...Our reference: MR 10661 P-authorquery-v11 AUTHOR QUERY FORM Journal: MR Please e-mail or fax your responses and any corrections to: E-mail: corrections.esch@elsevier.sps.co.in Article Number: 10661 Fax: +31 2048 52799 Dear Author, Please check your proof carefully and mark all corrections at the appropriate place in the proof (e.g., by using on-screen annotation in the PDF file) or compile them in a separate list. Note: if you opt to annotate the file with software other than Adobe Reader then please also highlight the appropriate place in the PDF file. To ensure fast publication of your paper please return your corrections within 48 hours. For correction or revision of any artwork, please consult http://www.elsevier.com/artworkinstructions. Any queries or remarks that have arisen during the processing of your manuscript are listed below and highlighted by flags in the proof. Click on the ‘Q’ link to go to the location in the proof. Location in article Query / Remark: click on the Q link to go Please insert your reply or correction at the corresponding line in the proof Q1 Q2 Q3 Q4 Please confirm that given names and surnames have been identified correctly. Kindly check whether the affiliation ‘a’ is okay as typeset, and correct if necessary. Kindly check whether the identification of corresponding author and details are okay as typeset, and correct if necessary. Kindly check and approve the edit of this line ‘It is known that the breakdown of MIM capacitors is...’...
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...oxygen in the deposition is mentioned and detailed reactions are shown for one of the existing models of amorphous hydrogenated carbon film growth (a-C:H). The subplantation process for hydrogen free amorphous carbon (a-C) is discussed. A simple application example for the growth of a-C:H film using an oxygen-acetylene torch is included. INTRODUCTION Several review papers portray the preparation and state of the art of DLC films [1-5]. There are basically two different types of DLC films: amorphous hydrogenated carbon (a-C:H), and amorphous carbon (a-C). They are differentiated on the number of sp3 (diamond like) vs. sp2 (graphite like) bonds, and the role that hydrogen (or OH) plays in the formation and structure of the film. A diamond like structure exists when sp3 bonds form between carbon atoms during the growing of a carbon film. The sp3 fraction is defined as: (Eq. 1) As the sp3 fraction increases the film tend more towards diamond properties and behavior. Diamond is a crystal with sp3 fraction of 1. The first kind of DLC, that we will refer to as Amorphous Hydrogenated Carbon (a-C:H), hydrogen plays a fundamental role. A diamond like structure will not form without the presence of hydrogen, which can have a concentration up to 50% (atomic) of the final film obtained. The sp3 fraction in a-C:H films is usually less than 50%. There are an assortment of techniques used to deposit a-C:H films [1], all essentially based on chemical vapor deposition (CVD). The...
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...the multiple choice questions that follow the essay/shot answer questions, as a doc, docx or pdf file. Good Luck! 1. Differentiate between relative and absolute dating. List, define and discuss the principles used to define relative age. Discuss isotopic dating: what atomic particles are involved, what are some common isotopes that are used, and what are some uses of isotopic dating? Be sure to explain the calculation of the age of a rock. Relative dating is telling us the age of something compared to that of the substances around it, more plainly stated the sequence of events. Absolute dating tells how old something is, an amount of time can be associated with an object unlike in relative dating. There are four stratigraphy principles used to determine geologic history of a locality or a region: 1) original horizontally, 2) superposition, 3) lateral continuity, and 4) cross-cutting relationships. Original horizontally states that beds of sediment (sedimentary strata) deposited in water forms as horizontal or nearly horizontal layers. If rocks that are at inclined/folded have moved from their original position. The principal of superposition says that within deposition of sediment the oldest layer is at the...
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...encountered SiC material is thus man made. In this article, a solid-state reaction between silica sand and petroleum coke at very high temperature leads to the form the end product as silicon carbide. 2 Manufacturing of macro size SiC particle by Electric Furnace method A mixture of pure quarts sand and carbon in the form of finely ground coke is built up around a carbon conductor within a refractory kiln electrical resistance type furnace. When current is passed through the conductor the heat will produce which is bringing about a chemical reaction where the carbon in the coke and silicon in the sand are combined to form SiC and carbon monoxide gas. The temperatures in the core is around 2200° to 2700° C and about 1400° C at the outer layer of the furnace. The electricity requires to form the SiC is enormous and it could around 100,000 kW-h required per run. After completion of one run about 40 hours, the product consists of a core of green to black SiC crystals formed together, surrounded by partially or entirely unconverted raw material. The lumped product aggregate is crushed, ground, and screened into various sizes appropriate to the end use. Fig 2.1 Acheson’s Electrical furnace Acheson’s furnace has two electrodes which are connect to a graphite core laid within a surrounding mixture of reactant carbon, salt and sand. When an electric current is passed through the graphite core, it heats the surroundings, resulting in the formation of SiC and the expulsion of carbon...
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...Lecture 1 Introduction to Semiconductor Devices Reading: Notes and Anderson2 Chapters 1.1-1.3, 1.7-1.9 Georgia Tech ECE 3080 - Dr. Alan Doolittle Atoms to Operational Amplifiers •The goal of this course is to teach the fundamentals of non-linear circuit elements including diodes, LEDs, LASER diodes, transistors (BJT and FET) , and advanced device concepts such as microwave compound semiconductors and state of the art devices. •Due to the diverse coverage from various professors for ECE3040, you will repeat (for some) some of the material from 3040. Specifically, you will learn about the fundamentals of electron movement in semiconductor materials and develop this basic knowledge of how we can construct devices from these materials that can control the flow of electrons and light in useful ways. Georgia Tech ECE 3080 - Dr. Alan Doolittle Market Study Silicon is and will for a very long time be the dominant material used for electronics. However, MANY up and coming materials are slowly eating into silicon’s dominance. Compound semiconductors Compound semiconductors Organic and compound semiconductors Georgia Tech ECE 3080 - Dr. Alan Doolittle Devices we will study Bold indicates devices covered in depth in ECE 3040 P-N diode, heterojunction diodes, ballistic diodes, Schottky barrier diodes, Metal-Semiconductor Contacts, LEDs, Lasers, Solar Cells, Photodetectors, BJT, HBT, MOSFET, MESFET, JFET, Polarization Based Devices (III-Nitrides HEMTs...
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...Accepted Manuscript Title: Effect of layer thickness on thermal properties of multilayer thin films produced by PVD Authors: B. Tlili, C. Nouveau, M.J. Walock, M. Nasri, T. Gharib PII: DOI: Reference: To appear in: S0042-207X(11)00353-8 10.1016/j.vacuum.2011.09.008 VAC 5485 Vacuum Received Date: 20 February 2011 Revised Date: 5 September 2011 Accepted Date: 18 September 2011 Please cite this article as: Tlili B, Nouveau C, Walock MJ, Nasri M, Gharib T. Effect of layer thickness on thermal properties of multilayer thin films produced by PVD, Vacuum (2011), doi: 10.1016/ j.vacuum.2011.09.008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Effect of layer thickness on thermal properties of multilayer thin films produced by PVD B. Tlilia,b, C. Nouveaub, M J Walockc,a, M. Nasria, dT.Gharib. UR. Mécanique Appliquée, Ingénierie et Industrialisation (M.A.2I), ENIT, BP 37, Le Belvédère, 1002 Tunis, Tunisie b Laboratoire Bourguignon des Matériaux et Procédés (LaBoMaP), Centre Arts et Métiers ParisTech de Cluny, Rue Porte de Paris, F-71250 Cluny...
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...Ozone Layer Depletion: Effects and Causes of Ozone Depletion Ozone is a colorless gas found in the upper atmosphere of the Earth and formed by the action of ultraviolet radiation on oxygen. Ozone forms a layer in the stratosphere, which protects life on Earth from the harmful effects of ultraviolet radiation. Ads by Google Olay Total Effects 1 Bottle Fights 7 Signs of Ageing, Try Olay Total Effects Today! www.olay.in Today, one of the most discussed and serious environmental issues is the ozone layer depletion, the layer of gas that forms a protective covering in the Earth's upper atmosphere. Ozone is formed when oxygen molecules absorb ultraviolet photons and undergo a chemical reaction known as photo dissociation or photolysis, where a single molecule of oxygen breaks down to two oxygen atoms. The free oxygen atom (O), then combines with an oxygen molecule (O2) and forms a molecule of ozone (O3). The ozone molecules, in turn absorb ultraviolet rays between 310 to 200 nm wavelength and thereby prevent these harmful radiations from entering the Earth's atmosphere. In the process, ozone molecules split up into a molecule of oxygen and an oxygen atom. The oxygen atom (O) again combines with the oxygen molecule (O2) to regenerate an ozone (O3) molecule. Thus, the total amount of ozone is maintained by this continuous process of destruction and regeneration. Ozone layer depletion first captured the attention of the whole world in the later half of 1970 and since then, many discussions...
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...Element C Si Mn Cr Mo Ni Co Cu V W wt % 0.80 0.26 0.27 3.80 0.68 0.20 4.70 0.13 1.60 18.9 Table 2: Plasma nitriding conditions. U E D C B A Sample Code Un-nitrided sample 425 425 575 500 425 Temperature (°C) 25:75 50:50 75:25 75:25 75:25 Gas composition (N2:H2) 3. Results and discussion In this section, nitrided layer microstructure and composition, surface hardness and hardness profile, surface topography, and wear test results of the samples treated at different temperatures and gas mixtures are presented and compared with those of the un-nitrided one. Fig. 1 presents the typical microstructure of the heat treated tungsten tool steel. The microstructure consists of a matrix of martensite and spheroidized carbide precipitates. High speed steels contain a high content of elements such as molybdenum, chromium, tungsten, vanadium, and cobalt along with enough carbon to provide a large amount of stable carbides in the final structure. Secondary hardening after tempering is due to precipitation of mixed carbides. Image analysis by ImageJ software [29] revealed...
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...where it all starts. Nanomanufacturing is the manufacturing of nano-scale materials, structures, devices, and systems. There are two approaches to nanomanufacturing, the top-down approach or the bottom-up approach. The top-down approach reduces large pieces of material down to the nanoscale. This approach uses more material and can lead to waste if excess material isn’t used. The second approach, the bottom-up approach, creates products by starting at the atomic or molecular level and building the products from the ground up. This process is very time consuming. With these two approaches there are new processes that enable nanomanufacturing which are (Manufacturing at the Nanoscale): 1. Chemical vapor deposition – a process where chemicals react to produce pure high-performance films. 2. Molecular beam epaxity – a method for depositing highly controlled thin films 3. Atomic layer epaxity – a method for depositing one atom thick layers on a surface 4. Dip pen lithography - a process where the tip of an atomic force microscope is "dipped" into a chemical fluid and then used to "write" on a surface. 5. Nanoimprint lithography –...
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...Epitaxy Epitaxial Growth • Epitaxy means the growth of a single crystal film on top of a crystalline substrate. • For most thin film applications (hard and soft coatings, optical coatings, protective coatings) it is of little importance. • However, for semiconductor thin film technology it is crucial. Types of Epitaxy • Homoepitaxy – The film and the substrate are the same material. – Often used in Si on Si growth. – Epitaxially grown layers are purer than the substrate and can be doped independently of it. • Heteroepitaxy – Film and substrate are different materials. – Eg: AlAs on GaAs growth – Allows for optoelectronic structures and band gap engineered devices. Heteroepitaxy • Trying to grow a layer of a different material on top of a substrate leads to unmatched lattice parameters. • This will cause strained or relaxed growth and can lead to interfacial defects. • Such deviations from normal would lead to changes in the electronic, optic, thermal and mechanical properties of the films. Lattice Strains • • • • For many applications nearly matched lattices are desired to minimize defects and increase electron mobility. As the mismatch gets larger, the film material may strain to accommodate the lattice structure of the substrate. This is the case during the early stages of film formation (pseudomorphic growth) and with materials of the same lattice structure. The Si-Ge system is an example. If strain accommodation...
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...CHAPTER-1 INTRODUCTION Microelectromechanical systems (MEMS) are small integrated devices or systems that combine electrical and mechanical components. They range in size from the sub micrometer level to the millimeter level and there can be any number, from a few to millions, in a particular system. MEMS extend the fabrication techniques developed for the integrated circuit industry to add mechanical elements such as beams, gears, diaphragms, and springs to devices. Examples of MEMS device applications include inkjet-printer cartridges, accelerometer, miniature robots, microengines, locks inertial sensors microtransmissions, micromirrors, micro actuator (Mechanisms for activating process control equipment by use of pneumatic, hydraulic, or electronic signals) optical scanners, fluid pumps, transducer, pressure and flow sensors. New applications are emerging as the existing technology is applied to the miniaturization and integration of conventional devices. These systems can sense, control, and activate mechanical processes on the micro scale, and function individually or in arrays to generate effects on the macro scale. The micro fabrication technology enables fabrication of large arrays of devices, which individually perform simple tasks, but in combination can accomplish complicated functions. MEMS are not about any one application or device, nor are they defined by a single fabrication process or limited to a few materials. They are a fabrication approach that conveys...
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...Study Guide: Midterm Exam Concentrate your studies in the following areas. Questions for the Midterm Exam will come principally from this material. Lutgens and Tarbuck Textbook: Minerals (Chapter 1) * Know the definition of a mineral. a solid inorganic substance of natural occurrence * Know the basic definition of a rock. the solid mineral material forming part of the surface of the earth and other similar planets, exposed on the surface or underlying the soil or oceans * Know how atoms of the same element are related. Atoms of the same element must have the same number of protons which is the atomic number. What do they have in common? They all have protons * Know definitions for the following terms: valence electrons, an electron of an atom, located in the outermost shell (valence shell) of the atom, that can be transferred to or shared with another atom. An electron in one of the outer shells of an atom that can participate in forming chemical bonds with other atoms nucleus, the central and most important part of an object, movement, or group, forming the basis for its activity and growth. atom, the basic unit of a chemical element element, ion, and chemical compound. * Know the difference between ionic and covalent bonds. Ionic compounds contain a metal cation bonded to a nonmetal anion. This means that the first element in the compound's name and formula is to the left of the zig-zag line on the periodic table above. Covalent compounds contain NO...
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...ARTICLES PUBLISHED ONLINE: 18 MAY 2015 | DOI: 10.1038/NNANO.2015.89 Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency Hele Savin1*, Päivikki Repo1, Guillaume von Gastrow1, Pablo Ortega2, Eric Calle2, Moises Garín2 and Ramon Alcubilla2 The nanostructuring of silicon surfaces—known as black silicon—is a promising approach to eliminate front-surface reflection in photovoltaic devices without the need for a conventional antireflection coating. This might lead to both an increase in efficiency and a reduction in the manufacturing costs of solar cells. However, all previous attempts to integrate black silicon into solar cells have resulted in cell efficiencies well below 20% due to the increased charge carrier recombination at the nanostructured surface. Here, we show that a conformal alumina film can solve the issue of surface recombination in black silicon solar cells by providing excellent chemical and electrical passivation. We demonstrate that efficiencies above 22% can be reached, even in thick interdigitated back-contacted cells, where carrier transport is very sensitive to front surface passivation. This means that the surface recombination issue has truly been solved and black silicon solar cells have real potential for industrial production. Furthermore, we show that the use of black silicon can result in a 3% increase in daily energy production when compared with a reference cell with the same efficiency, due to its better angular...
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...of a mineral. A mineral is a naturally occurring substance that is solid and inorganic representable by a chemical formula, usually abiogenic, and has an ordered atomic structure. It is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition. The exact definition of a mineral is under debate, especially with respect to the requirement a valid species be abiogenic, and to a lesser extent with regard to it having an ordered atomic structure. * Know the basic definition of a rock. * In geology, rock is a naturally occurring solid aggregate of one or more minerals or mineraloids. For example, the common rock granite is a combination of the quartz, feldspar and biotite minerals. The Earth's outer solid layer, the lithosphere, is made of rock. * Know how atoms of the same element are related. What do they have in common? All atoms of the same element have the same number of protons in the nucleus and consequently have the same atomic number. All atoms of the same neutral element have the same number of electrons as well. Atoms of an element usually have the same number of neutrons as protons. Atoms of the same element that have a different number of neutrons are called isotopes. Isotopes have the same atomic number but different atomic masses. Atoms of an element share that element's chemical and physical properties, such as boiling point, melting point and stability. * Know definitions for...
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...Creation of Silicon Chips D'yara L.Williams South Carolina State University CS 304 - Introduction to Computer Organizatikns & Architecture Dr. Y. Kim Feburary 25, 2015 Did you know that microprocessors today have more than 30 layers of complex circuits compared to the 5 layered circuit discovered in 1971? Silicon chips are also known as a monolithic integrated circuits, die, or processors. They’re miniature electronic brains that are everywhere in the electronic world, which processes data in the form of electrical currents traveling along a circuit. The natural semi-conductor of integrated chips is manufactured using sand. Beach sand contains a high percentage of the principal ingredient, silica or silicon dioxide, the most abundant element on earth besides oxygen. The process of making silicon chips is called fabrication. A wafer is a thin silicon disk sliced from a cylindrical ingot that is used as the principal ingredient for building integrated circuits. The creation of silicon chips is processed by ensuring product specifications, architectural specifications, creating a logic design, compose a physical representation and finalizations. However, engineers experience a problem with desiring to make electronic devices simpler but more powerful. Although the first computers came about before its invention, the silicon microprocessor is the advancement that made the modern computer era explode. The ability to create a microelectric...
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