Heiji Watanabe

Learn More
A first-principles study of the electronic structures and dielectric properties of Si/SiO(2) interfaces is implemented. Comparing the interfaces with and without defects, we explore the relationship between the defects and the dielectric properties, and also discuss the effect of the defects on the leakage current between the gate electrode and silicon(More)
We demonstrate hard x-ray phase contrast imaging (XPCI) using a tabletop Talbot-Lau interferometer in which the x-ray source and source grating are replaced with an x-ray source with multiline metal targets embedded in a diamond substrate. This source realizes an array of linear x-ray sources of a few micrometers width without fabrication difficulty because(More)
Using multidot metal targets embedded in a diamond substrate, we created a single-grating Talbot-Lau interferometer and used it to capture two dimensional (2D) x-ray phase images. The ensemble of these targets constitutes a tiny virtual array of x-ray source and enables x-ray phase-contrast imaging with no source or absorption grating within a 1 m(More)
We propose low-damage and high-efficiency treatment of 4H-SiC(0001) surfaces using atmospheric pressure (AP) hydrogen plasma. Hydrogen radicals generated by the AP plasma was found to effectively remove damaged layers on SiC wafers and improve surface morphology by isotropic etching. Localized high-density AP plasma generated with a cylindrical rotary(More)
We investigated the origin of selective adsorption of titanium-binding ferritin (TBF), the outer surface of which is genetically modified with titanium-binding peptides (TBPs). By varying pH conditions (7-9), TBF adsorption behavior onto amphoteric and acidic oxide substrates was observed using atomic force microscopy, and the zeta potential of substrates(More)
The adsorption mechanism of titanium-binding peptide (TBP) on metal oxide substrates was investigated by evaluating the adsorption behavior of ferritins with various alanine-substituted TBPs. Results revealed that (a) a positively charged amino acid, lysine (K) or arginine (R), in TBP can anchor ferritin to negative zeta-potential substrates, (b) the(More)
We performed x-ray phase contrast imaging (XPCI) by Talbot-Lau interferometer using only a single transmission grating. Multiline metal targets embedded in a diamond substrate were irradiated with electrons to generate an array of x-ray lines of 1 μm width, which allowed XPCI within a 1 m source-detector distance in a configuration without a source or(More)
High-quality germanium oxynitride (GeON) gate dielectrics for Ge-based metal-oxide-semiconductor (MOS) devices were fabricated by plasma nitridation of ultrathin thermal oxides on Ge(100) substrates. Although ultrathin oxides with abrupt GeO<inf>2</inf>/Ge interfaces can be formed by conventional dry oxidation, air exposure results in serious electrical(More)
The electronic structures of lanthunum (La) incorporated hafnium (Hf)-based oxides (HfLaO) and their silicate (HfLaSiO) films were investigated by the Near Edge X-ray Absorption Fine Structure (NEXAFS) technique. The oxygen (O) K-edge spectra, which reflected the hybridized Hf 5d state with the O 2p orbital, were found to reveal features of the unoccupied(More)