使用发射光谱对感应耦合CF4/CH4等离子体中C2基团形成机理的研究

利用强度标定的发射光谱法，研究了感应耦合CF4₄/CH4₄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，CF2₂，CH，H和F等活 性基团外 ，还同时存在着C2₂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. C2₂随流量比R（R=［CH4 _{关键词： 发射光谱 感应耦合等离子体 2}基团')" href="#">C2₂基团

Studies on C22 radical by optical emission spectroscopy in an induc tively-coupled CF44/CH44 plasma

In this paper, actinometric optical emission spectroscopy (AOES) is used to inve stigate the discharge of CF4₄ and CH4₄ mixtures. Relat ive concentratio ns of radicals in an inductively_coupled plasma are determined as functions of rf input power, pressure and the gas flow ratio R (R=［CH4₄］/{［CH 4₄］+［CF4₄］}). It is found that CF，CF2₂ ，CH，H and F radicals exis t in the CF4₄/CH4₄ plasma as well as C2₂ radical. The relative co ncentration of C2₂ increases with increasing power, and shows a rev erse “U” shape tendency with increasing pressure. As R increases, the variati on of the relative concentration of C2₂ is not monotonical. It reac hes a ma ximum 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_pha se reaction from the reaction of CF and CH （ＣＦ＋ＣＨ→Ｃ２₂＋ＨＦ ） contribu tes to the production of C2₂ radical. At the same time, activation reaction model of radical collision is suggested. Result of simulation agrees well with that of experiment.