Time Variation of Plasma Properties in a Pulse-Time-Modulated Electron Cyclotron Resonance Discharge of Chlorine Gas

Time dependence of plasma parameters in a pulse-time-modulated electron cyclotron resonance plasma of Cl2and Ar gases is measured. It is found that Cl2plasma produces a large quantity of negative ions during afterglow and that decay times of electron density, electron temperature and sheath potential of Cl2plasma are much smaller than those of Ar plasma. The results suggest that the pulse modulation of Cl2plasma changes the flow of charged particles through the sheath region to the substrate surface and enables us to improve highly selective and charge-free poly-Si patterning.