|
Trichlorosilane
Trichlorosilane (TCS) is an inorganic compound with the formula HCl3Si. It is a colourless, volatile liquid. Purified trichlorosilane is the principal precursor to ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a siloxane polymer while giving off hydrochloric acid. Because of its reactivity and wide availability, it is frequently used in the synthesis of silicon-containing organic compounds. Production Trichlorosilane is produced by treating powdered metallurgical grade silicon with blowing hydrogen chloride at 300 °C in a hydrochlorination process. Hydrogen is also produced, as described in the chemical equation: :Si + 3 HCl → HCl3Si + H2 Yields of 80-90% can be achieved. The main byproducts are silicon tetrachloride (chemical formula SiCl4), hexachlorodisilane (Si2Cl6) and dichlorosilane (H2SiCl2), from which trichlorosilane can be separated by distillation. It is also produced from silicon tetrachloride in a dir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octadecyltrichlorosilane
Octadecyltrichlorosilane (ODTS or ''n''-octadecyltrichlorosilane) is an organosilicon compound with the formula . A colorless liquid, it is used as a silanization agent to prepare hydrophobic Stationary phase (chemistry), stationary phase, for reversed-phase chromatography. It is also evaluated for forming self-assembled monolayers on silicon dioxide substrates. Its structural chemical formula is CH3(CH2)17SiCl3. It is flammable and hydrolyzes readily with release of hydrogen chloride. Dodecyltrichlorosilane, an ODTS analog with shorter alkyl chain, is used for the same purpose. ODTS-poly-4-vinylphenol, PVP films are used in organic-substrate LCD displays. References {{reflist Organochlorosilanes Thin films ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorosilane
In inorganic chemistry, chlorosilanes are a group of reactive, chlorine-containing chemical compounds, related to silane () and used in many chemical processes. Each such chemical has at least one silicon-chlorine () bond. Trichlorosilane is produced on the largest scale. The parent chlorosilane is silicon tetrachloride (). Synthesis Hydrochlorosilanes These include chlorosilane , dichlorosilane , and, most importantly trichlorosilane . The idealized equation for the production of trichlorosilane is: : Methylchlorosilanes Methyltrichlorosilane , dimethyldichlorosilane , and trimethylsilyl chloride are produced by the Direct Process, the reaction of methyl chloride with a silicon-copper alloy. Each of these three methylchlorosilanes are common reagents in organosilicon chemistry. Reactions The methylchlorosilanes react with water to produce hydrogen chloride, giving siloxanes. In the case of trimethylsilyl chloride, the hydrolyzed product is hexamethyldisiloxane: : The ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysilicon
Polycrystalline silicon, or multicrystalline silicon, also called polysilicon, poly-Si, or mc-Si, is a high purity, polycrystalline form of silicon, used as a raw material by the solar photovoltaic and electronics industry. Polysilicon is produced from metallurgical grade silicon by a chemical purification process, called the Siemens process. This process involves distillation of volatile silicon compounds, and their decomposition into silicon at high temperatures. An emerging, alternative process of refinement uses a fluidized bed reactor which is lower cost. The photovoltaic industry also produces upgraded metallurgical-grade silicon (UMG-Si), using metallurgical instead of chemical purification processes for lower cost at the expense of purity. When produced for the electronics industry, polysilicon contains impurity levels of less than one part per billion (ppb), while polycrystalline solar grade silicon (SoG-Si) is generally less pure. In the 2010's, production shifte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorodecyltrichlorosilane
Perfluorodecyltrichlorosilane, also known as FDTS, is a colorless liquid chemical with molecular formula C10 H4 Cl3 F17 Si. FDTS molecules form self-assembled monolayers. They form covalent silicon–oxygen bonds to free hydroxyl (–OH) groups, such as the surfaces of glass, ceramics, or silica. Due to its heavily fluorinated tail group, a FDTS monolayer reduces surface energy. Deposition of a FDTS monolayer is achieved by a relatively simple process, also known as molecular vapor deposition (MVD) It usually deposits from a vapor phase, at room to near-to-room temperatures (50 °C) and is thus compatible with most substrates. The process is usually carried out in a vacuum chamber and assisted by the presence of water vapor. Treated surfaces have water repellent and friction reducing properties. For this reason, a FDTS monolayer is often applied to movable microparts of microelectromechanical systems (MEMS). A FDTS monolayer reduces surface energy and prevents sticking, so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siemens Process
Polycrystalline silicon, or multicrystalline silicon, also called polysilicon, poly-Si, or mc-Si, is a high purity, polycrystalline form of silicon, used as a raw material by the solar photovoltaic and electronics industry. Polysilicon is produced from metallurgical grade silicon by a chemical purification process, called the Siemens process. This process involves distillation of volatile silicon compounds, and their decomposition into silicon at high temperatures. An emerging, alternative process of refinement uses a fluidized bed reactor which is lower cost. The photovoltaic industry also produces upgraded metallurgical-grade silicon (UMG-Si), using metallurgical instead of chemical purification processes for lower cost at the expense of purity. When produced for the electronics industry, polysilicon contains impurity levels of less than one part per billion (ppb), while polycrystalline solar grade silicon (SoG-Si) is generally less pure. In the 2010's, production shifted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-assembled Monolayer
Self-assembled monolayers (SAM) are assemblies of organic molecules that form spontaneously on surfaces by adsorption and organize themselves into more or less distinct domains (head group, chain/backbone, and tail/end group). In some cases, molecules that form the monolayer do not interact strongly with the substrate. This is the case for porphyrins on highly oriented pyrolytic graphite, HOPG and two-dimensional supramolecular networks of perylenetetracarboxylic dianhydride, PTCDA on gold. In other cases, the head group has a strong affinity for the substrate and anchors the molecule. Such an SAM consisting of a head group, chain (labeled "tail"), and functional end group is depicted in Figure 1. Common head groups include thiols, silanes, and phosphonates. SAMs are created by the chemisorption of head groups onto a substrate from either the vapor or liquid phase followed by a slower organization of "tail groups". Initially, at small molecular density on the surface, adsorbate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Tetrachloride
Silicon tetrachloride or tetrachlorosilane is the inorganic compound with the formula SiCl4. It is a colorless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications. It is a part of the chlorosilane family. Preparation Silicon tetrachloride is prepared by the chlorination of various silicon compounds such as ferrosilicon, silicon carbide, or mixtures of silicon dioxide and carbon. The ferrosilicon route is most common. In the laboratory, can be prepared by treating silicon with chlorine at : : It was first prepared by Jöns Jakob Berzelius in 1823. Brine can be contaminated with silica when the production of chlorine is a byproduct of a metal refining process from metal chloride ore. In rare occurrences, the silicon dioxide in silica is converted to silicon tetrachloride when the contaminated brine is electrolyzed. Reactions Hydrolysis and related reactions Like other chlorosilanes or silanes, silicon tetrachl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallurgical Grade Silicon
Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Silicon is a significant element that is essential for several physiological and metabolic processes in plants. Silicon is widely regarded as the predominant semiconductor material due to its versatile applications in various electrical devices such as transistors, solar cells, integrated circuits, and others. These may be due to its significant band gap, expansive optical transmission range, extensive absorption spectrum, surface roughening, and effective anti-reflection coating. Because of its high chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrosilylation
Hydrosilylation, also called catalytic hydrosilation, describes the addition of Si-H bonds across unsaturated bonds."Hydrosilylation A Comprehensive Review on Recent Advances" B. Marciniec (ed.), Advances in Silicon Science, Springer Science, 2009. Ordinarily the reaction is conducted catalytically and usually the substrates are unsaturated organic compounds. Alkenes and alkynes give alkyl and vinyl silanes; aldehydes and ketones give silyl ethers, while esters provide alkyl silyl mixed acetals. Hydrosilylation has been called the "most important application of platinum in homogeneous catalysis." Scope and mechanism Hydrosilylation of alkenes represents a commercially important method for preparing organosilicon compounds. The process is mechanistically similar to the hydrogenation of alkenes. In fact, similar catalysts are sometimes employed for the two catalytic processes. The prevalent mechanism, called the Chalk-Harrod mechanism, assumes an intermediate metal complex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichlorosilane
Dichlorosilane, or DCS as it is commonly known, is a chemical compound with the formula H2SiCl2. In its major use, it is mixed with ammonia (NH3) in LPCVD chambers to grow silicon nitride in semiconductor processing. A higher concentration of DCS·NH3 (i.e. 16:1), usually results in lower stress nitride films. History Dichlorosilane was originally prepared by Stock and Somieski by the reaction of SiH4 with hydrogen chloride. Dichlorosilane reacts with water vapor to initially give monomeric prosiloxane: Monomeric polymerizes rapidly upon condensation or in solution.Seyferth, D., Prud'Homme, C., Wiseman, G., Cyclic Polysiloxanes from the Hydrolysis of Dichlorosilane, Inorganic Chemistry, 22, 2163-2167 Reactions and formation Most dichlorosilane results as a byproduct of the reaction of HCl with silicon, a reaction intended to give trichlorosilane. Disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Tetrachloride
Silicon tetrachloride or tetrachlorosilane is the inorganic compound with the formula SiCl4. It is a colorless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications. It is a part of the chlorosilane family. Preparation Silicon tetrachloride is prepared by the chlorination of various silicon compounds such as ferrosilicon, silicon carbide, or mixtures of silicon dioxide and carbon. The ferrosilicon route is most common. In the laboratory, can be prepared by treating silicon with chlorine at : : It was first prepared by Jöns Jakob Berzelius in 1823. Brine can be contaminated with silica when the production of chlorine is a byproduct of a metal refining process from metal chloride ore. In rare occurrences, the silicon dioxide in silica is converted to silicon tetrachloride when the contaminated brine is electrolyzed. Reactions Hydrolysis and related reactions Like other chlorosilanes or silanes, silicon tetrachl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichlorosilane
Dichlorosilane, or DCS as it is commonly known, is a chemical compound with the formula H2SiCl2. In its major use, it is mixed with ammonia (NH3) in LPCVD chambers to grow silicon nitride in semiconductor processing. A higher concentration of DCS·NH3 (i.e. 16:1), usually results in lower stress nitride films. History Dichlorosilane was originally prepared by Stock and Somieski by the reaction of SiH4 with hydrogen chloride. Dichlorosilane reacts with water vapor to initially give monomeric prosiloxane: Monomeric polymerizes rapidly upon condensation or in solution.Seyferth, D., Prud'Homme, C., Wiseman, G., Cyclic Polysiloxanes from the Hydrolysis of Dichlorosilane, Inorganic Chemistry, 22, 2163-2167 Reactions and formation Most dichlorosilane results as a byproduct of the reaction of HCl with silicon, a reaction intended to give trichlorosilane. Disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
