Application of laser-induced breakdown spectroscopy for real-time detection of contamination particles during the manufacturing process.

A stand-off laser-induced breakdown spectroscopy (LIBS) system was developed to determine the elemental composition of contamination particles during semiconductor manufacturing. It successfully detected laboratory-generated monodisperse (size=200  nm and 300 nm) CaCl2 particles and internally mixed particles of CaCl2 , MgCl2 , NaCl, and KCl. Temperature and pressure effects on the LIBS emission signals were investigated. The peak area and signal-to-noise ratio of the emission lines increased with the temperature (25°C-250°C). Stronger emission lines were observed at higher pressure. Although temperature and pressure affect the LIBS signals, the developed stand-off LIBS could be employed for real-time detection of the elemental composition of contamination particles.