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Electronic Devices and Semiconductor Manufacturing Commons™

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University of Malaya

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Full-Text Articles in Electronic Devices and Semiconductor Manufacturing

Optimized Transconductance Designs To Enhance The Linearity Performance Of Rf Front-End Receiver Circuits In 130 Nm Cmos Technology, Nandini Vitee Sep 2020

Optimized Transconductance Designs To Enhance The Linearity Performance Of Rf Front-End Receiver Circuits In 130 Nm Cmos Technology, Nandini Vitee

Student Works (2020-2029)

Highly linear front-end circuits are greatly desired for wireless receivers to improve the dynamic range. However, intermodulation distortions caused by the non-linear transconductor current limits the linearity of the front-end receiver circuit in CMOS technologies. In addition to the inherent nonlinear effect, the downscaling of CMOS further exacerbates the linearity of the circuit due to lower voltage headroom and high-field mobility. Thus, it is essential to develop effective circuit techniques that can aid linearity enhancement without jeopardizing other preferred performances such as low noise, high conversion gain, and low-power consumption. In this thesis, two different high linear transconductors are presented …

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Investigation Of Space-Charge-Limited Conduction Mechanisms In Fe3o4-Y-Fe2o3 Based On Sio2/N-Type Si Substrate, Nik Zumaihan Nik Nadia Aina Sep 2020

Investigation Of Space-Charge-Limited Conduction Mechanisms In Fe3o4-Y-Fe2o3 Based On Sio2/N-Type Si Substrate, Nik Zumaihan Nik Nadia Aina

Student Works (2020-2029)

In this work, thin films of functionalized Fe3O4-γ-Fe2O3 NPs deposited on n-type Si substrate was formed by self-assembly. The co-precipitation method was involved to synthesis the bare iron oxide NPs and the particles were altered to optimum pH 12 by using NH4OH. Iron oxide NPs were then undergone modification process with addition of 0.4 g oleic acid and 1.63 mmol functionalization 4-pentynoic acid. For electrical characterization of self-assembled 4-pentynoic acid functionalized Fe3O4-γ-Fe2O3 NPs on SiO2/n-Si substrate, the charge conduction mechanisms were quantitatively investigated and analyzed through the oxides for different heat treatment temperatures (70-300oC). In this study, the Ohm’s Law …

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Low-Power Cmos Cross-Coupled Differential-Drive Rectifier For Ambient Radio Frequency Energy Harvesting Systems, Sing Leung Gabriel Chong Aug 2020

Low-Power Cmos Cross-Coupled Differential-Drive Rectifier For Ambient Radio Frequency Energy Harvesting Systems, Sing Leung Gabriel Chong

Student Works (2020-2029)

Wireless Sensor Node (WSN) for the Internet of Things (IoT) and Internet of Everything (IoE) will require harvesting low-power ambient Radio Frequency (RF) energy to achieve self-power capabilities, alleviating the need of batteries. The research title of “Low-Power CMOS Cross-Coupled Differential-Drive Rectifier for Ambient Radio Frequency Energy Harvesting Systems” relates to the design of integrated circuit (IC) rectifiers for low-power ambient RF energy harvesting (RFEH) in complementary-metal-oxide-semiconductor (CMOS) technology. The adoption of CMOS for the rectifier designs is to achieve small physical form factor, low-cost, and system-on-chip (SoC) integration. The rectifier is the main circuit in an ambient RFEH system …

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Hybrid Microwave Power Amplifiers For Broadband Communication, Sangaran Pragash Aug 2020

Hybrid Microwave Power Amplifiers For Broadband Communication, Sangaran Pragash

Student Works (2020-2029)

The software-defined radio is the future of radio technology. The development of a broadband power amplifier is the most challenging radio component to design in achieving software-defined radio goals due to the PA gain-bandwidth limitation. The distributed power amplifier (DPA) overcomes the limitation by combining output power from several transistors in an additive fashion. Matrix Amplifier (MA) consists of two or more DPA stacked together in a multiplicative manner. In this project, a high power and high gain DPA for a two-way radio system is demonstrated. The DPA exhibits 10W output power and 32dB gain across the frequency range of …

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Comparison Of Pressure-Assist Silver Sintering To Tin Silver Solder Alloy As Die Attach Material In High Power Semiconductor, Tolentino Erik Nino Aug 2020

Comparison Of Pressure-Assist Silver Sintering To Tin Silver Solder Alloy As Die Attach Material In High Power Semiconductor, Tolentino Erik Nino

Student Works (2020-2029)

The research is focused on pressure-assisted silver sintering material that is compared to tin silver solder alloy paste as used in power electronics. Material characterization, electrical tests, and reliability tests were conducted in the experiment. After drying process, it was observed that the Ag sintering paste height was reduced to approximately 40 percent. Die attach shear test showed that the average reading is about from 200 to 600 grams which are already enough to hold the dice before proceeding to the pressure sintering process. X-ray revealed that the void percent for SnAg paste sample is about 1.5 percent while pressure-assist …

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3-Dimensional Carbon Micro-Electro Mechanical System (Mems) Electrode For Potential Dielectrophoretic Hepatic Cell Patterning Application, Wan Yahya Wan Nurlina Aug 2020

3-Dimensional Carbon Micro-Electro Mechanical System (Mems) Electrode For Potential Dielectrophoretic Hepatic Cell Patterning Application, Wan Yahya Wan Nurlina

Student Works (2020-2029)

The maintenance of liver tissue unique pattern remains a great challenge in the generation of functional engineered liver tissue in vitro. This thesis presents a carbon dielectrophoresis (DEP) based cell patterning for generating hepatic cell constructs, mimicking biological hepatic lobule. A new design of electrode named interdigitated radiating-strips electrode (IRSE) was simulated and optimized using COMSOL Multiphysics 4.2a. The simulation result proved that IRSE is capable to provide uniform distribution of electric field for generating three-dimensional (3D) DEP force. The use of carbon electrodes has been an alternative to traditional metal electrodes and insulator structures for DEP applications since more …

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Development Of Integrated Zinc Oxide Nanorods Coated Glass Substrate Sensing Device, Mohd Yusof Haziezol Helmi Feb 2020

Development Of Integrated Zinc Oxide Nanorods Coated Glass Substrate Sensing Device, Mohd Yusof Haziezol Helmi

Student Works (2020-2029)

A simple and practical cost-effective integrated zinc oxide (ZnO) nanorods coated glass substrate sensing device for humidity and formaldehyde vapor sensing applications is reported. The developed sensor device is composed of a commercial light-emitting diode (LED) and photodiode that correspondingly served as light source and detector which precisely positioned on a 3D printed sensor platform. A receiver circuit and Arduino platform were employed for signal amplification and processing. A uniform ZnO nanorods coating were grown on the surface of glass substrate via hydrothermal method by controlling the growth durations and coating length. A standard reference for the optimum working condition …

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Production Of Multiwall Carbon Nanotuse For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq May 2010

Production Of Multiwall Carbon Nanotuse For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq

Student Works (2010-2019)

Multiwall carbon nanotube/polyethylene oxide (PEO), multiwall carbon nanoube/polyvinyl alcohol(PVA) and multiwall carbon nanotube/ polyvinyl alcohol(PVA)/zinc oxide(ZnO) have been tested as chemical sensors and detailed study on the effect of different gas concentration and material properties on gas sensitivity is presented. Initial composites were prepared by a simple solution casting and characterized by x-ray diffraction for ZnO, Fourier transform infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM) to demonstrate crystallite size of ZnO, the morphology and surface area respectively. On the other hand, MWCNT/PEO , MWCNT/PVA , MWCNT/PVA/ZnO were prepared with different loading MWCNT and ZnO. The chemical sensing properties of …

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Vibrational Frequencies Of Magnetic Random Access Memory Materials., Lee Li Ling May 2010

Vibrational Frequencies Of Magnetic Random Access Memory Materials., Lee Li Ling

Student Works (2010-2019)

The advantages of MRAM are so overwhelming which acts as motivation for scientist in further investigation for better read and write operation. The types of materials used are closely related to the cell performance in forming the ferromagnetic layers. Thus,the vibrational frequencies of the MRAM materials are of interest. Clusters for the two types of combinations, FexNiy and FexCoyBz are built. Subsequently, vibrational frequencies of each cluster are calculated theoretically from the first principles. The secular determinant is large when the number of electrons in a cluster is large. For the simplest combination of Fe-Ni cluster, (atomic number of an …

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Production Of Multiwall Carbon Nanotube For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq Jan 2010

Production Of Multiwall Carbon Nanotube For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq

Student Works (2010-2019)

Multiwall carbon nanotube/polyethylene oxide (PEO), multiwall carbon nanoube/polyvinyl alcohol(PVA) and multiwall carbon nanotube/ polyvinyl alcohol(PVA)/zinc oxide(ZnO) have been tested as chemical sensors and detailed study on the effect of different gas concentration and material properties on gas sensitivity is presented. Initial composites were prepared by a simple solution casting and characterized by x-ray diffraction for ZnO, Fourier transform infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM) to demonstrate crystallite size of ZnO, the morphology and surface area respectively. On the other hand, MWCNT/PEO , MWCNT/PVA , MWCNT/PVA/ZnO were prepared with different loading MWCNT and ZnO. The chemical sensing properties of …

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Inductively Coupled Plasma Dry Etching Process On Planar Lightwave Circuit Fabrication., Chuah Khoon Seah Jan 2010

Inductively Coupled Plasma Dry Etching Process On Planar Lightwave Circuit Fabrication., Chuah Khoon Seah

Student Works (2010-2019)

The main objective of this project is to master state-of-the-art techniques and knowledge in silica etching in order to achieve high quality waveguide circuit on Planar Lightwave Circuit devices. Another objective is to optimize the clean room research strength, surface characterization, microscopy techniques and similar semiconductor manufacturing processes.Initially, these processes were conducted with wet etching method that utilized diluted hydrofluoric acid (HF) and buffered oxide etch (BOE). Several problems arising such as mask peel-off, poor sidewall profile and defect waveguide channel during the pattern transfer process due to its’ isotropic nature. Alternatively, dry etching method was conducted via Inductively Coupled …

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Optimization Of Inductively Coupled Plasma Dry Etching For Planar Waveguide Fabrication., Lim Weng Hong Jan 2010

Optimization Of Inductively Coupled Plasma Dry Etching For Planar Waveguide Fabrication., Lim Weng Hong

Student Works (2010-2019)

Optimization of the Inductively Coupled Plasma (ICP) dry etching process parameters has been carried out. Seven main etching characteristics were considered in order to produce good etching quality. These characteristics are glass etching rates, selectivity of chromium to glass etching rate, channel side wall roughness, channel side wall vertical profile, channel cleanliness, critical dimension and resolution. Several ICP parameters that are affecting the etching characteristic were optimized in this work. These optimised ICP parameters obtained from this work are ICP power (880 W), bias power (45 W), operating chamber pressure (10 mtorr), reactant gas composition, reactant gas flow rate (35sccm …

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Strained Quantum Well Heterostructure : Modeling And Simulation Of 980 Nm Laser, Yew Mun Hung Jan 2002

Strained Quantum Well Heterostructure : Modeling And Simulation Of 980 Nm Laser, Yew Mun Hung

Student Works (2000-2009)

This thesis concerns the study of a strained quantum well laser diode emitting at wavelength of about 980 nm which is suitable for pumping Er³⁺ doped fiber amplifiers. The concept of a strained quantum well in the design of the active medium of the laser diode is discussed. A model is proposed that incorporates features of the physical structural factors and characteristics of the structure. The theoretical background linked directly to the simulation of the model is to provide calculations and derivations of the optical properties of the modeled structure. Theoretical calculations were made taking into account the variation of …

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Oxidation-Induced Stacking Fault In (100) And (111) Silicon Wafers, Mei Keat Liang Jan 2002

Oxidation-Induced Stacking Fault In (100) And (111) Silicon Wafers, Mei Keat Liang

Student Works (2000-2009)

Oxidation-induced stacking fault (OISF) dimension and density change on (100) and (111) wafers, as a result of repeated preferential etching were studied using AFM. optical microscope and angular polishing techniques. Density on (100) and (111) wafers is independent of surface removal up to 3.0µm. This indicates the single layer nature of OISF formed from the sand blasted wafer. Besides having higher density, OISFs from (100) wafer were longer than OISF from (111) wafer. OISF width increases linearly with surface removal however the length does not change significantly with surface removal. ln the OISF normal depth studies using angular polishing technique, …

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Effects Of Argon Dilution Of Silane On The Optical Properties And Surface Morphology Of Hydrogenated Amorphous Silicon, Choon Kheam Lim Jan 2001

Effects Of Argon Dilution Of Silane On The Optical Properties And Surface Morphology Of Hydrogenated Amorphous Silicon, Choon Kheam Lim

Student Works (2000-2009)

Hydrogenated amorphous silicon (a.Si:H) was prepared using the d.c plasma grow discharge system. Two sets of samples were prepared and studied. The first set of samples referred to as the high argon dilution films were prepared from the discharge of pure silane at flow-rate of 5sccm and silane at the same flow-rate diluted in argon at flow-rates of 5, 10 and 15sccm. Similarly, the second set of sample referred to as the low argon dilution films were prepared from the discharge of pure silane at flow-rate of20sccm and silane at the same flow-rate diluted in argon at the flow-rates mentioned …

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High Frequency Characteristic Studies Of The N-Channel Enhancement Mode Power Mosfet Device, Rosli Sahrani Jan 2000

High Frequency Characteristic Studies Of The N-Channel Enhancement Mode Power Mosfet Device, Rosli Sahrani

Student Works (2000-2009)

The n-channel enhancement mode power MOSFET device which is known to have the highest switching speed among the controllable switches group is the device studied in this research work. This commercially packaged device manufactured. by Harris Semiconductor has a combination ofMOSFET and JFET structures superimposed. It has a p-type MOS gate and a reversed biased field induced pin junction laterally at the surface and a vertical JFET structure. A Keithley 590 C-V Analyz.er was used to characterize this device. High frequency (1MHz) capacitance-voltage (C-V) and conductance-voltage (G-V) characteristic were measw-ed across the gate-source, gate-drain and source-drain tenninals of the device. …

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