations

Silicon carbide (SiC) power semiconductor devices have emerged in the past decade as the most promising technology for next generation power electronic applications ranging for electric vehicles to grid-connected power routing and conversion interfaces. Several devices have been developed, and even some have been released commercially, including diodes, MOSFETs, JFETs, thyristors, gate turn-off thyristors, and IGBTs. The model development, characterization and experimental validation of SiC p-type Gate Turn-off Thyristors (GTO) is presented in this work. The GTO device in this work is being used as part of a SiC-based solid-state fault current limiter under development at the University of Arkansas' …

Fabrication Of Composite Nanomaterials For Thin Film Amorphous Silicon Solar Cells, Benjamin Seth Newton

Graduate Theses and Dissertations

A material with the precise combination of amorphous silicon and polycrystalline silicon would be able to take advantage of the high absorption capabilities of amorphous silicon and the electron transport capabilities of polycrystalline silicon. Polycrystalline nanostructures in the form of wires can also take advantage of other properties of light absorption, trapping and scattering inherent in nanowire structures. These properties of high absorption and electron transport in one device would lead to advances in the search for highly efficient low cost solar cells and sensors. In this work a thin film material composed of an array of polycrystalline silicon nanostructures …

Wideband Voltage Variable Attenuator With Fewer Components, Chin-Leong Lim

Chin-Leong Lim

RF/microwave amplifying devices have unit-to-unit gain variability. So, in some critical applications such as the low noise amplifier (LNA) in cellular basestations, the gain has to be adjusted in production using a voltage-variable attenuators (VVA). Constant impedance VVAs such as the PI and the bridged-TEE topologies require between 14 to 18 components, including 2 to 4 active devices, but their large dynamic (attenuation) range is wasted in this amplifier gain adjustment application. To create a more economical and smaller VVA for amplifier gain adjustment, we investigated a new circuit configuration comprising one active and four passive components. This paper describes …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, Krishneel Lal

Electrical Engineering

No abstract provided.

Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace

Gordon Wallace

The characterization of the dynamic response (including transfer function identification) of trilayer polypyrrole (PPy) type conducting polymer sensors is presented. The sensor was built like a cantilever beam with the free end stimulated through a mechanical lever system, which provided displacement inputs. The voltage generated and current passing between the two outer PPy layers as a result of the input was measured to model the output/input behavior of the sensors based on their experimental current/displacement and voltage/displacement frequency responses. We specifically targeted the low-frequency behavior of the sensor as it is a relatively slowsystem. Experimental transfer function models were generated …

Vva Extends Bw And Dynamic Range, Chin-Leong Lim

Chin-Leong Lim

Voltage-variable attenuators (VVAs) enable gain adjustment in a wide range of applications, including in cable-television (CATV), satellite-television (SATV) systems, and even test equipment and measurement systems. The PI VVA configuration using PIN diodes is ubiquitous in CATV and SATV systems owing to its low part count, small size, constant impedance, high linearity, and multi-decade bandwidth. Presently, this class of VVAs have been under severe miniaturization pressure in order to shrink end-product size. To create the industry's smallest CATV/SATV-suitable VVA, we integrated all necessary components into a multi-chip-on-board (MCOB) package measuring 3.8 x 3.8 x 1.0 mm (14 mm square footprint). …

Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi

Hossein Ameri Mahabadi

The article presents information on designing a low-noise frequency synthesizer for achieving low-phase-noise outputs past 8 GHz for digital microwave radios (DMRs). These synthesizers can be used with the DMRs, depending on advanced digital modulation such as quadrature-amplitude-modulation (QAM) and quadrature-phase-shift-keying (QPSK) formats.

Modeling And Development Of A Mems Device For Pyroelectric Energy Scavenging, Salwa Mostafa

Doctoral Dissertations

As the world faces an energy crisis with depleting fossil fuel reserves, alternate energy sources are being researched ever more seriously. In addition to renewable energy sources, energy recycling and energy scavenging technologies are also gaining importance. Technologies are being developed to scavenge energy from ambient sources such as vibration, radio frequency and low grade waste heat, etc. Waste heat is the most common form of wasted energy and is the greatest potential source of energy scavenging.

Pyroelectricity is the property of some materials to change the surface charge distribution with the change in temperature. These materials produce current as …

Structural, Electrical And Thermoelectric Properties Of Chromium Silicate Thin Films, Makram Abd El Qader

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thermoelectric devices can generate electrical power as a result of their ability to produce electrical currents in the presence of thermal gradients. They can also produce refrigerative cooling when electrical power is supplied to them. Among the potential semiconducting silicides, CrSi ₂ is attractive because of its high thermal and chemical stability and its potential for thermoelectric application. CrSi₂ /SiO₂ thin-film structures were prepared using RF sputtering. As deposited and annealed (300°C to 600°C) thin films were characterized for their structural, electrical, and thermoelectric transport properties. As-sputtered CrSi ₂ film is amorphous at room temperature and crystallizes around …

Full Custom Vlsi Design Of On-Line Stability Checkers, Chris Y. Lee

Master's Theses

A stability checker is a clocked storage element, much like a flip-flop, which detects unstable and late signals in the pipeline of a digital system. The On-line stability checker operates concurrently with its associated circuit-under-test (CUT). This thesis describes the full custom very-large-scale integration (VLSI) design and testing process of On-Line Stability Checkers. The goals of this thesis are to construct and test Stability Checker designs, and to create a design template for future class projects in the EE 431 Computer-Aided Design (CAD) of VLSI Devices course at Cal Poly.

A method for concurrent fault testing called On-line Stability Checking …

Exposing To Emf, Mahmoud Moghavvemi, Farhang Alijani, Hossein Ameri Mahabadi, Maryami Ashayer Soltan

Hossein Ameri Mahabadi

No abstract provided.

Assembly Of Low Phase Noise Sub-Millimeter Wave Local Oscillator In Ku Band Frequency, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

A design and fabrication of a dual-band synthesizer device is presented in this paper. The noise analysis in synthesizer loop block component is modeled individually. The Design methodology is elaborated along with the test results. The initial frequency synthesizer in 1.8-2.4GHz frequency range (L and S-band) is designed and it is multiplied by 8. Microstrip bandpass filters (LFCN) are used to filter out the spurious frequency contents; the final output frequency is 14-20GHz (Ku-band). Phase noise investigation, design steps, filter assembling of 14-20GHz synthesizer is presented in this paper.

Novel Client Booking System In Klcc Twin Tower Bridge, Hossein Ameri Mahabadi, R. Ameri

Hossein Ameri Mahabadi

This system should help managing the visitors and tour guides as well as scheduling tours to visit “Petronas Twin Towers Sky Bridge”. The system should at least support the following characteristics. It should keep track of visitors and or tourists. It should keep information about tour guides and their working hour and other related information about such employees. The administrators should be able to schedule their visiting hours. This is a work-flow system and it need to keep track of daily visitors. The requirement was meant for this system is straight forward and very clear with so little complexity. On …

A Compact Analytical Design Of Dual-Loop 18 Ghz Frequency Synthesizer To Enhance Signal Reliability In Digital Millimeter Radio Link System, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

In this paper a high resolution dual-loop 17.7–19.7 GHz frequency synthesizer is presented which is compatible with ITU-R (F.595-6) standards. The investigations of phase noise and spur frequency contents are discussed in detail. The simulated and measured phase noise and spur frequency contents are similar to one another. Phase noise of –81 dBc/Hz in 17.7 GHz at 10 KHz offset frequency is measured by (HP8560) series Spectrum analyzer and it matches with predicted measurements.

Purely Electronic Switching With High Uniformity, Resistance Tunability, And Good Retention In Pt-Dispersed Sio2 Thin Films For Reram, Albert Chen

Albert B Chen

Resistance switching memory operating by a purely electronic switching mechanism, which was first realized in Pt-dispersed SiO2 thin films, satisfies criteria including high uniformity, fast switching speed, and long retention for non-volatile memory application. This resistive element obeys Ohm's law for the area dependence, but its resistance exponentially increases with the film thickness, which provides new freedom to tailor the device characteristics.

Lna Lowers Noise, Raises Oip3 At 3.5 Ghz, Chin-Leong Lim

Chin-Leong Lim

A 3.5 GHz LNA with good noise figure, gain and linearity performances has been designed around a low-cost, QFN2x2-packaged monolithic integrated circuit (MMIC). Incorporation of bias regulator, ESD protection and stability network at chip-level reduces the external component count to 12. The proprietary 0.25 um EPHEMT process achieves +15-dB gain in single stage and less than 1 dB noise figure at 3.5 GHz.

Direct Measurement Of Graphene Adhesion On Silicon Surface By Intercalation Of Nanoparticles, Zong Zong, Chia-Ling Chen, Mehmet R. Dokmeci, Kai-Tak Wan

Kai-tak Wan

We report a technique to characterize adhesion of monolayered/multilayered graphene sheets on silicon wafer. Nanoparticles trapped at graphene-silicon interface act as point wedges to support axisymmetric blisters. Local adhesion strength is found by measuring the particle height and blister radius using a scanning electron microscope. Adhesion energy of the typical graphene-silicon interface is measured to be 151±28 mJ/m2. The proposed method and our measurements provide insights in fabrication and reliability of microelectromechanical/nanoelectromechanical systems.

Parylene-C Passivated Carbon Nanotube Flexible Transistors, Selvapraba Selvarasah, Xinghui Li, Ahmed A. Busnaina, Mehmet R. Dokmeci

Mehmet R. Dokmeci

Carbon nanotubes are extremely sensitive to the molecular species in the environment and hence require a proper passivation technique to isolate them against environmental variations for the realization of reliable nanoelectronic devices. In this paper, we demonstrate a parylene-C passivation approach for CNT thin film transistors fabricated on a flexible substrate. The CNT transistors are encapsulated with 1 and 3 μm thick parylene-C coatings, and the transistor characteristics are investigated before and after passivation. Our findings indicate that thin parylene-C films can be utilized as passivation layers for CNT transistors and this versatile technique can be readily applied for the …

Direct Measurement Of Graphene Adhesion On Silicon Surface By Intercalation Of Nanoparticles, Zong Zong, Chia-Ling Chen, Mehmet Dokmeci, Kai-Tak Wan

Mehmet R. Dokmeci

We report a technique to characterize adhesion of monolayered/multilayered graphene sheets on silicon wafer. Nanoparticles trapped at graphene-silicon interface act as point wedges to support axisymmetric blisters. Local adhesion strength is found by measuring the particle height and blister radius using a scanning electron microscope. Adhesion energy of the typical graphene-silicon interface is measured to be 151±28 mJ/m2. The proposed method and our measurements provide insights in fabrication and reliability of microelectromechanical/nanoelectromechanical systems.

Low-Voltage And Short-Channel Pentacene Field-Effect Transistors With Top-Contact Geometry Using Parylene-C Shadow Masks, Yoonyoung Chung, Boris Murmann, Selvapraba Selvarasah, Mehmet Dokmeci, Zhenan Bao

Mehmet R. Dokmeci

We have fabricated high-performance top-contact pentacene field-effect transistors using a nanometer-scale gate dielectric and parylene-C shadow masks. The high-capacitance gate dielectric, deposited by atomic layer deposition of aluminum oxide, resulted in a low operating voltage of 2.5 V. The flexible and conformal parylene-C shadow masks allowed fabrication of transistors with channel lengths of L = 5, 10, and 20 μm. The field-effect mobility of the transistors was μ = 1.14 (±0.08) cm²/V s on average, and the IMAX/IMIN ratio was greater than 10⁶.

Analysis Of Scratches Formed On Oxide Surface During Chemical Mechanical Planarization, Jae-Gon Choi, Y. Nagendra Prasad, In-Kwon Kim, In-Gon Kim, Woo-Jin Kim, Ahmed A. Busnaina, Jin-Goo Park

Ahmed A. Busnaina

Scratch formation on patterned oxide wafers during the chemical mechanical planarization process was investigated. Silica and ceria slurries were used for polishing the experiments to observe the effect of abrasives on the scratch formation. Interlevel dielectric patterned wafers were used to study the scratch dimensions, and shallow trench isolation patterned wafers were used to study the effect of polishing parameters, such as pressure and rotational speed (head/platen). Similar shapes of scratches (chatter type) were observed with both types of slurries. The length of the scratch formed might be related to the period of contact between the wafer and the pad. …

Parylene-C Passivated Carbon Nanotube Flexible Transistors, Selvapraba Selvarasah, Xinghui Li, Ahmed A. Busnaina, Mehmet R. Dokmeci

Ahmed A. Busnaina

Carbon nanotubes are extremely sensitive to the molecular species in the environment and hence require a proper passivation technique to isolate them against environmental variations for the realization of reliable nanoelectronic devices. In this paper, we demonstrate a parylene-C passivation approach for CNT thin film transistors fabricated on a flexible substrate. The CNT transistors are encapsulated with 1 and 3 μm thick parylene-C coatings, and the transistor characteristics are investigated before and after passivation. Our findings indicate that thin parylene-C films can be utilized as passivation layers for CNT transistors and this versatile technique can be readily applied for the …

Unidirectional Information Transfer With Cascaded All Spin Logic Devices: A Ring Oscillator, Srikant Srinivasan

Srikant Srinivasan

The authors have presented the first simulator that simultaneously describes magnetization dynamics as well as spin transport in multi-magnet ASL networks and used it to demonstrate the possibility of large scale functional spin logic blocks through the example of an All Spin ring oscillator.

Interfacial And Electrokinetic Characterization Of Ipa Solutions Related To Semiconductor Wafer Drying And Cleaning, Jin-Goo Park, Sang-Ho Lee, Ju-Suk Ryu, Yi-Koan Hong, Tae-Gon Kim, Ahmed A. Busnaina

Ahmed A. Busnaina

In this study, the interfacial and electrokinetic phenomena of mixtures of isopropyl alcohol (IPA) and deionized (DI) water in relation to semiconductor wafer drying is investigated. The dielectric constant of an IPA solution linearly decreased from 78 to 18 with the addition of IPA to DI water. The viscosity of IPA solutions increased as the volume percentage of IPA in DI water increased. The zeta potentials of silica particles and silicon wafers were also measured in IPA solutions. The zeta potential approached neutral values as the volume ratio of IPA in DI water increased. A surface tension decrease from 72 …

Experimental And Analytical Study Of Submicrometer Particle Removal From Deep Trenches, Kaveh Bakhtari, Rasim O. Guldiken, Ahmed A. Busnaina, Jin-Goo Park

Ahmed A. Busnaina

Particle removal from patterned wafers and trenches presents a tremendous challenge in semiconductor manufacturing. In this paper, the removal of 0.3 and 0.8 µm polystyrene latex (PSL) particles from high-aspect-ratio 500 µm deep trenches is investigated. An experimental, analytical, and computational study of the removal of submicrometer particles at different depths inside the trench is presented. Red fluorescent polystyrene latex (PSL) particles were used to verify particle removal. The particles are counted using scanning fluorescent microscopy. A single-wafer megasonic tank is used for the particle removal. The results show that once a particle is removed from the walls or the …