Optical spectroscopy techniques are widely used for the characterization of semiconductors and nanostructures. Confocal
Raman microscopy is useful to retrieve chemical and molecular information at the ultimate submicrometer resolution of
optical microscopy. Fast imaging capabilities, 3D confocal ability, and multiple excitation wavelengths, have increased
the power of the technique while making it simpler to use for material scientists. Recently, the development of the Tip
Enhanced Raman Spectroscopy (TERS) has opened the way to the use of Raman information at nanoscale, by combining
the resolution of scanning probe microscopy and chemical selectivity of Raman spectroscopy.
Significant advances have been reported in the field of profiling the atomic composition of multilayers, using the Glow
Discharge Optical Emission Spectroscopy technique, including real-time determination of etched depth by
interferometry. This allows the construction of precise atomic profiles of sophisticated multilayers with a few nm
resolution. Ellipsometry is another widely used technique to determine the profile of multilayers, and recent development
have provided enhanced spatial resolution useful for the investigation of patterned materials.
In addition to the advances of the different characterization techniques, the capability to observe the same regions at
micrometer scale at different stages of material elaboration, or with different instrument, is becoming a critical issue.
Several advances have been made to allow precise re-localization and co-localization of observation with different
complementary characterization techniques.