Ultrahigh lateral resolution spectromicroscopy beam line at ELETTRA (trieste)

• Published in: Surface and interface analysis 1992-09, Vol.18 (9), p.655-660
• Main Authors: Nataletti, P., Contarini, S., Gariazzo, C., Minnaja, N., Musicanti, M., Jark, W., Kiskinova, M., Melpignano, P., Morris, D., Rosei, R.
• Format: Article
• Language: English
• Subjects: Electron, positron and ion microscopes, electron diffractometers and related techniques; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics
• ISSN: 0142-2421; 1096-9918
• DOI: 10.1002/sia.740180904

This report presents the project for the development of a combined facility consisting of a high spatial resolution soft x‐ray scanning photoelectron microscope (SPEM) and a scanning tunnelling microscope (STM) that is going to be built in an ultrahigh vacuum (UHV) station on one of the undulator beam lines at ELETTRA, Trieste. The photon microprobe for SPEM will be generated using a zone plate diffraction optic. A special design of a spherical grating monochromator will provide the source for illuminating the zone plate. The emitted photoelectrons will be detected and analysed using a high‐energy resolution hemispherical analyser with a large acceptance angle. The performance of the SPEM is projected to be as follows: (1) a photon spot size on the sample of ∼50 × 50 nm2; (2) a tunable photon energy range of 200–800 eV, with an energy resolving power of 3000 at the carbon K‐edge; (3) a photon flux in the spot that is > 109 photons s−1 (0.1% body wt.)−1. The projected performance of the STM instrument ensures a lateral resolution better than 2 Å. The combination of SPEM and STM techniques will enable chemical and structural mapping within the same microscopic areas of the sample surface. Descriptions of the main beam line components together with some examples of possible applications of this unique tool are included in the paper.