PNNL

Abstract

Residual gas analyzer (RGA) and optical emission spectroscopy have been evaluated as potenial in-situ techniques for the detection of plasma-induced polymer surface degradation. The detection is based on the measurement of CO and CO2 species formed in the gas phase following oxidation of the degradation fragments released from the polymer surface. Experiments were performed on poly(ethylene-terephthalate) and UV-cured acrylic (tripropyleneglycol diacrylate) films exposed to O2 RF (13.56 MHz) plasmas. A linear correlation is obtained between the formation of CO and the polymer degradation rate over the entire experimental range, but discrepancy appears for the formation of CO2 at high treatment powers (degradation rate > 1.0 Mum/min.cm2). This behavior is attributed to a deficit of oxidizing agents relative to the generation of degradation fragements. The results suggest that both RGA and optical emission spectroscopy can be used to monitor in-situ and in real-time the degradation of polymer surfaces during plasma treatment.