High‐resolution, high‐throughput imaging with a multibeam scanning electron microscope

Abstract

Electron–electron interactions and detector bandwidth limit the maximal imaging speed of single-beam scanning electron microscopes. We use multiple electron beams in a single column and detect secondary electrons in parallel to increase the imaging speed by close to two orders of magnitude and demonstrate imaging for a variety of samples ranging from biological brain tissue to semiconductor wafers.Lay DescriptionThe composition of our world and our bodies on the very small scale has always fascinated people, making them search for ways to make this visible to the human eye. Where light microscopes reach their resolution limit at a certain magnification, electron microscopes can go beyond. But their capability of visualizing extremely small features comes at the cost of a very small field of view. Some of the questions researchers seek to answer today deal with the ultrafine structure of brains, bones or computer chips. Capturing these objects with electron microscopes takes a lot of time – maybe even exceeding the time span of a human being – or new tools that do the job much faster. A new type of scanning electron microscope scans with 61 electron beams in parallel, acquiring 61 adjacent images of the sample at the same time a conventional scanning electron microscope captures one of these images. In principle, the multibeam scanning electron microscope’s field of view is 61 times larger and therefore coverage of the sample surface can be accomplished in less time. This enables researchers to think about large-scale projects, for example in the rather new field of connectomics. A very good introduction to imaging a brain at nanometre resolution can be found within course material from Harvard University on http://www.mcb80x.org/# as featured media entitled ‘connectomics’.

Correlating 3D light to 3D electron microscopy for systems biology

“…For instance, the serial sectioning of a 5. [34,36], which can operate with up to 196 beams scanning in parallel [37], providing a breakthrough, particularly for array tomography.…”

A Multicore Path to Connectomics-on-Demand

“…This is only a tiny sliver of brain, about the size of a grain of sand, but it will contain about 100 thousand neurons and a billion synapses. The cubic millimeter will constitute about two petabytes of imagery that will be collected in about 6 months using a 61-beam electron microscope that generates half a terabyte of imagery per hour [15,38].…”

“…The physical part takes a piece of stained brain tissue embedded in a resin, slices it thousands of times using a special microtome device, and feeds these minute slices into an electron microscope that scans them and produces separate images of the slices [15,61]. The computational part of the pipeline, the focus of this paper, then takes the thousands of separate 2-dimensional images, reconstructs the 3-dimensional neurons within them, and produces skeletonizations or graphs that capture their morphological and connectivity properties.…”

Transmission electron imaging in the Delft multibeam scanning electron microscope 1

“…Several groups are doing these, e.g., Mohammadi-Gheidari and Kruit, 3 D. Zeidler and G. Dellemann, 4 and Enyama et al 5 Some published their experimental results, e.g., Mohammadi-Gheidari et al, 6 and Eberle et al 7 Zeiss also released a commercial multibeam SEM (MBSEM) which has 61 or 91 beams, with secondary electron (SE) detection.…”