Control of nano-particle generation, growth rate and crystallinity by changing external parameters in $SiH_{4}$ plasmas

Abstract

It is required to control the nano-particle generation, growth, and crystallinity in various plasma applications. In order to achieve this, it is essential to understand the interaction between nano-particles and plasma species which can be accomplished by the accurate measurement of both plasma and nano-particle parameters. However, despite the development of many nano-particle diagnostics, not many plasma diagnostics have been developed for dusty plasmas because of the presence of the nano-particle, negative ions, and reactive species. In this dissertation, therefore, by utilizing a floating probe and plasma emission spectroscopy which are less affected by reactive species, the interaction between nano-particles and plasma species was investigated and a study for controlling nano-particle generation, growth rate, and crystallinity was undertaken. The nano-particle growth pattern, spatial distribution, and morphology as well as plasma parameters were investigated in relatively low (capacitively-coupled plasma: $10^{9}-10^{10}cm^{-3}$) and relatively high (inductively-coupled plasma: $10^{10}-10^{11}cm^{-3}$) density plasmas. It is found that the plasma parameters are significantly changed with time, i.e., with nano-particle growth in low density plasmas while they are almost constant in high density plasmas. In addition, the nano-particle transport from the bulk plasma to the edge plasma occurs in high density plasmas and shapes of the produced nano-particles are different between low and high density plasmas. These results indicate that the nano-particles alter the plasma parameters by capturing electrons and ions while the high ion density causes the nano-particle transport toward the chamber wall and crystallization. A simple zero-dimensional fluid model was developed to quantitatively understand the interaction between nano-particles and plasma species and the calculated values are in good agreement with the measured values. Using the knowledge obtained re...