螺旋波激发氢等离子体光谱诊断

Spectroscopy diagnosis of hydrogen plasma excited by helicon-wave

利用螺旋波等离子体化学气相沉积(HWP-CVD)技术,以氢气为反应气体产生等离子体。通过采集氢的可见到紫外发射光谱,对等离子体进行了原位诊断,由氢Balm er系分析得到了不同实验参数对激发态氢原子相对密度的影响,通过对Fu lcher带的分析,得到实验参数对氢振动温度的影响。结果表明:低压氢等离子体状态可借用日冕模型来诊断;激发态氢原子密度随入射功率增加而增加,随压强增加而减少,氢分子振动温度随压强增加先增大后减小;电子温度和电子密度是低压氢等离子体状态变化的关键因素。

The hydrogen plasma was excited by using the technology of helicon-wave plasma chemical vapor deposition （HWP-CVD）. The characteristics of the plasma were investigated by using the vacuum ultraviolet-visible emission spectroscopy. The influence of experiment parameters on the relative density of the excited hydrogen atoms was analyzed through the analysis of the hydrogen Balmer lines, and that on the vibrational temperature of hydrogen was studied through the analysis of the hydrogen Fulcher band lines. The electron temperature, the electron density and the relative rate coefficient were analyzed. The experimental results indicate that the state of a low pressure hydrogen plasma can be diagnosed by the corona model and the density of the excited hydrogen atoms increases with the increas of the input power and decreases with the increase of the pressure, while the vibrational temperature of hydrogen molecules increases firstly and then decreases with the increase of the pressure. The electron temperature and electron density are the key factors for the variation of the low pressure hydrogen plasma state.