【摘要】 利用强度标定的发射光谱法 ,研究了感应耦合CF4 CH4 等离子体中空间基团的相对密度随宏观条件 (射频输入功率、气压和流量比 )的变化情况 .研究表明 :在所研究的碳氟 碳氢混合气体放电等离子体中除了具有丰富的CF ,CF2 ,CH ,H和F等活性基团外 ,还同时存在着C2 基团 ,其相对密度随着放电功率的提高而增加 ;随着气压的上升呈现倒“U”型的变化 .C2 随流量比R(R =[CH4 ] { [CH4 ]+[CF4 ]} )的变化不是单调的 ,其相对密度在R =7 5 %时存在一个极大值 ,并随着R进一步增加而减弱 ,然后趋于一个稳定值 .根据各基团相对密度的变化规律 ,认为等离子体中CF和CH基团的气相反应 (CF +CH→C2 +HF)是C2 基团产生的主要途径 ,并提出了形成C2 的基团碰撞的活化反应模型 ,据此进行的模拟计算的结果与实验相符 .更多还原

【Abstract】 In this paper, actinometric optical emission spectroscopy (AOES) is used to investigate the discharge of CF 4 and CH 4 mixtures. Relative concentrations of radicals in an inductively-coupled plasma are determined as functions of rf input power, pressure and the gas flow ratio R (R=[CH 4 ]/{[CH 4 ]+[CF 4 ]}). It is found that CF,CF 2 ,CH,H and F radicals exist in the CF 4 /CH 4 plasma as well as C 2 radical. The relative concentration of C 2 increases with increasing power, and shows a reverse “U” shape tendency with increasing pressure. As R increases, the variation of the relative concentration of C 2 is not monotonical. It reaches a maximum value when R=7.5%, then decreases followed by almost no change with the further increase of R. Based on these results, it is concluded that gas-phase reaction from the reaction of CF and CH (CF+CH→C 2+HF) contributes to the production of C 2 radical. At the same time, activation reaction model of radical collision is suggested. Result of simulation agrees well with that of experiment.更多还原