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Book Electrical Characterization of GaN and SiC Schottky Diodes and Non Mechanical Beam Steering Using Liquid Crystals

Download or read book Electrical Characterization of GaN and SiC Schottky Diodes and Non Mechanical Beam Steering Using Liquid Crystals written by Kandhar Kurhade and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis we investigated the electrical characteristics of GaN schottky diodes fabricated on a commercial LED wafer using Inductively Coupled Plasma Reactive Ion etching (ICP-RIE) techniques. We also researched the characteristics of commercially available SiC schottky diodes. Two main electrical characterization techniques were used in the investigation of these diodes, Current - Voltage Characterization and Capacitance - Voltage Characterization. Using I-V characteristics the ideality and the Barrier height of the Schottky diode was determined and the C-V characteristics were used to calculate the doping concentration of the device. These measurements were done at room temperature as well as different temperatures ranging from 100K to 300K for GaN diodes and 133K to 433K for SiC diodes to observe the dependence of Barrier height and the Ideality factor on the temperature. It was concluded that for GaN the ideality factor decreases with the increase in temperature while the barrier height increases with increase in temperature. The values of barrier height for GaN at 120K is 0.44eV and at 300K it is 0.81eV and the ideality factor at 120K is 0.96 and at 300K it is 0.6. The carrier concentration of the SiC remains constant through the three regions while the carrier concentration of GaN device increases as the reverse bias increases. GaN diode was also measured at two different frequencies to observe if there is any change in the C-V profile and the profile was similar for the two frequencies.Further this thesis comprises of a small novel device which is in the process of fabrication. It is a non-mechanical beam steerer which makes use of Liquid crystals to deviate a beam from its normal position. This thesis only includes the architecture used in the manufacturing of the device and the fabrication of a liquid crystal cell.

Book Electrical Studies on Schottky Barrier Diodes SBDs on Gallium Nitride GaN

Download or read book Electrical Studies on Schottky Barrier Diodes SBDs on Gallium Nitride GaN written by Asim Noor Elahi and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the thesis describes experiments made on both GaN Schottky barrier diodes (SBDs) and commercially available SiC Schottky barrier diodes (SBDs). The electrical characterizations on both devices were investigated. Current -- Voltage technique was used for finding the barrier height and the ideality factor. Capacitance -- Voltage characterization technique is also used to obtain the value of the carrier concentration of both GaN and SiC SBDs and also. Thermally Stimulated Capacitance (TSCAP) graph was used on GaN SBDs device to detect the traps and their concentrations. Charge based -- Deep Level Transients Spectroscopy (Q-DLTS) mechanism was applied to both GaN and SiC SBDs for the investigation of the deep charge trapping levels in both devices. The measurements employed included Schottky output characteristics at room temperature and at different temperature values.It is concluded from the experiments that the barrier height for both devices is increasing with the increase of the temperature whereas the ideality factor is decreasing with the increase of the temperature. The values of the barrier height and the ideality factor of GaN Schottky diode are 0.35 eV and 1.2 at 120K and 0.93 eV and 0.47 at 430K, respectively. The value of the barrier height and the ideality factor of SiC Schottky diode are 0.36 eV and 1.5 at 120K and 1.14 eV and 0.4 at 430K, respectively. Three different regions were selected to calculate the carrier concentration of the SiC and GaN SBDs from the C-V characteristics at room temperature. The carrier concentration of the SiC remains constant through the three regions while the carrier concentration of GaN device increases as the reverse bias increases. Two traps have been found by applying the TSCAP technique to GaN Schottky barrier diodes. The first trap was located at 200 K with a concentration of 2.28x1018 cm-3 and the second trap was located at 300 K with a concentration of 3.56x1017 cm-3. For Q-DLTS measurements, unfortunately no traps have been detected for both the GaN and SiC SBDs and therefore no DLTS signals can be shown from the this experiment.

Book Silicon Carbide Diodes Performance Characterization and Comparison with Silicon Devices

Download or read book Silicon Carbide Diodes Performance Characterization and Comparison with Silicon Devices written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers were electrically tested and characterized at room temperature. Performed electrical tests include steady state forward and reverse I-V curves, as well as switching transient tests performed with the diodes operating in a hard switch dc-to-dc buck converter. The same tests were performed in current state of the art silicon (Si) and gallium arsenide (GaAs) Schottky and pn junction devices for evaluation and comparison purposes. The SiC devices tested have a voltage rating of 200, 300, and 600 V. The comparison parameters are forward voltage drop at rated current, reverse current at rated voltage and peak reverse recovery currents in the dc to dc converter. Test results show that steady state characteristics of the tested SiC devices are not superior to the best available Si Schottky and ultra fast pn junction devices. Transient tests reveal that the tested SiC Schottky devices exhibit superior transient behavior. This is more evident at the 300 and 600 V rating where SiC Schottky devices showed drastically lower reverse recovery currents than Si ultra fast pn diodes of similar rating. Lebron-Velilla, Ramon C. and Schwarze, Gene E. and Trapp, Scott Glenn Research Center NASA/TM-2003-212511, E-14071, NAS 1.15:212511

Book The Properties of SiC Barrier Diodes Fabricated with Ti Schottky Contacts

Download or read book The Properties of SiC Barrier Diodes Fabricated with Ti Schottky Contacts written by Krishna Chaitanya Kundeti and published by . This book was released on 2017 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium (Ti) is a popular metal contact used in fabricating Schottky barrier diodes on silicon carbide (SiC) semiconductor. In this research, Ti/4H-SiC Schottky barrier diodes have been fabricated to investigate the effect of deposition temperature and annealing on the electrical characteristics of the fabricated devices. The parameters such as barrier height, ideality factor and on-resistance were determined from the current-voltage (I-V) and the capacitance-voltage (C-V) measurements at room temperature. The temperature-dependent electrical characteristics are realized by performing current-voltage-temperature (I-V-T) measurements. Furthermore, the material characterizations were performed using Auger Electron Spectroscopy (AES) and x-ray diffraction (XRD) measurements. Thin films of Titanium (Ti) as Schottky contacts were deposited on n-type 4H-SiC substrate by magnetron sputtering at different temperatures form room temperature ~25 °C to 900 °C. In addition, thermal processing was performed by annealing at 500 °C in vacuum and argon environment up to 60 hours and characterized using I-V, C-V, and I-V-T measurements accordingly. The diodes with Ti deposited at 200 °C yield better devices with an average ideality factor of 1.04 and Schottky barrier height of 1.13 eV. The electrical properties shows that the deposition of Schottky contact should be at least below 700 °C and the Schottky contact should be annealed at 500 °C for 12-36 hours in order to obtain acceptable quality of Schottky diode. We believe that these variations in the electrical properties are due to the change in the quality of interfacial layer. The variations in physical/compositional properties of Ti/SiC interface has been investigated using Auger electron spectroscopy and x-ray diffraction, which reveled mainly two kinds of phases: Ti5Si3 and Ti3SiC2 formed at the interfacial layer.

Book Conduction Mechanisms of Tungsten Diselenide Based Schottky Diodes

Download or read book Conduction Mechanisms of Tungsten Diselenide Based Schottky Diodes written by Achamma Bobby and published by LAP Lambert Academic Publishing. This book was released on 2011-01 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a study of physical and electrical behaviour of fabricated p-type WSe2 based Schottky diodes coated with different metals and of different thickness.The book opens with a brief narration on the importance of Schottky barrier diodes alongwith a discussion on transitional metal dichalcogenides with specific emphasis to WSe2. The theoretical aspects of Schottky barriers, the growth technique of WSe2 crystals, its structural and compositional characterizations, determination of type and carrier concentrations, method of fabrication of Schottky diodes etc are provided for background information.The detailed analysis of the electrical characterization of these WSe2 diodes is the main theme of the book. The book winds up wth the summary of the results obtained, the conclusions arrived at and a concise discussion on the prospective work.

Book Electrical Characterisation of Schottky Barrier Diodes Fabricated on GaAs by Electron Beam Metallisation

Download or read book Electrical Characterisation of Schottky Barrier Diodes Fabricated on GaAs by Electron Beam Metallisation written by Enoch Mpho Sithole and published by . This book was released on 2001 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Process Development for GaN Schottky Diodes

Download or read book Process Development for GaN Schottky Diodes written by Michael Thomas and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-performance Schottky contact metallizations on gallium nitride (GaN) are needed for high-power and/or high-temperature diodes. Device fabrication methods can have a significant effect on the performance of devices owing to defects introduced by processing, which can create states in the bandgap. Deep level optical spectroscopy (DLOS) is an important technique for characterizing the relative densities and energy levels of these defects. In order to use it, light must be able to penetrate into the active area of the device. This requirement necessitates changing an existing fabrication procedure while ensuring that the device performance is unchanged. Designing, implementing, and testing a DLOS-compatible GaN Schottky diode fabrication method was the goal of this thesis. This investigation demonstrates that DLOS-compatible rhenium Schottky diodes to GaN can be made with comparable performance to existing devices. Ideal rectifying characteristics were achieved. From current-voltage characterization of diodes immediately after fabrication, an average Schottky barrier height of 0.786 eV with a standard deviation of 0.050 eV was measured. Those same diodes had an average ideality factor of 1.02 with a standard deviation of

Book Electrical and Reliability Characterization of Schottky Power Diodes

Download or read book Electrical and Reliability Characterization of Schottky Power Diodes written by Frank M. Gift and published by . This book was released on 1981 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This program examined the barrier materials which were available in late 1978. Screening, electrical characterization and step stress testing were performed on six different processes power Schottky rectifiers. The proposed drafts of MIL-S-19500 detail specifications were prepared as part of this project. The data, proposed limits and related discussions are presented in this report. (Author).

Book The Gospel According to Saint Luke in the Text of the Authorised Version

Download or read book The Gospel According to Saint Luke in the Text of the Authorised Version written by and published by . This book was released on 1952 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: