Katsuyoshi Endo

Hard X-ray Diffraction-Limited Nanofocusing with Kirkpatrick-Baez Mirrors

Nanofocused X-ray beams are necessary for nanometer-scale spatial microscopy analysis. X-ray focusing using a Kirkpatrick-Baez setup with two total reflection mirrors is a promising method, allowing highly efficient and energy-tuneable focusing. In this paper, we report the development of ultraprecise mirror optics and the realization of a nanofocused hard-X-ray beam. Fabricated mirrors having a figure accuracy of 2 nm peak to valley height give ideal diffraction-limited focusing at the hard X-ray region. The focal size, defined as the full width at half maximum in the intensity profile, was 36 nm ×48 nm at an X-ray energy of 15 keV.

Atomic-scale evaluation of Si(111) surfaces finished by the planarization process utilizing SiO2 particles mixed with water

Flattening performance is evaluated on the atomic scale of Si(lll) surfaces finished by a precise surface-preparation method utilizing fine SiO 2 particles mixed with ultrapure water. An atomically flat Si( 111) surface with periodic steps, which is obtained by dipping into an NH 4 F solution, is processed by the surfacing method. The low-energy electron diffraction image of the processed surface exhibits a 1 X 1 pattern. Atomic force microscopy observations show that the periodic steps formed by the NH 4 F treatment are completely removed, and highly resolved scanning tunneling microscopy images reveal that the processed surface is composed of nanometer-scaled small terraces. From these results, it is speculated that fine powder particles in ultrapure water remove microbumps and apparent steps to flatten work surfaces, although they can etch some surface atoms inside a terrace.