Molecular precursors for nanostructure synthesis by direct-write approaches (FEBID/FIBID)

• Applicant: Privatdozent Dr. Sven Barth
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413942347

This project is based on focused electron beam deposition (FEBID) as well as complementary focused electron beam deposition (FEBID for the direct-writing of nanoscale deposits. The technique is based on a precisely controllable electron/ion beam of a scanning electron/ion microscope that induces a rapid decomposition of surface adsorbed precursor molecules. Therefore, the FEBID and FIBID processes could be described as a 3D printer for nanoscale objects. Under FEBID conditions, the electron induced cleavage of ligands is often incomplete but the generally targeted physical properties can be observed for metals. Binary deposits and single-source precursors for theses targeted materials are not often described. In FEBID the electron-stimulated fragmentation is supported by thermal effects at room temperature or slightly above, these conditions can produce incomplete ligand cleavage depending on intermediates formed on the substrate surface. Thus, FIBID is a complementary method that can also provide additional information since the ions, which have much higher mass and size than electrons, can additionally provide a momentum transfer and thus completing a fragmentation of the precursor and cleaner deposits. This project targets the synthesis of precursors with high vapor pressure tailored for the FEBID/FIBID methods. Mechanistic investigations will provide further insight in the processes involved in electron and ion induced precursor decomposition. The results will provide more guidelines for a specific precursor design strategy. The targeted materials are metal silicides and metal sulphides to provide insight in the single-source precursor approach for these direct-write approaches. Moreover, temperature variations and post-growth strategies for further processing will be investigated. The successful growth of nanostructures via FEBID/FIBID will allow the investigation of fundamental physical properties and relate these properties to the deposits morphological and microstructural features.

• DFG Programme: Research Grants