Controlled additive fabrication of metallic nanostructures with focused soft X-rays

• Applicant: Dr. Andreas Späth
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400181425

Focused X-ray beam induced deposition (FXBID) is a novel approach for the controlled fabrication of metallic nanostructures. It combines the concepts of X-ray lithography and focused electron beam induced deposition from metal organic precursor molecules. Since FXBID is based on X-ray absorption, deposition rates are influenced by incident photon energy. This enables energy-selective nanofabrication. Preliminary studies of the proposer and his collaborators resulted in a successful proof of concept. Within the next step a deeper understanding of the precursor fragmentation processes is required. This issue will be addressed by gas-phase studies on the energy-dependent decay channels of photo-excited precursor molecules and on the resulting fragmentation rates upon interaction with secondary electrons. These studies will link incident photon energy with resulting deposition rate aiming on improved energy-selective FXBID. Further investigations on precursor-substrate interactions and in-situ purification techniques (e.g, co-dosing of reactive gases, annealing, hot substrate etc.), will define optimum experimental conditions for fabrication of pure metallic deposits with interesting electronic and/or magnetic properties. High-resolution Fresnel zone plates will be used to evaluate the resolution limit of FXBID. Finally, the properties of FXBID nanostructures and their overall limits will be investigated in detail.The proposed project addresses several open issues on the scientific basics of FXBID and will demonstrate its potential as an alternative to established nanofabrication techniques.

• DFG Programme: Research Grants
• International Connection: Italy, Switzerland
• Cooperation Partners: Dr. Kevin Prince; Dr. Jörg Raabe
• Co-Investigator: Benedikt Rösner