Progress in the Preparation of Cross-Sectional TEM Specimens by Ion-Beam Thinning

Abstract

Abstract In transmission electron microscopy (TEM), often the preparation of samples is the most critical part. Specimens have to have disk geometries of 3 mm diameter laterally, and they have to be transparent for the electron beam vertically. Therefore, a specimen thickness in the range of some 1–10 nm has to be achieved by the preparation process. While shrinking the specimen dimensions, care has to be taken to recover the materials properties in the nm-regime. We report and shortly discuss some TEM specimen preparation techniques mainly used in the Stuttgart TEM specimen preparation laboratory. Furthermore, we demonstrate how more advanced techniques lead to a more reliable preparation of weakly-bonded metal/SrTiO3 interfaces. In addition, the advantage of low-voltage ion-milling is demonstrated by a case study for bulk SrTiO3. As a result, low-voltage ion polishing as a final step in the TEM specimen preparation by conventional ion-thinning turns out to significantly increase the specimen quality. In...