Preparing patterned samples for XPEEM

Although the larges field of view of the SPELEEM is about 50µm, we can only move plus minus 2 mm from the manipulator central position. Thus, it is impossible to scan the entire sample area, the nanostructures must be placed in proximity to the cartridge centre. Thus, when mounting the sample on the cartridge, it is essential to be able to see where the nanostructures are, so that they can moved towards the centre. In order to do this, it is useful to put visible markers on the sample. The schemes shown below were contributed by our collaborators, and you're invited to copy and adapt the idea to your case.

Left hand side of the Figure: a metal (typically Au) film is evaporated on one quadrant on the sample; holes are created in the film by lift-off technique or by etching, which leaves the sample surface free. The nanostructures must be placed inside the most central holes. The main advantages of this procedure are twofold: it is easy to find the pattern, because produces contrast in XPEEM and LEEM. The edge of the quadrant can be found quickly. From here, one can use the micrometers to move and find the structures (remember to bring a map of the sample!). If different nanostructures are placed in different holes, there will be no need to exchange samples.

Right hand side of the Figure: mounting the sample so that the target is centerd to the hole in the Mo spider cap is easyly done. In the microscope, one moves the X coordinate until finding the on streight line parallel to the Y axis. Then one moves along Y, following the pattern edge-line and eventually finding the nanostructures!