使用发射光谱对H2稀释情况下的感应耦合H2/C4F8等离子体中碳氟基团的研究

在射频输入功率为400W，气压为0.8Pa的条件下，使用光强标定的发射光谱方法研究了感应耦合H₂/C₄F₈等离子体中CF, CF₂, H和F基团的相对密度随流量比R=H₂/(H₂+C₄F₈)的变化情况，而HF基团相对密度的变化由四级质谱仪探测得到。结果表明等离子体活性先随着R的增加而升高，然后随着R的进一步增加而下降。在流量比从0逐渐上升到0.625的过程中，CF和CF₂基团的相对密度不断降低。实验中测得的CF基团的相对密度CF]与理论计算得到的CF]有很好的一致性说明了电子与CF2基团的碰撞反应是CF基团产生的主要原因。文中还讨论了HF基团。

Study of effect of H2 addition on the production of fluorocarbon radicals in H2C4F8 inductively coupled plasma via optical emission spectroscopy actinometry

C₄F₈ plasma with the addition of H₂ is generated by the inductively coupled plasma (ICP) method. The relative densities of CF,CF₂, H and F radicals are determined by actinometric optical emission spectroscopy (AOES) as a function of the gas flow rate ratio R=H₂/(H₂+C₄F₈ at a pressure of 0.8 Pa and an input r.f.power of 400W, while that of HF is measured by quadrupole mass spectrometry (QMS). The results show that plasma activity increases firstly and then decreases with increasing R. As the gas flow rate ratio R changes from 0 to 0.625, relative densities of both CF and CF₂ decrease, and the relative CF] has a similar tendency as the calculated CF], indicating that CF radicals are generated mainly by the electron impact dissociation of CF₂ radicals. Production of HF is also discussed.