FTIR-ATR spectroscopy in thin film studies: The importance of sampling depth and deposition substrate

► The substrate properties must be considered for the analysis of FTIR-ATR spectra. ► Band assignment depends strongly on the used FTIR measurement mode. ► FTIR-ATR spectroscopy is powerful for the study of thin film molecular organisation. ► Townsend DBD leads to more ordered SiOxHy layers than filamentary DBD.