One of the shortcomings of the atom probe analysis method was its restrictions in specimen shape. To achive a very high electric field on specimen surface, specimens must be needles of ~100 nm diameter at the tip. The object of interest such as grain boundaries, interphase interfaces, specific region of devices must be located near the tip of the needle like specimens. This kind of selective specimen preparation used to be extremely difficult by the electropolishing technique. However, the development of the microfabrication method using the focused ion beam (FIB) technique made site specific specimen preparation possible.

The site specific specimen preparation method is shown using an annimation below. .