Probing radicals in hot wire decomposition of silane using single photon ionization

Radicals produced by the hot wire-induced decomposition of silane have been identified using vacuum ultraviolet single photon ionization (SPI). This laser-based technique uses 118 nm photons (10.5 eV) to ionize gas phase species; the resulting photoions are detected using time-of-flight mass spectrometry. The major silicon-containing gas-phase species identified by SPI during hot-wire activation of silane gas are Si, SiH3, and Si2H6. These results demonstrate that single photon ionization can be a powerful probe for in situ, real-time detection of multiple species in hot wire chemical vapor deposition.