Optical Diagnostics of a Pulsed Inductively Coupled Nitrogen Plasma

抄録

Temporal variation of electron energy distribution through a pulsed inductively coupled nitrogen plasma is discussed by the temporally resolved measurements of optical emission spectroscopy and laser-induced fluorescence. The intense intensity peak of the first negative band emission (N₂⁺) immediately after RF power application to the plasma is likely to be caused by the rapid increase and subsequent decrease in a ≈3-eV electron population because the electron impact excitation of ground state N₂⁺ ions is assumed to cause the first negative band emission. The intensity peak for the second positive band emission (N₂), the threshold energy of which is ≈11 eV, is also observed but even smaller than the first negative band emission, indicating the smaller enhancement of an electron population at ≈11 eV than that at ≈3 eV during electron heating after the RF power application.