Here is the abstract you requested from the imaps_2019 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|A Microscope Employing Grazing Angle Optics for Thin Film IR Spectroscopy|
|Keywords: Thin Film IR Spectroscopy, coupling microscopes, Thin Films|
|The coupling of imaging with spectroscopy provides a powerful combination for the microscopic characterization of materials and the chemical identification of microscopic specimens. The origins of coupling microscopes with infrared spectrometers date to 1949. However, more widespread usage awaited the arrival of Fourier transform infrared (FT-IR) instruments. Commercially available FT-IR microscopes appeared in the early 1980s. Continuous instrumental and methods innovation has propelled the IR microscopy field, increasing performance and driving new applications. This presentation shall describe a new grazing angle FT-IR microscope for use in studies of thin films and contaminants. Several applications of this specialized microscope from the electronics industry shall also be shown. For thin films (< 1 m thickness) on reflective surfaces, high angles of incidence yield a higher electric field amplitude at the reflective surface and therefore, greater band absorbances. For metals and p-polarized radiation, the electric field amplitude is maximum near 80 degrees from normal to the surface. For analysis of contaminants in thin film coatings and for spatially resolved characterization of thin films, it is desirable to spectroscopically measure smaller areas and sample sizes than is currently possible. A microscope that employs grazing angle optics was developed for this purpose. We will discuss the design and performance of this grazing angle microscope. The microscope is mounted to the external beam of a Fourier transform IR (FT-IR) spectrometer and delivers IR radiation from 60-85 degrees relative to the surface normal. The system employs aperture masks to define the sampled area. Grazing angle germanium attenuated total reflection (ATR) optics allow characterization of thin films on dielectric substrates. Microspectroscopic measurements of films on metal and dielectric surfaces will be discussed including lubrication thickness determinations on storage media, molecular characterization of conducting polymers on flexible substrates, and comparative measurements of polymer films on gold, silicon, and glass substrates.|