Fourier Transform Infrared (FTIR) spectroscopy is a fast, well established, and non-destructive technique used to identify materials. It is particularly effective with organics and polymeric materials. FTIR micro-spectroscopy applies this technique to samples as small as 5 um across.
The FTIR spectrometer measures the infrared absorption or reflectance spectrum to determine vibrational frequencies, which provides information on chemical structure and bonding. The spatial resolution of this technique is in the order of 10 um, enabling it to determine the composition of very small features on various substrates. The technique can also study dopants in glasses and semiconductors.
Thin films over metals, or contamination on metallic surfaces, can be identified with the Grazing Angle Objective (GAO).
FTIR is complementary to Raman spectroscopy and photoluminescence. For spectral searches, MuAnalysis maintains an online library of infrared absorption spectra containing more than 7000 entries, and custom entries are kept up to date with technological trends.