Preparation for tomography in FIB-SEM
Compared to conventional TEM tomography, the 3D acquisition achieved in a Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) is completely different. Thanks to the gallium ion beam in addition to a conventional SEM with a large chamber, a much bigger sample can be put into the machine and tilted to 54 degrees (the angular difference between FIB and SEM on our system is 54°) with its top surface perpendicular to the FIB. Then the ion beam mill into the depth of a specific operator chosen area revealing structures in a new dimension other than the surface. In order to expose a cross-section with features at a certain depth, an appropriate volume of the material needs to be removed so that the electron beam can reach deep enough to image the target features.