螺旋波等离子体化学气相沉积纳米硅薄膜的光学发射谱研究

利用光学发射谱技术对螺旋波等离子体化学气相沉积纳米硅薄膜的等离子体内活性粒子的光发射特征进行了原位测量.研究了薄膜沉积过程中各实验参量对活性基团SiH^*， H^β以及H^α的发射谱强度的影响.实验结果表明，静态磁场的加入可显著提高反应气体 的解离效率 ；适当的氢稀释可以提高氢活性粒子的浓度，而过高的氢稀释比将使含硅活性基团浓度显著 减小；提高射频馈入功率整体上可以使各活性粒子的浓度增加，并有利于提高到达衬底表面 氢活性粒子的相对比例.结合螺旋波等离子体色散关系和等离子体特点对以上结果进行了分 析.该结果为螺旋波等离子体沉积纳米硅薄膜过程的理解及制备工艺参数的调整提供了基础 数据. 关键词： 光学发射谱 螺旋波等离子体化学气相沉积 纳米硅薄膜

Optical emission diagnosis of helicon-wave-plasma-enhanced chemical vapor deposition of nanocrystalline silicon

Optical emission spectroscopy (OES) is used to diagnose the active species emission in the helicon_wave_plasma_enhanced chemical vapor deposition of nanocrystalline silicon. The effects of the experimental parameters on OES intensity of SiH ^*, H^β and H^α have been studied. Ｅxperiment r esults indicate that the ma gnetic field confinement makes the reactant molecules dissociate efficiently. Ap propriate hydrogen dilution can increase the density of hydrogen active species, while higher dilution makes the concentration of silicon_contained active spec ies decrease. The density of the active species increases monotonically with in creasing input rf power, and a relatively higher concentration of hydrogen act ive species reaching the substrate surface can be achieved. Experiment results obtained are analyzed based on the dispersive relation and the characteristic o f the helicon wave plasma, which offer the basic data for the understanding of t he process of nanocrstalline silicon deposition and adjusting its experimental p arameters.