Temperature dependence of the infrared absorption cross-sections of neutral species commonly found in fluorocarbon plasmas

Abstract

This article serves as a reference for the analysis of Fourier transform infrared spectroscopy data from processing plasmas. Until now, there has been a lack of accurate reference data for addressing the problems of species identification and density measurements in cases of increasing gas temperatures. Our results show that, while the integrated absorption cross-sections do not change significantly as temperature increases, the temperature of the absorbing species can be estimated from the rotational band maximum in most cases. Integrated absorption cross-sections for c-C3F6, C4F8, C3F8, C2F6, C2F4, and CF4 are presented for all fundamental bands in the 650 cm−1 to 2000 cm−1 region. In addition, the binary combination bands up to 4000 cm−1 are presented for all species. The temperature of each species has been varied to correspond to neutral temperatures commonly found in processing plasmas.