Download or read book Transition Metal Oxide Thin Films Integration on SrTiO3 written by Wei Guo (Ph. D.) and published by . This book was released on 2021 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metals (TMs) have an immense range of intriguing physical properties and phenomena. Transition metals and transition metal oxides (TMOs) play a very important role in modern day scientific research and industry. TMs and TMOs exhibit an even broader range of structural, electrical, magnetic, and optical properties when fabricated as thin films on other materials compared to their the bulk forms. SrTiO3 (STO) is a widely used cubic perovskite oxide material known for its excellent electronic properties. When TMs and TMOs are integrated on STO, effects based on their interaction with STO have lead researchers to explore the physics behind such effects and their possible industrial device applications. In this thesis, we will mainly focus on the integration of TMs and TMOs with STO and with epitaxial STO grown on Si. The interactions of the transition metal Pt and rare earth metal Eu when deposited on STO by molecular beam epitaxy (MBE) were investigated. For Pt growth on STO, I investigated the properties of ultrathin Pt as a function of coverage on TiO2-terminated SrTiO3 substrate at different temperatures. I used in situ x-ray photoelectron spectroscopy (XPS), ex situ scanning electron microscopy (SEM) and atomic force microscopy (AFM) to observe the evolution of the electronic structure and surface morphology of Pt. I compared the electronic structure of Pt and the different growth patterns at low and high temperatures. I also performed high temperature annealing of low temperature-grown samples and found a “bubble-up” behavior of the continuous film. We also performed ultra-high vacuum deposition of Eu metal on STO (001) and achieved EuO epitaxy on STO via oxygen scavenging. I explored the oxygen scavenging behavior of Eu using STO films on Si by varying the STO thickness and Eu deposition temperature. In situ XPS was used to investigate the electronic structure of the nominal Eu/STO/Si stack. Our XPS results on the Eu/EuO stack revealed an unusual downward band bending at the interface. This is supported by density functional theory calculations by Gao. This work has been published in J. Appl. Phys. 121, 105302 (2017) and J. Appl. Phys. 124, 235301 (2018). Theoretical calculations performed in our group predicted the existence of a 2-dimensional electron gas (2DEG) at the EuO/STO interface and demonstrated that the 2DEG location can be controlled if an additional layer of BaTiO3 is included. To explore this effect on the 2DEG, I performed soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) with our collaborators at the Swiss Light Source. The results are currently being summarized for publication. For possible applications in Si photonics, I performed a detailed study of dry oxidation of a Si substrate below a thin epitaxial SrTiO3. Annealing time and temperature are the key factors to optimize the SiO2 thickness. I developed a theoretical model based on a modification of the Deal-Grove-Massoud formalism that predicted the thickness of SiO2 formed underneath STO as a function of time and temperature. The model fits the experimental data well. This work has been published in J. Appl. Phys. 127, 055302 (2020). In addition, I performed preliminary studies on free-standing STO membranes. I developed a fabrication process and performed Raman measurements. We also proposed a quantum well structure design of BaSnO3/SrTiO3/Al2O3 to make use of the conduction offset as large as ~3.5eV between BaSnO3 (BSO) and Al2O3. The whole deposition process is done by MBE and characterized by reflection high energy electron diffraction (RHEED) and XPS to confirm the BSO film quality. We are still working on improving the quantum well quality to be able to make multiple quantum well structures

Download or read book Thin Film Metal Oxides written by Shriram Ramanathan and published by Springer Science & Business Media. This book was released on 2009-12-03 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin Film Metal-Oxides provides a representative account of the fundamental structure-property relations in oxide thin films. Functional properties of thin film oxides are discussed in the context of applications in emerging electronics and renewable energy technologies. Readers will find a detailed description of deposition and characterization of metal oxide thin films, theoretical treatment of select properties and their functional performance in solid state devices, from leading researchers. Scientists and engineers involved with oxide semiconductors, electronic materials and alternative energy will find Thin Film Metal-Oxides a useful reference.

Download or read book Integration of Functional Oxides with Semiconductors written by Alexander A. Demkov and published by Springer Science & Business Media. This book was released on 2014-02-20 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the basic physical principles of the oxide/semiconductor epitaxy and offers a view of the current state of the field. It shows how this technology enables large-scale integration of oxide electronic and photonic devices and describes possible hybrid semiconductor/oxide systems. The book incorporates both theoretical and experimental advances to explore the heteroepitaxy of tuned functional oxides and semiconductors to identify material, device and characterization challenges and to present the incredible potential in the realization of multifunctional devices and monolithic integration of materials and devices. Intended for a multidisciplined audience, Integration of Functional Oxides with Semiconductors describes processing techniques that enable atomic-level control of stoichiometry and structure and reviews characterization techniques for films, interfaces and device performance parameters. Fundamental challenges involved in joining covalent and ionic systems, chemical interactions at interfaces, multi-element materials that are sensitive to atomic-level compositional and structural changes are discussed in the context of the latest literature. Magnetic, ferroelectric and piezoelectric materials and the coupling between them will also be discussed. GaN, SiC, Si, GaAs and Ge semiconductors are covered within the context of optimizing next-generation device performance for monolithic device processing.

Download or read book A Study of Structure Induced Phase Phenomena in Perovskite Oxide Thin Films written by Jason Lapano and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The three core tenants of materials science are theory, synthesis, and characterization. A solid theoretical framework is required for understanding of the problem at hand and using that knowledge to advance new areas of research. Synthesis of pristine materials is required to study the theory in a physical system and prevent misinterpretation of results. Complex structures and compositions are often the most interesting, and when defects and impurities are of interest, perfectly-imperfect samples are required which are often the most challenging to synthesize. Characterization of these materials is equally as important and complex, requiring careful sample preparation and experimental setups. Further, it is not always clear how to observe the property of scientific interest, and new characterization techniques must be developed. This dissertation focuses on using these three tenants to understand and advance the field of transition metal perovskite complex oxides using thin films of the incipient ferroelectrics CaTiO3 and SrTiO3 and antiferromagnetic Mott-Insulators LaVO3 and YVO3. The knowledge gained in this thesis can be applied to other complex oxide materials in better understanding magnetic and electronic transitions, high Tc superconductivity and quantum hall effect. Coupled with the relatively simple structure and ease of integration of multiple different chemical compounds into a single heterostructure leads to near numerous avenues to design functionality into materials.The first sections of this thesis begin with (1) an introduction to the basic science and past work in perovskite oxides, followed by (2) exploring the most common and promising synthesis routes, and finally (3) the various characterization methods used. The 4th chapter addresses the specific challenges of growth of ternary complex oxide thin films in an industrially profitable fashion. The three primary criterion that these deposition methods must adhere to is that they must (a) control film stoichiometry to less than 1% deviations, (b) deposit conformal coatings over standard 8 silicon wafers, (c) and exhibit deposition rates in excess of 1 m/hr. We show that these can be achieved using a hybrid molecular beam (hMBE) epitaxy approach and outline a route for commercially viable growth of complex oxides on silicon. This method is applied directly to the deposition of SrTiO3 on silicon for virtual single crystal perovskite substrates. The 5th chapter of this thesis discusses the effect of epitaxial strain, stoichiometry and interfacial coupling in heterostructures of complex oxides. In the (SrTiO3)n(CaTiO3)n series of superlattices grown by hMBE, it is found that interfacial energies play a large role in dictating the macroscopic properties, particularly ferroelectricity. In coherently strained thin films, both CaTiO3 and SrTiO3 exhibit relaxor-like ferroelectric behavior below room temperature. However, certain superlattices of these materials show nonpolar behavior when probed using second harmonic generation (SHG). High resolution scanning transmission electron microscopy (STEM) reveals that the symmetry in the superlattice is different from the individual parent compounds at the same strain state. It is found these are directly related to the high density of interfacial layers present in the films. Further, interfacial mixing of the constituent layers on certain superlattices leads to the development of a Ca1-xSrxTiO3 alloy which develops a ferroelectric moment at low temperatures, leading to spurious SHG signals. The findings of this experiment highlight the sensitivity of these complex layered structures to strain, stoichiometry, distortion coupling effects, and interfacial mixing.

Download or read book Metal Oxide Based Thin Film Structures written by Nini Pryds and published by Elsevier. This book was released on 2017-09-07 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxide-Based Thin Film Structures: Formation, Characterization and Application of Interface-Based Phenomena bridges the gap between thin film deposition and device development by exploring the synthesis, properties and applications of thin film interfaces. Part I deals with theoretical and experimental aspects of epitaxial growth, the structure and morphology of oxide-metal interfaces deposited with different deposition techniques and new developments in growth methods. Part II concerns analysis techniques for the electrical, optical, magnetic and structural properties of thin film interfaces. In Part III, the emphasis is on ionic and electronic transport at the interfaces of Metal-oxide thin films. Part IV discusses methods for tailoring metal oxide thin film interfaces for specific applications, including microelectronics, communication, optical electronics, catalysis, and energy generation and conservation. This book is an essential resource for anyone seeking to further their knowledge of metal oxide thin films and interfaces, including scientists and engineers working on electronic devices and energy systems and those engaged in research into electronic materials. - Introduces the theoretical and experimental aspects of epitaxial growth for the benefit of readers new to the field - Explores state-of-the-art analysis techniques and their application to interface properties in order to give a fuller understanding of the relationship between macroscopic properties and atomic-scale manipulation - Discusses techniques for tailoring thin film interfaces for specific applications, including information, electronics and energy technologies, making this book essential reading for materials scientists and engineers alike

Download or read book Transition Metal Oxide Thin Film based Chromogenics and Devices written by Pandurang Ashrit and published by . This book was released on 2017 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interfaces in Electronic Materials written by L. Cook and published by The Electrochemical Society. This book was released on 2006 with total page 362 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 Oxide Materials at the Two dimensional Limit written by Kristy Joy Kormondy and published by . This book was released on 2017 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emergent phenomena in transition metal oxide films are receiving considerable attention with the development of techniques for the preparation of well-controlled oxide surfaces. On the macroscopic scale, such display novel physics phenomena including superconductivity, magnetism, ferroelectricity, and more. On the nanometer scale, the properties of epitaxial interfaces are further impacted by strain, band alignment, and crystal imperfections that may affect the long-range as well as the short-range order. Furthermore, symmetry lowering at the interface creates entirely new environments that are not accessible in the bulk environment. Thus, thin-film oxide materials are increasingly important in many applications. My work focuses on epitaxial oxides of the perovskite, spinel, and rocksalt structure and covers two main phenomena: (1) the two-dimensional electron gas at epitaxial oxide interfaces, and (2) thin epitaxial electro-optic oxides. Because polar oxides are of prominent interest as a mechanism for the formation of the two-dimensional electron gas, I start with a study of polar semiconductor Co3O4. Ellipsometry reveals a direct band gap of 0.75 eV, and magnetic measurements show the signature of antiferromagnetic ordering at 49 K, higher than the typical bulk value. Next, I look closer at the role of defects by studying the highly conducting layer at the crystalline [gamma]-alumina/SrTiO3 (STO) interface which is attributed to oxygen vacancies. Annealing in oxygen is found to reduce the carrier density and turn a conductive sample into an insulator. Building upon these results, I show that even at room temperature, out-diffusion of oxygen from SrTiO3 during epitaxy of highly spin-split semiconductor EuO epitaxy creates a highly conductive layer of oxygen vacancies on the SrTiO3 side of the interface. The films are ferromagnetic with a Curie temperature of 70 K and display giant magnetoresistance below the transition temperature. Leveraging this approach offers an as-yet unexplored route to seamlessly integrate ferromagnetism and the oxide two-dimensional electron gas for the development of novel nano-oxide spintronic devices. The large effective Pockels coefficient for high-quality epitaxial BaTiO3 (BTO) films on Si distinguishes BaTiO3 as a highly promising material for integrated silicon nanophotonics. However, the linear electro-optic effect in BaTiO3 thin films determined in previous experiments clearly shows deteriorated properties compared to bulk BTO crystals. First, I study BaTiO3 films of varied thickness in order to quantify the Pockels coefficient with respect to crystalline orientation. As a next step, I report on the strong dependence of the Pockels effect in BaTiO3 thin films on their microstructure, and provide guidelines on how to engineer thin films with strong electro-optic response. The 25× enhancement of the Pockels coefficient indicates a promising route to increase the performance of nonlinear oxides in the two-dimensional limit for the development of novel hybrid silicon photonic platform.

Download or read book Interplay Between Magnetic and Dielectric Phenomena at Transition Metal Oxide Interfaces written by Daniel Schumacher and published by Forschungszentrum Jülich. This book was released on 2013 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ULSI Process Integration 6 written by C. Claeys and published by The Electrochemical Society. This book was released on 2009-09 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: ULSI Process Integration 6 covers all aspects of process integration. Sections are devoted to 1) Device Technologies, 2) Front-end-of-line integration (gate stacks, shallow junctions, dry etching, etc.), 3) Back-end-of-line integration (CMP, low-k, Cu interconnect, air-gaps, 3D packaging, etc.), 4) Alternative channel technologies (Ge, III-V, hybrid integration), and 5) Emerging technologies (CNT, graphene, polymer electronics, nanotubes).

Download or read book Multicomponent Oxide Films for Electronics Volume 574 written by Marilyn Hawley and published by . This book was released on 1999-10-06 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exceptional properties of multicomponent oxides, combined with the inability of simpler materials to meet the increasing demands of the electronics industry, have motivated tremendous interest and activity in utilizing multicomponent oxides for electronic applications. For these applications, it is often desirable to integrate complex oxides in thin-film form with other materials. This book focuses on common materials issues involved in the processing and characterization of multicomponent oxides and how these issues relate to device applications. Papers range from theoretical explanations of the magnetic and electronic properties of transition metal oxides, to integration with silicon technology. Noteworthy is the progress being made in the deposition and characterization of these complex materials, as well as their applicability in ferroelectric memories, MOSFETs, optical devices, infrared imaging arrays, etc. Topics include: epitaxial multicomponent oxide film growth; properties, characterization and modeling; properties of multicomponent oxides; and multicomponent oxide devices.

Download or read book Chemical Solution Deposition of Functional Oxide Thin Films written by Theodor Schneller and published by Springer Science & Business Media. This book was released on 2014-01-24 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first text to cover all aspects of solution processed functional oxide thin-films. Chemical Solution Deposition (CSD) comprises all solution based thin- film deposition techniques, which involve chemical reactions of precursors during the formation of the oxide films, i. e. sol-gel type routes, metallo-organic decomposition routes, hybrid routes, etc. While the development of sol-gel type processes for optical coatings on glass by silicon dioxide and titanium dioxide dates from the mid-20th century, the first CSD derived electronic oxide thin films, such as lead zirconate titanate, were prepared in the 1980’s. Since then CSD has emerged as a highly flexible and cost-effective technique for the fabrication of a very wide variety of functional oxide thin films. Application areas include, for example, integrated dielectric capacitors, ferroelectric random access memories, pyroelectric infrared detectors, piezoelectric micro-electromechanical systems, antireflective coatings, optical filters, conducting-, transparent conducting-, and superconducting layers, luminescent coatings, gas sensors, thin film solid-oxide fuel cells, and photoelectrocatalytic solar cells. In the appendix detailed “cooking recipes” for selected material systems are offered.

Download or read book Strain induced Phenomenon in Complex Oxide Thin Films written by Ryan Haislmaier and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Complex oxide materials wield an immense spectrum of functional properties such as ferroelectricity, ferromagnetism, magnetoelectricity, optoelectricity, optomechanical, magnetoresistance, superconductivity, etc. The rich coupling between charge, spin, strain, and orbital degrees of freedom makes this material class extremely desirable and relevant for next generation electronic devices and technologies which are trending towards nanoscale dimensions. Development of complex oxide thin film materials is essential for realizing their integration into nanoscale electronic devices, where theoretically predicted multifunctional capabilities of oxides could add tremendous value. Employing thin film growth strategies such as epitaxial strain and heterostructure interface engineering can greatly enhance and even unlock novel material properties in complex oxides, which will be the main focus of this work. However, physically incorporating oxide materials into devices remains a challenge. While advancements in molecular beam epitaxy (MBE) of thin film oxide materials has led to the ability to grow oxide materials with atomic layer precision, there are still major limitations such as controlling stoichiometric compositions during growth as well as creating abrupt interfaces in multi-component layered oxide structures. The work done in this thesis addresses ways to overcome these limitations in order to harness intrinsic material phenomena.The development of adsorption-controlled stoichiometric growth windows of CaTiO3 and SrTiO3 thin film materials grown by hybrid MBE where Ti is supplied using metal-organic titatnium tetraisopropoxide material is thoroughly outlined. These growth windows enable superior epitaxial strain-induced ferroelectric and dielectric properties to be accessed as demonstrated by chemical, structural, electrical, and optical characterization techniques. For tensile strained CaTiO3 and compressive strained SrTiO3 films, the critical effects of nonstoichiometry on ferroelectric properties are investigated, where enhanced ferroelectric responses are only found for stoichiometric films grown inside of the growth windows, whereas outside of the optimal growth window conditions, ferroelectric properties are greatly deteriorated and eventually disappear for highly nonstoichiometric film compositions. Utilizing these stoichiometric growth windows, high temperature polar phase transitions are discovered for compressively strained CaTiO3 films with transition temperatures in excess of 700 K, rendering this material as a strong candidate for high temperature electronic applications. Beyond the synthesis of single phase materials using hybrid MBE, a methodology is presented for constructing layered (SrTiO3)n/(CaTiO3)n superlattice structures, where precise control over the unit cell layering thickness (n) is demonstrated using in-situ reflection high energy electron diffraction. The effects of interface roughness and layering periodicity (n) on the strain-induced ferroelectric properties for a series of n=1-10 (SrTiO3)n/(CaTiO3)n superlattice films are investigated. It is found that the stabilization of a ferroelectric phase is independent of n, but is however strongly dominated by the degree of interface roughness which is quantified by measuring the highest nth order X-ray diffraction peak splitting of each superlattice film. A counter-intuitive realization is made whereby a critical amount of interface roughness is required in order to enable the formation of the predicted strain-stabilized ferroelectric phase, whereas sharp interfaces actually suppress this ferroelectric phase from manifesting. It is shown how high-quality complex oxide superlattices can be constructed using hybrid MBE technique, allowing the ability to control layered materials at the atomic scale. Furthermore, a detailed growth methodology is provided for constructing a layered n=4 SrO(SrTiO3)n Ruddlesden-Popper (RP) phase by hybrid MBE, where the ability to deposit single monolayers of SrO and TiO2 is utilized to build the RP film structure over a time period of 5 hours. This is the first time that a thin film RP phase has been grown using hybrid MBE, where an a stable control over the fluxes is demonstrated during relatively long time periods of growth, which advantageously facilitates the synthesis of high-quality RP materials with excellent structural and chemical homogeneity.Additionally, this work demonstrates some major advancements in optical second harmonic generation (SHG) characterization techniques of ferroelectric thin film materials. The SHG characterization techniques developed here proved to be the bread-and-butter for most of the work performed in this thesis, providing a powerful tool for identifying the existence of strain-induced ferroelectric phases, including their temperature dependence and polar symmetry. The work presented in this dissertation will hopefully provide a preliminary road map for future hybrid MBE growers, scientists and researchers, to develop and investigate epitaxial strain and heterostructure layering induced phenomena in other complex oxide systems.

Download or read book Science and Technology of Integrated Ferroelectrics written by Carlos Pazde-Araujo and published by CRC Press. This book was released on 2001-01-11 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to present in one volume some of the most significant developments that have taken place in the field of integrated ferroelectrics during the last decade of the twentieth century. The book begins with a comprehensive introduction to integrated ferroelectrics and follows with fifty-three papers selected by Carlos Paz de Araujo, Orlando Auciello, Ramamoorthy Ramesh, and George W. Taylor. These fifty-three papers were selected from more than one thousand papers published over the last eleven years in the proceedings of the International Symposia on Integrated Ferroelectrics (ISIF). These papers were chosen on the basis that they (a) give a broad view of the advances that have been made and (b) indicate the future direction of research and technological development. Readers who wish for a more in-depth treatment of the subject are encouraged to refer to volumes 1 to 27 of Integrated Ferroelectrics, the main publication vehicle for papers in this field.

Download or read book Oxide Thin Films Multilayers and Nanocomposites written by Paolo Mele and published by Springer. This book was released on 2015-03-26 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of the science of nanostructured oxides. It details the fundamental techniques and methodologies involved in oxides thin film and bulk growth, characterization and device processing, as well as heterostructures. Both, experts in oxide nanostructures and experts in thin film heteroepitaxy, contribute the interactions described within this book.

Download or read book Electric Field Effect on Transition Metal Oxide Thin Films written by Tao Wu and published by . This book was released on 2002 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: