title: Ultrathin specimen preparation by a low-energy Ar-ion milling method.
abstract: The low-energy Ar-ion milling method was used to prepare ultrathin specimens for transmission electron microscope observation. The samples were thinned initially by a usual focused ion beam technique or typical Ar-ion milling with a high energy of 2-10 keV and were thinned additionally by an Ar-ion beam with an energy less than 1 keV, typically 500-900 eV. This low-energy ion beam was scanned over the specimen, and secondary electrons induced by the ion beam could be detected to form secondary electron images with a resolution of a few micrometre. Because a desired area can be selected and thinned by the low-energy ion beam, redeposition or cross contamination from irradiation of a metal grid that supports the sample can be prevented. It was shown that the low-energy Ar-ion beam thins a surface amorphous damage layer preferentially and effectively rather than a crystal specimen. Images from ultrathin specimens of two different materials revealed a detailed structure.
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan. mitome.masanori@nims.go.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Mitome