Highly conductive and pure gold nanostructures grown by electron beam induced deposition

Abstract

This work introduces an additive direct-write nanofabrication technique for producing extremely conductive gold nanostructures from a commercial metalorganic precursor. Gold content of 91 atomic % (at. %) was achieved by using water as an oxidative enhancer during direct-write deposition. A model was developed based on the deposition rate and the chemical composition, and it explains the surface processes that lead to the increases in gold purity and deposition yield. Co-injection of an oxidative enhancer enabled Focused Electron Beam Induced Deposition (FEBID)—a maskless, resistless deposition method for three dimensional (3D) nanostructures—to directly yield pure gold in a single process step, without post-deposition purification. Gold nanowires displayed resistivity down to 8.8 μΩ cm. This is the highest conductivity achieved so far from FEBID and it opens the possibility of applications in nanoelectronics, such as direct-write contacts to nanomaterials. The increased gold deposition yield and the ultralow carbon level will facilitate future applications such as the fabrication of 3D nanostructures in nanoplasmonics and biomolecule immobilization.

Mechanical Properties of 3D Nanostructures Obtained by Focused Electron/Ion Beam-Induced Deposition: A Review

“…However, there are exceptions, and high purity material of cobalt, iron, gold, and silver can be deposited directly [20][21][22][23][24][25]. Furthermore, for these and other metals, current research activities successfully concentrate on novel precursor design and in situ or post-growth purification techniques [26][27][28][29][30][31][32][33][34] and their simulation [35].…”

Focused Electron Beam-Based 3D Nanoprinting for Scanning Probe Microscopy: A Review

“…In other cases, material purity is of highest importance. In recent years, different approaches have been demonstrated, including gas-/laser-/temperature-assisted approaches during [72,[83][84][85][86][87][88] or after deposition [44,[89][90][91]. Although different in execution, the common element for most of these approaches is the tendency for morphological disruption during carbon removal, which becomes even more challenging for freestanding 3D nano-architectures [44,84].…”

Ice lithography for 3D nanofabrication

“…Apart from carbon and oxygen containing organic chemicals, organometallic compound that contains most elements of the periodic table is a very interesting class of organic chemicals. FEBID using organometallic precursors showed that pure gold (Au) [32] and superconducting tungsten (W) nanowires [33] can be formed. Using liquid phase precursors, FEBID can also deposit silver (Ag) and copper (Cu) structures [34], respectively.…”