SPRITE Annular Backscattered Electron Detectors:
Silicon PhotomultiplieR Imaging Technology for Electrons

Small and Magical

PulseTor has developed a new BSED detector based on our unique SoM technology.

SPRITE detectors use multiple SiPM chips – from 1X1 mm2 to 1X1 cm2 – as the substrate for thin scintillators. A typical SPRITE detector may have four 4X4 mm2 devices around an annulus, to be mounted under the SEM Polepiece in the conventional manner.

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An assembly of four YAG SoMs around the annulus in the region defined by the red ellipse. The rest of the circuit is the amplification section – which, in this case, is integrated into a single PCB.
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Another implementation, in which four 4X4 YAG SoMs are arranged along one axis through the center of the annulus, and four 1X1 YAG SoMs aligned along the perpendicular axis.

The segmentation is illustrated by the set of images below from the A, B and C devices individually, then the image formed by the sum of the three SoMs. It allows the ability to clearly understand the the topogrpahical relationships.

SPRITE Technology combines SoMs
for
Outstanding Topographic Detail

Click buttons to see A, B, and C device images individually, and then the combined image:

Another way to take advantage of the unique architecture enabled by SoM technology is to use different scintillator materials in the same detector.

A schematic representation of two YAG SoMs on one axis and two ZnO SoMs on the other. The ZnO, used uncoated, will be sensitive to BSEs with energies as low as 200 eV, while the YAG, with its normal ITO conductive coating, remains insesitive to such low energy electrons, responding only to electrons having energies of 2 keV and greater.
A similar use of eight 4X4 SoMs, but connected in pairs to retain the 4 channel concept.