F. Tochikubo et al., INFLUENCE OF AR METASTABLE ON THE DISCHARGE STRUCTURE IN AR AND NA MIXTURE IN RF DISCHARGES AT 13.56-MHZ, JPN J A P 1, 33(7B), 1994, pp. 4271-4275
The influence of Ar metastable atoms on the discharge structure in rf
glow discharges is investigated in Ar and N-2 mixed gas experimentally
and theoretically. The purpose of adding a small amount of N-2 is to
control the metastable density. Time- and space-resolved optical emiss
ion spectroscopy is applied to investigate the behavior of high-energy
electrons. The density profile of Ar metastables in Ar and Na mixture
is estimated from the optical emission intensity of the second positi
ve band of N-2, which results from the energy transfer from Ar metasta
bles to N-2 molecules. The decreases of current and optical emission i
ntensity, as well as the Ar metastable density with increase of N-2 ra
tio, are observed. It is concluded that ionization through metastables
is one of the important processes in increasing the plasma density, e
specially at higher pressures.