Main Page | See live article | Alphabetical index




Name Trichlorosilane
Chemical formula HSiCl3
Appearance Colourless liquid


Formula weight 135.5 amu
Melting point 146 K (-127 °C)
Boiling point 305 K (32 °C)
Density 1.34 ×103 kg/m3 (liquid)
Solubility decomposes in water


ΔfH0gas ? kJ/mol
ΔfH0liquid ? kJ/mol
ΔfH0solid ? kJ/mol
S0gas, 1 bar ? J/mol·K
S0liquid, 1 bar ? J/mol·K
S0solid ? J/mol·K


Ingestion May cause nausea, vomiting, kidney damage.
Inhalation May cause burning in chest, dizziness, pulmonary edema, cardiac irregularity, kidney damage.
Skin Possible burns, esepcially on wet skin.
Eyes Produces burning and tearing with possible cornea damage.
More info Hazardous Chemical Database
SI units were used where possible. Unless otherwise stated, standard conditions were used.

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 principle 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.


Industrially, trichlorosilane is produced by blowing hydrochloric acid 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.