|
ALCVD
Atomic layer epitaxy (ALE), more generally known as atomic layer deposition (ALD), is a specialized form of thin film growth (epitaxy) that typically deposit alternating monolayers of two elements onto a substrate. The crystal lattice structure achieved is thin, uniform, and aligned with the structure of the substrate. The reactants are brought to the substrate as alternating pulses with "dead" times in between. ALE makes use of the fact that the incoming material is bound strongly until all sites available for chemisorption are occupied. The dead times are used to flush the excess material. It is mostly used in semiconductor fabrication to grow thin films of thickness in the nanometer scale. Technique This technique was invented in 1974 and patented the same year (patent published in 1976) by Dr. Tuomo Suntola at the Instrumentarium company, Finland. Dr. Suntola's purpose was to grow thin films of Zinc sulfide to fabricate electroluminescent flat panel displays. The main trick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Vapor Deposition
Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber. Microfabrication processes widely use CVD to deposit materials in various forms, including: monocrystalline, polycrystalline, amorphous, and epitaxial. These materials include: silicon ( dioxide, carbide, nitride, oxynitride), carbon (fiber, nanofibers, nanotubes, diamond and graphene), fluorocarbons, filaments, tungsten, titanium nitride and various high-κ dielectrics. The term ''chemical vapour deposition'' was coined 1960 by ''John M. Blocher, Jr.'' who intended to differentiate ''chemic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epitaxy
Epitaxy refers to a type of crystal growth or material deposition in which new crystalline layers are formed with one or more well-defined orientations with respect to the crystalline seed layer. The deposited crystalline film is called an epitaxial film or epitaxial layer. The relative orientation(s) of the epitaxial layer to the seed layer is defined in terms of the orientation of the crystal lattice of each material. For most epitaxial growths, the new layer is usually crystalline and each crystallographic domain of the overlayer must have a well-defined orientation relative to the substrate crystal structure. Epitaxy can involve single-crystal structures, although grain-to-grain epitaxy has been observed in granular films. For most technological applications, single domain epitaxy, which is the growth of an overlayer crystal with one well-defined orientation with respect to the substrate crystal, is preferred. Epitaxy can also play an important role while growing superlatti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Layer Deposition
Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas-phase chemical process; it is a subclass of chemical vapour deposition. The majority of ALD reactions use two chemicals called precursors (also called "reactants"). These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. A thin film is slowly deposited through repeated exposure to separate precursors. ALD is a key process in fabricating semiconductor devices, and part of the set of tools for synthesising nanomaterials. Introduction During atomic layer deposition a film is grown on a substrate by exposing its surface to alternate gaseous species (typically referred to as precursors or reactants). In contrast to chemical vapor deposition, the precursors are never present simultaneously in the reactor, but they are inserted as a series of sequential, non-overlapping pulses. In each of these pulses the precursor molecules react wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monolayer
A monolayer is a single, closely packed layer of atoms, molecules, or cells. In some cases it is referred to as a self-assembled monolayer. Monolayers of layered crystals like graphene and molybdenum disulfide are generally called 2D materials. Chemistry A Langmuir monolayer or insoluble monolayer is a one-molecule thick layer of an insoluble organic material spread onto an aqueous subphase in a Langmuir-Blodgett trough. Traditional compounds used to prepare Langmuir monolayers are amphiphilic materials that possess a hydrophilic headgroup and a hydrophobic tail. Since the 1980s a large number of other materials have been employed to produce Langmuir monolayers, some of which are semi-amphiphilic, including polymeric, ceramic or metallic nanoparticles and macromolecules such as polymers. Langmuir monolayers are extensively studied for the fabrication of Langmuir-Blodgett film (LB films), which are formed by transferred monolayers on a solid substrate. A Gibbs monolayer or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor Fabrication
Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuit (IC) chips such as modern computer processors, microcontrollers, and memory chips such as NAND flash and DRAM that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps (such as surface passivation, thermal oxidation, planar diffusion and junction isolation) during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications. The entire manufacturing process takes time, from start to packaged chips ready for shipment, at least six to eight weeks (tape-out only, not including the circuit design) and is performed in highly specialized semiconductor fabrication plants, also called foundries or fabs. All fabrication takes place inside a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuomo Suntola
Tuomo Suntola (born 1943) is a Finnish physicist, inventor, and technology leader. He is best known for his pioneering research in materials science, developing the thin film growth technique called atomic layer deposition. Early life Suntola was born in Tampere, Pirkanmaa, in 1943, during Continuation War. He showed interest in technology early on, building wooden replicas of second world war aircraft. In his teens his interests expanded and he progressed to radios and amplifiers. Education and career In 1971, Tuomo Suntola earned his PhD in semiconductor physics from the Helsinki University of Technology. After completing his PhD, Suntola made his first industrial development while working at VTT Technical Research Centre of Finland, a thin film humidity sensor "Humicap" for Vaisala, Vaisala Oy, a Finnish company specialized in meteorological instruments. In 1974 Suntola started the development of thin film electroluminescent displays in the Finnish company Instrumentarium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Sulfide
Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics. Structure ZnS exists in two main crystalline forms. This dualism is an example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically.. The transition from the sphalerite form to the wurtzite form occurs at around 1020 °C. A tetragonal form is also known as the very rare mineral called polhemusite, with the formula . Applicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroluminescent Display
Electroluminescent Displays (ELDs) are a type of flat panel display created by sandwiching a layer of electroluminescent material such as GaAs between two layers of conductors. When current flows, the layer of material emits radiation in the form of visible light. Electroluminescence (EL) is an optical and electrical phenomenon where a material emits light in response to an electric current passed through it, or to a strong electric field. The term "electroluminescent display" describes displays that use neither LED nor OLED devices, that instead use traditional electroluminescent materials. Beneq is the only manufacturer of TFEL (Thin Film Electroluminescent Display) and TAESL displays, which are branded as LUMINEQ Displays. The structure of a TFEL is similar to that of a passive matrix LCD or OLED display, and TAESL displays are essentially transparent TEFL displays with transparent electrodes. TAESL displays can have a transparency of 80%. Both TEFL and TAESL displays use chip- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat Panel Display
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment. Flat-panel displays are thin, lightweight, provide better linearity and are capable of higher resolution than typical consumer-grade TVs from earlier eras. They are usually less than thick. While the highest resolution for consumer-grade CRT televisions was 1080i, many flat-panel displays in the 2020s are capable of 1080p and 4K resolution. In the 2010s, portable consumer electronics such as laptops, mobile phones, and portable cameras have used flat-panel displays since they consume less power and are lightweight. As of 2016, flat-panel displays have almost completely replaced CRT displays. Most 2010s-era flat-panel displays use LCD or light-emitting diode (LED) technologies, sometimes combined. Most LCD screens are back-lit with color filters used to display colors. In many cases, flat-panel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moore's Law
Moore's law is the observation that the number of transistors in a dense integrated circuit (IC) doubles about every two years. Moore's law is an observation and projection of a historical trend. Rather than a law of physics, it is an empirical relationship linked to gains from experience in production. The observation is named after Gordon Moore, the co-founder of Fairchild Semiconductor and Intel (and former CEO of the latter), who in 1965 posited a doubling every year in the number of components per integrated circuit, and projected this rate of growth would continue for at least another decade. In 1975, looking forward to the next decade, he revised the forecast to doubling every two years, a compound annual growth rate (CAGR) of 41%. While Moore did not use empirical evidence in forecasting that the historical trend would continue, his prediction held since 1975 and has since become known as a "law". Moore's prediction has been used in the semiconductor industry to g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millennium Technology Prize
The Millennium Technology Prize ( fi, Millennium-teknologiapalkinto) is one of the world's largest technology prizes. It is awarded once every two years by Technology Academy Finland, an independent foundation established by Finnish industries, academic institutions, and the state of Finland. The patron of the prize is the President of Finland. The Millennium Technology Prize is Finland's tribute to innovations for a better life. The aims of the prize are to promote technological research and Finland as a high-tech Nordic welfare state. The prize was inaugurated in 2004. The Prize The idea of the prize came originally from the Finnish academician Pekka Jauho, with American real estate investor and philanthropist Arthur J Collingsworth encouraging its establishment.Millenni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylaluminium
Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2( CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially important compound, closely related to triethylaluminium. Structure and bonding The structure and bonding in Al2R6 and diborane are analogous (R = alkyl). In Al2Me6, the Al-C(terminal) and Al-C(bridging) distances are 1.97 and 2.14 Å, respectively. The Al center is tetrahedral. The carbon atoms of the bridging methyl groups are each surrounded by five neighbors: three hydrogen atoms and two aluminium atoms. The methyl groups interchange readily intramolecularly. At higher temperatures, the dimer cracks into monomeric AlMe3. Synthesis TMA is prepared via a two-step process that can be summarized as follows: :2 Al + 6 CH3Cl + 6 Na → Al2(CH3)6 + 6 NaCl Applications Catalysis Starting with the invention of Ziegler-Natta catalysis, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_20.jpg "Click for more on -> Flat Panel Display")
