Download or read book Thermal Conduction Phenomena in Nanostructured Semiconductor Devices and Materials written by Mr. Zijian Li and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal phenomena have become very important in a variety of nanostructured semiconductor devices and materials. The reduced dimensions and large interface densities lead to complex thermal phenomena which do not occur in bulk materials and larger devices. Successful designs of high-performance semiconductor devices, including phase change memory (PCM) and high electron mobility transistors (HEMT), rely on the accurate thermal characterization of thin film materials and improved understanding of nanoscale energy transport physics. This thesis addresses nanoscale thermal transport problems relevant for three promising electronics technologies. The first part of this work investigates thermal conduction phenomena in phase change memory. A combination of frequency-domain electrical thermometry and suspended microstructure design are used to measure the in- and out-of-plane thermal conductivities of thin-film Ge2Sb2Te5 in the amorphous and crystalline phases. The preferential grain orientation and mixed phase distribution lead to a reduced in-plane thermal conductivity that is 60% -- 80% of the out-of-plane value. Anisotropic heat conduction benefits PCM devices by reducing the programming current and mitigating the thermal disturbance to adjacent cells. A fully coupled electrothermal simulation unveils the detailed transient phase distribution during a programming operation, enabling more efficient structural designs for multilevel memory operation. This research extends the thermal characterization and modeling techniques to diamond-based high electron mobility transistors. The high thermal conductivity of the diamond provides superior thermal performance and allows for up to 10x higher power density. Nanoheaters down to 50 nm wide are patterned by electron-beam lithography in order to measure the thermal resistance experienced by the single transistor channel, the multi-gate configuration, and the device package. The thermal resistance data reveals the critical role of thermal interface between the GaN device layer and the diamond substrate. This work established a criterion for the diamond technology to be viable in HEMT applications. Specifically, the thermal interface resistance needs to be less than 30 m2K/GW. The lengthscales of thermal conduction studied in this research are further scaled down to a few nanometers in the final portion of this work. This work measures the thermal properties of the mirror material for extreme ultra-violet (EUV) lithography as the next-generation semiconductor manufacturing technology. The thermal transport across the interfaces of drastically different materials, such as the Mo/Si multilayers (2.8 nm / 4.1 nm), is important in the performance and reliability of the EUV mirrors. This work demonstrates strong anisotropy in the thermal conductivities of the multilayers, where the in-plane conductivity is 13 times higher than the out-of-plane value, owing to the high density of metal-semiconductor interfaces. This research reveals that thermal conduction in such periodic multilayer composites is largely determined by the nonequilibrium electron-phonon physics. A new model indicates that two additional mechanisms -- quasi-ballistic phonon transport normal to the metal film and inelastic electron-interface scattering -- can also impact conduction in metal-dielectric multilayers with period below 10 nm, the critical length scale for the EUV mirrors.

Download or read book Nanostructured Semiconductors written by Konstantinos Termentzidis and published by CRC Press. This book was released on 2017-09-01 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is devoted to nanostructures and nanostructured materials containing both amorphous and crystalline phases with a particular focus on their thermal properties. It is the first time that theoreticians and experimentalists from different domains gathered to treat this subject. It contains two distinct parts; the first combines theory and simulations methods with specific examples, while the second part discusses methods to fabricate nanomaterials with crystalline and amorphous phases and experimental techniques to measure the thermal conductivity of such materials. Physical insights are given in the first part of the book, related with the existing theoretical models and the state of art simulations methods (molecular dynamics, ab-initio simulations, kinetic theory of gases). In the second part, engineering advances in the nanofabrication of crystalline/amorphous heterostructures (heavy ion irradiation, electrochemical etching, aging/recrystallization, ball milling, PVD, laser crystallization and magnetron sputtering) and adequate experimental measurement methods are analyzed (Scanning Thermal Microscopy, Raman, thermal wave methods and x-rays neutrons spectroscopy).

Download or read book Thermal Phenomena in Nanostructured Materials and Devices written by Amy Marie Marconnet and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructuring leads to unique material properties and combinations of properties not naturally available in bulk materials. The study of these properties is critical to improving the device performance and reliability for a range of applications including electronics, thermoelectrics, and nanophotonics. This work focuses on efforts to push the thermal conductivity of nanostructured materials to the extremes: the thermal conductivity of carbon nanotubes (CNT) and nanotube-based materials can exceed that of metals, while the introduction of nanoscale boundaries (e.g. nanoscale pores in silicon nanowires) yields extremely low thermal conductivity materials. Furthermore, this nanostructuring also leads to unique combinations of properties. Porous silicon nanowires are a step towards the desired electron-crystal, phonon-glass combination ideal for thermoelectric applications, while thermally-conductive, mechanically-compliant carbon nanotube films for promising for electronics packaging. This work first explores how the high axial thermal conductivity of carbon nanotubes can be leveraged effectively in thin film and composites through detailed understanding of the phonon transport and measurements of CNT-based films. This work then investigates how nanostructuring silicon significantly reduces the thermal conductivity through enhanced boundary scattering and the possibility of phononic crystal effects. Specifically, measurements of individual, porous silicon nanowires and arrays of silicon nanowires show significant reduction in the thermal conductivity compared to bulk silicon. A detailed model for reduced thermal conductivity due to phonon boundary scattering is developed in conjunction with measurements. Finally, this work also examines how the composition and annealing conditions impact both thermal transport and photoluminescence in silicon-rich silicon nitride films.

Download or read book Nanoscale Thermoelectrics written by Xiaodong Wang and published by Springer Science & Business Media. This book was released on 2013-11-18 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the efficient utilization of energy resources and the minimization of environmental damage, thermoelectric materials can play an important role by converting waste heat into electricity directly. Nanostructured thermoelectric materials have received much attention recently due to the potential for enhanced properties associated with size effects and quantum confinement. Nanoscale Thermoelectrics describes the theory underlying these phenomena, as well as various thermoelectric materials and nanostructures such as carbon nanotubes, SiGe nanowires, and graphene nanoribbons. Chapters written by leading scientists throughout the world are intended to create a fundamental bridge between thermoelectrics and nanotechnology, and to stimulate readers' interest in developing new types of thermoelectric materials and devices for power generation and other applications. Nanoscale Thermoelectrics is both a comprehensive introduction to the field and a guide to further research, and can be recommended for Physics, Electrical Engineering, and Materials Science departments.

Download or read book Thermal Conductivity 30 written by Daniela S. Gaal and published by DEStech Publications, Inc. This book was released on 2010 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale Phenomena written by Zikang Tang and published by Springer Science & Business Media. This book was released on 2007-11-22 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects selected lectures from the Third Workshop of the Croucher Advanced Study Institute on Nano Science and Technology, and showcases contributions from world-renowned researchers. The book presents in-depth articles on the latest developments in nanomaterials and nanotechnology, and provides a cross-disciplinary perspective covering physics and biophysics, chemistry, materials science, and engineering.

Download or read book Thermal and Electro Thermal System Simulation written by Márta Rencz and published by MDPI. This book was released on 2019-11-18 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing power levels and power densities in electronics systems, thermal issues are becoming more and more critical. The elevated temperatures result in changing electrical system parameters, changing the operation of devices, and sometimes even the destruction of devices. To prevent this, the thermal behavior has to be considered in the design phase. This can be done with thermal end electro-thermal design and simulation tools. This Special Issue of Energies, edited by two well-known experts of the field, Prof. Marta Rencz, Budapest University of Technology and Economics, and by Prof. Lorenzo Codecasa, Politecnico di Milano, collects twelve papers carefully selected for the representation of the latest results in thermal and electro-thermal system simulation. These contributions present a good survey of the latest results in one of the most topical areas in the field of electronics: The thermal and electro-thermal simulation of electronic components and systems. Several papers of this issue are extended versions of papers presented at the THERMINIC 2018 Workshop, held in Stockholm in the fall of 2018. The papers presented here deal with modeling and simulation of state-of-the-art applications that are highly critical from the thermal point of view, and around which there is great research activity in both industry and academia. Contributions covered the thermal simulation of electronic packages, electro-thermal advanced modeling in power electronics, multi-physics modeling and simulation of LEDs, and the characterization of interface materials, among other subjects.

Download or read book Comprehensive Semiconductor Science and Technology written by and published by Newnes. This book was released on 2011-01-28 with total page 3572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductors are at the heart of modern living. Almost everything we do, be it work, travel, communication, or entertainment, all depend on some feature of semiconductor technology. Comprehensive Semiconductor Science and Technology, Six Volume Set captures the breadth of this important field, and presents it in a single source to the large audience who study, make, and exploit semiconductors. Previous attempts at this achievement have been abbreviated, and have omitted important topics. Written and Edited by a truly international team of experts, this work delivers an objective yet cohesive global review of the semiconductor world. The work is divided into three sections. The first section is concerned with the fundamental physics of semiconductors, showing how the electronic features and the lattice dynamics change drastically when systems vary from bulk to a low-dimensional structure and further to a nanometer size. Throughout this section there is an emphasis on the full understanding of the underlying physics. The second section deals largely with the transformation of the conceptual framework of solid state physics into devices and systems which require the growth of extremely high purity, nearly defect-free bulk and epitaxial materials. The last section is devoted to exploitation of the knowledge described in the previous sections to highlight the spectrum of devices we see all around us. Provides a comprehensive global picture of the semiconductor world Each of the work's three sections presents a complete description of one aspect of the whole Written and Edited by a truly international team of experts

Download or read book Experimental and Theoretical Investigation of Thermal and Thermoelectric Transport in Nanostructures written by Arden Lot Moore and published by . This book was released on 2010 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents the development and application of analytical, numerical, and experimental methods for the study of thermal and electrical transport in nanoscale systems, with special emphasis on those materials and phenomena which can be important in thermoelectric and semiconductor device applications. Analytical solutions to the Boltzmann transport equation (BTE) using the relaxation time approximation (RTA) are presented and used to study the thermal and electrical transport properties of indium antimonide (InSb), indium arsenide (InAs), bismuth telluride (Bi2Te3), and chromium disilicide (CrSi2) nanowires. Experimental results for the thermal conductivity of single layer graphene supported by SiO2 were analyzed using an RTA-based model and compared to a full quantum mechanical numerical BTE solution which does not rely on the RTA. The ability of these models to explain the measurement results as well as differences between the two approaches are discussed. Alternatively, numerical solutions to the BTE may be obtained statistically through Monte Carlo simulation for complex geometries which may prove intractable for analytical methods. Following this approach, phonon transport in silicon (Si) sawtooth nanowires was studied, revealing that thermal conductivity suppression below the diffuse surface limit is possible. The experimental investigation of energy transport in nanostructures typically involved the use of microfabricated devices or non-contact optical methods. In this work, two such approaches were analyzed to ascertain their thermal behavior and overall accuracy as well as areas for possible improvement. A Raman spectroscopy-based measurement design for investigating the thermal properties of suspended and supported graphene was examined analytically. The resulting analysis provided a means of determining from measurement results the thermal interface conductance, thermal contact resistance, and thermal conductivity of the suspended and supported graphene regions. Previously, microfabricated devices of several different designs have been used to experimentally measure the thermal transport characteristics of nanostructures such as carbon nanotubes, nanowires, and thin films. To ascertain the accuracy and limitations of various microdevice designs and their associated conduction analyses, finite element models were constructed using ANSYS and measurements of samples of known thermal conductance were simulated. It was found that designs with the sample suspended were generally more accurate than those for which the sample is supported on a bridge whose conductance is measured separately. The effects of radiation loss to the environment of certain device designs were also studied, demonstrating the need for radiation shielding to be at temperatures close to that of the device substrate in order to accurately calibrate the resistance thermometers. Using a suspended microdevice like those analyzed using finite element analysis, the thermal conductivities of individual bismuth (Bi) nanowires were measured. The results were correlated with the crystal structure and growth direction obtained by transmission electron microscopy on the same nanowires. Compared to bulk Bi in the same crystal direction, the thermal conductivity of a single-crystal Bi nanowires of 232 nm diameter was found to be 3 - 6 times smaller than bulk between 100 K and 300 K. For polycrystalline Bi nanowires of 74 nm to 255 nm diameter the thermal conductivity was reduced by a factor of 18 - 78 over the same temperature range. Comparable thermal conductivity values were measured for polycrystalline nanowires of varying diameters, suggesting a grain boundary scattering mean free path for all heat carriers in the range of 15 - 40 nm which is smaller than the nanowire diameters. An RTA-based transport model for both charge carriers and phonons was developed which explains the thermal conductivity suppression in the single-crystal nanowire by considering diffuse phonon-surface scattering, partially diffuse surface scattering of electrons and holes, and scattering of phonons and charge carriers by ionized impurities such as oxygen and carbon of a concentration on the order of 1019 cm−3. Using a similar experimental setup, the thermoelectric properties (Seebeck coefficient, electrical conductivity, and thermal conductivity) of higher manganese silicide (HMS) nanostructures were investigated. Bulk HMS is a passable high temperature thermoelectric material which possesses a complex crystal structure that could lead to very interesting and useful nanoscale transport properties. The thermal conductivities of HMS nanowires and nanoribbons were found to be reduced by 50 - 60 % compared to bulk values in the same crystal direction for both nanoribbons and nanowires. The measured Seebeck coefficient data was comparable or below that of bulk, suggesting unintentional doping of the samples either during growth or sample preparation. Difficulty in determining the amorphous oxide layer thickness for nanoribbons samples necessitated using the total, oxide-included cross section in the thermal and electrical conductivity calculation. This in turn led to the determined electrical conductivity values representing the lower bound on the actual electrical conductivity of the HMS core. From this approach, the measured electrical conductivity values were comparable or slightly below the lower end of bulk electrical conductivity values. This oxide thickness issue affects the determination of the HMS nanostructure thermoelectric figure of merit ZT as well, though the lower bound values obtained here were found to still be comparable to or slightly smaller than the expected bulk values in the same crystal direction. Analytical modeling also indicates higher doping than in bulk. Overall, HMS nanostructures appear to have the potential to demonstrate measurable size-induced ZT enhancement, especially if optimal doping and control over the crystallographic growth direction can be achieved. However, experimental methods to achieve reliable electrical contact to quality four-probe samples needs to be improved in order to fully investigate the thermoelectric potential of HMS nanostructures.

Download or read book Simulation of Thermal Transport in Semiconductor Nanostructures written by Song Mei and published by . This book was released on 2017 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advancement of nanofabrication techniques, the sizes of semiconductor electronic and optoelectronic devices keep decreasing while the operating speeds keep increasing. High-speed operation leads to more heat generation and puts more thermal stress on the devices. Since the heat conduction in semiconductors is dominated by the lattice (i.e., phonons), understanding phonon transport in nanostructures is essential to addressing and alleviating the thermal-stress problem in these modern devices. In addition to the increased thermal stress, the advanced techniques that have allowed for the shrinking of the devices routinely rely on heterostructuring, doping, alloying, and the growth of intentionally strained layers to achieve the desired electronic and optical properties. These introduce impediments to phonon transport such as boundaries, interfaces, point defects (alloy atoms or dopants), and strain. Phonon transport is strongly affected by this nanoscale disorder. This dissertation examines how different types of disorder interact with phonons and degrade phonon transport. First, we study thermal transport in graphene nanoribbons (GNRs). GNRs are quasi-one-dimensional (quasi-1D) systems where the edges (boundaries) play an important role in reducing thermal conductivity. Additionally, the thermal transport in GNRs is anisotropic and depend on the GNR's chirality (GNR orientation and edge termination). We use phonon Monte Carlo (PMC) with full phonon dispersions to describe two highly-symmetric types of GNRs: the armchair GNR (AGNR) and the zigzag GNR (ZGNR). PMC tracks phonon in real space and we can explicitly include non-trivial edge structures. Moreover, the relatively low computational burden of PMC allows us to simulate samples up to 100 $\mu$m in length and predict an upper limit for thermal conductivity in graphene. We then investigate the thermal conductivity in III-V superlattices (SLs). SLs consist of alternating thin layers of different materials and III-V SLs are widely used in nanoscale thermoelectric and optoelectronic devices. The key feature in SLs is that it contains many interfaces, which dictates thermal transport. As III-V SLs are often fabricated using well-controlled techniques and have high-quality interfaces, we develop a model with only one free parameter---the effective rms roughness of the interfaces---to describe its twofold influence: reducing the in-plane layer thermal conductivity and introducing thermal boundary resistance (TBR) in the cross-plane direction. Both the calculated in-plane and cross-plane thermal conductivity of SLs agree with a number of different experiments. Finally, we study thermal conductivity of ternary III-V alloys. In modern optoelectronic devices, ternary III-V alloys are used more often than binary compounds because one can use composition engineering to achieve different effective masses, electron/hole barrier heights, and strain levels. Ternary alloys are usually treated under the virtual crystal approximation (VCA) where cation atoms are assumed to be randomly distributed and possess an averaged mass. This assumption is challenged by a discrepancy between different experiments, as well as the discrepancy between experiments and calculations. We use molecular dynamics (MD) to study the ternary alloy system as both atom masses and atom locations are explicitly tracked in MD. We discover that the thermal conductivity is determined by a competition between mass-difference scattering and the short-range ordering of the cations.

Download or read book Advanced Materials written by Ivan A. Parinov and published by Springer. This book was released on 2019-07-03 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes selected, peer-reviewed contributions from the 2018 International Conference on “Physics and Mechanics of New Materials and Their Applications”, PHENMA 2018, held in Busan, South Korea, 9–11 August 2018. Focusing on manufacturing techniques, physics, mechanics, and applications of modern materials with special properties, it covers a broad spectrum of nanomaterials and structures, ferroelectrics and ferromagnetics, and other advanced materials and composites. The authors discuss approaches and methods in nanotechnology; newly developed, environmentally friendly piezoelectric techniques; and physical and mechanical studies of the microstructural and other properties of materials. Further, the book presents a range of original theoretical, experimental and computational methods and their application in the solution of various technological, mechanical and physical problems. Moreover, it highlights modern devices demonstrating high accuracy, longevity and the ability to operate over wide temperature and pressure ranges or in aggressive media. The developed devices show improved characteristics due to the use of advanced materials and composites, opening new horizons in the investigation of a variety of physical and mechanical processes and phenomena.

Download or read book Nanoscale Phenomena written by Horst Hahn and published by Springer Science & Business Media. This book was released on 2009-09-18 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main intention of the editors of the book is the demonstration of the intrinsic correlation and mutual influence of three important components of nanoscience: new phenomena – nanomaterials – nanodevices. This is the organizing concept of the book. To discover new phenomena it is necessary to develop novel nanotechnological processes for fabrication of nanomaterials. Nanostructures and new phenomena serve as the base for the development of novel nanoelectronic devices and systems. The articles selected for the book illustrate this interrelation.

Download or read book Characterization of Nanostructured Materials for Thermal Conduction and Heat Transfer Control written by Alexandros el Sachat and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanotechnology for Electronic Applications written by Nabisab Mujawar Mubarak and published by Springer Nature. This book was released on 2022-01-17 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of the electronic applications of nanotechnology. It presents latest research in the areas of nanotechnology applied to the fields of electronics and energy. Various topics covered in this book include nanotechnology in electronic field, electronic chips and circuits, batteries, wireless devices, energy storage, semiconductors, fuel cells, defense and military equipment, and aerospace industry, This book will be useful for engineers, researchers and industry professionals primarily in the fields of electrical engineering engineering, materials science and nanotechnology.

Download or read book Impact of Thermal Conductivity on Energy Technologies written by Aamir Shahzad and published by BoD – Books on Demand. This book was released on 2018-09-05 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended to provide a deep understanding on the advanced treatments of thermal properties of materials through experimental, theoretical, and computational techniques. This area of interest is being taught in most universities and institutions at the graduate and postgraduate levels. Moreover, the increasing modern technical and social interest in energy has made the study of thermal properties more significant and exciting in the recent years. This book shares with the international community a sense of global motivation and collaboration on the subject of thermal conductivity and its wide spread applications in modern technologies. This book presents new results from leading laboratories and researchers on topics including materials, thermal insulation, modeling, steady and transient measurements, and thermal expansion. The materials of interest range from nanometers to meters, bringing together ideas and results from across the research field.

Download or read book The Physics of Phonons written by Gyaneshwar P. Srivastava and published by Routledge. This book was released on 2019-07-16 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: There have been few books devoted to the study of phonons, a major area of condensed matter physics. The Physics of Phonons is a comprehensive theoretical discussion of the most important topics, including some topics not previously presented in book form. Although primarily theoretical in approach, the author refers to experimental results wherever possible, ensuring an ideal book for both experimental and theoretical researchers. The author begins with an introduction to crystal symmetry and continues with a discussion of lattice dynamics in the harmonic approximation, including the traditional phenomenological approach and the more recent ab initio approach, detailed for the first time in this book. A discussion of anharmonicity is followed by the theory of lattice thermal conductivity, presented at a level far beyond that available in any other book. The chapter on phonon interactions is likewise more comprehensive than any similar discussion elsewhere. The sections on phonons in superlattices, impure and mixed crystals, quasicrystals, phonon spectroscopy, Kapitza resistance, and quantum evaporation also contain material appearing in book form for the first time. The book is complemented by numerous diagrams that aid understanding and is comprehensively referenced for further study. With its unprecedented wide coverage of the field, The Physics of Phonons will be indispensable to all postgraduates, advanced undergraduates, and researchers working on condensed matter physics.

Download or read book Nano Microscale Heat Transfer written by Zhuomin M. Zhang and published by Springer Nature. This book was released on 2020-06-23 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt: This substantially updated and augmented second edition adds over 200 pages of text covering and an array of newer developments in nanoscale thermal transport. In Nano/Microscale Heat Transfer, 2nd edition, Dr. Zhang expands his classroom-proven text to incorporate thermal conductivity spectroscopy, time-domain and frequency-domain thermoreflectance techniques, quantum size effect on specific heat, coherent phonon, minimum thermal conductivity, interface thermal conductance, thermal interface materials, 2D sheet materials and their unique thermal properties, soft materials, first-principles simulation, hyperbolic metamaterials, magnetic polaritons, and new near-field radiation experiments and numerical simulations. Informed by over 12 years use, the author’s research experience, and feedback from teaching faculty, the book has been reorganized in many sections and enriched with more examples and homework problems. Solutions for selected problems are also available to qualified faculty via a password-protected website.• Substantially updates and augments the widely adopted original edition, adding over 200 pages and many new illustrations;• Incorporates student and faculty feedback from a decade of classroom use;• Elucidates concepts explained with many examples and illustrations;• Supports student application of theory with 300 homework problems;• Maximizes reader understanding of micro/nanoscale thermophysical properties and processes and how to apply them to thermal science and engineering;• Features MATLAB codes for working with size and temperature effects on thermal conductivity, specific heat of nanostructures, thin-film optics, RCWA, and near-field radiation.