Stub Preparation
Conductivity
A significant portion of beam electrons do not generate signal and may distort images or damage samples.
There must be a conductive pathway to carry excess electrons to ground.
If needed, you may sputter coat your sample with a thin layer of metal, e.g. 4nm Ir
Stub Stacks
All parts provided to interface samples to the stage are conductive, including:
The stub
The sample holder
The stage
Your goal is to create a good conductive pathway between your sample and the stub.
A good conductive pathway provides another escape if the substrate is not very conductive or if the sample is particularly thick.
Conductive Sample
Nonconductive Sample
Nonconductive Sample
Cross Section Stubs
The goals and steps are similar for cross section imaging.
Keep the surface of interest as close to the top edge of the stub or sample holder as possible.
Some SEMs have strict height limits and can only image very short cross section samples.