TRANSPORT OF ARGON IONS IN AN INDUCTIVELY-COUPLED HIGH-DENSITY PLASMAREACTOR

The first direct observation of the velocity distribution of the metas table Ar-+((2)G(9/2)) ions in the presheath of an inductively coupled plasma has been achieved by using the Doppler shifted laser induced f luorescence technique. Drift of the ions along the electric field in t he presheath is observed and distribution functions of the velocity in both parallel and perpendicular directions, relative to the E field, are deduced at 5 and 40 mTorr. Present results show that in high densi ty plasmas the velocity distribution of the metastable ions is directl y related to that of the ground state argon ions, Neutral gas temperat ure of around 600 K is also measured from the absorption profile of a diode laser beam, set on one of the 772.4 nm argon lines. (C) 1997 Ame rican Institute of Physics.