Advancing Design Possibilities during 3D Nanoprinting

The ongoing trend of miniaturization in science and technology is raising an increasing demand on reliable fabricationtechniques able to build structures at the nanoscale. In contrast to highly developed and powerful lithography processroutes particle beam induced deposition processes recently have entered the realms of true 3-dimensional printingat the nanoscale [1]. Highly localized deposition is achieved by accurately controlling the movement of the e-beamenabling the fabrication of even complex 3D structures with nanoscale features in the sub-20 nm region [2]. Thoughessential for particular applications (e.g. nano-plasmonics [3] and 3D-magnetic lattices [4]), such delicate structuresshow low mechanical rigidity and limited thermal and electrical conductivities which confines possible applications.Additionally, branch dimensions are determined for a given beam parameter setting and closely related to the desiredstructure’s geometry, which in turn means that they cannot be chosen freely [5]. Consequently, it is highly desirableto establish a fabrication procedure which allows deliberate control over branch dimensions to remedy the formermentioned challenges. With this motivation in mind, we introduce beam blurring as an additional depositionparameter and explore its effects on fabrication of 3D structures (Fig 1a). Besides the intended diameter tunabilitythe growth efficiency increases, caused by a shift in the working regime due to reduced current densities in beamimpact regions and thus reduced precursor consumption per unit area (Fig 1b). In addition, unwanted proximalgrowth beneath 3D branches was strongly delayed, further increasing 3D-FEBID´s reliability. On-purpose beamblurring therefore poses a viable route of crucially expanding the flexibility of this technique, enabling controlled andtunable branch dimensions for meshed objects while improving growth rates and reducing parasitic growth.