A Novel Pulsed High-density Plasma Process for Nanoparticle Synthesis

U. Helmersson, D. Söderström, I. Pilch, S. Pillay, N. Brenning
Linköping University, SE

Keywords: nanoparticles, plasma


Today there are various plasma techniques where material is sputtered and used to synthesize nanoparticles. However, we have been unable to identify anyone ionizing the sputtered material in such a process. The advantage of ionizing the source material is that it increases its trapping onto negatively charged nanoparticles (NPs) in the plasma resulting in a significant increase in productivity. In this work we have performed both simulations and experiments to verify the increased productivity. The experiments were performed using high power impulses to generate high plasma densities, similar to thin films synthesized by high power impulse magnetron sputtering. The dense plasma yields a high degree of ionization of the sputtered metal species. Solid metal cylinders of Cu, Ag, Ti, and Mo were used as hollow cathodes for the synthesis of NPs. By tuning the process parameters, pulsing energy, pulsing frequency, etc., the particle size can range from approximately 5 nm to 700 nm in diameter.