Determination of Ar metastable atom densities in Ar and Ar / H 2 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 (NAr,m) in inductively coupled Ar and Ar/H2 plasmas were obtained using a model combining electrical probe measurements of electron density (Ne) and temperature (Te), 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 NAr,m as the Ar pressure and the addition of H2 to Ar are changed comparatively to recent adsorption spectroscopy measurements.