We aim at resolving deca-nanometer features in microelectronic samples using a laboratory SEM-based X-ray tomography
microscope. Such a system produces X-rays through the interaction between a focused SEM electron beam and a metallic
target. The effective source size of the X-ray beam can be adjusted by varying the target material and geometry. For
instance, the use of tungsten nanowires (few hundred nanometers of length) combined with a high electron beam current
leads to an increased X-ray flux generated in a reduced volume, necessary for detecting interface details of the analyzed
object. It improves resolution and signal-to-noise ratio (SNR), but is also sensitive to electron beam-target instabilities
during the scan. To improve robustness, a FFT-based image correlation is integrated in the process through a closed-loop
control scheme. It allows stabilizing the electron beam on the target and to preserve the X-ray flux intensity and alignment.
Also, a state of the art high-resolution scientific-CMOS (sCMOS) X-ray detector was installed, allowing to reduce noise
and to increase quantum efficiency. Results show that such numerical and equipment improvements lead to significant
gains in spatial resolution, SNR and scanning time of the SEM-based tomography. It paves the way to routine, high
resolution, 3D X-ray imaging in the laboratory.
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