Download or read book Growth and Characterization of Wide Bandgap Semiconductor Oxide Thin Films written by Susmita Ghose and published by . This book was released on 2017 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide bandgap semiconductors are receiving extensive attention due to their exceptional physical and chemical properties making them useful for high efficiency and high power electronic devices. Comparing other conventional wide bandgap materials, monoclinic Îø-Ga2O3 also represents an outstanding semiconductor oxide for next generation of UV optoelectronics and high temperature sensors due to its wide band gap (~4.9eV). This new semiconductor material has higher breakdown voltage (8MV/cm) and n-type conductivity which make it more suitable for potential application as high power electronics. The properties and potential applications of these wide bandgap materials have not yet fully explored. In this study, the growth and characterization of single crystal b-Ga2O3 thin films grown on c-plane sapphire (Al2O3) substrate using two different techniques; molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) techniques has been investigated. The influence of the growth parameters of MBE and PLD on crystalline quality and surface has been explored. Two methods have been used to grow Ga2O3 using MBE; one method is to use elemental Ga and the second is the use of a polycrystalline Ga2O3 compound source with and without an oxygen source. Using the elemental Ga source, growth rate of b-Ga2O3 thin films was limited due to the formation and desorption of Ga2O molecules. In order to mitigate this problem, a compound Ga2O3 source has been introduced and used for the growth of crystalline b-Ga2O3 thin films without the need for additional oxygen since this source produces Ga-O molecules and additional oxygen. Two different alloys (InGa)2O3 and (AlGa)2O3 has been grown on c-plane sapphire substrate by pulsed laser deposition technique to tune the bandgap of the oxide thin films from 3.5-8.6 eV suitable for applications such as wavelength-tunable optical devices, solid-state lighting and high electron mobility transistors (HEMTs). The crystallinity, chemical bonding, surface morphology and optical properties have been systematically evaluated by a number of in-situ and ex-situ techniques. The crystalline Ga2O3 films showed pure phase of (2 Ì501) plane orientation and in-plane XRD phi-scan exhibited the six-fold rotational symmetry for b-Ga2O3 when grown on sapphire substrate. The alloys exhibit different phases has been stabilized depending on the compositions. Finally, a metal-semiconductor-metal (MSM) structure deep-ultraviolet (DUV) photodetector has been fabricated on Îø-Ga2O3 film grown with an optimized growth condition has been demonstrated. This photodetector exhibited high resistance as well as small dark current with expected photoresponse for 254 nm UV light irradiation suggesting Îø-Ga2O3 thin films as a potential candidate for deep-UV photodetectors. While the grown Ga2O3 shows high resistivity, the electrical properties of (In0.6Ga0.4)2O3 and (In0.8Ga0.2)2O3 alloys show low resistivity with a high carrier concentration and increasing mobility with In content.

Download or read book Growth and Characterization of Wide Band gap Group III Oxide Semiconductors by MOCVD written by Armando Hernandez (Jr.) and published by . This book was released on 2021 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation work is focused on the deposition of gallium oxide (Ga2O3) thin films by metal organic chemical vapor deposition (MOCVD) method. This material belongs to a special group of wide bandgap oxide semiconductors with high optical transmittance and high levels of conductivity. The importance of this material is generated by the wide range of applications of electronic and optoelectronic devices such as MOSFET's, photo diodes, solar cells, LED's, laser diodes, sensors etc. Through MOCVD technique, an implementation of a Si4+ dopant was incorporated in the monoclinic Îø-Ga2O3 crystal structure on homoepitaxial and heteroepitaxial Îø-Ga2O3 single crystal wafers. The MOCVD process allowed us to deposit at a growth rate of 1 Îơm/hour while controlling the electrical transport properties with this dopant. These films were carefully characterized by surface morphology, crystal structure, levels of conductivity and trapping defects. The work shows that the electron density and conductivity of MOCVD Ga2O3 films are mainly governed by the interplay between dopant concentration, C concentration and the presence of trapping defects in the films, which is most likely applicable for other oxide films grown by MOCVD. Conductive films of Ga2O3 with resistivity in the order of 0.07 Î♭.cm were successfully grown. The electron density in most of these films was in the range of 1019 cm8́23 but the mobility was limited to 1.5 cm2/V)́5s. Higher mobility of 30 cm2/V)́5s was obtained in some films at the expense of carrier concentration by reducing Si doping level resulting in resistivity in the order of 0.3 Î♭.cm. This range of conductivity and mobility is relevant for field-effect transistors (FET) and the applications of Ga2O3 as transparent FET in Deep Ultra-Violet (DUV) technology. The second part of this work focuses on investigating the electronic and crystal structure properties of an indium gallium oxide alloy (IGO) doped with Si4+ ions through MOCVD technique on c-sapphire substrate. This work aims to find a tunable range for engineering the band gap of this new alloyed material by incorporating indium into the lattice of the Îø-Ga2O3 crystal structure. Various dopant ratios were also implemented to adjust the electrical properties of (IGO) and highly conductive IGO films were realized through Si doping.

Download or read book Growth and Characterization of Thin Film Semiconductors written by Samikshya Prasai and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film metal oxide semiconductors have always been the materials of interest for various device applications due to their wide bandgap and interesting electrical properties. The role of defects in controlling these properties of the materials has also been widely known through extensive research. In order to use these materials for advanced device applications, it is necessary to characterize defects and understand their effect on the electrical properties. The main objective of this thesis is to study three different thin film metal oxide semiconductor samples of Gallium Indium Oxide named as depositions 55, 68 and 70 deposited by using the MOCVD technique. The samples were characterized to examine their electrical properties, and defects were studied to explain the origin of the electrical conductivity and resistivity shown by each of these samples. The samples were measured using Hall effect measurements for electrical characterization, and X-ray Diffraction (XRD) was used for structural characterization. Positron Annihilation Spectroscopy (PAS) technique was applied to study the vacancy type defects in these depositions. Hall effect results indicate that deposition 55 is the most conductive with high electron mobility and low value of sheet resistance, and it is found that this sample exhibits n-type conductivity. The electrical characterization data suggests that deposition 68 is the most resistive among the three depositions with high value of sheet resistance. Deposition 70 was found to exhibit n-type conductivity but showed higher value of sheet resistance as compared to deposition 55. Among the various techniques used for PAS, we applied Doppler Broadening Spectroscopy (DBS) for defects characterization of the depositions. DBS results show the presence of vacancy type defects in all of the three samples and indicate the crucial role of defects in the electrical properties exhibited by the thin films. The defects measurements were analyzed, and it is suggested that higher defect concentration are associated with higher resistivity. For deposition 68, native defects are indicated to act as deep electron traps that reduce the carrier concentration and make the sample resistive. This work has been supported by: the National Science Foundation (NSF) under grant number DMR-2005064.

Download or read book Growth Processing and Characterization of Gallium Oxide and Indium Gallium Oxide Thin Films written by Clifford Antonio Francis and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium oxide has been recognized as a promising Ultrawide-Bandgap(UWBG) semiconductor with a band gap ranging from 4.3-5.3eV. Beta gallium oxide, a polymorph of Gallium Oxide, has an ultra-wide bandgap of 4.9eV making it a great candidate for next-generation power electronics. In addition, UWBG semiconductors are capable of large breakdown voltage and has the potential of becoming a high-effciency switching device. The electrical characteristics are then analyzed using a Hall effect. Some samples are often annealed or doped to improve their electrical properties. The work presented in this thesis shows the process of recently developed gallium oxide flms with a focus on indium gallium oxide samples. The result of our research shows that signifcant changes to the electrical properties of gallium oxide films can be achieved through doping and annealing. In order to utilize the powerful properties of gallium oxide, this work incorporated indium to grow indium gallium oxide. Homogeneous and heterogeneous samples of indium gallium oxide were grown on the MOCVD with a unique recipe that allowed for controlled precursor injection. Furthermore, growth parameters were varied to test their effectiveness in the interplay between indium oxide and gallium oxide growth. The samples were then characterized using X-ray Diffraction(XRD) and Hall effect system. The XRD system allows for further understanding between the growth parameters and the resulting structure of the material. The combination of the XRD system and Hall effects allows for a great correlation between the MOCVD growth parameters and the resulting film qualities. Samples are annealed in hydrogen to enhance their electrical properties. Our experiments demonstrate enhanced electrical characteristics and even p-type conductivity can be produced with effective growth processing.

Download or read book Wide Bandgap Semiconductors written by Jeffrey Lapp and published by . This book was released on 2020 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern technological applications require high performance materials that possess novel properties to efficiently operate in a wide range of conditions. In this work, the performance enhancement of ZnO thin films was studied, while basic research on the optical properties of Ga2O3 thin films was performed. Two approaches for the enhancement of the UV band edge photoluminescence (PL) in sputtered ZnO films were studied. One that used surface coating, and another that employed annealing in a non-oxidizing environment. It was found that by combining both methods, annealing at an optimal temperature followed by the deposition of a coating, a significant enhancement of the luminescence can be achieved. Three types of coatings were investigated, Al2O3, SiO2, and MgO. It was found that MgO, due to its strong bond energy, is an effective coating material for the passivation of the surfaces of the ZnO films. The UV-PL intensity of MgO coated ZnO was found to increase by a factor of ~ 52 relative to an uncoated film. The effectiveness of the coating layer was discussed in terms of competing mechanisms to surface passivation, such as the adsorption of OH-groups, which can act as surface traps and diminish PL intensity. Moreover, annealing at 900℗ʻ C prior to the deposition of the coating was found to be an important step in realizing the optimal performance of the coating material. A visible luminescence study indicated that the annealing process diminishes the presence of native defects that can act as bulk-like nonradiative centers that impact the UV luminescence. An initial study of gallium oxide (Ga2O3) thin films was performed to determine the optical properties of this ultra-wide bandgap semiconductor. Îø-Ga2O3 thin films were grown via RF sputtering in two growth environments with different oxygen concentrations. Prior to characterization, a post growth annealing step was accomplished. An oxygen-rich growth environment resulted in highly defective films that resulted in broad, intense photoluminescent (PL) emissions accompanied by a weak deep ultraviolet peak. Adjustment to a lower oxygen content during growth resulted in higher quality films that display five resolved PL peaks in the UV range, including band edge emissions of ~ 4.85 eV that match the band edge values obtained via transmission spectroscopy. Additional peaks at ~ 3.14 eV and ~ 3.56 eV were attributed to donor-acceptor recombination and self-trapped hole emissions, respectively. Designation of the self-trapped hole emissions at ~ 3.56 eV was verified by its absence in the PL spectra when sub-bandgap 3.8 eV excitation is used. Post-growth annealing in an oxygen environment instead of in air resulted in a blue shift of the PL spectra of ~ 120 meV and decreased the intensity of the ~3.56 eV STH related peak. These results indicate that the defect concentration in these films is highly sensitive to their oxygen content, which makes this material ideal for use in oxygen sensing devices.

Download or read book Ultrawide Bandgap Semiconductors written by and published by Academic Press. This book was released on 2021-07-26 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrawide Bandgap Semiconductors, Volume 107 in the Semiconductors and Semimetals series, highlights the latest breakthrough in fundamental science and technology development of ultrawide bandgap (UWBG) semiconductor materials and devices based on gallium oxide, aluminium nitride, boron nitride, and diamond. It includes important topics on the materials growth, characterization, and device applications of UWBG materials, where electronic, photonic, thermal and quantum properties are all thoroughly explored. Contains the latest breakthrough in fundamental science and technology development of ultrawide bandgap (UWBG) semiconductor materials and devices Provides a comprehensive presentation that covers the fundamentals of materials growth and characterization, as well as design and performance characterization of state-of-the-art UWBG materials, structures, and devices Presents an in-depth discussion on electronic, photonic, thermal, and quantum technologies based on UWBG materials

Download or read book Synthesis and Characterization of Wide Band Gap Semiconductor Thin Films written by Sindhura Vadlamani and published by . This book was released on 2003 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thin Films and Heterostructures for Oxide Electronics written by Satishchandra B. Ogale and published by Springer Science & Business Media. This book was released on 2005-11-21 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxides form a broad subject area of research and technology development which encompasses different disciplines such as materials science, solid state chemistry, physics etc. The aim of this book is to demonstrate the interplay of these fields and to provide an introduction to the techniques and methodologies involving film growth, characterization and device processing. The literature in this field is thus fairly scattered in different research journals covering one or the other aspect of the specific activity. This situation calls for a book that will consolidate this information and thus enable a beginner as well as an expert to get an overall perspective of the field, its foundations, and its projected progress.

Download or read book Growth Characterization and Device Demonstration of Ultra Wide Bandgap Ga2O3 by Low Pressure Chemical Vapor Deposition written by Subrina Rafique and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High power semiconductor device technology has significant impact on the society as they can directly contribute to worldwide energy conservation. The main market segments for high-power, high-frequency semiconductor devices are industrial motors, hybrid and electric vehicles, RF and power supply, wireless infrastructure and broadcast and communication satellites. Si-based technology has been serving the power electronics market till today. However, Si based power devices are approaching their theoretical performance limits from the viewpoint of material properties. Wide bandgap (WBG) semiconductors featured with higher breakdown electric field have tremendous advantages over existing Si based technology. They can operate at higher voltages, temperatures and switching frequencies with greater efficiencies resulting in less loss. They also enable significantly reduced system level volumes due to decreased cooling requirements and smaller passive components contributing to overall lower system costs. Once widely used, wide bandgap semiconductor based power electronics technologies can save over 25% of the worldwide annual energy consumption. Ultra-wide bandgap (UWBG) semiconductor material gallium oxide (Ga2O3) with a room temperature bandgap of ~4.9 eV, much higher than GaN (Eg~3.4 eV) and SiC (Eg~3.2 eV), is a promising candidate for next generation power devices and deep ultraviolet (DUV) photodetectors (PDs). It possesses excellent material properties and outstanding chemical and thermal stability at elevated temperatures. Most attractively, Ga2O3 substrate can be produced by low cost and scalable melting based methods. In this dissertation, a new epitaxial method based on low pressure chemical vapor deposition (LPCVD) is developed and demonstrated for the first time to grow high quality Ga2O3 based thin films and nanomaterials with fast growth rate and controllable doping. For the LPCVD growth of Ga2O3, argon (Ar) is employed as carrier gas. High purity gallium pellets (Alfa Aesar, 99.99999%) are used as the group III precursor. Oxygen (O2) and Silicon Tetrachloride (SiCl4) are the group VI precursor and n-dopant source, respectively. Proof of concept prototypes of ß-Ga2O3 thin films based PDs and Schottky barrier diode (SBD) have been demonstrated using LPCVD grown Ga2O3 thin films. The maximum room temperature electron Hall mobility achieved for LPCVD heteroepitaxial Ga2O3 thin films is 106.6 cm2/V·s with an n-type carrier concentration of 4.83x1017 cm3. The room temperature carrier concentrations achieved so far for the (010) and (001) LPCVD homoepitaxial thin films are ~1.4x1018 cm−3 and ~6.6x1017 cm−3 with mobilities of ~72 cm2/V. s and ~42 cm2/V. s respectively. Advancement of LPCVD growth of high quality ß-Ga2O3 will open up new opportunities for high performance power electronic and optoelectronic devices.

Download or read book Growth and Characterization of Wide gap Semiconducting Oxide and Chalcogenide Thin Films by Pulsed Laser Deposition written by Paul F. Newhouse and published by . This book was released on 2008 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: The preparation and characterization of thin film oxides and chalcogenides by pulsed laser deposition (PLD) is presented. An overview of fundamental PLD concepts are presented and are followed by a description implementation and development of the PLD systems at OSU. We present the results of thin film growth of high electron mobility In2O3:W in which we have prepared films exhibiting □ > 100 cm2/Vs on vitreous SiO2 substrates. The growth of Cu3TaQ 4 (Q = S, Se) films is outlined as a two step process consisting of PLD of ceramic targets followed by ex-situ annealing in chalcogenide vapor. Also, BiCuOSe thin films have been prepared in-situ and exhibit a high hole mobility up to 4 cm2/Vs. A discussion of their electronic structure is presented which explains the nature of the low band gap energy on the basis of deep Bi 6p level at the conduction band minimum. Finally, the results of BaBiO3 thin film preparation are presented in which both polycrystalline and highly (00l) oriented samples were grown.

Download or read book New Applications for Wide Bandgap Semiconductors Volume 764 written by Materials Research Society. Meeting and published by . This book was released on 2003-09-29 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide-bandgap semiconductors such as SiC, GaN and related alloys, BN and related alloys, ZnGeSiN2, ZnO, and others continue to find new applications in solid-state lighting, sensors, filters, high-power electronics, biological detection, and spintronics. Improved bulk and epitaxial growth, processing, device design, and understanding of the physics of transport in heterostructures are all necessary for realization of these new technologies. The papers in this book span a range of subjects from material growth and characterization to the processing and application of devices in the electronic, as well as the optoelectronic, fields. Topics include: special invited papers; growth, processing and devices; novel applications for wide-bandgap semiconductors; oxides, heterostructures and devices; processing and devices and emerging areas.

Download or read book Overview of Growth Characterization and Device Development in Large Bandgap Semiconductor Thin Films written by Robert Foster Davis and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wide Bandgap Semiconductor Electronics And Devices written by Uttam Singisetti and published by World Scientific. This book was released on 2019-12-10 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'This book is more suited for researchers already familiar with WBS who are interested in developing new WBG materials and devices since it provides the latest developments in new materials and processes and trends for WBS and UWBS technology.'IEEE Electrical Insulation MagazineWith the dawn of Gallium Oxide (Ga2O₃) and Aluminum Gallium Nitride (AlGaN) electronics and the commercialization of Gallium Nitride (GaN) and Silicon Carbide (SiC) based devices, the field of wide bandgap materials and electronics has never been more vibrant and exciting than it is now. Wide bandgap semiconductors have had a strong presence in the research and development arena for many years. Recently, the increasing demand for high efficiency power electronics and high speed communication electronics, together with the maturity of the synthesis and fabrication of wide bandgap semicon-ductors, has catapulted wide bandgap electronics and optoelectronics into the mainstream.Wide bandgap semiconductors exhibit excellent material properties, which can potentially enable power device operation at higher efficiency, higher temperatures, voltages, and higher switching speeds than current Si technology. This edited volume will serve as a useful reference for researchers in this field — newcomers and experienced alike.This book discusses a broad range of topics including fundamental transport studies, growth of high-quality films, advanced materials characterization, device modeling, high frequency, high voltage electronic devices and optical devices written by the experts in their respective fields. They also span the whole spectrum of wide bandgap materials including AlGaN, Ga2O₃and diamond.

Download or read book Thin Films and Heterostructures for Oxide Electronics written by Satishchandra B. Ogale and published by Springer. This book was released on 2008-11-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxides form a broad subject area of research and technology development which encompasses different disciplines such as materials science, solid state chemistry, physics etc. The aim of this book is to demonstrate the interplay of these fields and to provide an introduction to the techniques and methodologies involving film growth, characterization and device processing. The literature in this field is thus fairly scattered in different research journals covering one or the other aspect of the specific activity. This situation calls for a book that will consolidate this information and thus enable a beginner as well as an expert to get an overall perspective of the field, its foundations, and its projected progress.

Download or read book Gallium Oxide written by Masataka Higashiwaki and published by Springer Nature. This book was released on 2020-04-23 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive coverage of the new wide-bandgap semiconductor gallium oxide (Ga2O3). Ga2O3 has been attracting much attention due to its excellent materials properties. It features an extremely large bandgap of greater than 4.5 eV and availability of large-size, high-quality native substrates produced from melt-grown bulk single crystals. Ga2O3 is thus a rising star among ultra-wide-bandgap semiconductors and represents a key emerging research field for the worldwide semiconductor community. Expert chapters cover physical properties, synthesis, and state-of-the-art applications, including materials properties, growth techniques of melt-grown bulk single crystals and epitaxial thin films, and many types of devices. The book is an essential resource for academic and industry readers who have an interest in, or plan to start, a new R&D project related to Ga2O3.

Download or read book Wide Bandgap Semiconductor Materials and Devices 20 written by S. Jang and published by The Electrochemical Society. This book was released on 2019-05-17 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue of ECS Transactions includes papers based on presentations from the symposium "Wide Bandgap Semiconductor Materials and Devices 20," originally held at the 235th ECS Meeting in Dallas, Texas, May 26-30, 2019.

Download or read book Surface Defects in Wide Bandgap LiF SiO2 and ZnO Crystals written by Utkirjon Sharopov and published by Springer Nature. This book was released on with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: