Impacts of plasma fluctuation on growth of nanoparticles in low pressure reactive VHF discharge plasmas*

Here we discuss impacts of plasma fluctuation on nanostructure formation using plasmas. We studied the effects of plasma fluctuation on the growth of nanoparticles in capacitively-coupled VHF discharges with amplitude modulation (AM) using 2 dimensional laser light scattering method [1]. AM gives an artificial plasma fluctuation. Nanoparticles grow more slowly for higher AM levels, which causes the density of nanoparticles to increase by 100{\%}, their size to decrease by 23{\%}, and narrower size dispersion. The increase in the nucleation density of nanoparticles by AM causes a decrease in the radical flux to a nanoparticle. Eventually we obtained a diagram of the three particle growth modes of positive feedback, negative feedback, and independent ones. We also have developed a simple theory of particle growth in reactive plasmas. The theory predicts experimental results well. Our approach can be applied to realize precise control of a wide variety of nanostructure formations.\\[4pt] [1] K. Kamataki, et al., J. Inst. 7 (2012) C04017.