Expanding Capabilities of Focused Electron Beam Based 3D Nano-Printing: From Meshes Towards Closed 3D Nano-Architectures

Focused electron beam induced deposition (FEBID) is an aspiring technology for next-generation direct-write fabrication on the nano-scale. While FEBID-based fabrication of freestanding, 3D mesh-like nano-architectures has already reached a high level of precision, predictability and reliability[1,2], we now expand those single wire designs towards closed and semi-closed 3D nano-architectures. This opens up numerous possibilities as well as new challenges that will need further research in the future. Although 3D growth of meshed objects is meanwhile well understood, the expansion to closed basic building blocks namely vertical walls, rises new challenges. In particular, beam induced heating was found to entail partly unexpected effects at exposed regions such as edges or corners. Hence, we currently focus on the fundamental understanding of the growth behaviour for vertical walls, which will form the basis for any further expansion concerning their shape (e.g. circles or triangles) and / or their inclination angles to enable highly precise fabrication of closed and semi-closed 3D nano-architectures. In a combined approach between experiments and simulations, we develop a growth model, which in turn can compensate for such drawbacks to approach the intrinsic precision limits during 3D-FEBID. This will lead to predictable and reproducible fabrication of even complex 3D nano-architectures as essential element on the route towards a generic 3D nano-printing technology for future applications in various fields of research and development.