The work presented in this article represents the third and final part of a series of articles which present a systematic evaluation of iodoheptafluoropropane (C3F7I) as a potential replacement for perfluorocompound chemistries in dielectric etch applications. In the experiments discussed in this series, 1- and 2-iodoheptafluoropropane based etch processes had been employed in a via etch application in an inductively coupled high density plasma etch tool. Part I of this article discusses etch process behavior of 1- and 2-iodoheptafluoropropane, while Part Il examines films deposited by the I-iodo isomer. This article will focus on the composition of the process effluent stream, as characterized by Fourier transform infrared (FTIR) spectroscopy. Data generated by both isomers of the compound will be presented and compared to those generated by conventional (C3F8- and C2F6-based) etch processes. Significant reductions in global warming emission (on the order of 80%-85%) were obtained relative to the conventional processes. Additionally, FTIR data were correlated with process and film analysis data presented in Parts I and II to generate better understanding of key plasma mechanisms in iodofluorocarbon etch environments.