Automated Metrology on the Verticality of Cross-Sectioned Channel Hole at V-NAND with Over 200 Layers by Transmission Electron Microscope

In this paper, we present a nanoscale verticality measurement method for V-NAND with 200 or more layers of high layers using an automated transmission electron microscope, which has been developed a lot in the analysis field. Nanoscale measurements in cross-sectional images in 3D-NAND with such a high layer do not include both the top and bottom areas in one image of FOV. Therefore, it is very difficult for a person to objectively measure the etching angle or verticality of the channel hole. We experimented the verticality measurement of a channel hole in the two images in different areas using an automated transmission electron microscope imaging and measurement. In this paper, we present the results and analysis of the experiment and detailed metrology methods.

Dielectric Imaging of Fixed HeLa Cells by In-Liquid Scanning Dielectric Force Volume Microscopy

Mapping the dielectric properties of cells with nanoscale spatial resolution can be an important tool in nanomedicine and nanotoxicity analysis, which can complement structural and mechanical nanoscale measurements. Recently we have shown that dielectric constant maps can be obtained on dried fixed cells in air environment by means of scanning dielectric force volume microscopy. Here, we demonstrate that such measurements can also be performed in the much more challenging case of fixed cells in liquid environment. Performing the measurements in liquid media contributes to preserve better the structure of the fixed cells, while also enabling accessing the local dielectric properties under fully hydrated conditions. The results shown in this work pave the way to address the nanoscale dielectric imaging of living cells, for which still further developments are required, as discussed here.

Dating habitability with nanoscale measurements of Early Mars

<p>The earliest known physical records of Mars and Earth lie in microscopic grains of zirconium-rich geochronology minerals such as zircon and baddeleyite. The reconstruction of the pressure and temperature histories of these phases is one of the few ways in which we can bracket the onset of conditions permissive of microbiota survival, and requires an integration of several nanoscale measurement techniques. This presentation will overview a recent, detailed investigation of zircons and baddeleyite from Mars [1], the earliest known from planets to date, as well as comparator studies of thermally and/or shock metamorphosed samples from the Earth and Moon. The approach is to spatially correlate measurements of the chemical and orientation microstructure of individual grains in order to characterize thermal, shock and diffusion history and better interpret U-Pb geochronology data. Also revealed are proxies for high temperature metamorphism such as nanoclusters of Pb and trace elements and nanoveins of impact melt as well as trace elements introduced through subsequent lower-temperature hydrothermal metamorphism. The techniques required include electron microscopy and cathodoluminescence (CL), Electron Backscatter Diffraction (EBSD), Transmission Kikuchi diffraction (TKD), mass spectrometry, and Atom Probe Tomography (APT). The Mars records were collected from a population of zircon and baddeleyite grains within five meteoritic fragments of polymict breccia (e.g. NWA 7034, NWA 7475). These data were compared to those from analogue sites of heavily bombarded Archean crust such as the central uplift of the Vredefort structure of South Africa, the Earth’s largest and oldest recognized impact crater, the Sudbury impact structure in Canada, and Apollo samples of the lunar regolith. The Mars population of grains reveals little evidence of the nanofeatures of heavily bombarded and heated crust, and no exposure to life-limiting pressures or temperature since crystallization 4.48 billion years ago. The conclusion is that global, planet-shaping bombardment effects on Mars, such as those which created its distinctive hemispheric dichotomy, had ceased by the time these grains and their associated crust crystallized. It follows that Mars entered a window of habitable conditions very early in solar system history, a pathway likely mirrored by the Earth. In this way nanoscale measurements, required to investigate microscopic mineral grains, serve as important tools for reconstructing important time periods in planetary evolution and abiogenesis.</p><p>Reference:</p><p>[1] DE Moser, GA Arcuri, DA Reinhard, LF White, JR Darling, IR Barker, DJ Larson, AJ Irving, FM McCubbin, KT Tait, J Roszjar, A Wittmann, C Davis (<strong>2019</strong>) Decline of giant impacts on Mars by 4.48 billion years ago and an early opportunity for habitability. <strong><em>Nature Geoscience </em></strong>12,  522–527.</p>

A comparison of nanoscale measurements with the theoretical models of real and nominal contact areas

In this study, an experimental method is proposed to measure the real area of contact between an alumina sphere and an Al surface based on the adhesive transfer of the Au film and the scanning electron microscope in the back-scattered mode. A thin film of Au is sputtered on the alumina sphere before the indentation with the Al surface. After indentation, the interfaces of the alumina sphere and Al surface are observed by the scanning electron microscope. The contact area can be identified based on both the distributions of the alumina and Au on the alumina sphere and Al surface, respectively. The measured contact area at different nominal pressures are compared to predictions made by several popular theoretical elastic-plastic rough surface contact models.