Berlin 2012 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 1: Interfaces and Thin Films I

CPP 1.3: Talk

Monday, March 26, 2012, 10:15–10:30, C 130

Imaging of carbon nanomembranes with helium-ion microscopy — •Andre Beyer, Andrey Turchanin, and Armin Gölzhäuser — Physics of Supramolecular Systems, University of Bielefeld, 33615 Bielefeld, Germany

Helium-ion microscopy (HIM) is similar to scanning electron microscopy but it employs helium ions for scanning a sample instead of electrons. The resulting images are more surface sensitive with a higher resolution as compared to scanning electron microscopy. Here we present a study about imaging extremely thin nano-scale objects: carbon nanomembranes which consist exclusively of atoms near the surface. Such freestanding nanomembranes with a thickness of 1 nm are made from self-assembled monolayers (SAMs) by cross-linking and subsequent transfer to transmission electron microscopy (TEM) grids or other suitable substrates. We show that these nanomembranes exhibit a substantially higher contrast in helium-ion microscopes as compared to electron microscopes. Cross-linking of SAMs is performed by large area exposures with electrons or photons which yield extended nanomembranes. On the other hand, patterned exposures allow the fabrication of nanosieves, i.e. perforated nanomembranes. Advantages in imaging such patterned cross-linked SAMs as well as freestanding nanosieves with the helium-ion microscope will be discussed.