Silicon vapor solid reaction

Westwater, J. Gosain, D.P. Tomiya, S. Usui, S. Ruda, H. Growth of silicon nanowires via gold/ silane vapor-liquid-solid reaction. J. Vac. Sci. Technol. B 1997, 15 (3), 554. 

Nanoporous SiC-based materials are difficult to obtain due to the high formation temperature. Disordered nanoporous silicon carbide ceramics can be fabricated by a solid-gas reaction of ordered mesoporous carbon replica with silicon vapor [82], and a chemical vapor infiltration of dimethyldichlorosilane inside mesoporous silica following by the removal of silica [83]. Recently, highly ordered mesoporous SiC materials with uniform pore sizes and ultralarge surface areas have been synthesized by fully impregnating polycarbosilane... 

Skell and Owen " have studied the reactions of Si atoms with methylsilanes by heating solid silicon, resistively, to 1400°C in vacuo followed by co-condensation with the substrates on the liquid-nitrogen-cooled walls. The silicon vapor thus obtained may contain some Si2 and Si3 species, but the monoatomic Si atoms should be predominant at low pressures." ... 

Previously, trifluorosilyl groups have been bound to phosphorus (40) and silicon via the SiF (g), fluorine-bond insertion-mechanism (41). The new compound HgCSiFs) is readily hydrolyzed, but it can be stored for long periods of time in an inert atmosphere. It is a volatile, white solid that is stable up to at least 80°C. The preparation of bis(trifluoro-silyDmercury, of course, raises the possibility of (a) synthesis of the complete series of trifluorosilyl, "silametallic compounds, as had previously been done for bis(trifluoromethyl)mercury by using conventional syntheses, and (b) transfer reactions similar to those in Section II, as well as (c) further exploration of the metal-vapor approach. The compound Hg(SiF.,)j appears also to be a convenient source of difluoro-silane upon thermal decomposition, analogous to bis(trifluoromethyl)-mercury ... 

Zinc oxide in solid or fine particle form is kept in a reactor cavity that is subjected to irradiation from solar concentrators [92], The dissociation products are zinc (vapor) and oxygen for this first reaction AG=0 at about 2235K [91], The reactor is made of materials like inconel steel, zirconia, silicon carbide or graphite [68,89,92], The graphite is used in special designs to avoid direct contact with chemical species [68], The dissociation products are then cooled rapidly to separate zinc and oxygen, transporting the... 

The SiC coating is processed based on the reaction of SiO vapor and carbon materials. Commercial SiO powders (99.9% pure) are provided as the silicon source. The carbon materials are placed on the SiO powder bed via a carbon felt as illustrated in Fig. 10.1. This assembly is covered with carbon sheets in an alumina crucible to keep the SiO gas pressure in the crucible, and heated in a vacuum furnace at various temperatures from 1150 to 1550°C in vacuum (about 0.03 Pa) for periods of time between 1 and 90 minutes. It is necessary to heat at a temperature greater than 1150°C for the vaporization of solid SiO. 

In chemical vapor deposition (CVD), a semiconducting or insulating solid material is formed in a reaction between a gaseous species and a species adsorbed on the surface of silicon wafers (disks about 10 cm in diameter and 1 mm thick). The coated wafers are subjected to further processing to produce the microelectronic chips in computers and most other electronic devices in use today. 

The generation of the species discussed in this article is different from the two classical methods mentioned above Solid silicon is vaporized and the extremely reactive silicon atoms create the envisaged molecules in the moment of co-deposition by reaction with the selected partner (such as oxygen, silane, or methane) on the surface of the cold matrix holder. The products remain... 

---