Influence of nitrogen on the optical properties of particles in a low pressure argon-silane radio-frequency discharge

In the last few years, laboratory dusty plasmas have been actively studied in connection with in pollution control in plasma reactors for surface treatments. An increasing interest is now devoted to the positive aspect of tailored microparticulates with applications in several technological areas. Light scattering, in the Mie regime, is used to determine by in situ-diagnostics both size and optical index values. From multi angles and crossed polarization data, size and optical indices have been obtained. Size determination in the range (40-110 nm) are compared with direct measurements from ex-situ T.E.M. (Transmission Electronic Microscopy) analysis for particulates growth in an ArSiH4 RF reactor. The material modifications of the particulates due to an addition of nitrogen have been evidenced by Mie scattering data in the two situations of simultaneous or delayed nitrogen pulsed gas flows