SiH4

Silane, with the chemical formula SiH4, is a colorless, highly reactive gas that serves as the hydride of silicon. It is widely used as a precursor in silicon deposition processes for the semiconductor industry and related technologies.

Silane has a tetrahedral molecular geometry and exists as a simple covalent compound. Its physical properties include a boiling point of about −111.8 °C and a melting point well below that (around −185 °C), making it a gas at room temperature. It is considerably reactive and, in air, can ignite spontaneously in many forms. Silane readily hydrolyzes in moisture to form silicon-containing species and hydrogen gas: SiH4 + 4 H2O → Si(OH)4 + 4 H2. The silicon-containing species may further condense to silica.

Production and handling of silane involve several industrial routes, including the reduction or disproportionation of silicon-containing precursors and, in laboratory settings, preparation from silicon and hydrogen sources. In practice, silane is stored and transported under inert atmosphere or with stringent controls to prevent exposure to air. Handling requires appropriate detectors and ventilation due to its pyrophoric and flammable nature, as well as measures to prevent uncontrolled hydrolysis and hydrogen accumulation.

Applications of silane are dominated by its use in chemical vapor deposition and related processes to deposit silicon and silicon-containing films for microelectronics, photovoltaics, and specialty coatings. As a reactive silicon source, it enables various fabrication methods for semiconductor devices, while its handling and safety requirements reflect its flammability and chemical reactivity.