Amorphous Oxide Semiconductors

AMORPHOUS OXIDE SEMICONDUCTORS A singular resource on amorphous oxide semiconductors edited by a world-recognized pioneer in the field In Amorphous Oxide Semiconductors: IGZO and Related Materials for Display and Memory, the Editors deliver a comprehensive account of the current status of—and latest developments in—transparent oxide semiconductor technology. With contributions from leading international researchers and exponents in the field, this edited volume covers physical fundamentals, thin-film transistor applications, processing, circuits and device simulation, display and memory applications, and new materials relevant to amorphous oxide semiconductors. The book makes extensive use of structural diagrams of materials, energy level and energy band diagrams, device structure illustrations, and graphs of device transfer characteristics, photographs and micrographs to help illustrate the concepts discussed within. It also includes: A thorough introduction to amorphous oxide semiconductors, including discussions of commercial demand, common challenges faced during their manufacture, and materials design Comprehensive explorations of the electronic structure of amorphous oxide semiconductors, structural randomness, doping limits, and defects Practical discussions of amorphous oxide semiconductor processing, including oxide materials and interfaces for application and solution-process metal oxide semiconductors for flexible electronics In-depth examinations of thin film transistors (TFTs), including the trade-off relationship between mobility and reliability in oxide TFTs Perfect for practicing scientists, engineers, and device technologists working with transparent semiconductor systems, Amorphous Oxide Semiconductors: IGZO and Related Materials for Display and Memory will also earn a place in the libraries of students studying oxides and other non-classical and innovative semiconductor devices. WILEY SID Series in Display Technology Series Editor: Ian Sage, Abelian Services, Malvern, UK The Society for Information Display (SID) is an international society which has the aim of encouraging the development of all aspects of the field of information display. Complementary to the aims of the society, the Wiley-SID series is intended to explain the latest developments in information display technology at a professional level. The broad scope of the series addresses all facets of information displays from technical aspects through systems and prototypes to standards and ergonomics.

Ultra-wide Bandgap Semiconductors (UWBG) covers the most recent progress in UWBG materials, including sections on high-Al-content AlGaN, diamond, B-Ga2O3, and boron nitrides. The coverage of these materials is comprehensive, addressing materials growth, physics properties, doping, device design, fabrication and performance. The most relevant and important applications are covered, including power electronics, RF electronics and DUV optoelectronics. There is also a chapter on novel structures based on UWBG, such as the heterojunctions, the low-dimensional structures, and their devices. This book is ideal for materials scientists and engineers in academia and R&D searching for materials superior to silicon carbide and gallium nitride. Provides a one-stop resource on the most promising ultra-wide bandgap semiconducting materials, including high-Al-content AlGaN, diamond, β-Ga2O3, boron nitrides, and low-dimensional materials Presents comprehensive coverage, from materials growth and properties, to device design, fabrication and performance Features the most relevant applications, including power electronics, RF electronics and DUV optoelectronics

Electronic devices based on oxide semiconductors are the focus of much attention, with crystalline materials generating huge commercial success. Indium–gallium–zinc oxide (IGZO) transistors have a higher mobility than amorphous silicon transistors, and an extremely low off-state current. C-axis aligned crystalline (CAAC) IGZO enables aggressive down-scaling, high reliability, and process simplification of transistors in displays and LSI devices. This original book introduces the CAAC-IGZO structure, and describes the physics and technology of this new class of oxide materials. It explains the crystallographic classification and characteristics of crystalline oxide semiconductors, their crystallographic characteristics and physical properties, and how this unique material has made a major contribution to the field of oxide semiconductor thin films. Two further books in this series describe applications of CAAC-IGZO in flat-panel displays and LSI devices. Key features: Introduces the unique and revolutionary, yet relatively unknown crystalline oxide semiconductor CAAC-IGZO Presents crystallographic overviews of IGZO and related compounds. Offers an in-depth understanding of CAAC-IGZO. Explains the fabrication method of CAAC-IGZO thin films. Presents the physical properties and latest data to support high-reliability crystalline IGZO based on hands-on experience. Describes the manufacturing process the CAAC-IGZO transistors and introduces the device application using CAAC-IGZO.

This book describes the application of c-axis aligned crystalline In-Ga-Zn oxide (CAAC-IGZO) technology in large-scale integration (LSI) circuits. The applications include Non-volatile Oxide Semiconductor Random Access Memory (NOSRAM), Dynamic Oxide Semiconductor Random Access Memory (DOSRAM), central processing unit (CPU), field-programmable gate array (FPGA), image sensors, and etc. The book also covers the device physics (e.g., off-state characteristics) of the CAAC-IGZO field effect transistors (FETs) and process technology for a hybrid structure of CAAC-IGZO and Si FETs. It explains an extremely low off-state current technology utilized in the LSI circuits, demonstrating reduced power consumption in LSI prototypes fabricated by the hybrid process. A further two books in the series will describe the fundamentals; and the specific application of CAAC-IGZO to LCD and OLED displays. Key features: • Outlines the physics and characteristics of CAAC-IGZO FETs that contribute to favorable operations of LSI devices. • Explains the application of CAAC-IGZO to LSI devices, highlighting attributes including low off-state current, low power consumption, and excellent charge retention. • Describes the NOSRAM, DOSRAM, CPU, FPGA, image sensors, and etc., referring to prototype chips fabricated by a hybrid process of CAAC-IGZO and Si FETs.

Transparent flexible electronics is an emerging technology which makes use of wide band gap semiconductors that can be processed at low temperatures on glass or plastic substrates. Electronic systems that cover large area and curved surfaces together with transparency bring the possibility of numerous applications that are outside the scope of rigid wafer based electronics. Flexible electronics, electronic textiles, a wearable wellness system, and sensory skin are some of the applications of flexible electronics. The key factor in the realization of transparent electronics is the development of high performance fully transparent thin film transistors. Thin film transistors (TFTs) based on transparent conducting amorphous oxide semiconductors (TAOS) such as InGaZnO (IGZO), zinc tin oxide (ZTO), zinc indium tin oxide (ZITO), etc. provide additional functionalities like transparency, high field effect mobility and potential for room temperature processing. The performance of these TAOS based TFTs are superior to their silicon (a-Si:H TFTs) and organic TFTs.Though there are monographs and books on a-Si:H TFTs and organic TFTs, a book on TAOS based TFTs is rare. This book introduces the work of graduate students and beginners to the field of amorphous semiconductors. The mass production of this kind of TFTs on large area substrates involves the complications associated with controlling the composition of oxide compound semiconductor thin film material. Pulsed laser deposition allows for the growth of an oxide semiconductor in a very high oxygen rich environment while co-sputtering is an effective technique for the growth of a multicomponent film and to control the film chemical composition in a systematic and easy way. These manufacturing aspects will be of interest to those working in the industry. The review on the n channel, p channel TFTs, and the detailed description for the extraction of various TFT parameters like the threshold voltage, field effect mobility, sub threshold slope and on-off ratio, etc. will be ready for those working in the field of transparent electronics.

Amorphous semiconductors are subtances in the amorphous solid state that have the properties of a semiconductor and which are either covalent or tetrahedrally bonded amorphous semiconductors or chelcogenide glasses. Developed from both a theoretical and experimental viewpoint Deals with, amongst others, preparation techniques, structural, optical and electronic properties, and light induced phenomena Explores different types of amorphous semiconductors including amorphous silicon, amorphous semiconducting oxides and chalcogenide glasses Applications include solar cells, thin film transistors, sensors, optical memory devices and flat screen devices including televisions

Introduction to Thin Film Transistors reviews the operation, application and technology of the main classes of thin film transistor (TFT) of current interest for large area electronics. The TFT materials covered include hydrogenated amorphous silicon (a-Si:H), poly-crystalline silicon (poly-Si), transparent amorphous oxide semiconductors (AOS), and organic semiconductors. The large scale manufacturing of a-Si:H TFTs forms the basis of the active matrix flat panel display industry. Poly-Si TFTs facilitate the integration of electronic circuits into portable active matrix liquid crystal displays, and are increasingly used in active matrix organic light emitting diode (AMOLED) displays for smart phones. The recently developed AOS TFTs are seen as an alternative option to poly-Si and a-Si:H for AMOLED TV and large AMLCD TV applications, respectively. The organic TFTs are regarded as a cost effective route into flexible electronics. As well as treating the highly divergent preparation and properties of these materials, the physics of the devices fabricated from them is also covered, with emphasis on performance features such as carrier mobility limitations, leakage currents and instability mechanisms. The thin film transistors implemented with these materials are the conventional, insulated gate field effect transistors, and a further chapter describes a new thin film transistor structure: the source gated transistor, SGT. The driving force behind much of the development of TFTs has been their application to AMLCDs, and there is a chapter dealing with the operation of these displays, as well as of AMOLED and electrophoretic displays. A discussion of TFT and pixel layout issues is also included. For students and new-comers to the field, introductory chapters deal with basic semiconductor surface physics, and with classical MOSFET operation. These topics are handled analytically, so that the underlying device physics is clearly revealed. These treatments are then used as a reference point, from which the impact of additional band-gap states on TFT behaviour can be readily appreciated. This reference book, covering all the major TFT technologies, will be of interest to a wide range of scientists and engineers in the large area electronics industry. It will also be a broad introduction for research students and other scientists entering the field, as well as providing an accessible and comprehensive overview for undergraduate and postgraduate teaching programmes.

Amorphous materials differ significantly from their crystalline counterparts in several ways that create unique issues in their use. This book explores these issues and their implications, and provides a full treatment of both experimental and theoretical studies in the field. Advances in Amorphous Semiconductors covers a wide range of studies on hydrogenated amorphous silicon, amorphous chalcogenides, and some oxide glasses. It reviews structural properties, properties associated with the charge carrier-phonon interaction, defects, electronic transport, photoconductivity, and some applications of amorphous semiconductors. The book explains a number of recent advances in semiconductor research, including some of the editors' own findings. It addresses some of the problems associated with the validity of the effective mass approximation, whether K is a good quantum number, and the concepts of phonons and excitons. It also discusses recent progress made in understanding light-induced degradations in amorphous semiconductors, which is seen as the most limiting problem in device applications. The book presents a comprehensive review of both experimental and theoretical studies on amorphous semiconductors, which will be useful to students, researchers, and instructors in the field of amorphous solids.