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Akira Uedono - One of the best experts on this subject based on the ideXlab platform.

  • Study of Interactions of Hf and Sio2 Film for High-$k$ Materials
    Japanese Journal of Applied Physics, 2006
    Co-Authors: Te−wei Chiu, Akira Uedono, Masaaki Tanabe, Ryu Hasunuma, Kikuo Yamabe
    Abstract:

    Hf adsorption on thin Sio2 Films was carried out using an ultrahigh-vacuum system with e-beam evaporation. The interaction of adsorbed Hf and Sio2 Films was studied by Auger electron spectroscopy (AES), atomic force microscopy (AFM), and current–voltage (I–V) measurements. The leakage current of the Sio2 Films increased with Hf adsorption temperature. The dielectric properties of the Sio2 layer were markedly degraded by Hf adsorption even at 300 °C. Additionally, Hf adsorbed on a Sio2 (6.3 nm)/Si substrate at 900 °C penetrated through the Sio2 layer and reacted with the Si substrate forming large concavities. Otherwise, Si diffused from the Sio2/Si interface to the surface of adsorbed Hf.

  • Positronium formation in Sio2 Films grown on Si substrates studied by monoenergetic positron beams
    Journal of Applied Physics, 1994
    Co-Authors: Akira Uedono, Long Wei, Shoichiro Tanigawa, Ryoichi Suzuki, Hideaki Ohgaki, Tomohisa Mikado, Takao Kawano, Yuzuru Ohji
    Abstract:

    The annihilation characteristics of positrons in Sio2 Films grown on Si substrates were studied by using monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of incident positron energy for Sio2 (166 nm)/Si specimens fabricated by thermal oxidation. From the measurements, it was found that about 90% of positrons implanted into the Sio2 Film annihilate from positronium (Ps) states. This fact was due to the trapping of positrons by open‐space defects and a resultant enhanced formation of Ps in such regions. For the Sio2 Film grown at 650 °C, the lifetime of ortho‐Ps was found to be shorter than that in the Film grown at 1000 °C. This result suggests that the volume of open‐space defects in the Sio2 Film decreased with decreasing the growth rate of the Sio2 Film.

  • Sio2 Films deposited on Si substrates studied by monoenergetic positron beams
    Journal of Applied Physics, 1994
    Co-Authors: Akira Uedono, Long Wei, Shoichiro Tanigawa, Ryoichi Suzuki, Hideaki Ohgaki, Tomohisa Mikado, K. Fujino
    Abstract:

    Variable‐energy positron beams were utilized to study Sio2 Films grown on Si substrates. Annihilation characteristics of positrons in the Sio2 Films were found to be dominated by the formation probability of positronium (Ps). For the Sio2 Film grown by wet oxidation, a high formation probability of Ps was found by measurements of Doppler broadening profiles of the annihilation radiation and those of lifetime spectra. For Sio2 Films grown by an atmospheric‐pressure chemical vapor deposition technique using tetraethylorthosilicate and ozone, however, the formation probability of Ps drastically decreased. The inhibition of the Ps formation was attributed to interactions between positrons and –OH bonds.

  • Characterization of Sio2 Films grown on Si substrates by monoenergetic positron beams
    Le Journal de Physique IV, 1993
    Co-Authors: Akira Uedono, Long Wei, Shoichiro Tanigawa, Ryoichi Suzuki, Hideaki Ohgaki, Tomohisa Mikado
    Abstract:

    Variable-energy positron beams were utilized to characterize Sio2 Films grown on Si substrates. For a Sio2 Film grown by wet oxidation, a high formation probability of positronium (Ps) was found by measurements of Doppler broadening profiles of the annihilation radiation and those of lifetime spectra. For the Sio2 Films grown by a chemical vapor deposition technique, the formation probability of Ps was found to decrease. This was attributed to interactions between positrons and -OH bonds and to the trapping of positrons by point defects. In order to know annihilation characteristics of Ps in the Sio2 Films in more detail, a lifetime spectrum for a vitreous silica glass was also measured

Dun Zhang - One of the best experts on this subject based on the ideXlab platform.

  • an efficient way to prepare hydrophobic antireflective Sio2 Film by sol gel method
    Materials Letters, 2016
    Co-Authors: Wenwen Dou, Peng Wang, Dun Zhang
    Abstract:

    A single-layer hydrophobic antireflective Sio2 Film was prepared by sol-gel method. High transmittance (97%) and large static water contact angle (130.6 degrees) were realized simultaneously through a simple and efficient way. Tetraethoxysilane (TEOS) was used as a precursor to prepare Sio2 sol. A dip-pulling method was used to prepare the thin Film. We controlled the Film thickness by regulating pulling speed for making the transmittance of the Film to reach a peak at about 550 nm. The surface of the Film was covered with uniform particles of 20-30 nm and pores of 50-60 nm as shown in the SEM images. 1H, 1H, 2H, 2H-perfluorodecyltrichoxy silane (PFDS) was introduced to replace the hydroxyl (-OH) groups and decrease the surface energy of the Film. The appropriate Sio2 particle size and porosity in the Film and low surface energy give the hydrophobic antireflective Sio2 Film with high transmittance and large static water contact angle. (C) 2016 Elsevier B.V. All rights reserved.

G Hughes - One of the best experts on this subject based on the ideXlab platform.

Q. Wang - One of the best experts on this subject based on the ideXlab platform.

  • Field-induced electric switching in sol–gel-derived Sio2 Films
    Applied Physics Letters, 2003
    Co-Authors: Scott Ward, Q. Wang
    Abstract:

    The switching dynamics of sol–gel-derived Sio2 Films is investigated using voltage pulses over durations from 300 ns to 1 s and amplitudes from 1 to 20 V. The Sio2 Film was fabricated using a spin-coating technique and annealed at 100 °C. The shortest switching transit time is found to be on the order of 10 ns. A delay time ranging from 100 ns to 500 ms is usually observed prior to switching, which changes exponentially with the electric field at switching, and also depends strongly on the area of the device.

Hiroyuki Oyanagi - One of the best experts on this subject based on the ideXlab platform.