Download or read book Radiation Effects in Silicon Carbide written by A.A. Lebedev and published by Materials Research Forum LLC. This book was released on 2017 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews the most interesting research concerning the radiation defects formed in 6H-, 4H-, and 3C-SiC under irradiation with electrons, neutrons, and some kinds of ions. The electrical parameters that make SiC a promising material for applications in modern electronics are discussed in detail. Specific features of the crystal structure of SiC are considered. It is shown that, when wide-bandgap semiconductors are studied, it is necessary to take into account the temperature dependence of the carrier removal rate, which is a standard parameter for determining the radiation hardness of semiconductors. The carrier removal rate values obtained by irradiation of various SiC polytypes with n- and p-type conductivity are analyzed in relation to the type and energy of the irradiating particles. The influence exerted by the energy of charged particles on how radiation defects are formed and conductivity is compensated in semiconductors under irradiation is analyzed. Furthermore, the possibility to produce controlled transformation of silicon carbide polytype is considered. The involvement of radiation defects in radiative and nonradiative recombination processes in SiC is analyzed. Data are also presented regarding the degradation of particular SiC electronic devices under the influence of radiation and a conclusion is made regarding the radiation resistance of SiC. Lastly, the radiation hardness of devices based on silicon and silicon carbide are compared.

Download or read book Radiation Effects in Silicon Carbide written by Tomonori Baba and published by . This book was released on 2018 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Effects in Silicon Carbide SiC Micro Nanoelectromechanical Systems M NEMS written by Hailong Chen and published by . This book was released on 2020 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation is of great importance in both fundamental science (e.g., understanding black holes, exploring the time evolution and the origin of the universe) and technological applications (e.g., diagnosing and treating diseases in medicine, and producing electricity at nuclear plant). Among all the radiation studies, radiation in semiconductor materials attracts the most attention in the information era with numerous semiconductor devices operating in space and on earth. Although silicon (Si) still dominates the semiconductor industry, a number of wide bandgap (WBG) semiconductors have demonstrated advantages in harsh environment applications. Among them, silicon carbide (SiC), with a family of polytypes and excellent properties such as wide bandgap (2.3-3.2 eV), high displacement energies (20-35 eV), excellent elastic modulus (~200-700 GPa) and outstanding thermal conductivity (~500 W m-1K-1), has shown great potential for high temperature, high power, and radiation resistant applications. A quite large body of work has been performed during recent decades to understand the radiation effects in the SiC electronic devices, such as field effect transistors (FETs), bipolar junction transistors (BJTs), and diodes. Meantime, while micro/nanoelectromechanical systems (M/NEMS) have gained tremendous advancements and made great impact on many important applications including inertial sensing (e.g., gyroscopes, accelerators), radio-frequency (RF) signal processing and communication, radiation study in M/NEMS has been quite limited, especially for those based on beyond-Si materials. This dissertation makes an initial thrust toward investigating radiation effects in SiC M/NEMS. First, we develop an innovative 3D integrated MEMS platform, by exploiting a scheme consisting of an array of vertically stacked SiC thin diaphragms (and Si ones for comparison). This integrated design and configuration not only scientifically enables probing different radiation effects (with clear reference and control samples) in a 3D fashion, but also economically evades very expensive, repetitive tests on individual devices. Further, we demonstrate cantilever-shaped 3C-SiC multimode MEMS resonators for real-time detection of ultraviolet (UV) radiation. In parallel, we have also developed Si counterparts of the SiC devices to help elucidate how SiC behaves differently from Si for radiation sensing and detecting. Finally, we explore the displacement and ionizing irradiation effects in SiC NEMS switching devices to gain comprehensive and in-depth understanding of the science behind the radiation effects in nanoscale structures made of thin SiC on SiO2. The investigation of NEMS switches before, during, and after proton and X-ray irradiation reveals how energetic particles cause threshold voltage modification, due to the dislocation damage in SiC crystal and how ionizing effects may affect the performance of these nanoscale devices.

Download or read book Shall We Tax Philanthropy written by and published by . This book was released on 1906* with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Effects and Micromechanics of SiC written by and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of Silicon Carbide composite materials for structural applications in fusion energy systems is mainly motivated by the prospect that fusion power systems utilizing the material will have a much more favorable environmental impact. The research team at UCLA was the first to identify the potential advantages of SiC/SiC composite materials through early System Studies. Consequently, two three-year term grants have been awarded to the team, in order to focus on modeling the effects of irradiation on key properties that have been recognized by the community as fundamental to the successful development of the composite. Two main tasks, which are further subdivided into several subtasks each, have been pursued during the course of research during the period: December 1990 through November 1996. The first task deals with modeling the effects of irradiation on the dimensional stability of SiC. To achieve this goal, a substantial effort was launched for modeling the evolution of the microstructure under irradiation. Rate and Fokker-Planck theories have been advanced to model the complex multi-component system of SiC under irradiation. The effort has resulted in a deeper understanding of the interaction between displacement damage components, and transmutant helium gas atoms. Utilizing the methods of Molecular Dynamics (MD) and Monte Carlo (MC), the energetics of defects and the basic displacement mechanisms in SiC have been fully delineated. An advanced Fokker-Planck approach was formulated to determine the phase content and size distribution of damage microstructure in SiC. Finally, a rate theory model was developed and successfully applied to the experimental swelling data on SiC. In the second task, the authors investigated the mechanical behavior of SiC/SiC composites under the irradiation conditions of fusion reactors. The main focus of the second task has been on developing models for the micro-mechanics of cracks in the fiber reinforced matrix of the silicon carbide composite. The effects of irradiation on inducing inelastic deformations in the fiber and the matrix were emphasized. Brief reviews for the results of their research are given here, followed by copies of 26 journal publications resulting from the work supported under this grant.

Download or read book Effects of Nuclear Radiation on Silicon Carbide Diodes written by Lester E. Schott and published by . This book was released on 1967 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Radiation Damage in Silicon Carbide written by Hanchen Huang and published by . This book was released on 1995 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Modeling of Radiation Phenomenon in SiC for Nuclear Applications written by Hyunseok Ko and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide (SiC) material has been investigated for promising nuclear materials owing to its superior thermo-mechanical properties, and low neutron cross-section. While the interest in SiC has been increasing, the lack of fundamental understanding in many radiation phenomena is an important issue. More specifically, these phenomena in SiC include the fission gas transport, radiation induced defects and its evolution, radiation effects on the mechanical stability, matrix brittleness of SiC composites, and low thermal conductivities of SiC composites. To better design SiC and SiC composite materials for various nuclear applications, understanding each phenomenon and its significance under specific reactor conditions is important. In this thesis, we used various modeling approaches to understand the fundamental radiation phenomena in SiC for nuclear applications in three aspects: (a) fission product diffusion through SiC, (b) optimization of thermodynamic stable self-interstitial atom clusters, (c) interface effect in SiC composite and their change upon radiation. In (a) fission product transport work, we proposed that Ag/Cs diffusion in high energy grain boundaries may be the upper boundary in unirradiated SiC at relevant temperature, and radiation enhanced diffusion is responsible for fast diffusion measured in post-irradiated fuel particles. For (b) the self-interstitial cluster work, thermodynamically stable clusters are identified as a function of cluster size, shape, and compositions using a genetic algorithm. We found that there are compositional and configurational transitions for stable clusters as the cluster size increases. For (c) the interface effect in SiC composite, we investigated recently proposed interface, which is CNT reinforced SiC composite. The analytical model suggests that CNT/SiC composites have attractive mechanical and thermal properties, and these fortify the argument that SiC composites are good candidate materials for the cladding. We used grand canonical monte carlo to optimize the interface, as a part of the stepping stone for further study using the interface.

Download or read book The Effect of Grain Size on the Radiation Response of Silicon Carbide and Its Dependence on Irradiation Species and Temperature written by and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years the push for green energy sources has intensified, and as part of that effort accident tolerant and more efficient nuclear reactors have been designed. These reactors demand exceptional material performance, as they call for higher temperatures and doses. Silicon carbide (SiC) is a strong candidate material for many of these designs due to its low neutron cross-section, chemical stability, and high temperature resistance. The possibility of improving the radiation resistance of SiC by reducing the grain size (thus increasing the sink density) is explored in this work. In-situ electron irradiation and Kr ion irradiation was utilized to explore the radiation resistance of nanocrystalline SiC (nc-SiC), SiC nanopowders, and microcrystalline SiC. Electron irradiation simplifies the experimental results, as only isolated Frenkel pairs are produced so any observed differences are simply due to point defect interactions with the original microstructure. Kr ion irradiation simulates neutron damage, as large radiation cascades with a high concentration of point defects are produced. Kr irradiation studies found that radiation resistance decreased with particle size reduction and grain refinement (comparing nc-SiC and microcrystalline SiC). This suggests that an interface-dependent amorphization mechanism is active in SiC, suggested to be interstitial starvation. However, under electron irradiation it was found that nc-SiC had improved radiation resistance compared to single crystal SiC. This was found to be due to several factors including increased sink density and strength and the presence of stacking faults. The stacking faults were found to improve radiation response by lowering critical energy barriers. The change in radiation response between the electron and Kr ion irradiations is hypothesized to be due to either the change in ion type (potential change in amorphization mechanism) or a change in temperature (at the higher temperatures of the Kr ion irradiation, critical energy barriers can be overcome without the assistance of stacking faults). The dependence of the radiation response of SiC on grain size is not as straight forward as initially presumed. The stacking faults present in many nc-SiC materials boost radiation resistance, but an increased number of interfaces may lead to a reduction in radiation response.

Download or read book Reliability And Radiation Effects In Compound Semiconductors written by Allan H Johnston and published by World Scientific. This book was released on 2010-04-27 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on reliability and radiation effects in compound semiconductors, which have evolved rapidly during the last 15 years. It starts with first principles, and shows how advances in device design and manufacturing have suppressed many of the older reliability mechanisms.It is the first book that comprehensively covers reliability and radiation effects in optoelectronic as well as microelectronic devices. It contrasts reliability mechanisms of compound semiconductors with those of silicon-based devices, and shows that the reliability of many compound semiconductors has improved to the level where they can be used for ten years or more with low failure rates.

Download or read book RADIATION DAMAGE IN DIAMOND AND SILICON CARBIDE PART II written by and published by . This book was released on 1955 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Displacement Damage in Silicon Carbide Detectors Resulting from Neutron Irradiation written by Behrooz Khorsandi and published by . This book was released on 2007 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: A conclusion of this thesis is SiC detectors that are placed in the thermal neutron region of a graphite moderator-reflector reactor have a chance to survive at least one reactor refueling cycle, while their count rates are acceptably high.

Download or read book Radiation Effects and Micromechanics of SiC SiC Composites December 1 1990 November 14 1993 and Modeling the Mechanical Behavior of SiC SiC Composites in Fusion Environments November 15 1993 November 14 1996 Final Report December 1 1990 November 14 1996 written by and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of Silicon Carbide composite materials for structural applications in fusion energy systems is mainly motivated by the prospect that fusion power systems utilizing the material will have a much more favorable environmental impact. The research team at UCLA was the first to identify the potential advantages of SiC/SiC composite materials through early System Studies. Consequently, two three-year term grants have been awarded to the team, in order to focus on modeling the effects of irradiation on key properties that have been recognized by the community as fundamental to the successful development of the composite. Two main tasks, which are further subdivided into several subtasks each, have been pursued during the course of research during the period: December 1990 through November 1996. The first task deals with modeling the effects of irradiation on the dimensional stability of SiC. To achieve this goal, a substantial effort was launched for modeling the evolution of the microstructure under irradiation. Rate and Fokker-Planck theories have been advanced to model the complex multi-component system of SiC under irradiation. The effort has resulted in a deeper understanding of the interaction between displacement damage components, and transmutant helium gas atoms. Utilizing the methods of Molecular Dynamics (MD) and Monte Carlo (MC), the energetics of defects and the basic displacement mechanisms in SiC have been fully delineated. An advanced Fokker-Planck approach was formulated to determine the phase content and size distribution of damage microstructure in SiC. Finally, a rate theory model was developed and successfully applied to the experimental swelling data on SiC. In the second task, the authors investigated the mechanical behavior of SiC/SiC composites under the irradiation conditions of fusion reactors. The main focus of the second task has been on developing models for the micro-mechanics of cracks in the fiber reinforced matrix of the silicon carbide composite. The effects of irradiation on inducing inelastic deformations in the fiber and the matrix were emphasized. Brief reviews for the results of their research are given here, followed by copies of 26 journal publications resulting from the work supported under this grant.

Download or read book The Effect of Irradiation on Siliconized silicon Carbide Coatings for Graphite written by J. L. Jackson and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Dynamics Simulation of Radiation Damage Production in Cubic Silicon Carbide written by JM. Perlado and published by . This book was released on 2001 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide (SiC) is a candidate material for nuclear fusion reactor blankets; hence the importance of investigating its response to irradiation. Molecular dynamics (MD) simulations are a powerful tool to study radiation-damage production from the microscopic standpoint. Results of displacement-cascade MD simulations, conducted using the Tersoff potential to describe the interatomic forces, are presented herein. The number of point-defects produced in the material by silicon- (Si) and carbon- (C) primary knock-on atoms (PKAs) of increasing energy (between 0.25 and, respectively, 8 and 4 keV) is studied systematically. By comparison with standard theoretical models, threshold-displacement-energy (TDE) values of practical usefulness for SiC are derived. The effect of irradiation temperature is also allowed for. Qualitatively, the C sublattice turns out to be more heavily damaged than the Sisublattice. The effect of the irradiation temperature becomes visible only above ?2000 K.

Download or read book Neutron Irradiation Effects on High Nicalon Silicon Carbide Fibers written by and published by . This book was released on 1996 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of neutron irradiation on the mechanical properties and microstructure of SiC and SiC-based fibers is a current focal point for the development of radiation damage resistant SiC/SiC composites. This report discusses the radiation effects on the Nippon Carbon Hi-Nicalon{trademark} fiber system and also discusses an erratum on earlier results published by the authors on this material. The radiation matrix currently under study is also summarized.

Download or read book The Effect of Neutron Irradiation on Silicon Carbide Fibers written by and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nine types of SiC fiber have been exposed to neutron radiation in the Advanced Test Reactor at 250 C for various lengths of time ranging from 83 to 128 days. The effects of these exposures have been initially determined using scanning electron microscopy. The fibers tested were Nicalon{trademark} CG, Tyranno, Hi-Nicalon{trademark}, Dow Corning SiC, Carborundum SiC, Textron SCS-6, polymethysilane (PMS) derived SiC from the University of Michigan, and two types of MER SiC fiber. This covers a range of fibers from widely used commercial fibers to developmental fibers. Consistent with previous radiation experiments, Nicalon fiber was severely degraded by the neutron irradiation. Similarly, Tyranno suffered severe degradation. The more advanced fibers which approach the composition and properties of SiC performed well under irradiation. Of these, the Carborundum SiC fiber appeared to perform the best. The Hi-Nicalon and Dow Corning Fibers exhibited good general stability, but also appear to have some surface roughening. The MER fibers and the Textron SCS-6 fibers both had carbon cores which adversely influenced the overall stability of the fibers.