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How Fibics Prepares an "H-bar" TEM Sample for FIB
Step 1 - Obtaining an Aperture Grid
Fibics uses an aperture grid or slotted grid with a 1mm hole. When working with a thin (<~100 microns) grid, we place the grid on top of a glass slide and use a scalpel to cut away a portion of the grid (see the image below). When dealing with a thicker grid, we clip off the top of the grid with a pair of cutters. During both procedures, we ensure that grid warping is minimal.
Aperture Grid
OR
Slotted Grid

Step 2 - Creating a Specimen Slice
Fibics sections a portion of a specimen to create a slice that is approximately 1mm x 2.5mm. We ensure that any feature of interest on the specimen is positioned roughly in the center of the slice (see the image below). The slice must be thinned to 60 µm or less, so we cut a thin slice sample to meet the desired thickness specifications. We then grind or lap down one face of the sample. If the sample has a particular feature of interest, then we lap to within 30 µm of the feature. With or without a specific feature of interest, we finish the polished face with 3 µm or finer abrasive.
Feature of Interest Feature of Interest

Step 3 - Grid and Slice Come Together
By using a TEM suitable adhesive, such as M-Bond 610 epoxy, we mount the sample onto the grid with the polished face down. Once the sample is mounted, we use a parallel lapping tool to thin the sample to less than 60 µm. Any feature of interest on the sample should end up in the center, as shown in the diagram below. The sample is now ready for the FIB!
Specimen Mounting Specimen Mounting

Schematic Representation Showing Relative Viewing Angles of a Specimen in the FIB as the Sample is Being Thinned, and in the TEM as the Sample is Being Observed

FIB Viewing Angle TEM Viewing Angle