Berlin 2012 – scientific programme
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MI: Fachverband Mikrosonden
MI 8: Poster – Microanalysis and microscopy
MI 8.13: Poster
Wednesday, March 28, 2012, 15:00–17:30, Poster E
Test-objects for emission electron microscopy — •Sergej A. Nepijko and Gerd Schönhense — Institute of Physics, University of Mainz, 55099 Mainz, Germany
The resolution of emission electron microscopes approaches some nanometers which rises the need for new test-objects. Microfields due to a work function difference Δφ deform the trajectories of electrons forming the image which leads to a distortion of the emission electron microscopy image and a decrease of lateral resolution. We discuss three possibilities to fabricate test-objects, avoiding microfields: (i) Application of bias voltage Vb= Δφ between substrate and film. (ii) Δφ can be compensated by a relief h being equivalent to a smooth surface with distribution of potential V(x,y)=-Eext·h(x,y), here Eext is extractor voltage. The maximal lateral resolution is realized close to the centre of such a test-object. (iii) The third possibility is that the work function of a semiconducting substrate is adjusted by ion-implantation to the work function of a structured metal film.