等离子体增强化学气相沉积中对尘埃颗粒诊断

Diagnostics of dust particles in plasma chemical vapor deposition process emission spectroscopy and Langmuir probe

采用SiH4,C2H4和Ar在射频容性耦合柱状放电室中产生了尘埃颗粒,利用发射光谱测得射频尘埃等离子体放电室中的一些基本碎片的发射光谱,并给出了这些碎片的光发射强度随着实验条件变化的曲线。随着功率和气压的增加,碎片的光发射强度逐步增加,尤其是随功率增加得更快,这说明功率对硅烷和乙烯的离解作用明显。随着硅烷和乙烯流量的增加,碎片的光发射强度随之下降。利用朗缪尔探针的实验结果得出尘埃密度的变化趋势,给出了尘埃密度随射频功率变化的曲线,其结果与硅烷和乙烯的离解变化趋势基本吻合。

Dust particles were produced in situ using reactive mixtures （SiH4/CzH4/Ar） in radio-frequency（RF） discharge. To get more information about dusty plasma, Langmuir probe and optical emission spectroscopy diagnoses were introduced. Then the emission intensities of Si＋ 390.6 nm, Si2＋ 380.6 nm and C＋ 426.7 nm as a function of pressure, RF power, and flow rates of SiH4/C2 H4 were presented. The emission intensities of Si＋ , Si＋ and C＋ are enhanced with the increase of gas pressure and RF power. But as the flow rates of Sill4/Cz H4 increase, the emission intensities are weakened. By using Langmuir probe, the densi- ty 0f dust particles was calculated from electron density and ion density, and then variation of the dust particle density with RF power was derived, which is basically consistent with the trend of Sill4/C2 H4 dissociation.