Low Temperature Hydrogen Plasma Diagnosis

Helicon-wave plasma is a kind of high density and low pressure plasma. It has prospective applications such as in VISI (very large-scale intergration) process, micro-electronic-mechanic system fabrication, new thin film material and nano -material preparation, surface treatment and ion gas lasers. In this dissertation, the setup of helicon-wave plasma chemical vapor deposition and the plasma diagnosis system including Langmuir probe and optical emission spectroscopy diagnosis are presented, and the characteristics of helicon-wave plasma are investigated by using vacuum ultraviolet-visible emission spectroscopy acquired in this experiment.Chapter I reviews the applications of plasma, several plasma sources and the plasma diagnosis technology. Chapter II presents a simple description of the generation and propagation characteristics of helicon wave. In Chapter III, the theory of diagnosis technology and corresponding experimental setup are described: (1)After having considered the characteristics of helicon wave plasma, we have carefully designed a RF (radio frequency) compensated probe and the correspondin -g circuit based on the theory proposed by professor Godyak and Chen; (2)The optical emission spectroscopy technique in the range of 200-900 nm is employed to detect in situ the activated species in the plasma. First, the photon emission from the plasma center is transferred to a C-T monochromater after being focused by a quartz lens system. Then the signal is received by a photomultiplier tube of high spectral sensitivity and passed sequentially through a micro-current amplifier and DAS card. Finally, the signal is stored and analyzed by a personal computer. Inchapter IV, the hydrogen plasma is excited by the technology of helicon-wave plasma chemical vapor deposition and the characteristics of the plasma is investigated by the vacuum ultraviolet-visible emission spectroscopy acquired in this experiment: â‘ The influence of experiment parameters on the relative density of excited hydrogen atom is analyzed from hydrogen Balmer lines; â‘¡The influence on the vibratinoal temperature of excited hydrogen is known through the analysis of hydrogen Fulcher band lines. The relationship between the vibratinoal temperature of ground hydrogen and the ratio of Fulcher band lines is analyzed; â‘¢The gas temperature of plasma is investigated through the analysis of the rotational spectrum of hydrogen G-B transitional band lines.The helicon-wave plasma chemical vapor deposition and the plasma diagnosis experimental setup presented in this paper will be helpful for the perspective mechanism of chemical vapor deposition processing .