Expanding FEBID-Based 3D-Nanoprinting toward Closed High-Fidelity Nanoarchitectures

Abstract

3D-nanoprinting via focused electron beam induced deposition (FEBID) is a highly flexible additive-fabrication technique that has gained importance in the past few years for its variable design possibilities on the micro and nanoscale. In this work, we show the transition from mesh-like toward closed (sheetlike) structures and the development of necessary compensations (height correction, temperature compensation, and proximity correction) to minimize deviations between the target structure and the actual deposit. To accomplish this, we investigate the growth behavior, the influence of beam heating, and the electron trajectories in extensive experimental series as well as finite-difference simulations. Out of this, we derive a modular Python tool taking all compensations into account, enabling the controlled and accurate deposition of 3D-nanostructures in an individually adjusted layer-by-layer approach. This approach forms the basis for accurately fabricating closed, sheet-like objects on the nanoscale and lays the foundation for depositing complex nanoarchitectures for various applications in research and development.

3‐D‐Druck: Nanodruck mit Elektronenstrahlen

“…Oben: 3-D-Deponate von Nanowänden unterschiedlicher Breite (W) hin zum vertikalen Nanodraht. 2) Unten: Ein Modell zum Schreibprozess und das daraus resultierende FEBID-Mikro-Deponat einer Amphore.…”

“…So lassen sich Punkte, Säulen und Wände bis hin zu komplexen dreidimensionalen Objekten schreiben (Abbildung rechts). 2,3) Der FEBID-Prozess Jeder, der REM-Bilder aufnimmt, kennt die ungewollte FEBID-Abscheidung durch Kohlenwasserstoffrestgase in der REM-Kammer. Diese Effekte werden in der Regel vernachlässigt, da die flächigen Abscheidungen oberflächenkonform und sehr dünn sind und so die Bildinformation nicht beeinflussen.…”

Controlled Morphological Bending of 3D-FEBID Structures via Electron Beam Curing

“…Especially 3D-FEBID, where true three-dimensional architectures are built via slow lateral movements, is a very powerful tool that enables novel application concepts for plasmonics [ 12 ], nanomagnetics [ 18 , 19 , 20 ] and 3D-nanoprobe fabrication for scanning probe microscopy [ 21 , 22 ], among others. The technique that was mainly used to build mesh-like structures in the past [ 23 , 24 ], was recently expanded to closed or sheet-like objects, which strongly improved its options in terms of design flexibility [ 25 , 26 , 27 , 28 ]. This transition, however, entailed new challenges in terms of growth stability and spatially varying growth rates depending on the object dimensions as well as the position of the deposition point within said structure.…”

“…Since the most commonly used precursor (MeCpPt (IV) Me 3 ) notoriously exhibits rather high carbon contents, due to incomplete dissociation processes, the deposited structures hold low metal contents around [ 29 , 30 ]. This has a tremendous impact on the temperature conditions during the growth process, as the energy brought into the system by the electron beam can only be dissipated towards the substrate through the carbon-dominated material, which is a poor thermal conductor [ 28 , 31 ]. This geometry-dependent electron beam heating [ 32 , 33 ] leads in turn to an increased desorption of precursor molecules, which slows down the growth rate [ 34 ], leading to non-uniform conditions for deposition, especially for narrow but tall 3D nanostructures.…”

“…This geometry-dependent electron beam heating [ 32 , 33 ] leads in turn to an increased desorption of precursor molecules, which slows down the growth rate [ 34 ], leading to non-uniform conditions for deposition, especially for narrow but tall 3D nanostructures. The deviations of the deposited object shapes from originally intended geometries can be compensated to some extent by adjusting the individual dwell times accordingly [ 27 , 28 ]. For receiving higher electrical and thermal conductivities [ 35 ] and/or changing the mechanical properties of the material [ 36 ], different post-growth approaches have been introduced, that enable precise modification of the nano-granularity [ 37 , 38 ] or even the entire removal of carbon [ 29 , 30 , 39 ].…”