Relative domination between Cl/sup +/ and Cl2/sup +/ ions in time-modulated inductively coupled Cl2 plasma investigated with laser-induced fluorescence technique

Time-modulated plasma etching has been newly applied to the etching of semiconductor devices. In this etching technique, the electron temperature is lowered by cutting-off plasma discharge periodically. In this study, we simultaneously measure the relative densities of Cl/sub 2//sup +/ and metastable chlorine atomic ions Cl/sup +*/ in the time-modulated ICP and CW plasma by laser-induced fluorescence (LIF) technique and discuss their relative importance in the positive ions.