Fabrication of high quality plan-view TEM specimens using the focused ion beam

• Focused ion beam preparation of high quality plan-view TEM specimens.
• Specimens characterised by TEM techniques and atomic force microscopy.
• Low defect density and good thickness uniformity.
• Lorentz imaging of ferromagnetic oxide shows preservation of the Curie temperature.
• The technique is readily applicable to a wide range of heteroepitaxial systems.

We describe a technique using a focused ion beam instrument to fabricate high quality plan-view specimens for transmission electron microscopy studies. The technique is simple, site-specific and is capable of fabricating multiple large, >100 μm2 electron transparent windows within epitaxially grown thin films. A film of La0.67Sr0.33MnO3 is used to demonstrate the technique and its structural and functional properties are surveyed by high resolution imaging, electron spectroscopy, atomic force microscopy and Lorentz electron microscopy. The window is demonstrated to have good thickness uniformity and a low defect density that does not impair the film's Curie temperature. The technique will enable the study of in-plane structural and functional properties of a variety of epitaxial thin film systems.