Chemical microimaging and microspectroscopy of surfaces with a photoemission microscope

Rie applied element sensitive photoemission electron microscopy (PEEM) to investigate surfaces of devices built from complex materials. Conventional PEEM suffers from lack of information about the chemical composition of the imaged surface, Such information can be obtained by PEEM via tuning the photon energy to X-ray absorption edges. To apply spectromicroscopy we acquired and subtracted microscopic images using photon energies just below and at the edges. The resulting difference gives a micro-image of the lateral distribution of a specific element. Microspectroscopy is performed by recording the intensity of secondary electrons in selected spots during a sweep of the photon energy. We applied both methods to microstructured devices using soft X-ray synchrotron radiation and found that small local defects and chemical differences can be easily detected.