Karl Franzens University Graz
Graz University of Technology
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Karl Franzens University Graz | Graz University of Technology | |
Focused electron beam nanoprinting: How to twist physics with chemistry for nanoscale metal additive manufacturing Amongst various 3D additive manufacturing methods reviewed for metals [1], nanoprinting with focused electron beams offers most shape flexibility together with smallest print size. Rooted in high-tech industry as powerful maskless, minimally invasive nanofabrication platform for mask repair and cantilever probe functionalization, it is maturing towards a versatile printing tool for 2D and 3D nano-architectured functional materials where material, shape and small-scale requirements can be met by its inherent lithographic capabilities. Demonstrators comprise sensors based on granular material (metal grains in carbon matrix), scanning probe tips, and applications in superconductivity, nanomagnetics, and photonics [2-4]. A persevering challenge for now is the limited number of pure materials that can be reproducibly e-beam nanoprinted. This is related to the volatile metalorganic molecules used as typical precursors to continuously supply the metal atoms for nanoprinting. The organic ligands bound to the metal atom centre atom render the metal volatile and reversibly adsorbable on the substrate to enable for spatially selective electron beam nanoprinting. The successful complete removal of these organic ligands from the metal atom and the substrate not alone depends on electron induced molecule fragmentation being the working principle of FEB nanoprinting. We will discuss several other factors including the type of molecule adsorption and nanoprinting process parameters, which can also fundamentally influence the metal content in the FEB nanoprinted material [5]. This talk also addresses the addition of etch gases, pulsed laser heating, and specific irradiation parameters to improve this situation [5-7] as well as the functionalization of small-scale e-beam nanoprinted architectures via atomic layer deposition (ALD) and physical vapour deposition (PVD). |