Micro-Raman & Micro-PL Spectrometer

The increasing densification and miniaturisation of devices in microelectronics components demands analytical techniques with a very high spatial resolution, in general higher than the limit set by far field diffraction of visible light. This offers a problem for optical techniques, such as micro-Raman spectroscopy (µRS). µRS takes an important place for the measurement of local mechanical stress. In this technique, the light beam of a laser is focused through an optical microscope on the sample. The scattered light is collected through the same microscope and directed into a spectrometer, and send to a CCD detector, to analyse the spectrum. A typical Raman instrument is shown in Fig. 1. It is clear that this is a rather complex optical instrument.