SURFACE-ENHANCED INFRARED EXTERNAL REFLECTION SPECTROSCOPY AT LOW REFLECTIVE SURFACES AND ITS APPLICATION TO SURFACE-ANALYSIS OF SEMICONDUCTORS, GLASSES, AND POLYMERS

A surface-enhanced infrared reflection spectroscopy has been developed for the characterization of thin organic films on low reflective substrates. The substrates we studied were BaF2, Ge, microscope slide glass, and poly(acrylonitrile-butadiene-styrene) resin. The sensitivity of the reflection infrared spectroscopy at these surfaces is remarkably improved by evaporating very thin silver films on the sample surfaces. The same results were obtained also by casting thin organic films on metal-coated substrates. The improvement of the spectral sensitivity is due to the enhancement of the incident infrared field at the metal surfaces. We show that this technique is promising as a surface analytical tool for semiconductors and Insulators. The optimum optical conditions to obtain the spectra are discussed experimentally and theoretically.