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

聚焦X射线束诱导沉积（FXBID）是一种新型的可控制备金属纳米结构的方法。它结合了X射线光刻和聚焦电子束诱导金属有机前体分子沉积的概念。由于FXBID基于X射线吸收，因此沉积速率受入射光子能量的影响。这实现了能量选择性纳米纤维。对提议者及其合作者的初步研究导致了概念的成功证明。在下一步中，需要对前体碎裂过程有更深入的了解。这个问题将通过气相研究光激发前体分子的能量依赖性衰变通道和与二次电子相互作用后产生的碎片率来解决。这些研究将入射光子能量与所得沉积速率联系起来，旨在改进能量选择性FXBID。进一步研究吸附剂-衬底相互作用和原位纯化技术（例如，反应气体的共计量、退火、热衬底等），将定义制造具有感兴趣的电子和/或磁性的纯金属沉积物的最佳实验条件。高分辨率菲涅耳波带片将用于评估FXBID的分辨率极限。最后，FXBID纳米结构的特性及其总体限制将被详细研究。拟议的项目解决了FXBID科学基础上的几个开放问题，并将展示其作为现有纳米纤维技术替代品的潜力。

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.