Branched High Aspect Ratio Nanostructures Fabricated by Focused Helium Ion Beam Induced Deposition of an Insulator

Abstract

Helium ion beam induced deposition using the gaseous precursor pentamethylcyclopentasiloxane is employed to fabricate high aspect ratio insulator nanostructures (nanopillars and nanocylinders) that exhibit charge induced branching. The branched nanostructures are analyzed by transmission electron microscopy. It is found that the side branches form above a certain threshold height and that by increasing the flow rate of the precursor, the vertical growth rate and branching phenomenon can be significantly enhanced, with fractalesque branching patterns observed. The direct-write ion beam nanofabrication technique described herein offers a fast single-step method for the growth of high aspect ratio branched nanostructures with site-selective placement on the nanometer scale.

Use of PtC Nanotips for Low-Voltage Quantum Tunneling Applications

“…As shown in Figure 2a, an Omniprobe lift-out Cu (copper) grid is used to deposit several tips based on FIBID and FEBID. Unlike FEBID or helium-FIBID [43][44][45][46][47], Ga-FIB deposition cannot directly fabricate sharp tips with a thickness of a few tens of nanometers. For the EDX analysis, this is basically not of importance; however, for the later investigation by means of STM analysis, comparable geometries should be produced in order to compare the results.…”

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

“…Adapted with permission of Royal Society of Chemistry, from [ 240 ], Building with ions: towards direct write of platinum nanostructures using in situ liquid cell helium ion microscopy, Ievlev et al, 9(35), Copyright 2017; permission conveyed through Copyright Clearance Center, Inc. (h) Branched nanopillars obtained by helium FIBID of an insulator precursor, imaged by (S)TEM. Adapted from [ 241 ]. Copyright 2021 Allen, licensed under a Creative Commons Attribution 4.0 International License, https://creativecommons.org/licenses/by/4.0/.…”

“…Indeed, helium and neon FIBID of pad structures using the precursor pentamethylcyclopentasiloxane has been shown to yield resistivities two to three orders of magnitude higher than those achieved by gallium FIBID [ 199 ]. Helium FIBID of nanopillars using an insulator precursor has also been shown to result in the formation of side branches on the main body of the pillar, attributed to a charging effect [ 192 , 241 ] ( Figure 7h ).…”

Editorial for the Special Issue on Nanofabrication with Focused Electron/Ion Beam Induced Processing

“…Accordingly, this Special Issue showcases seven research articles and one review article that focus on the current status of nanofabrication using focused electron/ion beam induced processing. These articles particularly explore the following aspects of these technologies: (1) purification of FEBID nanostructures [ 1 ], (2) high-resolution nanostructures using FEBID [ 2 ], (3) a new approach for the nanofabrication of metallic nanostructures based on FEB [ 3 ], (4) tuning of diameters in 3D FEBID nanostructures [ 4 ], (5) evolution of the microstructure and resistivity in Pt Ga + FIBID deposits with in situ heating [ 5 ], (6) nanofabrication using Ga + FIB-induced processing for photonic applications [ 6 ], and (7) fabrication of 3D FIBID nanostructures using He + FIB [ 7 , 8 ].…”

“…Authors have found heating effects that impact the segment angle and the feature size of complex 3D structures. On the other hand, Frances Allen et al [ 8 ] have reported the fabrication and characterization of 3D insulator nanostructures with a high aspect ratio. Particularly, she has grown nanopillars and nanocylinders that exhibit charge induced branching, and moreover, she has analyzed their microstructure by transmission electron microscopy.…”