Method for Cross-sectional Thin Specimen Preparation from a Specific Site Using a Combination of a Focused Ion Beam System and Intermediate Voltage Electron Microscope and Its Application to the Characterization of a Precipitate in a Steel

In this study, we discuss a method for cross-sectional thin specimen preparation from a specific site using a combination of a focused ion beam (FIB) system and an intermediate voltage transmission electron microscope (TEM). A FIB-TEM compatible specimen holder was newly developed for the method. The thinning of the specimen using the FIB system and the observation of inside structure of the ion milled area in a TEM to localize a specific site were alternately carried out. The TEM fitted with both scanning transmitted electron detector and secondary electron detector enabled us to localize the specific site in a halfway milled specimen with the positional accuracy of better than 0.1 &mgr;m. The method was applied to the characterization of a precipitate in a steel. A submicron large precipitate was thinned exactly at its center for the characterization by a high-resolution electron microscopy and an elemental mapping.