Chemical vapour deposition reactions

In the case of glass, however, no great variations in behaviour between different types are expected because of their very similar structure and surface composition. Chemical vapour deposition reactions had already been tried by the last century, for instance in the refinement and deposition of silicon by reduction of SiF4 and SiCU with alkali metals [71] and in the refining of Ni using Ni-carbonyl in the Mond process [72,73]. The major impact of chemical vapour deposition on thin-film technology took place, starting some 60 years ago, when refractory compounds such as metal carbides, nitrides, silicides, borides and oxides as well as mixed phases of... 

Warwick, M. E. A. and Binions, R. (2011) On the Effects of Electric Fields in Aerosol Assisted Chemical Vapour Deposition Reactions of Vanadyl Acetylacetonate Solutions in Ethanol. Journal of Nanoscience and Nanotechnology 11,8126-31. 

In practical applications, gas-surface etching reactions are carried out in plasma reactors over the approximate pressure range 10 -1 Torr, and deposition reactions are carried out by molecular beam epitaxy (MBE) in ultrahigh vacuum (UHV below 10 Torr) or by chemical vapour deposition (CVD) in the approximate range 10 -10 Torr. These applied processes can be quite complex, and key individual reaction rate constants are needed as input for modelling and simulation studies—and ultimately for optimization—of the overall processes. 

Molecular dissociation and chain reactions in chemical vapour deposition... 

Chemical vapour deposition (CVD) Chemical reaction causing gaseous M, compound to split up and release M, to deposit on M2 Healed Mj Igas solid 2 M, Cr M2 Fe... 

Plasma Enhanced Chemical Vapour Deposition (PECVD) Chemical vapour deposition (CVD) reactions commonly occur at high temperatures (Table II). The use of a plasma to generate chemically reactive species in conjunction with CVD overcomes one of the most common... 

SiHCl3 (boiling point 31.8°C) is subjected to fractional distillation and removed from Fe, B and A1 halides. Finally pure SiHCl3 is converted into silicon by chemical vapour deposition according to the reaction ... 

Growth of crystals from vapour may be divided into two categories depending on whether the change, vapour—> crystal, is physical or chemical. When the composition of the vapour and the crystal is the same, the process is physical examples are sublimation-condensation and sputtering. The process is termed chemical when a chemical reaction occurs during the growth in such a case, the composition of the solid is different from the vapour. The use of chemical vapour deposition (CVD) as a... 

Carbides and nitrides can be prepared in many ways (chemical vapour deposition, physical vapour deposition, precipitation of salts containing metal, carbon and oxygen followed by reduction and annealing, reaction of a metal or its oxides with a gas or with solid carbon). Carbides and nitrides are often nonstoichiometric with complex phase diagrams.4-9 The compounds sometimes contain multiple phases and impurities, notably oxygen. This can lead to even more complex compounds, like oxycarbides, carbonitrides or oxycarbonitrides. 

There are two ways in which coatings can be applied thermomechanical processes (e.g. detonation gun, flame spraying and plasma spraying) and vapour phase deposition processes. The latter category can be subdivided into CVD (chemical vapour deposition) and PVD (physical vapour deposition). In the case of a CVD process, a chemical reaction takes place in an oven and as a result the coating material is formed and deposited on the object. Figures 11.7.9 and 11.7.10 are representations of two methods to apply coatings. 

Chemical Vapour Deposition involves a very complex mixture of gases and/or ions, causing numerous uncontrollable side reactions. From a chemical point of view, these reactions are extremely difficult to monitor. A basic understanding of all reactions occurring in a CVD experiment is lacking at the present time. 

Chemical vapour deposition (CVD) In CYD (see Section 4.2.1) process reactant vapours (e.g. metal chlorides) are transported to the substrate where they are adsorbed on the surface, the reaction and subsequent crystal growth occurring on the substrate surface. Deposition rates typically lie in the 1-10 pmhrx. 

Deposition occurs by adsorption or reaction from a gas phase. This method may ensure excellent dispersion and very well controlled distribution of the active species. Chemical vapour deposition is an example of gas-phase deposition. 

The CO2 laser-induced multiphoton decomposition of silanes, known to be a really homogeneous reaction, was utilized for the chemical vapour deposition of fluorine containing SiC films from the parent (fluoromethyl)silanes [25, 26]. In contrast to work with H3CS1H3, irradiation of (fluoromethyl)silanes with a single unfocused CO2 laser pulse at fluence of S 0.9 Jcm" tuned to absorption bands of either the SiH bending or the CF stretching vibrations results in an explosive reaction. This is accompanied by an intense chemoluminescence when the sample pressure exceeds a certain limit in the range of 0.1-6.7 kPa (Fig. 1). 

Methyltrichlorosilane (CH3SiCl3, MTS) is an appropriate precursor to deposit SiC-layers on various carrier materials using chemical vapour deposition. MTS is decomposed according to the following overall equation of reaction ... 

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