J. Phys. IV France 09 (1999) Pr8-519-Pr8-528
Laser CVD of silicon nanoclusters and in-situ process chataracterizationA. Goossens1, W.F.A. Besling2 and J. Schoonman1
1 Laboratory for Inorganic Chemistry, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
2 Philips Research, Prof. Holstlaan 4, 5656 AA Eindhoven, The Netherlands.
Raman scattering in combination with laser-induced fluorescence (LIF) has been used to identify intermediates during the nucleation and growth of nanosized silicon clusters created 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. Also a Raman signal of Si2H6 is observed. The dissociation temperature is determined inside the reaction zone with rotational Raman of H2 and equals 605 K which is far below the thermal decomposition temperature of silane. Amorphous silicon nanoclusters are formed and show remarkable optical effects which can be explained with quantum confinement of excitons. The size of these clusters is between 0.8 and 3 nm
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