Generation of SI nanoparticles using plasma technology for novel device and energy storage application

Silicon nanoparticles are widely studied as a building block for various applications. M. L. Ostraat et al.[1] and S. Koliopoulou et al.[2] studied NFGM (nano floating gate memory), and S. Oda[3] studied electron characteristics of Si nanoparticles. H. Shirai et al.[4] studied optical characteristics of crystalline silicon nanoparticles. In addition, silicon nanoparticles can be applied for energy devices such as 2nd generation battery. In this paper, we investigated the generation of Si nanoparticles using pulse plasma technology. An inductively-coupled plasma chamber with RF power (13.56 MHz) was designed for this study. DC-bias was applied between the substrate and grounded grid installed above the substrate to increase the particle collection efficiency and to avoid film formation on the substrate, Moreover, in order to control the structure of silicon nanoparticle, we implemented heater inside the substrate. Experiments were performed with various pulse periods to generate nanoparticles with various sizes. Transmission electron microscopy (TEM) was used to measure the shape, structure and size of nanoparticles. TEM images showed that the generated nanoparticles have spherical shape with highly monodisperse size distribution. The structure is originally amorphous but we could change its structure to crystal by annealing. We employed a widely used plasma technology, so we except that it can be easily applied to industry with small modification.