Scanning Electron Microscopes with Integrated Raman Spectrometer Revealing New Complementary Information

Scanning electron microscopes (SEM) delivers a magnified view of tiny structures in materials. The resolution goes down to a few nanometer. Different detectors like secondary electron detectors and back scattered detectors enable the investigation of samples in surface sensitive or contrast enhanced modes. In addition energy dispersive x-ray detectors (EDX) reveal information about the existing elements and metals in the specimen. This chemical analysis is limited to a certain atomic number (atomic number Z = 4, Beryllium). To overcome this limitation Raman spectroscopy was integrated into the scanning electron microscope. Raman spectroscopy is not able to detect metals but adds information about elements below Beryllium, thus enables the differentiation between oxides and organic as well as inorganic material. It also provides an interpretation of the actual stoichiometry, the strain and stress, crystal symmetry, orientation, doping and crystallinity [1].