Figure 4

Sketch and cross-sectional images of a volume containing gold structures in a silicon substrate.

The top left side of the picture shows a schematic sketch of the investigated volume of a nanostructured silicon sample. Due to the fact that XCT exploits the surface reflection as a reference, the sketch in the middle of the picture shows the volume how it is expected to be measured. The false color plots in the right and lower part of the picture show slices through the volume indicated by the red, green and blue lines. The plots are retrieved by calculating the Fourier-transform of the measured XUV spectrum for the respective lateral position. Due to the short coherence length of the employed XUV radiation, the axial resolution is better than 18 nm. All buried layers appear clearly visible and separated from each other.