scholarly journals Electron-driven and thermal chemistry during water-assisted purification of platinum nanomaterials generated by electron beam induced deposition

2018 ◽  
Vol 9 ◽  
pp. 77-90 ◽  
Author(s):  
Ziyan Warneke ◽  
Markus Rohdenburg ◽  
Jonas Warneke ◽  
Janina Kopyra ◽  
Petra Swiderek
Keyword(s):  
Electron Beam ◽  
Direct Write ◽  
Reaction Products ◽  
Thermal Desorption Spectrometry ◽  
Thermal Chemistry ◽  
Volatile Products ◽  
Versatile Tool ◽  
Electron Beam Induced Deposition ◽  
Electron Stimulated Desorption ◽  
The Stability

Focused electron beam induced deposition (FEBID) is a versatile tool for the direct-write fabrication of nanostructures on surfaces. However, FEBID nanostructures are usually highly contaminated by carbon originating from the precursor used in the process. Recently, it was shown that platinum nanostructures produced by FEBID can be efficiently purified by electron irradiation in the presence of water. If such processes can be transferred to FEBID deposits produced from other carbon-containing precursors, a new general approach to the generation of pure metallic nanostructures could be implemented. Therefore this study aims to understand the chemical reactions that are fundamental to the water-assisted purification of platinum FEBID deposits generated from trimethyl(methylcyclopentadienyl)platinum(IV) (MeCpPtMe3). The experiments performed under ultrahigh vacuum conditions apply a combination of different desorption experiments coupled with mass spectrometry to analyse reaction products. Electron-stimulated desorption monitors species that leave the surface during electron exposure while post-irradiation thermal desorption spectrometry reveals products that evolve during subsequent thermal treatment. In addition, desorption of volatile products was also observed when a deposit produced by electron exposure was subsequently brought into contact with water. The results distinguish between contributions of thermal chemistry, direct chemistry between water and the deposit, and electron-induced reactions that all contribute to the purification process. We discuss reaction kinetics for the main volatile products CO and CH4 to obtain mechanistic information. The results provide novel insights into the chemistry that occurs during purification of FEBID nanostructures with implications also for the stability of the carbonaceous matrix of nanogranular FEBID materials under humid conditions.

scholarly journals Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

2017 ◽  
Vol 8 ◽  
pp. 2410-2424 ◽  
Author(s):  
Julie A Spencer ◽  
Michael Barclay ◽  
Miranda J Gallagher ◽  
Robert Winkler ◽  
Ilyas Unlu ◽  
...  
Keyword(s):  
Electron Beam ◽  
Structural Integrity ◽  
High Surface ◽  
High Surface Area ◽  
Chloride Ions ◽  
Residual Chlorine ◽  
Scanning Electron Microscopy Data ◽  
Electron Beam Induced Deposition ◽  
Electron Stimulated Desorption ◽  
Microscopy Data

The ability of electrons and atomic hydrogen (AH) to remove residual chlorine from PtCl2 deposits created from cis-Pt(CO)2Cl2 by focused electron beam induced deposition (FEBID) is evaluated. Auger electron spectroscopy (AES) and energy-dispersive X-ray spectroscopy (EDS) measurements as well as thermodynamics calculations support the idea that electrons can remove chlorine from PtCl2 structures via an electron-stimulated desorption (ESD) process. It was found that the effectiveness of electrons to purify deposits greater than a few nanometers in height is compromised by the limited escape depth of the chloride ions generated in the purification step. In contrast, chlorine atoms can be efficiently and completely removed from PtCl2 deposits using AH, regardless of the thickness of the deposit. Although AH was found to be extremely effective at chemically purifying PtCl2 deposits, its viability as a FEBID purification strategy is compromised by the mobility of transient Pt–H species formed during the purification process. Scanning electron microscopy data show that this results in the formation of porous structures and can even cause the deposit to lose structural integrity. However, this phenomenon suggests that the use of AH may be a useful strategy to create high surface area Pt catalysts and may reverse the effects of sintering. In marked contrast to the effect observed with AH, densification of the structure was observed during the postdeposition purification of PtC x deposits created from MeCpPtMe3 using atomic oxygen (AO), although the limited penetration depth of AO restricts its effectiveness as a purification strategy to relatively small nanostructures.

scholarly journals Continuum models of focused electron beam induced processing

2015 ◽  
Vol 6 ◽  
pp. 1518-1540 ◽  
Author(s):  
Milos Toth ◽  
Charlene Lobo ◽  
Vinzenz Friedli ◽  
Aleksandra Szkudlarek ◽  
Ivo Utke
Keyword(s):  
Electron Beam ◽  
Substrate Surface ◽  
Input Parameter ◽  
Reaction Pathways ◽  
Continuum Models ◽  
Direct Write ◽  
Reaction Products ◽  
Wide Range ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Focused electron beam induced processing (FEBIP) is a suite of direct-write, high resolution techniques that enable fabrication and editing of nanostructured materials inside scanning electron microscopes and other focused electron beam (FEB) systems. Here we detail continuum techniques that are used to model FEBIP, and release software that can be used to simulate a wide range of processes reported in the FEBIP literature. These include: (i) etching and deposition performed using precursors that interact with a surface through physisorption and activated chemisorption, (ii) gas mixtures used to perform simultaneous focused electron beam induced etching and deposition (FEBIE and FEBID), and (iii) etch processes that proceed through multiple reaction pathways and generate a number of reaction products at the substrate surface. We also review and release software for Monte Carlo modeling of the precursor gas flux which is needed as an input parameter for continuum FEBIP models.

scholarly journals Pattern generation for direct-write three-dimensional nanoscale structures via focused electron beam induced deposition

2018 ◽  
Vol 9 ◽  
pp. 2581-2598 ◽  
Author(s):  
Lukas Keller ◽  
Michael Huth
Keyword(s):  
Electron Beam ◽  
3D Structure ◽  
Three Dimensional ◽  
Pattern Generation ◽  
Proximity Effects ◽  
Writing Strategies ◽  
Direct Write ◽  
Nanoscale Structures ◽  
Geometrical Description ◽  
Electron Beam Induced Deposition

Fabrication of three-dimensional (3D) nanoarchitectures by focused electron beam induced deposition (FEBID) has matured to a level that highly complex and functional deposits are becoming available for nanomagnetics and plasmonics. However, the generation of suitable pattern files that control the electron beam’s movement, and thereby reliably map the desired target 3D structure from a purely geometrical description to a shape-conforming 3D deposit, is nontrivial. To address this issue we developed several writing strategies and associated algorithms implemented in C++. Our pattern file generator handles different proximity effects and corrects for height-dependent precursor coverage. Several examples of successful 3D nanoarchitectures using different precursors are presented that validate the effectiveness of the implementation.

scholarly journals Ligand Size and Chain Length Study of Silver Carboxylates in Focused Electron Beam Induced Deposition

2021 ◽  
Author(s):  
Jakub Jurczyk ◽  
Katarzyna Madajska ◽  
Luisa Berger ◽  
Leo Brockhuis ◽  
Thomas Edward James Edwards ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Flux ◽  
Silver Content ◽  
High Sensitivity ◽  
Crystal Formation ◽  
Direct Fabrication ◽  
Versatile Tool ◽  
Electron Beam Induced Deposition ◽  
Nano Crystal ◽  
High Silver

Focused electron beam induced deposition is a versatile tool for the direct fabrication of complex-shaped nanostructures with unprecedented shape fidelity and resolution. While the technique is well-established for various materials, the direct electron beam writing of silver is still in its infancy. Here, five different silver carboxylates, three fluorinated: [Ag2(µ-O2CCF3)2], [Ag2(µ-O2CC2F5)2], [Ag2(µ-O2CC3F7)2] and two containing hydrogen: [Ag2(µ-O2CCMe2Et)2] and [Ag2(µ-O2CtBu)2] were examined and compared as potential precursors for focused electron beam induced deposition. All of the compounds show high sensitivity to electron dissociation and efficient dissociation of Ag-O bonds. The as-deposited materials showed high silver content from 42 at.% to above 70at.% and silver nano-crystal formation with impurities of carbon and fluorine incorporated between metal grains. A correlation of the number of carbon atoms in the precursor ligands and silver content of the deposited structures was found. The highest silver contents were achieved for compounds with the shortest CF chains. The deposited silver content depends on the balance of electron induced ligand co-deposition and thermal ligand desorption. Low electron flux is advantageous for high silver content. Our findings demonstrate that silver carboxylates constitute a promising group of precursors for focused electron beam nanoprinting of high silver content materials.

scholarly journals The rational design of a Au(I) precursor for focused electron beam induced deposition

2017 ◽  
Vol 8 ◽  
pp. 2753-2765 ◽  
Author(s):  
Ali Marashdeh ◽  
Thiadrik Tiesma ◽  
Niels J C van Velzen ◽  
Sjoerd Harder ◽  
Remco W A Havenith ◽  
...  
Keyword(s):  
Electron Beam ◽  
Rational Design ◽  
Solid Phase ◽  
Single Step ◽  
Steric Effects ◽  
Nanometer Scale ◽  
Direct Write ◽  
High Volatility ◽  
The Stability ◽  
Aurophilic Interactions

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au–Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe3, they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe3 and MeAuPMe3 shows that Au–Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au–Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au.

scholarly journals Low-dose patterning of platinum nanoclusters on carbon nanotubes by focused-electron-beam-induced deposition as studied by TEM

2013 ◽  
Vol 4 ◽  
pp. 77-86 ◽  
Author(s):  
Xiaoxing Ke ◽  
Carla Bittencourt ◽  
Sara Bals ◽  
Gustaaf Van Tendeloo
Keyword(s):  
Carbon Nanotubes ◽  
Electron Beam ◽  
Low Dose ◽  
Direct Write ◽  
Pt Nanoclusters ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Physical Deposition ◽  
Electron Beam Induced Deposition ◽  
Beam Parameters

Focused-electron-beam-induced deposition (FEBID) is used as a direct-write approach to decorate ultrasmall Pt nanoclusters on carbon nanotubes at selected sites in a straightforward maskless manner. The as-deposited nanostructures are studied by transmission electron microscopy (TEM) in 2D and 3D, demonstrating that the Pt nanoclusters are well-dispersed, covering the selected areas of the CNT surface completely. The ability of FEBID to graft nanoclusters on multiple sides, through an electron-transparent target within one step, is unique as a physical deposition method. Using high-resolution TEM we have shown that the CNT structure can be well preserved thanks to the low dose used in FEBID. By tuning the electron-beam parameters, the density and distribution of the nanoclusters can be controlled. The purity of as-deposited nanoclusters can be improved by low-energy electron irradiation at room temperature.

scholarly journals Combined Focused Electron Beam-Induced Deposition and Etching for the Patterning of Dense Lines without Interconnecting Material

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Sangeetha Hari ◽  
P. H. F. Trompenaars ◽  
J. J. L. Mulders ◽  
Pieter Kruit ◽  
C. W. Hagen
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Secondary Electron ◽  
Direct Write ◽  
Post Processing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Backscattered Electron ◽  
Electron Beam Induced Deposition ◽  
Gaussian Line

High resolution dense lines patterned by focused electron beam-induced deposition (FEBID) have been demonstrated to be promising for lithography. One of the challenges is the presence of interconnecting material, which is often carbonaceous, between the lines as a result of the Gaussian line profile. We demonstrate the use of focused electron beam-induced etching (FEBIE) as a scanning electron microscope (SEM)-based direct-write technique for the removal of this interconnecting material, which can be implemented without removing the sample from the SEM for post processing. Secondary electron (SE) imaging has been used to monitor the FEBIE process, and atomic force microscopy (AFM) measurements confirm the fabrication of well separated FEBID lines. We further demonstrate the application of this technique for removing interconnecting material in high resolution dense lines using backscattered electron (BSE) imaging to monitor the process.

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