MPCVD等离子体的发射光谱研究

在2.45 GHz, 800 W微波等离子体化学气相沉积装置上，利用发射光谱对CH₄/H₂等离子体进行在线诊断，分析了等离子体中存在的基团，研究了甲烷浓度对各基团浓度及基团的空间分布的影响。结果表明：等离子体中存在CH, H_α, H_β, H_γ, C₂ 基团和Mo杂质原子，随着甲烷浓度的升高，各基团的发射光谱强度均有增加，其中C₂基团强度显著增加。CH与H_α基团的发射光谱强度比值随甲烷浓度的增加变化不大，而C₂与H_α基团的发射光谱强度的比值随甲烷浓度的增加而显著增大。另外，甲烷浓度的增加使得等离子体中各基团在空间分布的均匀性变差。

Optical Emission Spectroscopy of MPCVD Plasma

The plasma of CH₄/H₂ was diagnosed with optical emission spectroscopy on a high-pressure microwave plasma apparatus at 2.45 GHz. The existing radicals in the plasma and the influence of the methane concentration on radical concentration and distribution were researched. The results indicate that the radicals of CH，H_α，H_β，H_γ，C₂ and little impurity atom Mo exist in the plasma. The intensity of emission spectrum of the radicals increases with the increase in the methane concentration, especially the intensity of C₂ has a notable increase. The ratio of the intensity of the CH to H_α is unchanging with the increase in methane concentration, while that of C₂ to H_α has a marked increase. The uniformity of the space distribution of the radicals becomes worse with the increase in methane concentration.