Precursor sticking coefficient determination from indented deposits fabricated by electron beam induced deposition

• Alexander Kuprava and
• Michael Huth

Beilstein J. Nanotechnol. 2025, 16, 35–43, doi:10.3762/bjnano.16.4

• Alexander Kuprava Michael Huth Physics Institute, Goethe University Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany 10.3762/bjnano.16.4 Abstract A fast simulation approach for focused electron beam induced deposition (FEBID) numerically solves the diffusion–reaction equation

• precursor parameters needed for this model. In this work we introduce such a method to derive the precursor sticking coefficient as one member of the precursor parameter set. The method is based on the analysis of the different growth regimes in FEBID, in particular the diffusion-enhanced growth regime in

• substantially smaller than the sticking coefficients previously assumed for Me3CpPtMe (1.0). Furthermore, depositions performed at different substrate temperatures indicate a temperature dependence of the sticking coefficient. Keywords: adsorption; continuum model; FEBID; nanofabrication; sticking coefficient

Ion-induced surface reactions and deposition from Pt(CO)₂Cl₂ and Pt(CO)₂Br₂

• Mohammed K. Abdel-Rahman,
• Patrick M. Eckhert,
• Atul Chaudhary,
• Johnathon M. Johnson,
• Jo-Chi Yu,
• Lisa McElwee-White and
• D. Howard Fairbrother

Beilstein J. Nanotechnol. 2024, 15, 1427–1439, doi:10.3762/bjnano.15.115

• Focused ion beam-induced deposition (FIBID) and focused electron beam-induced deposition (FEBID) are vacuum-based, charged-particle bottom-up nanofabrication techniques that directly fabricate metal containing nanostructures as a consequence of the reactions between ions or electrons and organometallic

• techniques, they do not require the use of organic solvents present in traditional lithography. Indeed, FEBID/FIBID can be considered as alternatives to commonly used methods such as chemical vapor deposition (CVD) and atomic layer deposition (ALD), particularly for area-selective, as opposed to conformal

• , deposition strategies in various applications, such as circuit editing and lithographic mask repair in the semiconductor industry [7][8][9][10][11][12] as well as the growth of functional materials for magnetism [13][14][15][16], superconductivity [17], and sensing [18][19]. Compared to FEBID, FIBID operates

New design of operational MEMS bridges for measurements of properties of FEBID-based nanostructures

• Bartosz Pruchnik,
• Krzysztof Kwoka,
• Ewelina Gacka,
• Dominik Badura,
• Piotr Kunicki,
• Andrzej Sierakowski,
• Paweł Janus,
• Tomasz Piasecki and
• Teodor Gotszalk

Beilstein J. Nanotechnol. 2024, 15, 1273–1282, doi:10.3762/bjnano.15.103

• Photonics, Łukasiewicz Research Network, Lotników 32/46, 02-668, Warsaw, Poland 10.3762/bjnano.15.103 Abstract Focused electron beam-induced deposition (FEBID) is a novel technique for the development of multimaterial nanostructures. More importantly, it is applicable to the fabrication of free-standing

• contacts characterised by leakage resistances above 100 GΩ, which provide a platform for comprehensive measurements of properties (i.e., resistance) of free-standing FEBID structures. We also present a use case scenario in which an opMEMS bridge is used to measure the resistance of a free-standing FEBID

• nanostructure. Keywords: FEBID; MEMS; MEMS bridge; nanowires; opMEMS; Introduction Nanoelectronics is the fastest developing branch of modern electronic technology. Reduced dimensions allow for lower power consumption of the circuit and higher operating speeds [1][2]. Even more advantages (e.g., developed

A low-kiloelectronvolt focused ion beam strategy for processing low-thermal-conductance materials with nanoampere currents

• Annalena Wolff,
• Nico Klingner,
• William Thompson,
• Yinghong Zhou,
• Jinying Lin and
• Yin Xiao

Beilstein J. Nanotechnol. 2024, 15, 1197–1207, doi:10.3762/bjnano.15.97

• light interactions with biological tissue [18] as well as focused electron beam-induced deposition (FEBID) [19]. The general approach to assess the beam-induced heat damage and undesired artifacts, regardless if working with ions [17], photons [18], or electrons [19], compares experiments to models

• heating effects that lead to noticeable changes in nanostructure deposition geometry during FEBID processes have recently been published [19]. These approaches, a thorough understanding of the parameters that govern the beam-induced heat damage as well as open source software, would also be beneficial for

Direct electron beam writing of silver using a β-diketonate precursor: first insights

• Katja Höflich,
• Krzysztof Maćkosz,
• Chinmai S. Jureddy,
• Aleksei Tsarapkin and
• Ivo Utke

Beilstein J. Nanotechnol. 2024, 15, 1117–1124, doi:10.3762/bjnano.15.90

• without the need for a resist or development step. Here, we employ for the first time a silver β-diketonate precursor for focused electron beam-induced deposition (FEBID). The used compound (hfac)AgPMe3 operates at an evaporation temperature of 70–80 °C and is compatible with commercially available gas

• . “Experimental” section) for focused electron beam-induced deposition (FEBID). (hfac)AgPMe3 is a white to light yellow solid, which was used before for chemical vapor deposition [32] and for growing silver nanoparticles by atomic layer deposition [33]. Like for other silver precursors, a pronounced halo and a

• elemental silver at the bottom, the formation mechanism of which deserves further investigation. Experimental FEBID was carried out in a Hitachi S3600 tungsten filament scanning electron microscope (SEM). The precursor compound trimethylphosphine(hexafluoroacetylacetonato)silver(I), short (hfac)AgPMe3

Water-assisted purification during electron beam-induced deposition of platinum and gold

• Cristiano Glessi,
• Fabian A. Polman and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2024, 15, 884–896, doi:10.3762/bjnano.15.73

• beam-induced deposition (FEBID). It was recently achieved for gold deposits by the co-injection of a water precursor and the gold precursor Au(tfac)Me2. In this work results are reported, using the same approach, on a different gold precursor, Au(acac)Me2, as well as the frequently used platinum

• microscope using commercially available components and chemicals, which paves the way for a broader application of direct etching-assisted FEBID to obtain pure metallic structures. Keywords: FEBID; gold; nanofabrication; platinum; purification; Introduction Focused electron beam-induced deposition (FEBID

• ) is a nanofabrication technique that allows for the direct writing of three-dimensional nanostructures [1][2][3]. In FEBID, a gaseous precursor, often an organometallic compound, is injected in the vacuum chamber of a scanning electron microscope (SEM), adsorbed on a substrate, and dissociated by a

Electron-induced ligand loss from iron tetracarbonyl methyl acrylate

• Hlib Lyshchuk,
• Atul Chaudhary,
• Thomas F. M. Luxford,
• Miloš Ranković,
• Jaroslav Kočišek,
• Juraj Fedor,
• Lisa McElwee-White and
• Pamir Nag

Beilstein J. Nanotechnol. 2024, 15, 797–807, doi:10.3762/bjnano.15.66

• (FEBID); FEBID precursor; iron tetracarbonyl methyl acrylate; Introduction In recent years, a wave of interest in the electron-induced loss of ligands from organometallic and coordination compounds appeared, which has been motivated by the need to understand focused electron beam-induced deposition

• (FEBID). FEBID is an emerging method for the fabrication of 3D nanostructures. It relies on the local decomposition of precursors in the focal area of an electron beam [1][2][3][4]. In the case of deposition of metals, the interaction with the electrons should ideally lead to a cleavage of all metal

• properties, which could be used in nanosensing applications [9]. Common FEBID precursors for iron are Fe(CO)5, Fe2(CO)9, Fe3(CO)12, and Fe(C5H5)2. The first one, iron pentacarbonyl, has attracted perhaps the highest amount of attention from the point of view of the elementary reaction with electrons. The

Electron-induced deposition using Fe(CO)₄MA and Fe(CO)₅ – effect of MA ligand and process conditions

• Hannah Boeckers,
• Atul Chaudhary,
• Petra Martinović,
• Amy V. Walker,
• Lisa McElwee-White and
• Petra Swiderek

Beilstein J. Nanotechnol. 2024, 15, 500–516, doi:10.3762/bjnano.15.45

• new precursor for focused electron beam-induced deposition (FEBID), was investigated by surface science experiments under UHV conditions. Auger electron spectroscopy was used to monitor deposit formation. The comparison between Fe(CO)4MA and Fe(CO)5 revealed the effect of the modified ligand

• architecture on the deposit formation in electron irradiation experiments that mimic FEBID and cryo-FEBID processes. Electron-stimulated desorption and post-irradiation thermal desorption spectrometry were used to obtain insight into the fate of the ligands upon electron irradiation. As a key finding, the

• heteroleptic precursor Fe(CO)4MA, thus, offers the possibility to suppress contributions of thermal reactions, which can compromise control over the deposit shape and size in FEBID processes. Keywords: autocatalytic growth; cryo-EBID; electron beam-induced deposition; heteroleptic iron precursor; thermal

Sidewall angle tuning in focused electron beam-induced processing

• Sangeetha Hari,
• Willem F. van Dorp,
• Johannes J. L. Mulders,
• Piet H. F. Trompenaars,
• Pieter Kruit and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2024, 15, 447–456, doi:10.3762/bjnano.15.40

• ., Delftechpark 37j, 2628 XJ, Delft, Netherlands Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands 10.3762/bjnano.15.40 Abstract Structures fabricated using focused electron beam-induced deposition (FEBID) have sloped sidewalls because of the very nature of the deposition process. For

• applications this is highly undesirable, especially when neighboring structures are interconnected. A new technique combining FEBID and focused electron beam-induced etching (FEBIE) has been developed to fabricate structures with vertical sidewalls. The sidewalls of carbon FEBID structures have been modified

• etching the deposit from below, resulting in under-etched structures. The evolution of the sidewall angle during etching has also been experimentally observed in a scanning electron microscope by continuously monitoring the secondary electron detector signal. Keywords: electron lithography; FEBID; FEBIE

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• microscopy (SPM), the tip plays a fundamental role in the achievable lateral resolution of the image. The focused electron-beam induced deposition (FEBID) [34] technique has been adapted to fabricate tips for SPM, for example, to enhance commercial platinum–iridium alloy (Pt-Ir)-coated conductive tips [35

• ], or to realize laterally grown high-aspect ratio nanopillars [36]. We realize sharp, vertically grown conductive tips at the apex of the Si-N cantilever using FEBID with a Pt precursor gas. Figure 6 shows the resulting structure. We obtain the conical shape by stacking multiple depositions with

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• [17]. The central protrusion in the etch profiles is observed in ex situ AFM profiles at high doses in case of singular lines and large triangular patterns. Its origin is unlikely due to amorphous carbon co-deposition from the residual vapor impurities. Such transition from the deposition (FEBID) of

• FEBID materials were taken into account. The topographical changes in silica can be a consequence of removing Si and O atoms by OH− groups, which are the product of adsorbed water molecules upon electron beam exposure. The related process of silica removal by hot water molecules at a high pressure has

A combined gas-phase dissociative ionization, dissociative electron attachment and deposition study on the potential FEBID precursor [Au(CH₃)₂Cl]₂

• Elif Bilgilisoy,
• Ali Kamali,
• Thomas Xaver Gentner,
• Gerd Ballmann,
• Sjoerd Harder,
• Hans-Peter Steinrück,
• Hubertus Marbach and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2023, 14, 1178–1199, doi:10.3762/bjnano.14.98

• Iceland, Dunhagi 3, 107 Reykjavík, Iceland Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany Carl Zeiss SMT GmbH, 64380 Roßdorf, Germany 10.3762/bjnano.14.98 Abstract Motivated by the potential of focused-electron-beam-induced deposition (FEBID) in the

• composition and morphology of FEBID deposits fabricated in an ultrahigh-vacuum (UHV) chamber were explored on different surfaces and at varied beam currents. In the gas phase, dissociative ionization was found to lead to significant carbon loss from this precursor, and about 50% of the chlorine was on average

• removed per dissociative ionization incident. On the other hand, in dissociative electron attachment, no chlorine was removed from the parent molecule. Contrary to these observations, FEBID in the UHV setup was found to yield a quantitative loss and desorption of the chlorine from the deposits, an effect

Fragmentation of metal(II) bis(acetylacetonate) complexes induced by slow electrons

• Janina Kopyra and
• Hassan Abdoul-Carime

Beilstein J. Nanotechnol. 2023, 14, 980–987, doi:10.3762/bjnano.14.81

• electron beam with an organometallic target (e.g., focused electron beam-induced deposition, FEBID) is a promising technique for direct 3D deposition of high-purity materials with minimum residual carbon in the product on the surface [4][5]. The FEBID precursor molecules adsorb and diffuse on the surface

Low-energy electron interaction and focused electron beam-induced deposition of molybdenum hexacarbonyl (Mo(CO)₆)

• Po-Yuan Shih,
• Maicol Cipriani,
• Christian Felix Hermanns,
• Jens Oster,
• Klaus Edinger,
• Armin Gölzhäuser and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2022, 13, 182–191, doi:10.3762/bjnano.13.13

• (CO)6 in comparison to focused electron beam-induced deposition (FEBID) of this precursor. The DEA and DI experiments are compared to previous work, differences are addressed, and the nature of the underlying resonances leading to the observed DEA processes are discussed in relation to an earlier

• electron transmission study. Relative contributions of individual ionic species obtained through DEA and DI of Mo(CO)6 and the average CO loss per incident are calculated and compared to the composition of the FEBID deposits produced. These are also compared to gas phase, surface science and deposition

• studies on W(CO)6 and we hypothesize that reductive ligand loss through electron attachment may promote metal–metal bond formation in the deposition process, leading to further ligand loss and the high metal content observed in FEBID for both these compounds. Keywords: dissociative electron attachment

Chemical vapor deposition of germanium-rich CrGe_x nanowires

• Vladislav Dřínek,
• Stanislav Tiagulskyi,
• Roman Yatskiv,
• Jan Grym,
• Radek Fajgar,
• Věra Jandová,
• Martin Koštejn and
• Jaroslav Kupčík

Beilstein J. Nanotechnol. 2021, 12, 1365–1371, doi:10.3762/bjnano.12.100

• carbon–platinum composite using focused electron beam-induced deposition (FEBID) (Supporting Information File 1, Figure S10). The resistivity of the nanowire–deposit system was estimated to be 2.7 kΩ·cm (Figure 5). This value is significantly higher than the previously reported resistivity for nominally

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• presents a detailed computational protocol for the atomistic simulation of formation and growth of metal-containing nanostructures during focused electron beam-induced deposition (FEBID). The protocol is based upon irradiation-driven molecular dynamics (IDMD), a novel and general methodology for computer

• fragmentation and the related mechanism of nanostructure formation and growth using FEBID, which are essential for the further advancement of FEBID-based nanofabrication. The developed computational methodology is general and applicable to different precursor molecules, substrate types, and irradiation regimes

• . The methodology can also be adjusted to simulate the nanostructure formation by other nanofabrication techniques using electron beams, such as direct electron beam lithography. In the present study, the methodology is applied to the IDMD simulation of the FEBID of Pt(PF3)4, a widely studied precursor

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

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing

• Christian Preischl,
• Linh Hoang Le,
• Elif Bilgilisoy,
• Armin Gölzhäuser and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26

• h at 70 °C. Then, a repetition of rinsing in DMF and ethanol was applied to the samples in order to remove physically absorbed TPT molecules. The samples were consequently dried by a stream of nitrogen gas and preserved in argon environment until use in FEBID experiments. The FEBIP experiments were

Gold(I) N-heterocyclic carbene precursors for focused electron beam-induced deposition

• Cristiano Glessi,
• Aya Mahgoub,
• Cornelis W. Hagen and
• Mats Tilset

Beilstein J. Nanotechnol. 2021, 12, 257–269, doi:10.3762/bjnano.12.21

• Sciences, Dept. Imaging Physics, Lorentzweg 1, 2628CJ Delft, Netherlands 10.3762/bjnano.12.21 Abstract Seven gold(I) N-heterocyclic carbene (NHC) complexes were synthesized, characterized, and identified as suitable precursors for focused electron beam-induced deposition (FEBID). Several variations on the

• core Au(NHC)X moiety were introduced, that is, variations of the NHC ring (imidazole or triazole), of the alkyl N-substituents (Me, Et, or iPr), and of the ancillary ligand X (Cl, Br, I, or CF3). The seven complexes were tested as FEBID precursors in an on-substrate custom setup. The effect of the

• −. Keywords: Au(I) precursors; focused electron beam-induced deposition (FEBID); gold-NHC; gold precursors; nanofabrication; N-heterocyclic carbene; Introduction Focused electron beam-induced deposition (FEBID) is a nanofabrication technique that allows for the growth of three-dimensional free-standing

Electron beam-induced deposition of platinum from Pt(CO)₂Cl₂ and Pt(CO)₂Br₂

• Aya Mahgoub,
• Hang Lu,
• Rachel M. Thorman,
• Konstantin Preradovic,
• Titel Jurca,
• Lisa McElwee-White,
• Howard Fairbrother and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2020, 11, 1789–1800, doi:10.3762/bjnano.11.161

• platinum precursors, Pt(CO)2Cl2 and Pt(CO)2Br2, were designed for focused electron beam-induced deposition (FEBID) with the aim of producing platinum deposits of higher purity than those deposited from commercially available precursors. In this work, we present the first deposition experiments in a

• deposits contained halogen species and little or no carbon, while the SEM deposits contained only small amounts of halogen species but high carbon content. Results from this study highlight the effect that deposition conditions can have on the composition of deposits created by FEBID. Keywords: energy

• -dispersive X-ray spectroscopy (EDX); focused electron beam-induced deposition (FEBID); nanofabrication; platinum precursors; scanning electron microscopy (SEM); thermogravimetric analysis (TGA); Introduction Focused electron beam-induced deposition (FEBID) is a direct-write nanopatterning technique. FEBID

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

• Lukas Keller and
• Michael Huth

Beilstein J. Nanotechnol. 2018, 9, 2581–2598, doi:10.3762/bjnano.9.240

• Lukas Keller Michael Huth Institute of Physics, Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany 10.3762/bjnano.9.240 Abstract Fabrication of three-dimensional (3D) nanoarchitectures by focused electron beam induced deposition (FEBID) has matured to a level that highly

• plating [7], to name a few. In this work, focused electron beam induced deposition [8] (FEBID) is used as a mask-less direct-writing technique that allows for the deposition of structures with a resolution of less than 10 nm in 2D [9][10]. The working principle of FEBID is as follows: A substrate, or any

• FEBID process, a more detailed look reveals a rather high degree of complexity. During a deposition event at a predefined beam position, precursor molecules are consumed, so that the precursor coverage on all exposed surface areas is space- and time-dependent. Since the deposition rate depends on both

High-throughput micro-nanostructuring by microdroplet inkjet printing

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222

• ]. Using electron-beam lithography, it is possible to generate such patterns with very high spatial precision [5]. Focused electron beam induced deposition (FEBID) even serves as a method to deposit 3D nanostructures without the need of masks [6]. A further and very successful method to write gold

Chemistry for electron-induced nanofabrication

• Petra Swiderek,
• Hubertus Marbach and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2018, 9, 1317–1320, doi:10.3762/bjnano.9.124

• -Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany, Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628CJ Delft, The Netherlands 10.3762/bjnano.9.124 Keywords: electron-induced chemistry, FEBID; FEBIP; nanofabrication; nanolithography; Electron

• beams can be used to induce, on a very small area, chemical reactions of adsorbed precursor molecules that either lead to etching of the underlying surface or deposition of material. The latter additive variant of FEBIP is focused electron beam induced deposition (FEBID), a powerful direct-write

• physical quantum-scale phenomena and thus novel functionalities [2]. However, their performance depends decisively on the precise control of the electron-induced precursor chemistry that is fundamental to FEBID. In FEBID, the precursor molecules are dosed into an electron microscope where they adsorb on a

A novel copper precursor for electron beam induced deposition

• Caspar Haverkamp,
• George Sarau,
• Mikhail N. Polyakov,
• Ivo Utke,
• Marcos V. Puydinger dos Santos,
• Silke Christiansen and
• Katja Höflich

Beilstein J. Nanotechnol. 2018, 9, 1220–1227, doi:10.3762/bjnano.9.113

• fluorine free copper precursor, Cu(tbaoac)2 with the chemical sum formula CuC16O6H26 is introduced for focused electron beam induced deposition (FEBID). FEBID with 15 keV and 7 nA results in deposits with an atomic composition of Cu:O:C of approximately 1:1:2. Transmission electron microscopy proved that

• measured from deposited pads was used to simulate the optical response of tip arrays fabricated out of the same precursor and showed good agreement with measurements. This paves the way for future plasmonic applications with copper-FEBID. Keywords: copper; Cu(tbaoac)2; focused electron beam induced

• decomposed by the electron beam and become visible as a darkening of the irradiated area [1]. By introducing a volatile precursor gas into the vacuum chamber [2][3] this focused electron beam induced deposition (FEBID) enables the fabrication of three-dimensional structures with nanometer precision [4]. The

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• nanowires (NWs) and square nanorings, which were deposited by focused electron beam induced deposition (FEBID) of a Co carbonyl precursor, are studied using off-axis electron holography (EH), Lorentz transmission electron microscopy (L-TEM) and magnetic force microscopy (MFM). EH shows that NWs deposited

• at remanence using L-TEM and MFM. Our results confirm the suitability of FEBID for nanofabrication of magnetic structures and demonstrate the versatility of TEM techniques for the study and manipulation of magnetic domain walls in nanostructures. Keywords: focused electron beam induced deposition

• focused electron beam induced deposition (FEBID) of Co carbonyl (Co2(CO)8). This is a direct-write technique performed in a scanning electron microscope (SEM) equipped with a gas injector system (GIS) [9]. It exploits secondary electron emission resulting from interaction of the primary electron beam with