Trichlorosilane

Trichlorosilane is a compound with the formula HSiCl3. It is a colourless, volatile liquid that fumes in air. It has a pungent odour and is used in various industrial applications, primarily for the production of silicon and various silicon-containing chemicals.

Chemical Properties

Trichlorosilane is a chlorosilane, which is a group of reactive, chlorine-containing silicon compounds, used in many chemical processes. Each molecule of trichlorosilane contains one atom of silicon, one atom of hydrogen, and three atoms of chlorine.

Production

Trichlorosilane is produced from silicon dioxide (SiO2) in a process that involves heating the SiO2 with hydrogen chloride (HCl) at high temperatures to produce SiHCl3. This process is known as the Müller-Rochow process.

Applications

The primary use of trichlorosilane is in the production of polycrystalline silicon, also known as polysilicon, a key material in the semiconductor industry. Trichlorosilane is converted to polysilicon via the Siemens process, in which the trichlorosilane is heated to high temperatures and reduced with hydrogen to produce polysilicon and hydrogen chloride.

Safety

Trichlorosilane is a highly reactive compound and can be hazardous if not handled properly. It can react violently with water to produce hydrochloric acid and heat, which can lead to fires or explosions. Therefore, it should be stored and used in a controlled environment and protective measures should be taken to avoid exposure.

See Also

• Silicon
• Chlorosilane
• Müller-Rochow process
• Siemens process