[en] Size and structure controlled, non-agglomerated nanoparticles are essential for many applications, such as electronics and energy storage. In this study, inductively coupled and square wave modulated RF (13.56 MHz) plasma was used to control the nanoparticle size, and a heater was installed inside the substrate to change the structure of Si nanoparticles from amorphous to crystalline. We found that the size of Si nanoparticles can be controlled by the plasma on-time. The nanoparticles were not agglomerated and grown mainly by surface deposition. The Si nanoparticles generated can be used in energy devices, such as secondary batteries, supercapacitors and solar cells.