Trichlorosilane

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Trichlorosilane
IUPAC name trichlorosilane
Other names silyl trichloride
Identifiers
CAS number [10025-78-2]
SMILES [H][Si](Cl)(Cl)Cl
Properties
Molecular formula HCl3Si
Molar mass 135.45 g mol−1
Appearance colourless liquid
Density 1.342
Melting point

−126.6 °C

Boiling point

32 °C

Solubility in water decomposes in H2O
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Trichlorosilane is a chemical compound containing silicon, hydrogen, and chlorine. At high temperatures, it decomposes to produce silicon, and as such, purified trichlorosilane is the principal source of ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a silicone 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.

[edit] Production

Industrially, trichlorosilane is produced by blowing hydrogen chloride through a bed of silicon powder at 300°C. There, they combine to make trichlorosilane and hydrogen according to the chemical equation

Si + 3 HCl → HSiCl3 + H2

A properly designed reactor can achieve a yield of 80-90% trichlorosilane. The major byproducts are silicon tetrachloride (chemical formula SiCl4), hexachlorodisilane (Si2Cl6), and dichlorosilane (H2SiCl2), from which trichlorosilane can be separated by distillation.

The reverse process is used to produce of silicon of higher purity.

[edit] References

|Semiconductors: Silicon: Substrate Manufacture: Polycrystalline Silicon Production

[edit] External links