Abstract

Lasers can be used to detect reactive species in plasmas and high-temperature gas-phase environments. Such information gives insight into the chemistry and physics associated with processing techniques such as plasma etching and chemical vapor deposition (CVD) which are used in the fabrication of microelectronic devices. Using tunable dye lasers and excimer lasers we have detected ${\text{Cl}}_2^{+}$ (in a Cl₂ radio frequency discharge), and InCl, GaCl, PH₃, P₂, AsH₃, and As₂, (in a CVD reactor), and have characterized their dependence on variables such as applied radio frequency, gas composition, flow rate, and temperature. Lasers can also be directed at the substrate surface to influence etching and deposition chemistry. For example, we have demonstrated epitaxial growth of InP thin films on (100) InP substrates by ArF excimer laser-induced photodecomposition of (CH₃)₃ln and P(CH₃)₃. The laser not only decomposes the parent compound in the gas phase, but also stimulates removal of carbon and anneals the film to promote epitaxy. Excimer laser stimulated growth of GaAs is also discussed.

© 1986 Optical Society of America