Generation of charged nanoparticles and their deposition during the synthesis of silicon thin films by chemical vapor deposition

Generation of charged nanoparticles in the gas phase has been frequently reported in many chemical vapor deposition (CVD) processes. In an effort to confirm whether charged nanoparticles are generated during the synthesis of silicon films by CVD, a differential mobility analyzer combined with a Faraday cup electrometer was connected to an atmospheric-pressure CVD reactor under typical conditions for silicon film growth. The size distribution of positively and negatively charged nanoparticles abundantly generated in the gas phase could be measured. An electric bias applied to the substrate holder affects the growth rate, the crystallinity and the morphology of the deposited films. The bias effect indicated that charged nanoparticles were actively involved in the film growth. (C) 2010 American Institute of Physics. [doi:10.1063/1.3452352]