ABSTRACT
The identification and study of microcontaminants or inhomogeneities in solid samples such as polymers, biological specimens, minerals, and semiconductor materials is an important application of analytical techniques. While many an alytical techniques such as optical microscopy, electron microprobe, SIMS, and others can provide valuable information on these chemical systems with very high spatial resolution, infrared spectroscopy (and the complementary technique, Raman spectroscopy) has been shown to be a very useful tool as well. The infrared absorption spectrum of molecular compounds contains bands that can be associated with specific functional groups present, and a plot of the variation of such absorption band intensities over the entire area of the sample under study can be considered to be a chemical map of the sample. Examples of such infrared mapping of semiconductor samples using a laser scanning near-infrared microscope [1,2] have been published in the literature. Most such applications of chemical imaging by infrared and Raman spectroscopy have been reviewed by Treado and Morris [3]. More recently, such chemical mapping or functional group imaging on a microscopic level using Fourier transform infrared (FT-IR) spectroscopy has become popular, and this FT-IR microimaging technique is reviewed in this chapter.
