Diagnostic Of Argon Metastable In DF-CCP By Diode-laser Absorption Spectroscopy

Temperature and density of Ar metastable in capacitively coupled plasma were measured by tunable diode-laser absorption spectroscopy. Effect of power, pressure, O2concentration and frequency on temperature and density of Ar metastable were studied. It was found that, at pressure lower than5Pa and power lower than70W, both Temperature and densities of1S5and1S3increased rapidly with power increasing, while at power larger than70W, both temperature and densities of1S5and1S3increased slowly. Pressure increase and O2added to Ar presented negative effect on temperature and density of Ar metastable. With pressure increasing, temperature and density of Ar metastable decreased, gradually. Meanwhile, with O2concentration increasing, temperature and density of Ar metastable drasticly decreased, temperature and density of Ar metastable decreased drasticly even only1%O2added to Ar. Density of Ar metastable increased faster with increasing high frequency power than low frequency power.