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Lely Method
The Lely method, also known as the Lely process or Lely technique, is a crystal growth technology used for producing silicon carbide crystals for the semiconductor industry. The patent for this method was filed in the Netherlands in 1954 and in the United States in 1955 by Jan Anthony Lely of Philips Electronics. The patent was subsequently granted on 30 September 1958, and was refined by D.R. Hamilton et al. in 1960, and by V.P. Novikov and V.I. Ionov in 1968. Overview The Lely method produces bulk silicon carbide crystals through the process of sublimation. Silicon carbide powder is loaded into a graphite crucible, which is purged with Argon gas and heated to approximately . The silicon carbide near the outer walls of the crucible sublimes and is deposited on a graphite rod near the center of the crucible, which is at a lower temperature. Several modified versions of the Lely process exist, most commonly the silicon carbide is heated from the bottom end rather than the wall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Vapor Transport Crucible-en
Physical may refer to: *Physical examination In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the pati ..., a regular overall check-up with a doctor * ''Physical'' (Olivia Newton-John album), 1981 ** "Physical" (Olivia Newton-John song) * ''Physical'' (Gabe Gurnsey album) * "Physical" (Alcazar song) (2004) * "Physical" (Enrique Iglesias song) (2014) * "Physical" (Dua Lipa song) (2020) *"Physical (You're So)", a 1980 song by Adam & the Ants, the B side to " Dog Eat Dog" * ''Physical'' (TV series), an American television series See also {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Growth
A crystal is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. Crystal growth is a major stage of a crystallization process, and consists of the addition of new atoms, ions, or polymer strings into the characteristic arrangement of the crystalline lattice. The growth typically follows an initial stage of either homogeneous or heterogeneous (surface catalyzed) nucleation, unless a "seed" crystal, purposely added to start the growth, was already present. The action of crystal growth yields a crystalline solid whose atoms or molecules are close packed, with fixed positions in space relative to each other. The crystalline state of matter is characterized by a distinct structural rigidity and very high resistance to deformation (i.e. changes of shape and/or volume). Most crystalline solids have high values both of Young's modulus and of the shear modulus of elasticity. This contras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found in only minute quantities in cer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor Industry
The semiconductor industry is the aggregate of companies engaged in the design and fabrication of semiconductors and semiconductor devices, such as transistors and integrated circuits. It formed around 1960, once the fabrication of semiconductor devices became a viable business. The industry's annual semiconductor sales revenue has since grown to over , as of 2018. The semiconductor industry is in turn the driving force behind the wider electronics industry, with annual power electronics sales of £135billion () as of 2011, annual consumer electronics sales expected to reach by 2020, tech industry sales expected to reach in 2019, and e-commerce with over in 2017. In 2019, 32.4% of the semiconductor market segment was for networks and communications devices. In 2021, the sales of semiconductors reached a record $555.9 billion, up 26.2 percent with sales in China reaching $192.5 billion, according to the Semiconductor Industry Association. A record 1.15 trillion semicondu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philips Electronics
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is still in Eindhoven. Philips was formerly one of the largest electronics companies in the world, but is currently focused on the area of health technology, having divested its other divisions. The company was founded in 1891 by Gerard Philips and his father Frederik, with their first products being light bulbs. It currently employs around 80,000 people across 100 countries. The company gained its royal honorary title (hence the ''Koninklijke'') in 1998 and dropped the "Electronics" in its name in 2013, due to its refocusing from consumer electronics to healthcare technology. Philips is organized into three main divisions: Personal Health (formerly Philips Consumer Electronics and Philips Domestic Appliances and Personal Care), Connecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is still in Eindhoven. Philips was formerly one of the largest electronics companies in the world, but is currently focused on the area of health technology, having divested its other divisions. The company was founded in 1891 by Gerard Philips and his father Frederik, with their first products being light bulbs. It currently employs around 80,000 people across 100 countries. The company gained its royal honorary title (hence the ''Koninklijke'') in 1998 and dropped the "Electronics" in its name in 2013, due to its refocusing from consumer electronics to healthcare technology. Philips is organized into three main divisions: Personal Health (formerly Philips Consumer Electronics and Philips Domestic Appliances and Personal Care), Connecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublimation (phase Transition)
Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Sublimation is an endothermic process that occurs at temperatures and pressures below a substance's triple point in its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid. The reverse process of sublimation is deposition or desublimation, in which a substance passes directly from a gas to a solid phase. Sublimation has also been used as a generic term to describe a solid-to-gas transition (sublimation) followed by a gas-to-solid transition (deposition). While vaporization from liquid to gas occurs as evaporation from the surface if it occurs below the boiling point of the liquid, and as boiling with formation of bubbles in the interior of the liquid if it occurs at the boiling point, there is no such distinction for the solid-to-gas transition which always occurs as sublimation from the surface. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crucible
A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. While crucibles were historically usually made from clay, they can be made from any material that withstands temperatures high enough to melt or otherwise alter its contents. History Typology and chronology The form of the crucible has varied through time, with designs reflecting the process for which they are used, as well as regional variation. The earliest crucible forms derive from the sixth/fifth millennium B.C. in Eastern Europe and Iran. Chalcolithic Crucibles used for copper smelting were generally wide shallow vessels made from clay that lacks refractory properties which is similar to the types of clay used in other ceramics of the time. During the Chalcolithic period, crucibles were heated from the top by using blowpipes.Hauptmann A., 2003, ''Developments in copper Metallurgy During the Fourth and Third Millennia B.C. at Feinan'', Jorda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deposition (phase Transition)
Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation. Applications Examples One example of deposition is the process by which, in sub-freezing air, water vapour changes directly to ice without first becoming a liquid. This is how frost and hoar frost form on the ground or other surfaces. Another example is when frost forms on a leaf. For deposition to occur, thermal energy must be removed from a gas. When the air becomes cold enough, water vapour in the air surrounding the leaf loses enough thermal energy to change into a solid. Even though the air temperature may be below the dew point, the water vapour may not be able to condense spontaneously if there is no way to remove the latent heat. When the leaf is introduced, the supercooled water vapour immediately begins to conden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature Gradient
A temperature gradient is a physical quantity that describes in which direction and at what rate the temperature changes the most rapidly around a particular location. The temperature gradient is a dimensional quantity expressed in units of degrees (on a particular temperature scale) per unit length. The SI unit is kelvin per meter (K/m). Temperature gradients in the atmosphere are important in the atmospheric sciences (meteorology, climatology and related fields). Mathematical description Assuming that the temperature ''T'' is an intensive quantity, i.e., a single-valued, continuous and differentiable function of three-dimensional space (often called a scalar field), i.e., that :T=T(x,y,z) where ''x'', ''y'' and ''z'' are the coordinates of the location of interest, then the temperature gradient is the vector quantity defined as :\nabla T = \begin , , \end Physical processes Climatology On a global and annual basis, the dynamics of the atmosphere (and the oce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Furnace
An induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. Induction furnace capacities range from less than one kilogram to one hundred tons, and are used to melt iron and steel, copper, aluminum, and precious metals. The advantage of the induction furnace is a clean, energy-efficient and well-controlled melting process, compared to most other means of metal melting. Most modern foundries use this type of furnace, and many iron foundries are replacing cupola furnaces with induction furnaces to melt cast iron, as the former emit much dust and other pollutants. Induction furnaces do not require an arc, as in an electric arc furnace, or combustion, as in a blast furnace. As a result, the temperature of the charge (the material entered into the furnace for heating, not to be confused with electric charge) is no higher than required to melt it; this can prevent loss of valuable alloying elements. The one major drawback to indu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acheson Process
The Acheson process was invented by Edward Goodrich Acheson to synthesize silicon carbide (SiC) and graphite. Process The process consists of heating a mixture of silicon dioxide (SiO2), in the form of silica or quartz sand, and carbon, in its elemental form as powdered coke, in an iron bowl. In the furnace, the silicon dioxide, which sometimes also contains other additives along with ferric oxide and saw dust is melted surrounding a graphite rod, which serves as a core. These rods are inserted in such a way that they are held in contact with each other through the particles of coke, which is commonly called coke bed. An electric current is passed through the graphite rods. which heats the mixture to 1700–2500 °C. The result of the carbothermic reaction is a layer of silicon carbide (especially in its alpha and beta phases) forming around the rod and emission of carbon monoxide (CO). There are four chemical reactions in the production of silicon carbide: # C + S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
