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Yasushi Kagoshima

Publications and source records attributed to Yasushi Kagoshima.

4 recordsLinked to original sources
PubMed2006

Crystallinity estimation of thin silicon-on-insulator layers by means of diffractometry using a highly parallel X-ray microbeam.

An X-ray microbeam with a small angular divergence and a narrow energy bandwidth has been produced at BL24XU at SPring-8. The beam size was measured to be 3.1 microm and 1.6 microm in the horizontal and vertical directions, respectively, and the horizontal angular divergence was 4.0 arcsec. Using this microbeam the crystallinity estimation of thin layers on silicon-on-insulator (SOI) wafers is demonstrated. In reciprocal-space maps the lattice tilt variations were 80 arcsec and more than 220 arcsec in the SOI layers on bonded and SIMOX wafers, respectively. In equi-tilt maps, the typical equi-tilt areas of the SOI layers were 7 microm and 4 microm in size on the bonded and SIMOX wafers, respectively.

Biophysical Phenomena↗
PubMed2002

High-resolution hard X-ray phase-contrast microscopy with a large-diameter and high-numerical-aperture zone plate.

An imaging transmission hard X-ray microscope has been constructed at beamline BL24XU of SPring-8. It makes use of a phase zone plate made of tantalum with a diameter of 1 mm and an outer-most zone width of 50 nm, aiming at a wide field of view and a high spatial resolution. The performance test was carried out at a photon energy of 10 keV. A field of view as wide as approximately 200 microm in diameter was achieved. The spatial resolution was measured to be 220 nm by analyzing a knife-edge image. Further, a line-and-space pattern as fine as 100 nm could be imaged. By placing a phase plate made of gold in the back focal plane of the zone plate, phase-contrast microscopy using Zernike's method was also carried out. The feasibility of phase-contrast microscopy for observing transparent samples was successfully demonstrated by imaging small polystyrene particles.

Journal Article↗
PubMed2002

Trace elemental analysis of drugs of abuse using synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF).

Synchrotron radiation total reflection X-ray fluorescence spectroscopy (SR-TXRF) was utilized to analyze various trace elements in small amounts of drugs of abuse. Sample amounts of 1 microL solutions containing 10 microg of drugs (methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, cocaine, and heroin) were spotted on silicon wafers for direct analysis. In addition, a leaflet of marijuana was set directly on a silicon wafer, and opium in the form of a soft lump was smeared on another silicon wafer for analysis. In these experiments, about 10 pg of contaminant elements could be detected. For example, in a seized methamphetamine sample, iodine was found, which could be indicative of synthetic route. In seized 3,4-methylenedioxymethamphetamine samples, variable amounts of phosphorus, calcium, sulfur, and potassium were found, which could not be detected in a control 3,4-methylenedioxymethamphetamine sample. For marijuana and opium, two spectral patterns were obtained that were far different from each other and could be easily discriminated. Using SR-TXRF, pg amounts of each trace element in 10 microg of various drugs can be easily detected, which is not the case either for a standard TXRF experimental system or for other elemental analysis techniques.

Journal Article↗