Determination of Ar metastable atom densities in Ar and Ar/H2 inductively coupled low-temperature plasmas

Ar metastable atoms are important energy carriers and surface interacting species in low-temperature plasmas that are difficult to quantify. Ar metastable atom densities (N-Ar,N-m) in inductively coupled Ar and Ar/H-2 plasmas were obtained using a model combining electrical probe measurements of electron density (N-e) and temperature (T-e), with analysis of spectrally resolved Ar plasma optical emission based on 3p -> 1s optical emission ratios of the 419.8 nm line to the 420.1 nm line. We present the variation of N-Ar,N-m as the Ar pressure and the addition of H-2 to Ar are changed comparatively to recent adsorption spectroscopy measurements.