Raising the Standard of Specimen Preparation for Aberration-Corrected TEM and STEM

Cerchiara, R. R.; Fischione, Paul; Liu, J.; Matesa, J. M.; Robins, Alan; Fraser, Hamish L.; Genç, Arda

doi:10.1017/s1551929510001197

Cited by 22 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are several recent improvements to focused ion‐milling technology designed to mitigate damage in FIB‐TEM sections (Mayer et al , 2007). These include low‐energy (500 eV to 2.5 keV) final milling using Ar + ions (Cerchiara et al , 2011) or in situ low‐energy (500 eV to 2 keV) FIB milling using Ga + ions (Bals et al , 2007). Although these techniques have been applied to soft materials, their effectiveness has only been measured through TEM inspection of the surface amorphous damage layer or implanted defects in the sample.…”

Section: Introductionmentioning

confidence: 99%

Minimizing damage during FIB sample preparation of soft materials

Bassim

Gregorio

Kilcoyne

et al. 2011

Journal of Microscopy

158

143

View full text Add to dashboard Cite

SummaryAlthough focused ion beam (FIB) microscopy has been used successfully for milling patterns and creating ultra-thin electron and soft X-ray transparent sections of polymers and other soft materials, little has been documented regarding FIB-induced damage of these materials beyond qualitative evaluations of microstructure. In this study, we sought to identify steps in the FIB preparation process that can cause changes in chemical composition and bonding in soft materials. The impact of various parameters in the FIB-scanning electron microscope (SEM) sample preparation process, such as final milling voltage, temperature, ion beam overlap and mechanical stability of soft samples, was evaluated using two test-case materials systems: polyacrylamide, a low melting-point polymer, and Wyodak lignite coal, a refractory organic material. We evaluated changes in carbon bonding in the samples using X-ray absorption near-edge structure spectroscopy (XANES) at the carbon K edge and compared these samples with thin sections that had been prepared mechanically using ultramicrotomy. Minor chemical changes were induced in the coal samples during FIB-SEM preparation, and little effect was observed by changing ion-beam parameters. However, polyacrylamide was particularly sensitive to irradiation by the electron beam, which drastically altered the chemistry of the sample, with the primary damage occurring as an increase in the Correspondence to: N. D.

show abstract

Section: Introductionmentioning

confidence: 99%

Minimizing damage during FIB sample preparation of soft materials

Bassim

Gregorio

Kilcoyne

et al. 2011

Journal of Microscopy

158

143

View full text Add to dashboard Cite

show abstract

“…The Ga ion beam energy was gradually decreased from 30 to 5 keV to limit the amorphous layers introduced at higher energies 48 . Using a NanoMill (model 1040, E. A. Fischione Instruments, Inc., Export, PA, United States), final Ar ion polishing was performed with milling energies of 900 eV and subsequently 500 eV with an inclination angle of 10 degrees with respect to the sample surface 49 . Finally, sample A exhibits a thickness gradient with a lowest thickness of 20 nm and the second one includes steps of 30, 55, 85, 110 and 135 nm thickness.…”

Section: Methodsmentioning

confidence: 99%

Influence of plasmon excitations on atomic-resolution quantitative 4D scanning transmission electron microscopy

Beyer

Krause

Robert

et al. 2020

Sci Rep

View full text Add to dashboard Cite

Scanning transmission electron microscopy (STEM) allows to gain quantitative information on the atomic-scale structure and composition of materials, satisfying one of todays major needs in the development of novel nanoscale devices. The aim of this study is to quantify the impact of inelastic, i.e. plasmon excitations (PE), on the angular dependence of STEM intensities and answer the question whether these excitations are responsible for a drastic mismatch between experiments and contemporary image simulations observed at scattering angles below $$\sim $$ ∼ 40 mrad. For the two materials silicon and platinum, the angular dependencies of elastic and inelastic scattering are investigated. We utilize energy filtering in two complementary microscopes, which are representative for the systems used for quantitative STEM, to form position-averaged diffraction patterns as well as atomically resolved 4D STEM data sets for different energy ranges. The resulting five-dimensional data are used to elucidate the distinct features in real and momentum space for different energy losses. We find different angular distributions for the elastic and inelastic scattering, resulting in an increased low-angle intensity ($$\sim $$ ∼ 10–40 mrad). The ratio of inelastic/elastic scattering increases with rising sample thickness, while the general shape of the angular dependency is maintained. Moreover, the ratio increases with the distance to an atomic column in the low-angle regime. Since PE are usually neglected in image simulations, consequently the experimental intensity is underestimated at these angles, which especially affects bright field or low-angle annular dark field imaging. The high-angle regime, however, is unaffected. In addition, we find negligible impact of inelastic scattering on first-moment imaging in momentum-resolved STEM, which is important for STEM techniques to measure internal electric fields in functional nanostructures. To resolve the discrepancies between experiment and simulation, we present an adopted simulation scheme including PE. This study highlights the necessity to take into account PE to achieve quantitative agreement between simulation and experiment. Besides solving the fundamental question of missing physics in established simulations, this finally allows for the quantitative evaluation of low-angle scattering, which contains valuable information about the material investigated.

show abstract

“…Moreover, low energy argon ion milling in a Nanomill was applied in order to limit the amount of amorphous material on the surfaces of the TEM sample and reducing the size of the dead layers accordingly. The viewing direction was chosen to be [−110], i.e., along the step edges of the majority steps on the former Si surface (compare, e.g., Figure a).…”

Section: Proving Charge Neutrality At the Gap–si Interface By 4dstemmentioning

confidence: 99%

Advanced Electron Microscopy for III/V on Silicon Integration

Beyer

Volz

2019

Adv Materials Inter

View full text Add to dashboard Cite

The combination of III/V semiconductors with Si is very attractive, since it allows the fabrication of high efficient optoelectronic devices like solar cells, lasers or the integration of III/V transistors on Si substrates. However, the growth of polar III/V materials on nonpolar Si holds several challenges. The different valences of group III and group V atoms as well as Si possibly give rise to the formation of charged defects, i.e., antiphase boundaries, as well as to charge accumulation at the interface between the different materials. Accordingly, the interfaces present, i.e., the ones between antiphase and main phase and the one between III/V and Si, eventually limit any device's performance. Electron microscopy, in particular transmission electron microscopy, has proven to be a valuable tool to acquire quantitative information from III/V–Si heterostructures. Among this information are defect densities as well as the structure of the involved interfaces at spatial resolutions down to the atomic level. Moreover, information on charge distribution can be retrieved. In this review, the authors collocate the results gained for the model system GaP on Si utilizing various electron microscopy related techniques.

show abstract

Raising the Standard of Specimen Preparation for Aberration-Corrected TEM and STEM

Cited by 22 publications

References 2 publications

Minimizing damage during FIB sample preparation of soft materials

Minimizing damage during FIB sample preparation of soft materials

Influence of plasmon excitations on atomic-resolution quantitative 4D scanning transmission electron microscopy

Advanced Electron Microscopy for III/V on Silicon Integration

Contact Info

Product

Resources

About