AVS 50th International Symposium
    Nanometer Structures Tuesday Sessions
       Session NS-TuP

Paper NS-TuP16
Imaging of DNA Strands with the Low Energy Electron Point Source (LEEPS) Microscope

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: A. Eisele, Universität Marburg, Germany
Authors: A. Eisele, Universität Marburg, Germany
B. Völkel, Universität Heidelberg, Germany
M. Grunze, Universität Heidelberg, Germany
A. Gölzhäuser, Universität Marburg, Germany
Correspondent: Click to Email
A low energy electron point source (LEEPS) microscope is used to image freestanding DNA multistrands. These span 100 nm wide openings in a thin silicon sample holder. The holographic images are analyzed by assuming a mask model and vacuum wave propagation. We extract the correct source-to-object distance by the analysis of cuts through numerical reconstructions in the object region with an accuracy of 40 nm. Upon variation of the lateral and axial source position, the reconstructions show reproducible object structures and focus behavior. The smallest reproducibly resolved features have dimensions of 1 nm. Due to the low energy (40 eV) of the field emitted electrons, LEEPS microscopes generate images with a much higher contrast than conventional electron microscopes.