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[Keyword] oxide(116hit)

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  • Counter-Measures for Relay Failures due to Dynamic Welding: A Robust Engineering Design

    Thomas J. SCHOEPF  

     
    PAPER-Electromechanical Devices and Components

      Vol:
    E92-C No:5
      Page(s):
    728-735

    In prior work, contact welding phenomena were observed in automotive relays during break of motor inrush current. The switching performance of the type of relay investigated could be correlated with the parameters: over-travel, coil suppression, and the break current. In the present work the author further explores the impact of both the contact material (silver tin oxide versus fine grain silver) and the contact surface topography (brand new and pre-aged contacts). He further assesses the robustness of the system "relay" with those parameters using the Taguchi methods for robust design. Furthermore, the robustness of two alternative automotive relay types will be discussed.

  • Conducting Polymer Based Nucleic Acid Sensor for Environment Monitoring

    Bansi Dhar MALHOTRA  Nirmal PRABHAKAR  Pratima R. SOLANKI  

     
    INVITED PAPER

      Vol:
    E91-C No:12
      Page(s):
    1889-1893

    Nucleic acid sensor based on polyaniline has been fabricated by covalently immobilizing double stranded calf thymus (dsCT) DNA onto perchlorate (ClO- 4) doped polyaniline (PANI) film deposited onto indium-tin-oxide (ITO) glass plate using 1-(3-(dimethylamino) propyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS) chemistry. These dsCT-DNA-PANI/ITO and PANI/ITO electrodes have been characterized using square wave voltammetry, electrochemical impedance, and Fourier-transform-infra-red (FTIR) measurements. This disposable dsCT-DNA-PANI/ITO bioelectrode is stable for about four months, can be used to detect arsenic trioxide (0.1 ppm) in 30 s.

  • High-κ Dielectric Layers for Bioelectronic Applications

    Dirk BORSTLAP  Jurgen SCHUBERT  Willi ZANDER  Andreas OFFENHAUSSER  Sven INGEBRANDT  

     
    INVITED PAPER

      Vol:
    E91-C No:12
      Page(s):
    1894-1898

    In many different bioelectronic applications silicon field-effect devices such as transistors or nanowires are used. Usually native or thermally grown silicon oxides serve as interfacing layer to the liquid. For an effective voltage to current conversion of the devices, the main demands for interface layers are low leakage current, low defect density, and high input capacitance. In this article we describe the fabrication and characterization of ultra-thin silicon oxide/high-κ material stacks for bioelectronics. A combination of ultra-thin silicon oxide and DyScO3 revealed the best results. This material stack is particularly interesting for future fabrication of field-effect devices for bioelectronic applications.

  • Characterization of Zinc Oxide and Pentacene Thin Film Transistors for CMOS Inverters

    Hiroyuki IECHI  Yasuyuki WATANABE  Hiroshi YAMAUCHI  Kazuhiro KUDO  

     
    PAPER-Transistors

      Vol:
    E91-C No:12
      Page(s):
    1843-1847

    We fabricated both thin film transistors (TFTs) and diodes using zinc oxide (ZnO) and pentacene, and investigated their basic characteristics. We found that field-effect mobility is influenced by the interface state between the semiconductor and dielectric layers. Furthermore, the complementary metal oxide semiconductor (CMOS) inverter using a p-channel pentacene field-effect transistor (FET) and an n-channel ZnO FET showed a relatively high voltage gain (8-12) by optimizing the device structure. The hybrid complementary inverters described here are expected for application in flexible displays, radio frequency identification cards (RFID) tags, and others.

  • A Complementary-Coupled CMOS LC Quadrature Oscillator

    Seok-Ju YUN  Dae-Young YOON  Sang-Gug LEE  

     
    PAPER-Electronic Circuits

      Vol:
    E91-C No:11
      Page(s):
    1806-1810

    A novel CMOS LC quadrature oscillator (QO) which adopts complementary-coupling circuitry has been proposed. The performance improvement in I/Q phase error and phase noise of the proposed QO, is explained in comparison with conventional QOs. The proposed QO is implemented in 0.18 µm CMOS technology along with conventional QOs. The measurement result of the proposed QO shows -133.5 dBc/Hz of phase noise at 1 MHz offset and 0.6 I/Q phase difference, while oscillating at 1.77 GHz. The proposed QO shows more than 6.5 dB phase noise improvement compared to that of the conventional QOs over the offset frequency range of 10 K-1 MHz, while dissipating 4 mA from 1.4 V supply.

  • Estimation of Optimum Ion Energy for the Reduction of Resistivity in Bias Sputtering of ITO Thin Films

    Kiyoshi ISHII  Yoshifumi SAITOU  Kengo FURUTANI  Hiroshi SAKUMA  Yoshito IKEDA  

     
    PAPER

      Vol:
    E91-C No:10
      Page(s):
    1653-1657

    Tin-doped indium oxide (ITO) thin films were prepared on a polyethylene terephthalate (PET) foil by bias sputtering. In the absence of a substrate bias, films having a high resistivity of 210-2 Ωcm were formed. On the other hand, by the application of an rf substrate bias, films having a low resistivity of 2.610-4 Ωcm were formed. The energy of ions that bombarded the substrate during bias sputtering was estimated by a simulation of the ion acceleration. The optimum ion-energy required for the reduction of resistivity was found to be approximately 50 eV.

  • Investigation of Low-Damage Sputter-Deposition of ITO Films on Organic Emission Layer

    Hao LEI  Keisuke ICHIKAWA  Meihan WANG  Yoichi HOSHI  Takayuki UCHIDA  Yutaka SAWADA  

     
    PAPER

      Vol:
    E91-C No:10
      Page(s):
    1658-1662

    The damage to the organic layer of aluminum (III) bis(2-methyl-8-quninolinato)-4-phenylphenolate (BAlq) film was investigated on the basis of the change in photoluminescence (PL) intensity. To suppress the bombardment of the substrate with high-energy particles such as γ-electrons and negative oxygen ions, we used a facing-target sputtering (FTS) system. A marked reduction, however, of the PL intensity of the organic layer was still observed upon the deposition of an indium tin oxide (ITO) film on the organic film. To reduce this reduction, we proposed the insertion of a sector-shaped metal shield near the target electrode, and we showed its effectiveness in reducing the damage. This reduction of the damage is thought to be caused by the elimination of γ-electrons incident to the organic film surface escaping from the target area near the substrate side. We confirmed that high-energy electron bombardment leads to a significant reduction of PL intensity of the organic layer. This indicates that high-energy electrons incident to the organic film surface play a key role in the damage of the organic layer during the sputtering process.

  • Observation of Blue-Light Emission from Tantalum Oxide Films Deposited by Radio-Frequency Magnetron Sputtering

    Kenta MIURA  Hiroki MIYAZAKI  Osamu HANAIZUMI  

     
    PAPER

      Vol:
    E91-C No:10
      Page(s):
    1669-1672

    We obtained blue photoluminescence from tantalum oxide films deposited by radio-frequency magnetron sputtering after annealing. The maximum peak intensity of the photoluminescence was observed from a sample annealed at 600 for 20 min, and the peak wavelength was approximately 430 nm. Tantalum oxide films that emit blue light may be useful materials for novel active optical devices utilizing Ta2O5/SiO2 multilayered photonic crystals.

  • Circuit Performance Degradation of Switched-Capacitor Circuit with Bootstrapped Technique due to Gate-Oxide Overstress in a 130-nm CMOS Process

    Jung-Sheng CHEN  Ming-Dou KER  

     
    PAPER-Electronic Circuits

      Vol:
    E91-C No:3
      Page(s):
    378-384

    The MOS switch with bootstrapped technique is widely used in low-voltage switched-capacitor circuit. The switched-capacitor circuit with the bootstrapped technique could be a dangerous design approach in the nano-scale CMOS process due to the gate-oxide transient overstress. The impact of gate-oxide transient overstress on MOS switch in switched-capacitor circuit is investigated in this work with the sample-and-hold amplifier (SHA) in a 130-nm CMOS process. After overstress on the MOS switch of SHA with unity-gain buffer, the circuit performances in time domain and frequency domain are measured to verify the impact of gate-oxide reliability on circuit performances. The oxide breakdown on switch device degrades the circuit performance of bootstrapped switch technique.

  • "Front Drive" Display Structure for Color Electronic Paper Using Fully Transparent Amorphous Oxide TFT Array

    Manabu ITO  Masato KON  Chihiro MIYAZAKI  Noriaki IKEDA  Mamoru ISHIZAKI  Yoshiko UGAJIN  Norimasa SEKINE  

     
    INVITED PAPER

      Vol:
    E90-C No:11
      Page(s):
    2105-2111

    We demonstrate a novel display structure for color electronic paper for the first time. Fully transparent amorphous oxide TFT array is directly deposited onto color filter array and combined with E Ink Imaging Film. Taking advantage of the transparent property of the oxide TFT, the color filter and TFT array are positioned at the viewing side of the display. This novel "Front Drive" display structure facilitates the alignment of the color filter and TFT dramatically.

  • Pre-Conditioning Automotive Relay Contacts to Increase Their Resistance to Dynamic Welding

    Thomas J. SCHOEPF  Abdellah BOUDINA  Robert D. ROWLANDS  Brent T. REPP  

     
    PAPER-Relays & Switches

      Vol:
    E90-C No:7
      Page(s):
    1441-1447

    Electromechanical switching devices such as relays may be surprisingly forgiving to occasional, but temporary, electrical stress beyond specification. Consequently delayed openings due to welded contacts on the order of milliseconds usually have been unnoticed and hence have not been reason for concern. However, as electrical systems of vehicles are getting "smarter" and more and more diagnostic routines are being implemented, even such short delay times may be translated as errors. Pre-conditioning contact surfaces has been explored as a measure to increase the welding resistance and eliminate contact opening delays. The 20-A-class relay investigated has been optimized to break occasional current peaks up to 80 ADC.

  • Effect of Humidity on Growth of Oxide Film on Surface of Copper Contacts

    Terutaka TAMAI  

     
    PAPER-Contact Phenomena

      Vol:
    E90-C No:7
      Page(s):
    1391-1397

    Contact surfaces are exposed to the atmosphere in general applications. Therefore, gases in the atmosphere such as oxygen and H2O are adsorbed on and react with the contact surface. Products formed on the surface such as copper oxide films degrade contact resistance characteristics. This surface contamination is an important problem for electrical contact applications. The author has studied the effect of humidification on contact resistance characteristics. In this paper, the effect of humidity on the growth of an oxide film on a copper surface was clarified. An increase in the humidity results in a decrease in the thickness, in contrast, a decrease in the humidity increases the thickness linearly. Changes in the oxide film thickness based on the level of humidity were measured by ellipsometry. Surface state changes influenced by humidification were analyzed topographically using a scanning tunneling microscope. The mechanism of the effect of humidity on the film thickness was discussed on the basis of the deduction of the copper oxide film by H2 from the adsorbed H2O. Moreover, the changes in contact resistance levels for both static and sliding contacts due to humidity were measured, and a dependence on humidity was found.

  • Analysis of the Behavior of Cuprous Oxide by Acceleration Test for Evaluation of Heat and Fire Phenomena of Imperfectly Connected Electrical Terminal

    Yoichi AOYAMA  Hisa NUMA  Ryo FUJITA  

     
    PAPER-Contact Phenomena

      Vol:
    E90-C No:7
      Page(s):
    1398-1404

    To evaluate heat and fire phenomena caused by accumulated microslide motion on an imperfectly connected electrical terminal, an acceleration test method using vibrator was developed. The process from the generation of CuO to that of Cu2O has been reproduced. The influence of current is investigated, and it is found that as current increases, CuO generation time T1 and Cu2O generation time T2 decrease for pure copper, however when current exceeds 3 A, we could not produce CuO or Cu2O. The contact resistances of a Cu terminal and wire, compared with the terminal material were investigated in terms of the effects of current and ambient temperature.

  • Physical Origin of Stress-Induced Leakage Currents in Ultra-Thin Silicon Dioxide Films

    Tetsuo ENDOH  Kazuyuki HIROSE  Kenji SHIRAISHI  

     
    PAPER-Ultra-Thin Gate Insulators

      Vol:
    E90-C No:5
      Page(s):
    955-961

    The physical origin of stress-induced leakage currents (SILC) in ultra-thin SiO2 films is described. Assuming a two-step trap-assisted tunneling process accompanied with an energy relaxation process of trapped electrons, conditions of trap sites which are origin of SICL are quantitatively found. It is proposed that the trap site location and the trap state energy can be explained by a mean-free-path of hole in SiO2 films and an atomic structure of the trap site by the O vacancy model.

  • Evidences for Adsorption of Heptyl Viologen Cation Radicals in Thin Deposition Layers on ITO Electrodes by Slab Optical Waveguide Spectroscopy

    Yusuke AYATO  Akiko TAKATSU  Kenji KATO  Naoki MATSUDA  

     
    PAPER-Evaluation of Organic Materials

      Vol:
    E89-C No:12
      Page(s):
    1750-1754

    In situ observations were mainly performed by using slab optical waveguide (SOWG) spectroscopy synchronized with potential step measurements to investigate the time dependent spectral change of the adsorbed heptyl viologen cation radicals (HV+) in thin deposition layer on indium-tin-oxide (ITO) electrodes. Several absorption bands, which indicated a monomer and dimer of HV+ were co-adsorbed on ITO electrode surface with a monolayer or a few layers deposition, were observed in UV-visible region. The time dependent spectra yielded some important molecular information for the adsorption phenomena of HV+ on the electrode surface. All observed absorption bands disappeared completely when the electrode potential of -200 mV vs. Ag/AgCl was applied, which indicated the adsorbed HV+ species were electrochemically reoxidized on the ITO electrode.

  • RFCV Test Structure Design for a Selected Frequency Range

    Wutthinan JEAMSAKSIRI  Abdelkarim MERCHA  Javier RAMOS  Stefaan DECOUTERE  Florence CUBAYNES  

     
    PAPER

      Vol:
    E88-C No:5
      Page(s):
    817-823

    The problems with the CV characterization on very leaky (thin) nitrided oxide are mainly due to the measurement precision and MOS gate dielectric model accuracy. By doing S-parameter measurement at RF frequency and using simple but reasonably accurate model, we can obtain proper CV curves for very thin nitrided gate dielectrics. Regarding the measurement frequency we propose a systematic method to find a frequency range in which we can select measurement frequencies for all biases to obtain a full CV curve. Moreover, we formulated the first order relationship between the measurement frequency range and the test structure design for CV characterization. With the established formulae, we redesigned the test structures and verified that the formulae can be used as a guideline for the test structure design for RFCV measurements.

  • Improvement in Retention/Program Time Ratio of Direct Tunneling Memory (DTM) for Low Power SoC Applications

    Kouji TSUNODA  Akira SATO  Hiroko TASHIRO  Toshiro NAKANISHI  Hitoshi TANAKA  

     
    PAPER-Memory

      Vol:
    E88-C No:4
      Page(s):
    608-613

    A direct tunneling memory (DTM) with ultra-thin tunnel oxide and depleted floating gate has been proposed for low power embedded RAM. To achieve excellent charge retention characteristics with ultra-thin tunnel oxide, floating gate depletion is adopted to utilize the band bending at the interface between floating gate and tunnel oxide in charge retention period. The depleted floating gate is also effective to suppress the degradation of program/erase speed caused by the gate re-oxidation process. These effects were evaluated by the device and process simulations and confirmed by the experimental data. As a consequence, both fast programming time and superior retention time have been achieved, which is a promising performance as a low power embedded RAM for system-on-a-chip (SoC) applications.

  • Electrical Characterization of Aluminum-Oxynitride Stacked Gate Dielectrics Prepared by a Layer-by-Layer Process of Chemical Vapor Deposition and Rapid Thermal Nitridation

    Hideki MURAKAMI  Wataru MIZUBAYASHI  Hirokazu YOKOI  Atsushi SUYAMA  Seiichi MIYAZAKI  

     
    PAPER-Si Devices and Processes

      Vol:
    E88-C No:4
      Page(s):
    640-645

    We investigated the use of AlOx:N/SiNy stacked gate dielectric as an alternate gate dielectric, which were prepared by alternately repeating sub-nanometer deposition of Al2O3 from an alkylamine-stabilized AlH3 + N2O gas mixture and rapid thermal nitridation in NH3. The negative fix charges, being characteristics of almina, were as many as 3.91012 cm-2 in the effective net charge density. The effective dielectric constant and the breakdown field were 8.9 and 8 MV/cm, respectively, being almost the same as pure Al2O3. And we have demonstrated that the leakage current through the AlOx:N/SiNy stacked gate dielectric with a capacitance equivalent thickness (CET) of 1.9 nm is about two orders of magnitude less than that of thermally-grown SiO2. Also, we have confirmed the dielectric degradation similar to the stress-induced leakage current (SILC) mode and subsequent soft breakdown (SBD) reported in ultrathin SiO2 under constant current stress and a good dielectric reliability comparable to thermally-grown ultrahin SiO2. From the analysis of n+poly-Si gate metal-insulator-semiconductor field effect transistor (MISFET) performance, remote coulomb scattering due to changes in the gate dielectric plays an important role on the mobility degradation of MISFET with AlON/SiON gate stack.

  • Effect of Driving Frequency on the EL Characteristics of Thick Ceramic Insulating Type TFEL Devices Using Y2O3-Based Phosphor Emitting Layer

    Toshihiro MIYATA  Yasuyuki SUZUKI  Kazuhiko IHARA  Tadatsugu MINAMI  

     
    INVITED PAPER

      Vol:
    E87-C No:11
      Page(s):
    1970-1974

    The driving frequency dependence of EL characteristics were investigated in thick ceramic insulating type thin-film electroluminescent (TFEL) devices with various Mn-activated Y2O3-based phosphor thin-film emitting layers driven by a sinusoidal wave voltage. High luminous efficiencies of approximately 10 and 1 lm/W were obtained in the TFEL devices driven at 60 Hz and 1 kHz, respectively. The difference in luminous efficiency was mainly caused by the increase of input power in 1 kHz-driven-devices resulting from a dielectric loss of a thick BaTiO3 ceramic sheet used as the insulating layer. The correlation between the sound emission from the devices and the effective power consumed in the devices was found with variations in both the applied voltage and the frequency. The higher input power of the 1 kHz-driven-device may be attributable to sound emissions resulting from the piezo-electricity of BaTiO3 ceramics.

  • High Rate Sputter-Deposition of TiO2 Films Using Oxide Target

    Yoichi HOSHI  Tomoki TAKAHASHI  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    227-231

    The sputter-deposition process of TiO2 thin films was investigated. When an oxide target is used, high-rate deposition above 57 nm/min can be realized by sputtering under a condition of low oxygen gas content. Under this sputtering condition, a Ti rich surface layer is formed by selective sputtering of oxygen atoms, and a large amount of Ti atoms are sputtered from this layer. The deposition rate, however, decreases steeply as the oxygen gas content increases. This decrease can be explained as follows. When a sufficient amount of oxygen gas is supplied into the chamber during sputtering, the oxygen atoms which are missing from the target surface by selective sputtering are filled up immediately. This leads to a very low deposition rate of the film, because only oxygen atoms are sputtered from the target. Therefore, the suppression of the incidence of oxygen gas to the target surface and a sufficient of oxygen supply to the substrate are necessary to realize the high-rate deposition of stoichiometric TiO2 films. From this point of view, using an oxide target instead of a metal target is useful for realizing a stable high-rate deposition of the film, since the amount of oxygen gas introduced in to the sputtering chamber can be reduced significantly. In addition, it was confirmed that pulse sputtering method is a useful technique for the deposition of TiO2 thin films. Meanwhile, low-voltage sputtering technique was difficult to use for the film deposition because of its low deposition rate.

41-60hit(116hit)