J. Phys. IV France 09 (1999) Pr8-545-Pr8-550
In-situ Raman spectroscopy and laser-induced fluorescence during laser chemical vapor precipitation of silicon nanoparticlesW.F.A. Besling1, A. Goossens2 and J. Schoonman2
1 Philips Research, Prof. Holstlaan 4, 5656 AA Eindhoven, The Netherlands.
2 Laboratory for Inorganic Chemistry, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
Raman scattering in combination with laser-induced fluorescence (LIF) has been used to identify molecules and intermediates during the nucleation and growth of nanosized silicon particles by CO2 laser excitation of silane. Upon switching on the CO2 laser, the silane Raman peak height decreases due to a decrease in species number density and LIF peaks emerge due to presence of SiH2 radicals. The dissociation temperature has been determined inside the reaction zone and a value of 605 K is obtained. The nucleation and growth mechanism starts with the insertion of the SiH2 radicals into the Si-H bond of silane which is demonstrated by the formation of disilane. Amorphous nanosized silicon particles are obtained at reactor pressures of 50 torr and are collected on a cold finger. Keywords : Chemical Vapor Precipitation, CO2 laser excitation, nanosized silicon, Raman spectroscopy, laser-induced fluorescence, SiH2 radicals
© EDP Sciences 1999