Figure 1.

Diagram of sub-slice imaging in the SBEM. (a) Surface of the sample block is imaged by scanning a focused electron probe from a field emission source across a region of interest and collecting backscattered electrons (BSEs) with an annular detector. Sample block is raised by height ≥ 25 nm, and a section of that thickness is shaved off using a diamond knife mounted in the SBEM’s in situ microtome. The newly exposed surface is then re-imaged. This process is repeated until an image stack is collected from the desired sample volume, 70 slices in this illustration. (b,c) Series of backscattered electron images captured at energy E₁ and E₂, respectively. (d,e) 3D reconstruction of single-energy image series from (b,c), respectively. (f) Dual-energy reconstruction gives sub-slice resolution.