Hydration of magnesia cubes: a helium ion microscopy study

• Ruth Schwaiger,
• Johannes Schneider,
• Gilles R. Bourret and
• Oliver Diwald

Beilstein J. Nanotechnol. 2016, 7, 302–309, doi:10.3762/bjnano.7.28

• these oxides are in physical contact with a solid substrate such as the ones used for immobilization to perform electron or ion microscopy imaging. We used helium ion microscopy (HIM) and investigated morphological changes of vapor-phase-grown MgO cubes after vacuum annealing and pressing into foils of

• images are not directly compromised [16]. In addition to the high SE-yield, helium ion microscopy allows the use of low beam currents for imaging [7]. For biological materials and polymers, HIM is preferable to SEM for high resolution imaging due to the problems related to electron-beam-induced damage

• that were grown and processed in dry vacuum environments prior to imaging with helium ion microscopy. The volume expansions observed are attributed to surface reactions between the MgO cubes and water molecules originating as physisorbed species from an indium foil that was employed as a conductive

Focused particle beam-induced processing

• Michael Huth and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1883–1885, doi:10.3762/bjnano.6.191

• alleviate the resolution-limiting issues in FEBID on solid substrates is the employment of helium ion microscopy (HIM). In its current development stage, HIM is mainly used for imaging applications, providing enhanced contrast for surface features as compared to scanning electron microscopy. Along this

• polymerization that is a basis for the creation of ultrathin nanomembranes. Finally, André Beyer and coworkers show impressive HIM images of ultrathin carbon nanomembranes [17], which is a clear indication of the potential of the bourgeoning fields of helium ion microscopy and lithography towards nanofabrication

Imaging of carbon nanomembranes with helium ion microscopy

• André Beyer,
• Henning Vieker,
• Robin Klett,
• Hanno Meyer zu Theenhausen,
• Polina Angelova and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1712–1720, doi:10.3762/bjnano.6.175

• nanomembrane; helium ion microscopy; self-assembled monolayers; Introduction Carbon nanomembranes (CNMs) are extremely thin and homogeneous two-dimensional objects consisting of a monolayer of laterally cross-linked molecules. They are made by exposing a self-assembled monolayer (SAM) of aromatic molecules

• particle microscopy techniques such as scanning electron microscopy (SEM) or helium ion microscopy (HIM). As illustrated in Supporting Information File 1, Figure S1, SEM shows a low signal-to-noise-ratio for freestanding CNMs, especially at higher magnifications, due to charging issues [4][16]. This tends

• compensation as otherwise the membrane will easily rupture due to local charging. Conclusion We have shown that helium ion microscopy is a very effective technique for characterizing CNMs. Additionally, CNMs have proven to be ideal test objects for evaluating the imaging characteristics of a HIM. The large

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• narrow beam divergence angle of about 0.5 mrad [15][16], which is ten times less than the best beam divergence angle possible in SEM. The large depth of focus makes helium ion microscopy (HIM) a very promising tool for scanning reflection microscopy. During the last decade the imaging capabilities of HIM

• accumulated surface charge plays te role of positive sample bias. The impact of the charging on the height of the surface steps is negligible. Conclusion In summary, we investigated the capabilities of a scanning reflection helium ion microscopy technique that was realized in a helium ion microscope for the

• limiting factor for the observation of the atomic steps. Thus, the further enhancement of the detection system is desirable to reduce the measurement time and to avoid sputtering of a sample. In conclusion, reflection helium ion microscopy is a promising tool for the investigation of surface morphology and

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• , which allowed for an ex situ observation of the cross-linking process by helium ion microscopy (HIM). In this way, three growth regimes of cross-linked areas were identified: formation of nuclei, one-dimensional (1D) and two-dimensional (2D) growth. The evaluation of the corresponding HIM images

• attachment; helium ion microscopy; ion beam-organic molecules interactions; self-assembled monolayers; Introduction Carbon nanomembranes (CNMs) with monomolecular thickness and macroscopic lateral size represent a new type of functional two-dimensional (2D) materials [1]. A universal scheme to fabricate

• Freestanding carbon nanomembranes were successfully fabricated from aromatic self-assembled monolayers by using helium ion beam lithography. Three distinct stages of the crosslinking process, i.e., the initial nucleation, 1D growth and 2D growth, were observed ex situ by helium ion microscopy. Such a sequence

Digging gold: keV He⁺ ion interaction with Au

• Vasilisa Veligura,
• Gregor Hlawacek,
• Robin P. Berkelaar,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2013, 4, 453–460, doi:10.3762/bjnano.4.53

• crystals; helium ion microscopy; ion beam/solid interactions; vacancies in crystals; Introduction The helium ion microscope allows the projection of a He+ beam of several tens of kiloelectronvolts with a diameter of 0.4 nm [1] onto a sample. This makes HIM an attractive tool for surface patterning and

• Vasilisa Veligura Gregor Hlawacek Robin P. Berkelaar Raoul van Gastel Harold J. W. Zandvliet Bene Poelsema Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands 10.3762/bjnano.4.53 Abstract Helium ion

• microscopy (HIM) was used to investigate the interaction of a focused He+ ion beam with energies of several tens of kiloelectronvolts with metals. HIM is usually applied for the visualization of materials with extreme surface sensitivity and resolution. However, the use of high ion fluences can lead to

Physics, chemistry and biology of functional nanostructures

• Paul Ziemann and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2012, 3, 843–845, doi:10.3762/bjnano.3.94

• properties. With respect to tools, immediate examples are the continuous improvements of scanning-probe measurements such as scanning tunneling or scanning force microscopy (STM, AFM) [2] and their numerous variants often combined with scanning electron microscopy (SEM) or scanning helium ion microscopy

Nano-structuring, surface and bulk modification with a focused helium ion beam

• Daniel Fox,
• Yanhui Chen,
• Colm C. Faulkner and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2012, 3, 579–585, doi:10.3762/bjnano.3.67

• ion microscopy; nanofabrication; TEM; Introduction Ion beams are widely used to modify the physical and chemical properties of the surface of materials with a high degree of control. Ion beam irradiation can be used to modify and control a material’s optical [1], electrical [2], magnetic [3] and

• cross section allowing direct observation of the extended effects of high dose irradiation. The effect of the irradiation on the crystal structure of the material is presented. Applications of the sample modification process are presented and further prospects discussed. Keywords: EELS; EFTEM; helium

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

• Gregor Hlawacek,
• Vasilisa Veligura,
• Stefan Lorbek,
• Tijs F. Mocking,
• Antony George,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

• , Montanuniversitaet Leoben, Franz Josef Straße 18, 8700 Leoben, Austria Inorganic Material Science, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands 10.3762/bjnano.3.58 Abstract Background: Helium ion microscopy is a new high-performance alternative to classical

• ion microscopy; ion scattering; thin layers; Introduction The helium ion microscope (HIM) has established itself as a high-performance alternative to the classic scanning electron microscope (SEM). The superior resolution and the outstanding performance on insulating samples are well-known facts [1

• . This dechanneling contrast is particularly well suited for the visualization of ultrathin layers of light elements on heavier substrates. Our results also highlight the importance of proper vacuum conditions for channeling-based experimental methods. Keywords: channeling; contrast mechanism; helium

Channeling in helium ion microscopy: Mapping of crystal orientation

• Vasilisa Veligura,
• Gregor Hlawacek,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 501–506, doi:10.3762/bjnano.3.57

• sensitivity and the high resolution that can be achieved with helium ion microscopy make it a competitive technique for modern materials characterization. As in other techniques that make use of a charged particle beam, channeling through the crystal structure of the bulk of the material can occur. Results

• this with experiments, and develop a simple geometric model to predict channeling maxima. Conclusion: Channeling plays an important role in helium ion microscopy and has to be taken into account when trying to achieve maximum image quality in backscattered helium images as well as secondary electron

• images. Secondary electron images can be used to extract crystallographic information from bulk samples as well as from thin surface layers, in a straightforward manner. Keywords: channeling; crystallography; helium ion microscopy; ion scattering; Introduction The superior resolution of the helium ion