An FIB machine employs an energetic ion beam that can cut trenches in a semiconductor surface. Figure 1 shows a SEM picture of an FIBed semiconductor surface. For SEM and SPM surface imaging, specimen preparation methods must produce an unobstructed, precisely-located view of the desired object. For TEM analysis, preparation is more difficult, because the specimen has to be thinned to less than 0.1 micron in thickness due to the limited range of electrons transiting matter. It is possible for the person preparing the specimen to be lost in an ocean of tiny features on the surface of a specimen.
Sophisticated testers come to the rescue, providing fail-site coordinates.
FIB tools can then be used to mark the failed location. Again, for timely analysis regardless of the type of specimen being prepared, specimen preparation has to be accomplished in a matter of hours. Turnaround Time TAT is an extremely important variable in the semiconductor processing world. In high-volume laboratories, process time is typically one or two days, while queue time can be a week or more. One of the difficulties in managing a failure-analysis laboratory is that the usual rules of production planning do not apply.