Electronic Devices and Semiconductor Manufacturing Commons^™

Amorphous Boron Carbide-Amorphous Silicon Heterojunction Devices, Vojislav Medic

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

This dissertation will show successful development and characterization of amorphous boron carbide-amorphous silicon heterojunction device with potential for neutron detection. The amorphous hydrogenated boron carbide (a-BC:H) has been extensively researched as a semiconductor for neutron voltaic device fabrication. Naturally occurring boron contains 19.8% of boron isotope B¹⁰ that has a high absorption cross section of thermal neutrons at lower energies, and boron carbide contains 14.7% of that B¹⁰ isotope. Therefore, as a semiconductor compound of boron a-BC:H has the ability to absorb radiation, generate charge carriers, and collect those carriers. Previous work on a-BC:H devices investigated the fabrication …

Chatgpt As Metamorphosis Designer For The Future Of Artificial Intelligence (Ai): A Conceptual Investigation, Amarjit Kumar Singh (Library Assistant), Dr. Pankaj Mathur (Deputy Librarian)

Library Philosophy and Practice (e-journal)

Abstract

Purpose: The purpose of this research paper is to explore ChatGPT’s potential as an innovative designer tool for the future development of artificial intelligence. Specifically, this conceptual investigation aims to analyze ChatGPT’s capabilities as a tool for designing and developing near about human intelligent systems for futuristic used and developed in the field of Artificial Intelligence (AI). Also with the helps of this paper, researchers are analyzed the strengths and weaknesses of ChatGPT as a tool, and identify possible areas for improvement in its development and implementation. This investigation focused on the various features and functions of ChatGPT that …

Investigating The Capacitive Properties Of All-Inorganic Lead Halides Perovskite Solar Cells Using Energy Band Diagrams, Zahraa Ismail, Eman Farouk Sawires, Fathy Zaki Amer, Sameh Osama Abdellatif Dr

Electrical Engineering

Capacitance response of perovskite solar cells (PSCs) can be oppressed to deduce underlying physical mechanisms, both in the materials at external interfaces and in bulk materials. Accordingly, this paper investigates the Capacitance-Voltage (C-V) characteristic curves of cesium lead halides (CsPbX3: X = I, Br, or Cl) used as an active layer in PSCs. The SCAPS-1D simulator was used to harness the actual device (CsPbX3: X = I Br, or Cl) with material parameters from previous experimental work. The energy-band diagrams, J-V curves, and C-V curves of the three PSC structures were constructed and compared to carry out and investigate their …

Study The C-V Behavior Of Cesium-Lead Halides Perovskite Solar Cells Under Various Simulation Parameters, Zahraa Ismail, Eman Farouk Sawires, Fathy Zaki Amer, Sameh O. Abdellatif Dr

Electrical Engineering

Capacitance response of perovskite solar cells (PSCs) can be oppressed to deduce underlying physical mechanisms, both in the materials at external interfaces and in bulk materials. Accordingly, this paper investigates the Capacitance-Voltage (C-V) characteristic curves of cesium lead halides (CsPbX3: X = I, Br, or Cl) used as an active layer in PSCs. The SCAPS-1D simulator harnessed the actual device (CsPbX3: X = I Br, or Cl) with material parameters from previous experimental work. Three main simulation parameters were investigated: the thickness of the active layer, the doping, and the defects impacts.

Smart Charging Of Future Electric Vehicles Using Roadway Infrastructure, Sara Ahmed, Ethan Ahn, Mahmoud Reda Taha, Samer Dessouky, Moneeb Genedy, Daniel Fernandez, Ann Sebestian, Patience Raby

Data

Corresponding data set for Tran-SET Project No. 18ITSTSA03. Abstract of the final report is stated below for reference:

"Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways such as mechanical pressure and frictional heat, this study presented the development and implementation of an innovative charging technique for future electric vehicles (EVs) by fully utilizing the existing roadways and the state-of-the-art nanotechnology and power electronics. The project introduced a novel wireless charging system, SIC (Smart Illuminative Charging), that uses LEDs powered by piezoelectric nanomaterials as the energy transmitter source and thin film …

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. The …

Chaos-Based Cryptography For Cloud Computing, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

Cloud computing and poor security issues have quadrupled over the last six years and with the alleged presence of backdoors in common encryption ciphers, has created a need for personalising the encryption process by the client. In 2007, two Microsoft employees gave a presentation ``On the Possibility of a backdoor in the NIST SP800-90 Dual Elliptic Curve Pseudo Random Number Generators'' and was linked in 2013 by the New York Times with notes leaked by Edward Snowden. This confirmed backdoors were placed, allegedly, in a number of encryption systems by the National Security Agency, which if true creates an urgent …

Skin Effect Suppression In Infrared-Laser Irradiated Planar Multi-Walled Carbon Nanotube/ Cu Conductors, Kamran Keramatnejad, Yang Gao, Yunshen Zhou, Hossein Rabiee Glogir, Mengmeng Wang, Yongfeng Lu

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

Skin effect suppression in planar multi-walled carbon nanotube (MWCNT)/Copper (Cu) conductors was realized at the 0-10 MHz frequency range through infrared laser irradiation of MWCNTs, which were coated on the surface of the Cu substrate via the electrophoretic deposition (EPD) method. The effect of laser irradiation and its power density on electrical and structural properties of the MWCNT/Cu conductors was investigated using a wavelength-tunable CO2 laser and then comparing the performance of the samples prepared at different conditions with that of pristine Cu. The irradiation at λ=9.219 μm proved to be effective in selective delivery of energy towards depths close …

Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem To Produce Highly Efficient (Η T * ~ 33%) Solar Cell, Reza Asadpour, Raghu Vamsi Krishna Chavali, Mohammad Ryyan Khan, Muhammad Ashraful Alam

Department of Electrical and Computer Engineering Faculty Publications

As single junction photovoltaic (PV) technologies both Si heterojunction (HIT) and perovskite based solar cells promise high efficiencies at low cost. Intuitively a traditional tandem cell design with these cells connected in series is expected to improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics however we find that a traditional series connected tandem design suffers from low JSC due to band-gap mismatch and current matching constraints. Specifically a traditional tandem cell with state-of-the-art HIT ( η=24% ) and perovskite ( η=20% ) sub-cells provides only a modest tandem efficiency of η_T~ 25%. …

A Power Line Inspection Device, Brendan Gates

Honors College

The goal of this project is to create a functional power line inspection device which could replace the old inspection method of using helicopters. This microchip based robotic device is able to ride along a conductor and send video feed, encoder readouts, and temperature measurements to the user. The user operating system consists of an LCD screen, two potentiometers for motor control, and a screen to display video feed. Achieved specifications include a battery lifetime of 1 hour and 45 minutes, distance measurements within 1 inch, and temperature accuracy within 2 °C. This thesis includes a brief discussion on previous …

Critical Area Driven Dummy Fill Insertion To Improve Manufacturing Yield, Nishant Dhumane

Masters Theses 1911 - February 2014

Non-planar surface may cause incorrect transfer of patterns during lithography. In today’s IC manufacturing, chemical mechanical polishing (CMP) is used for topographical planarization. Since polish rates for metals and oxides are different, dummy metal fills in layout is used to minimize post-CMP thickness variability. Traditional metal fill solutions focus on satisfying density target determined by layout density analysis techniques. These solutions may potentially reduce yield by increasing probability of failure (POF) due to particulate defects and also impact design performance. Layout design solutions that minimize POF and also improve surface planarity via dummy fill insertions have competing requirements for line …

Efficient Modeling Techniques For Time-Dependent Quantum System With Applications To Carbon Nanotubes, Zuojing Chen

Masters Theses 1911 - February 2014

The famous Moore's law states: Since the invention of the integrated circuit, the number of transistors that can be placed on an integrated circuit has increased exponentially, doubling approximately every two years. As a result of the downscaling of the size of the transistor, quantum effects have become increasingly important while affecting significantly the device performances. Nowadays, at the nanometer scale, inter-atomic interactions and quantum mechanical properties need to be studied extensively. Device and material simulations are important to achieve these goals because they are flexible and less expensive than experiments. They are also important for designing and characterizing new …

Maximum Current In Nitride-Based Heterostructure Field-Effect Transistors, A. Koudymov, H. Fatima, Grigory Simin, J. Yang, M. Asif Khan, A. Tarakji, X. Hu, M. S. Shur, R. Gaska

Faculty Publications

We present experimental and modeling results on the gate-length dependence of the maximum current that can be achieved in GaN-based heterostructurefield-effect transistors(HFETs) and metal–oxide–semiconductor HFETs (MOSHFETs). Our results show that the factor limiting the maximum current in the HFETs is the forward gate leakage current. In the MOSHFETs, the gate leakage current is suppressed and the overflow of the two dimensional electron gas into the AlGaN barrier region becomes the most important factor limiting the maximum current. Therefore, the maximum current is substantially higher in MOSHFETs than in HFETs. The measured maximum current increases with a decrease in the gate …

Si3N4/Algan/Gan-Metal-Insulator-Semiconductor Heterostructure Field-Effect Transistors, X. Hu, A. Koudymov, Grigory Simin, J. Yang, M. Asif Khan, A. Tarakji, M. S. Shur, R. Gaska

Faculty Publications

We report on a metal–insulator–semiconductor heterostructurefield-effect transistor (MISHFET) using Si₃N₄ film simultaneously for channel passivation and as a gate insulator. This design results in increased radio-frequency (rf) powers by reduction of the current collapse and it reduces the gate leakage currents by four orders of magnitude. A MISHFET room temperature gate current of about 90 pA/mm increases to only 1000 pA/mm at ambient temperature as high as 300 °C. Pulsed measurements show that unlike metal–oxide–semiconductor HFETs and regular HFETs, in a Si₃N₄ MISHFET, the gate voltage amplitude required for current collapse is much higher …

Mechanism Of Radio-Frequency Current Collapse In Gan-Algan Field-Effect Transistors, A. Tarakji, Grigory Simin, N. Ilinskaya, X. Hu, A. Kumar, A. Koudymov, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

The mechanism of radio-frequency current collapse in GaN–AlGaN heterojunctionfield-effect transistors(HFETs) was investigated using a comparative study of HFET and metal–oxide–semiconductor HFET current–voltage (I–V) and transfer characteristics under dc and short-pulsed voltage biasing. Significant current collapse occurs when the gate voltage is pulsed, whereas under drain pulsing the I–V curves are close to those in steady-state conditions. Contrary to previous reports, we conclude that the transverse electric field across the wide-band-gap barrier layer separating the gate and the channel rather than the gate or surface leakage currents or high-field effects in the gate–drain spacing is responsible for the current collapse. We …

Effect Of Gate Leakage Current On Noise Properties Of Algan/Gan Field Effect Transistors, S. L. Rumyantsev, N. Pala, M. S. Shur, R. Gaska, M. E. Levinshtein, M. Asif Khan, Grigory Simin, X. Hu, J. Yang

Faculty Publications

The effect of the gate leakage current fluctuations on noiseproperties of AlGaN/GaN heterostructurefield effect transistors(HFETs) has been studied in conventional HFET structures and in AlGaN/GaN metal-oxide-semiconductorheterostructurefield effect transistors (MOS-HFETs). The comparison of the noiseproperties of conventional AlGaN/GaN HFETs and AlGaN/GaN MOS-HFETs fabricated on the same wafer, allowed us to estimate the contribution of the gate currentnoise to the HFET’s output noise. The effect of the gate current fluctuations on output noiseproperties of HFETs depends on the level of noise in the AlGaN/GaN HFETs. For the transistors with a relatively high magnitude of the Hooge parameter α∼10⁻³, even a …

Algan/Gan Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors On Sic Substrates, M. Asif Khan, X. Hu, A. Tarakji, Grigory Simin, J. Yang, R. Gaska, M. S. Shur

Faculty Publications

We report on AlGaN/GaN metal–oxide–semiconductor heterostructurefield-effect transistors (MOS-HFETs) grown over insulating 4H–SiC substrates. We demonstrate that the dc and microwave performance of the MOS-HFETs is superior to that of conventional AlGaN/GaN HFETs, which points to the high quality of SiO₂/AlGaNheterointerface. The MOS-HFETs could operate at positive gate biases as high as +10 V that doubles the channel current as compared to conventional AlGaN/GaN HFETs of a similar design. The gate leakage current was more than six orders of magnitude smaller than that for the conventional AlGaN/GaN HFETs. The MOS-HFETs exhibited stable operation at elevated temperatures up to 300 …

Deriving Of Single Intensive Picosecond Optical Pulses From A High-Power Gain-Switched Laser Diode By Spectral Filtering, S. N. Vainshtein, Grigory Simin, J. T. Kostamovaara

Faculty Publications

Single 25 ps/16 W optical pulses were achieved by spectral filtering from a multiheterostructure gain-switched laser diode with its quasisteady-state modes suppressed by a factor of 10³ as compared with the peak power. A significant transient spectrum broadening makes this possible provided that a very high dI/dt rate of the pumping current pulse is used. A simple numerical model is suggested which describes adequately both the spectral and transient features of the observed phenomenon. It follows from the model that single picosecond optical pulses can be obtained from any type of high power semiconductor laser.

A Stochastic Model For Crystal-Amorphous Transition In Low Temperature Molecular Beam Epitaxial Si(111), R. Venkatasubramanian, Suresh Gorantla, S. Muthuvenkatraman, Donald L. Dorsey

Electrical & Computer Engineering Faculty Research

Molecular beam epitaxial Si (111) grown below a certain temperature result in amorphous structure due to the limited surface mobility of atoms in finding correct epitaxial sites. In spite of many experimental and theoretical studies, the mechanism of crystal‐amorphous transition and its dynamics related to the growth conditions are not well understood. In this article, we present a theoretical model based on the formation of stacking fault like defects as a precursor to the amorphous transition of the layer. The model is simulated based on a stochastic model approach and the results are compared to that of experiments for temperatures …