Trichlorosilane

Trichlorosilane

Names
IUPAC name trichlorosilane
Other names silyl trichloride, silicochloroform
Identifiers
CAS Number	10025-78-2 N
3D model (JSmol)	Interactive image
ECHA InfoCard	100.030.026
EC Number	233-042-5
RTECS number	VV5950000
UN number	1295
CompTox Dashboard (EPA)	DTXSID4029301
SMILES [H][Si](Cl)(Cl)Cl
Properties
Chemical formula	HCl3Si
Molar mass	135.45 g/mol
Appearance	colourless liquid
Density	1.342×103 kg/m3
Melting point	−126.6 °C
Boiling point	31.8 °C
Solubility in water	hydrolysis
Hazards
NFPA 704 (fire diamond)	3 4 2 W
Flash point	−27 °C
Explosive limits	1.2–90.5%
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Trichlorosilane is a chemical compound containing silicon, hydrogen, and chlorine. At high temperatures, it decomposes to produce silicon, and therefore 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.

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 in the production of silicon of higher purity.

Application

Trichlorosilane is the basic ingredient used in the production of purified polysilicons.

References

• Semiconductors: Silicon: Substrate Manufacture: Polycrystalline Silicon Production

External links

• Polysilicon Plant in India.