Download or read book Structural Characterization of Epitaxial Graphene on Silicon Carbide written by Joanna R. Hass and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene, a single sheet of carbon atoms sp2-bonded in a honeycomb lattice, is a possible all-carbon successor to silicon electronics. Ballistic conduction at room temperature and a linear dispersion relation that causes carriers to behave as massless Dirac fermions are features that make graphene promising for high-speed, low-power devices. The critical advantage of epitaxial graphene (EG) grown on SiC is its compatibility with standard lithographic procedures.

Download or read book Epitaxial Graphene on Silicon Carbide written by Gemma Rius and published by CRC Press. This book was released on 2018-01-19 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book dedicated exclusively to epitaxial graphene on silicon carbide (EG-SiC). It comprehensively addresses all fundamental aspects relevant for the study and technology development of EG materials and their applications, using quantum Hall effect studies and probe techniques such as scanning tunneling microscopy and atomic resolution imaging based on transmission electron microscopy. It presents the state of the art of the synthesis of EG-SiC and profusely explains it as a function of SiC substrate characteristics such as polytype, polarity, and wafer cut as well as the in situ and ex situ conditioning techniques, including H2 pre-deposition annealing and chemical mechanical polishing. It also describes growth studies, including the most popular characterization techniques, such as ultrahigh-vacuum, partial-pressure, or graphite-cap sublimation techniques, for high-quality controlled deposition. The book includes relevant examples on synthesis and characterization techniques as well as device fabrication processing and performance and complements them with theoretical modeling and simulation studies, which are helpful in the fundamental comprehension of EG-SiC substrates and their potential use in electronic applications. It addresses the fundamental aspects of EG-SiC using quantum Hall effect studies as well as probe techniques, such as scanning tunneling microscopy or atomic resolution imaging based on transmission electron microscopy. It comprises chapters that present reviews and vision on the current state of the art of experts in physics, electronic engineering, materials science, and nanotechnology from Europe and Asia.

Download or read book Epitaxial Graphene on Silicon Carbide written by Gemma Rius and published by Jenny Stanford Publishing. This book was released on 2018-01-31 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This is the first book dedicated exclusively to epitaxial graphene on silicon carbide (EG-SiC). It addresses comprehensively all aspects relevant for the study and technology development of EG materials and their applications. It includes the state of the art on the synthesis of EG-SiC, which is profusely explained as a function of SiC substrate characteristics, such as polytype, polarity, and wafer cut, as well as both in situ and ex situ conditioning techniques, including H2 pre-deposition annealing, chemical mechanical polishing, etc. It generously describes growth studies including the most popular techniques for high quality and controlled deposition such as ultrahigh vacuum-processing, partial-pressure, or graphite cap controlled-sublimation techniques. The book includes relevant examples on synthesis and characterization techniques as well as device fabrication processing and performance and complements them with theoretical modeling and simulation studies, which are helpful in the fundamental comprehension of EG-SiC substrates and their potential use in electronic applications. It addresses the fundamental aspects of EG-SiC using quantum Hall effect studies as well as probe techniques, such as scanning tunneling microscopy or atomic resolution imaging based on transmission electron microscopy. It comprises chapters that present reviews and vision on the current state of the art of experts in physics, electronic engineering, materials science, and nanotechnology from Europe and Asia."--Provided by publisher.

Download or read book Epitaxial Graphene on Silicon Carbide written by Michael W. Sprinkle and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past several years, epitaxial graphene on silicon carbide has been transformed from an academic curiosity of social scientists to a leading candidate material to replace silicon in post-CMOS electronics. This has come with rapid development of growth technologies, improved understanding of epitaxial graphene on the polar faces of silicon carbide, and new device fabrication techniques. The contributions of this thesis include refinement and improved understanding of graphene growth on the silicon- and carbon-faces in the context of managed local silicon partial pressure, high-throughput epitaxial graphene thickness measurement and uniformity characterization by ellipsometry, observations of nearly ideal graphene band structures on rotationally stacked carbon-face multilayer epitaxial graphene, presentation of initial experiments on localized in situ chemical modification of epitaxial graphene for an alternate path to semiconducting behavior, and novel device fabrication methods to exploit the crystal structure of the silicon carbide substrate. The latter is a particularly exciting foray into three dimensional patterning of the substrate that may eliminate the critical problem of edge roughness in graphene nanoribbons.

Download or read book Characterization of Selective Epitaxial Graphene Growth on Silicon Carbide written by Farhana Zaman and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for post-CMOS nanoelectronics has led to the investigation of innovative device structures and materials. Graphene, a zero bandgap semiconductor with ballistic transport properties, has great potential to extend diversification and miniaturization beyond the limits of CMOS. The goal of this work is to study the growth of graphene on SiC using the novel method of selective graphitization. The major contributions of this research are as follows - First, epitaxial graphene is successfully grown on selected regions of SiC not capped by AlN deposited by molecular beam epitaxy. This contribution enables the formation of electronic-grade graphene in desired patterns without having to etch the graphene or expose it to any detrimental contact with external chemicals. Etching of AlN opens up windows to the SiC in desirable patterns for subsequent graphitization without leaving etch-residues (determined by XPS). Second, the impact of process parameters on the growth of graphene is investigated. Temperature, time, and argon pressure are the primary growth-conditions altered. A temperature of 1400oC in 1 mbar argon for 20 min produced the most optimal graphene growth without significant damage to the AlN capping-layer. Third, first-ever electronic transport measurements are achieved on the selective epitaxial graphene. Hall mobility of about 1550 cm2/Vs has been obtained to date. Finally, the critical limitations of the selective epitaxial graphene growth are enumerated. The advent of enhanced processing techniques that will overcome these limitations will create a multitude of opportunities for applications for graphene grown in this manner. It is envisaged to be a viable approach to fabrication of radio-frequency field-effect transistors.

Download or read book Epitaxial Graphene on Silicon Carbide Surfaces written by Christian Riedl and published by . This book was released on 2010 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Graphene Volume 1 written by Edvige Celasco and published by John Wiley & Sons. This book was released on 2019-06-28 with total page 875 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique multidisciplinary 8-volume set focuses on the emerging issues concerning graphene materials and provides a shared platform for both researcher and industry. The Handbook of Graphene comprises a set of 8 individual volumes that brings an interdisciplinary perspective to accomplish a more detailed understanding of the interplay between the synthesis, structure, characterization, processing, applications and performance of the advanced materials. The Handbook of Graphene comprises 140 chapters from world renowned experts. Volume 1 is solely focused on Growth, Synthesis, and Functionalization of Graphene. Some of the important topics include but not limited to: Graphite in metallic materials-growths, structures and defects of spheroidal graphite in ductile iron; synthesis and quality optimization; methods of synthesis and physico-chemical properties of fluorographenes; graphene-SiC reinforced hybrid composite foam: response to high strain rate deformation; atomic structure and electronic properties of few-layer graphene on SiC(001); features and prospects for epitaxial graphene on SiC; graphitic carbon/graphene on Si(111) via direct deposition of solid-state carbon atoms: growth mechanism and film characterization; chemical reactivity and variation in electronical properties of graphene on Ni(111) and reduced graphene oxide; chlorophyll and graphene: a new paradigm of biomimetic symphony; graphene structures: from preparations to applications; three-dimensional graphene-based structures: production methods, properties and applications; electrochemistry of graphene materials; hydrogen functionalized graphene nanostructure material for spintronic application; the impact of uniaxial strain and defect pattern on magnetoelectronic and transport properties of graphene; exploiting graphene as an efficient catalytic template for organic transformations: synthesis, characterization and activity evaluation of graphene-based catalysts; exfoliated graphene based 2D materials; synthesis and catalytic behaviors; functionalization of graphene with molecules and/or nanoparticles for advanced applications; carbon allotropes "between diamond and graphite": how to create semiconductor properties in graphene and related structures.

Download or read book Fabrication and Characterization of Nanopatterned Epitaxial Graphene Films for Carbon Based Electronics written by Zhimin Song and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we show that planar graphene ribbons have properties similar to those of nanotubes. Both exhibit semiconducting or metallic properties depending on crystal orientation. The band gap varies approximately as the inverse of the ribbon width. Both can be doped and gated. Due to these similarities, the patterned graphene also has nanotube like transport properties, which include coherent transport, ballistic transport, and high current capabilities. In essential contrast to nanotubes, graphene ribbons can be rationally patterned using standard electron beam lithography methods; functional graphene devices could be fabricated eliminating the need for metal interconnects on the wafer. This would remove many obstacles faced by carbon nanotubes, while retaining the benefits of high carrier mobility and quasi-1D transport. We have produced ultrathin epitaxial graphite films on single-crystal silicon carbide by vacuum graphitization, which show remarkable 2D electron gas (2DEG) behavior. The most highly ordered samples exhibit Shubnikov-de Haas oscillations that correspond to nonlinearities observed in the Hall resistance, indicating a potential new quantum Hall system. The transport properties, which are closely related to those of carbon nanotubes, are dominated by the single epitaxial graphene layer at the silicon carbide interface and reveal the Dirac nature of the charge carriers. Patterned structures show quantum confinement of electrons and phase coherence lengths beyond 1 micrometer at 4 kelvin, with mobilities exceeding 2.5 square meters per volt-second. We show that the high-mobility films can be patterned via conventional lithographic techniques, and we demonstrate modulation of the film conductance using a top-gate electrode. These key elements suggest electronic device applications based on nanopatterned epitaxial graphene (NPEG) with the potential for large-scale integration. The research created a foundation for graphene science and technology and established a path toward graphene-based nanoelectronics.

Download or read book Free standing Epitaxial Graphene on Silicon Carbide and Transport Barriers in Layered Materials written by Shriram Shivaraman and published by . This book was released on 2013 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is based on the topic of layered materials, in which different layers interact with each other via van der Waals forces. The majority of this thesis deals with epitaxial graphene (EG) obtained from silicon carbide (SiC). Free-standing epitaxial graphene (FSEG) structures are produced from EG using a photoelectrochemical (PEC) etching process developed for making suspended graphene structures on a large-scale. These structures are investigated for their mechanical and electrical properties. For doubly-clamped FSEG structures, a unique U-beam effect is observed which causes orders of magnitude increase in their mechanical resonance frequency compared to that expected using simple beam theory. Combined magnetotransport and Raman spectroscopy studies reveal that FSEG devices produced from nominally monolayer graphene on the Si-face of SiC exhibit properties of an inhomogeneously doped bilayer after becoming suspended. This suggests that the buffer layer which precedes graphene growth on the Si-face of SiC gets converted to a graphene layer after the PEC etching process. In the second theme of this thesis, transport barriers in layered materials are investigated. The EG-SiC interface is studied using a combination of electrical (I-V, C-V) and photocurrent spectroscopy techniques. It is shown that the interface may be described as having a Schottky barrier for electron transport with a Gaussian distribution of barrier heights. Another interface explored in this work is that between different layers of MoS2, a layered material belonging to the class of transition metal dichalcogenides. This interface maybe thought of as a one-dimensional junction. Fourpoint transport measurements indicate the presence of a barrier for electron transport at this interface. A simple model of the junction as a region with an increased threshold voltage and degraded mobility is suggested. The final chapter is a collection of works based on the topic of layered materials, which are not related to the main theme of the thesis. They include fabrication and characterization details of a dual-gated bilayer graphene device, an investigation of the graphene-Si interface and hexagonal boron nitride-based membranes. These are presented in the hope that they may be useful for further investigations along those directions.

Download or read book Epitaxial Graphene on SiIicon Carbide written by Sang Won Lee and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of free-standing graphene in 2004 has attracted wide attention in both scientific community and industry because of its unusual electronic structure and properties. Due to the possible applications of graphene, many attempts to produce high-quality wafer-scale graphene films have been actively tried in the materials science and other scientific communities. Thermal decomposition of silicon carbide (SiC) is currently considered as one of the most promising routes toward the synthesis of well-controlled and characterized graphene films for electronic applications. This thesis focuses on the synthesis, structure and properties of epitaxial graphene on SiC. In the first chapter, I will investigate the structural properties of EG layers grown on the C-face of 4H-SiC in vacuum or Ar environments using synchrotron-based X-ray diffraction. The qualities and characteristics of layers will be also correlated with carrier mobilities obtained from Hall measurements. Since the Ar atmosphere produced higher quality graphene films on SiC than in vacuum, the inert-gas mediated thermal decomposition of SiC is regarded so far as the most effective method for the controlled EG growth. However, most studies have been done on the Si-face of SiC because of its slower reaction kinetics, which results in relatively uniform film thickness compared to the C-face. Nevertheless, there is significant interest in the C-face of SiC due to the superior electrical properties of EG grown on C-face SiC as compared to that grown on the Si-face. We find that Ar background pressure produces uniform graphene films on the C-face and the electronic properties (i.e. carrier mobility) of the films surpass that of vacuum-grown films due to larger crystalline domains formed in EG when the Ar pressure is above a certain threshold. In the second chapter, I will propose an alternative low-temperature, spatially controlled and scalable epitaxial graphene synthesis technique based on laser-induced surface decomposition of SiC. The high temperatures required in the conventional method are not compatible with large-scale device integration where different materials must be deposited and patterned prior to the formation of the semiconductor layer and limit the synthesis to single-crystal SiC substrates. Our technique is compatible with large-scale device integration. Furthermore, laser synthesis of graphene offers the advantage of combining synthesis and patterning in one step as the process can be designed to form graphene devices in predetermined locations on the substrate. In the last chapter, I will compare the structural properties of laser-synthesized EG on the Si-face and on the C-face of SiC. EG films on the C-face of 4H-SiC were successfully synthesized without the formation of carbon nanotubes by our laser technique, which are usually observed on the C-face upon vacuum high temperature anneals. The structural properties of these films were investigated by grazing incidence X-ray diffraction (GIXD) using synchrotron radiation and transmission electron microscopy. Since the graphene formation by UV laser irradiation is partially a photophysical process, I will illustrate the structural implications of the differences between the two formation processes.

Download or read book Structural and Electrical Properties of Epitaxial Graphene Nanoribbons written by Sarah Elizabeth Bryan and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to perform a systematic investigation of the unique structural and electrical properties of epitaxial graphene at the nanoscale. As the semiconductor industry faces increasing challenges in the production of integrated circuits, due to process complexity and scaling limitations, new materials research has come to the forefront of both science and engineering disciplines. Graphene, an atomically-thin sheet of carbon, was examined as a material which may replace or become integrated with silicon nanoelectronics. Specifically, this research was focused on epitaxial graphene produced on silicon carbide. This material system, as opposed to other types of graphene, holds great promise for large-scale manufacturing, and is therefore of wide interest to the academic and industrial community. In this work, high-quality epitaxial graphene production was optimized, followed by the process development necessary to fabricate epitaxial graphene nanoribbon transistors for electrical characterization. The structural and electrical transport properties of the nanoribbons were elucidated through a series of distinct experiments. First, the size-dependent conductivity of epitaxial graphene at the nanoscale was investigated. Next, the alleviation of the detrimental effects revealed during the size-dependent conductivity study was achieved through the selective functionalization of graphene with hydrogen. Finally, two techniques were developed to allow for the complementary doping of epitaxial graphene. All of the experiments presented herein reveal new and important aspects of epitaxial graphene at the nanoscale that must be considered if the material is to be adopted for use by the semiconductor industry.

Download or read book Atomic and Molecular Manipulation written by and published by Elsevier. This book was released on 2011-07-13 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work with individual atoms and molecules aims to demonstrate that miniaturized electronic, optical, magnetic, and mechanical devices can operate ultimately even at the level of a single atom or molecule. As such, atomic and molecular manipulation has played an emblematic role in the development of the field of nanoscience. New methods based on the use of the scanning tunnelling microscope (STM) have been developed to characterize and manipulate all the degrees of freedom of individual atoms and molecules with an unprecedented precision. In the meantime, new concepts have emerged to design molecules and substrates having specific optical, mechanical and electronic functions, thus opening the way to the fabrication of real nano-machines. Manipulation of individual atoms and molecules has also opened up completely new areas of research and knowledge, raising fundamental questions of "Optics at the atomic scale", "Mechanics at the atomic scale", Electronics at the atomic scale", "Quantum physics at the atomic scale", and "Chemistry at the atomic scale". This book aims to illustrate the main aspects of this ongoing scientific adventure and to anticipate the major challenges for the future in "Atomic and molecular manipulation" from fundamental knowledge to the fabrication of atomic-scale devices. Provides a broad overview of the field to aid those new and entering into this research area Presents a review of the historical development and evolution of the field Offers a clear personalized view of current scanning probe microscopy research from world experts

Download or read book Fabrication Characterization and Modification of Epitaxial Graphene on 6H SiC 0001 Substrate written by 胡廷偉 and published by . This book was released on 2015 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Epitaxial Graphene Films on SiC written by Xuebin Li and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene is a single sheet of graphite. While bulk graphite is semimetal, graphene is a zero bandgap semiconductor. Band structure calculations show graphene has a linear energy dispersion relation in the low energy region close to the Dirac points where the conduction band and the valence band touch. Carriers in graphene are described as massless Dirac fermions in contrast to massive carriers in normal metals and semiconductors that obey a parabolic energy dispersion relation. The uniqueness of graphene band structure indicates its peculiar electronic transport properties.

Download or read book Production and Properties of Epitaxial Graphene on the Carbon Terminated Face of Hexagonal Silicon Carbide written by Yike Hu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene is widely considered to be a promising candidate for a new generation of electronics, but there are many outstanding fundamental issues that need to be addressed before this promise can be realized. This thesis focuses on the production and properties of graphene grown epitaxially on the carbon terminated face (C-face) of hexagonal silicon carbide leading to the construction of a novel graphene transistor structure. C-face epitaxial graphene multilayers are unique due to their rotational stacking that causes the individual layers to be electronically decoupled from each other. Well-formed C-face epitaxial graphene single layers have exceptionally high mobilities (exceeding 10,000 cm 2/Vs), which are significantly greater than those of Si-face graphene monolayers. This thesis investigates the growth and properties of C-face single layer graphene. A field effect transistor based on single layer graphene was fabricated and characterized for the first time. Aluminum oxide or boron nitride was used for the gate dielectric. Additionally, an all graphene/SiC Schottky barrier transistor on the C-face of SiC composed of 2DEG in SiC/Si2O 3 interface and multilayer graphene contacts was demonstrated. A multiple growth scheme was adopted to achieve this unique structure.

Download or read book Silicon Carbide written by Wolfgang J. Choyke and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the 1997 publication of "Silicon Carbide - A Review of Fundamental Questions and Applications to Current Device Technology" edited by Choyke, et al., there has been impressive progress in both the fundamental and developmental aspects of the SiC field. So there is a growing need to update the scientific community on the important events in research and development since then. The editors have again gathered an outstanding team of the world's leading SiC researchers and design engineers to write on the most recent developments in SiC.

Download or read book TRANSFERRED MONOLAYER AND AB STACKED BILAYER 0001 SiC EPITAXIAL GRAPHENE written by Hussain Ali Alsalman and published by . This book was released on 2016 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene is a leading two dimensional (2D) material with good technological potential. Currently, it is being scaled up in synthesis methods in order to meet future demands in technology markets. In this dissertation, a study of transferred epitaxial graphene (TEG) as a synthesis method, for large area monolayer and AB stacked bilayer Graphene, is presented. Monolayer epitaxial graphene (EG) is grown on the (0001) face of silicon carbide (SiC) in an argon atmosphere at a temperature of 1600 o C. Bilayer graphene can thereafter be synthesized if needed by intercalating the monolayer in a 100% hydrogen flow at 1050 oC to release what is known as the "buffer layer" into another graphene layer forming a bilayer. Either form of graphene can subsequently be transferred off the SiC substrate to mitigate the negative effects of the substrate. We develop a transfer process based on a gold adhesion layer and demonstrate for the first time, the transfer of high quality monolayer transferred epitaxial graphene (MTEG) and AB stacked bilayer transferred epitaxial graphene (BTEG). We use Raman characterization methods to determine the number and quality of graphene layers as well as orientation for bilayers which was made possible by contrast enhancement upon substrate transfer. We report these characteristics for the first time. Extensive structural characterization that have never been done before and were made possible by the successful transfer procedure, are presented in the Transmission Electron Microscopy (TEM) section. We successfully show suspended MTEG and BTEG samples which was never shown in literature before. We fabricate Transmission Line Measurement (TLM) structures to study the quality of the contact resistance for MTEG and BTEG. We report values in the range of 600 [OMEGA].[MICRO SIGN]m for MTEG and 2400 [OMEGA].[MICRO SIGN]m for BTEG. We also fabricate Field Effect Transistors (FETs) to study the field effect mobility and carrier concentration of MTEG and BTEG. We report average room temperature field effect mobility values of around 1700 cm2/V.s with best value of 2800 cm2/V.s for MTEG. This is over two times gain in mobility before transfer and is competitive with current leading synthesis methods. We measured the room temperature field effect mobility of BTEG to be 250 cm2/V.s on average and with a best value of 335 cm2/V.s. To the knowledge of the author, there are no reports in literature on the measured mobility of BTEG. We carry out annealing studies at argon ambient of 300 oC for TEG and show unique properties for BTEG in which a demonstrated ten orders of magnitude, higher moisture absorption than MTEG is shown. A section in this dissertation will be dedicated to related work on chemical vapor deposition (CVD) hexagonal boron nitride (h-BN) which is a complimentary 2D material to graphene. Improvements on CVD growth by electropolishing the copper substrate will be demonstrated where root mean square (RMS) surface roughness of starting material is reduced from 177 nm to 12 nm, considerably improving subsequent h-BN CVD growth. A procedure for the transfer of CVD graphene onto CVD h-BN as well as fabrication of Van der Paw structures will be presented. We show initial results of improvements in mobility when CVD h-BN is used as a substrate for CVD graphene.