Use of a high-dispersion spectrograph for optimized visible and UV Raman measurements on semiconductor materials

Implementation of higher spectral and spatial resolution in dispersive Raman microscopes, including access to a variety of excitation wavelengths, has proven beneficial in the semiconductor industry. UV adaptations accommodate measurement of smaller defects, higher sensitivity to thin films (to the exclusion of the substrate) and access to enhancement conditions for materials such as GaN-based photodiodes and lasers, and diamond. The availability of a high dispersion spectrograph, especially for UV wavelengths, avoids compromising spectral resolution. Examples of successful analysis requiring longer focal length, mirror-based spectrographs are shown; these include stress in silicon-based devices, Raman and PL of InGaN (which provides information on composition) and carbon nanotube studies.