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[Keyword] metal(132hit)

61-80hit(132hit)

  • Preparation of Double-Sided YBCO Films on LaAlO3 by MOD Using Commercially Available Coating Solution

    Takaaki MANABE  Jun Hyun AHN  Iwao YAMAGUCHI  Mitsugu SOHMA  Wakichi KONDO  Ken-ichi TSUKADA  Kunio KAMIYA  Susumu MIZUTA  Toshiya KUMAGAI  

     
    PAPER

      Vol:
    E89-C No:2
      Page(s):
    186-190

    The 5-cm-diameter double-sided YBa2Cu3O7 (YBCO) films were prepared by metal organic deposition (MOD) using a commercially available metal-naphthenate coating solution. Firstly, YBCO film was prepared by MOD on one side of a double-side-polished 5-cm-diameter LaAlO3 substrate. Secondly, another side was similarly coated with YBCO by MOD. After the latter processing, degradation of average Jc value in the first side was not observed; but the fluctuation of critical current density Jc slightly increased. The double-sided YBCO films showed average Jc values of 0.8-1.0 MA/cm2 at 77 K and microwave surface resistances Rs(12 GHz) of 0.86-1.07 mΩ at 70 K.

  • Efficient Dummy Filling Methods to Reduce Interconnect Capacitance and Number of Dummy Metal Fills

    Atsushi KUROKAWA  Toshiki KANAMOTO  Tetsuya IBE  Akira KASEBE  Wei Fong CHANG   Tetsuro KAGE  Yasuaki INOUE  Hiroo MASUDA  

     
    PAPER-Interconnect

      Vol:
    E88-A No:12
      Page(s):
    3471-3478

    Floating dummy metal fills inserted for planarization of multi-dielectric layers have created serious problems because of increased interconnect capacitance and the enormous number of fills. We present new dummy filling methods to reduce the interconnect capacitance and the number of dummy metal fills needed. These techniques include three ways of filling: 1) improved floating square fills, 2) floating parallel lines, and 3) floating perpendicular lines (with spacing between dummy metal fills above and below signal lines). We also present efficient formulas for estimating the appropriate spacing and number of fills. In our experiments, the capacitance increase using the conventional regular square method was 13.1%, while that using the methods of improved square fills, extended parallel lines, and perpendicular lines were 2.7%, 2.4%, and 1.0%, respectively. Moreover, the number of necessary dummy metal fills can be reduced by two orders of magnitude through use of the parallel line method.

  • A Practical Approach for Efficiently Extracting Interconnect Capacitances with Floating Dummy Fills

    Atsushi KUROKAWA  Toshiki KANAMOTO  Akira KASEBE  Yasuaki INOUE  Hiroo MASUDA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E88-A No:11
      Page(s):
    3180-3187

    We present a practical method of dealing with the influences of floating dummy metal fills, which are inserted to assist planarization by chemical-mechanical polishing (CMP) process, in extracting interconnect capacitances for system-on-chip (SoC) designs. The method is based on reducing the thicknesses of dummy metal layers according to electrical field theory. We also clarify the influences of dummy metal fills on the parasitic capacitance, signal delay, and crosstalk noise. Moreover, we address that interlayer dummy metal fills have more significant influences than intralayer ones in terms of the impact on coupling capacitances. When dummy metal fills are ignored, the error of capacitance extraction can be more than 30%, whereas the error of the proposed method is less than about 10% for many practical geometries. We also demonstrate, by comparison with capacitance results measured for a 90-nm test chip, that the error of the proposed method is less than 8%.

  • The Influence of the Stacked and Double Material Gate Structures on the Short Channel Effects in SOI MOSFETS

    Ehsanollah FATHI  Ashkan BEHNAM  Pouya HASHEMI  Behzad ESFANDYARPOUR  Morteza FATHIPOUR  

     
    PAPER-Device

      Vol:
    E88-C No:6
      Page(s):
    1122-1126

    An asymmetric Dual Metal Stack Gate (DMSG) SOI MOSFET transistor has been investigated for its enhanced electrical characteristics. A 2-D physical model has been proposed and its results have been confirmed by those obtained by simulation. These results predict better short channel effects such as drain induced barrier lowering (DIBL) characteristics and hot carrier effects for this device compared to those for conventional SOI MOSFETs. The effects of the Stacked Gate (SG) and Dual Metal Gate (DMG) structures on short channel effects are compared. It has been observed that SG reduces DIBL significantly, while DMG prevents the normal roll-off of the threshold voltage reduction.

  • Gate-Last MISFET Structures and Process for Characterization of High-k and Metal Gate MISFETs

    Takeo MATSUKI  Kazuyoshi TORII  Takeshi MAEDA  Yasushi AKASAKA  Kiyoshi HAYASHI  Naoki KASAI  Tsunetoshi ARIKADO  

     
    PAPER

      Vol:
    E88-C No:5
      Page(s):
    804-810

    We propose new test device structures, Gate-Last-formed structures, which are suitable for fundamental study of high-k gate insulator or metal gate electrode MISFETs. The gate insulator and electrode stack is formed after local interconnect pads connected with source and drain. The gate stack is build in trench formed by dry and wet etching and is non-self-aligned to the source and drain. The wet etching restricts damage formation on the exposed Si surface underneath the trench. Electrical characteristics are measurable just after exposure of surface of the local interconnect pads without conventional Al wiring. This structure can provide methods both for fundamental evaluation and for material selection of new gate stack materials by investigation of MISFET characteristics. This is achieved with short TAT and avoiding contamination penalty to a fab.

  • Effects of Electric Field on Metal-Induced Lateral Crystallization under Limited Ni-Supply Condition

    Gou NAKAGAWA  Noritoshi SHIBATA  Tanemasa ASANO  

     
    PAPER-Thin Film Transistors

      Vol:
    E88-C No:4
      Page(s):
    662-666

    The role of electric field in metal-induced lateral crystallization (MILC) of amorphous Si (a-Si) under limited Ni-supply condition has been investigated. The nominal lateral-growth rate was increased from 3.6 µm/h (no-electric field) to 23 µm/h at the positive electrode side and reduced to 2.8 µm/h at the negative electrode side in presence of the electric field of 20 V/cm. However, spontaneously nucleated needle-like Si crystals were observed in the enhanced positive electrode side, which have been found to be independent of the MILC. Further investigation under the condition where Ni in the supply region was removed on the way of crystallization revealed that the electric field enhanced crystallization greatly reduced. These results indicate that the electric field does not enhance the MILC growth but enhances the diffusion of Ni in a-Si which takes place prior to the MILC growth.

  • FDTD Simulation of Shielding Effectiveness of Metal-Coated Plastics for Pulsed Electromagnetic Fields

    Jianqing WANG  Tetsuji TSUCHIKAWA  Osamu FUJIWARA  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Vol:
    E88-B No:1
      Page(s):
    358-363

    The use of metal-coated plastics is increasing as shielding materials of electronic and information products due to their lightweight. In this paper, a finite-difference time-domain (FDTD) algorithm, based on the derivation of a time-domain representation of the surface impedance of an equivalent resistive film, was developed to analyze the electromagnetic penetration of pulsed electromagnetic fields through metal-coated plastics. The validity of the proposed algorithm, in both the far-field and near-field cases, was verified by comparing the calculated penetrated electromagnetic fields or shielding effectiveness with theoretical and measured ones. Good agreement between them demonstrated the usefulness of the FDTD algorithm.

  • A Template Matching Method Based on Marker-Controlled Watershed Segmentation

    Yi HU  Tomoharu NAGAO  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E87-D No:10
      Page(s):
    2389-2398

    This paper presents a new template matching method based on marker-controlled watershed segmentation (TMCWS). It is applied to recognize numbers on special metal plates in production lines where traditional image recognition methods do not work well. TMCWS is a shape based matching method that uses different pattern images and their corresponding marker images as probes to explore a gradient space of an unknown image to determine which pattern best matches a target object in it. Different from other matching algorithms, TMCWS firstly creates a marker image for each pattern, and then takes both the pattern image and its corresponding marker image as a template window and shifts this window across a gradient space pixel by pixel to do a search. At each position, the marker image is used to try to extract the contour of the target object with the help of marker-controlled watershed segmentation, and the pattern image is employed to evaluate the extracted shape in each trial. All of the pattern images and their corresponding marker images are tried and the pattern that best matches the target object is the recognition result. TMCWS contains shape extraction procedures and it is a high-level template matching method. Experiments are performed with this method on nearly 400 images of metal plates and the test results show its effectiveness in recognizing numbers in noisy images.

  • Availability of Resistive Boundary Condition for Thin Metallic Gratings Placed in Conical Mounting

    Hideaki WAKABAYASHI  Jiro YAMAKITA  Masamitsu ASAI  Hiroshi INAI  

     
    PAPER-Basic Electromagnetic Analysis

      Vol:
    E87-C No:9
      Page(s):
    1560-1567

    The scattering problem by metallic gratings has become one of fundamental problems in electromagnetics. In this paper, a thin metallic grating placed in conical mounting is treated as a lossy dielectric grating expressed by complex permittivity and thickness. The solution of the metallic grating by using the matrix eigenvalue calculations is compared with that of the plane grating by using the resistive boundary condition and the spectral Galerkin procedure, and the availability of the resistive boundary condition for thin metallic gratings in conical mounting is investigated. In order to improve the convergence of the solutions of thin metallic gratings, the spatial harmonics of flux densities which are continuous function instead of electromagnetic fields are used.

  • 40-Gbit/s 16-bit Burst Optical Packet Generator Based on Photonic Parallel-to-Serial Conversion

    Hirokazu TAKENOUCHI  Kiyoto TAKAHATA  Tatsushi NAKAHARA  Ryo TAKAHASHI  Hiroyuki SUZUKI  

     
    LETTER-Optoelectronics

      Vol:
    E87-C No:5
      Page(s):
    825-827

    We propose a burst optical packet generator based on a novel photonic parallel-to-serial conversion scheme, and demonstrate 40-Gbit/s 16-bit optical packet generation from 16-ch parallel low-voltage TTL data streams. It consists of electrical 4:1 parallel-to-serial converters that employ InP metal-semiconductor-metal photodetectors, and an optical time-domain multiplexer with electroabsorption modulators. The proposed optical packet generator is suitable for burst optical packet generation and overcomes the electronic bandwidth limitation, which is prerequisite for achieving high-speed photonic packet switched networks. In addition, it can be driven by simple low-cost low-power CMOS logic circuits, and is compact and extensible in terms of the number of input channels due to the effective combination of electrical and optical multiplexing.

  • Design of Novel Parallel-Coupled Band-Pass Filter with Dielectric Guide in Coupled Sections

    Ic-Pyo HONG  Seong-Kyun PARK  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E87-C No:3
      Page(s):
    423-424

    In this letter, we present the new type parallel-coupled band-pass filter (BPF) which uses the dielectric guide in coupled sections with finite metallization thickness. A mode-matching method has been used to analyze this new structure and the simulation results are shown and validated through comparison with other available data. The results in this letter show that the dielectric guide of coupled lines with finite metal strips can be newly added to the design parameters of the parallel-coupled BPF structure and other microwave applications.

  • Magnetic and Electric Properties of Fe3O4 Thin Films Sputtered on Metallic Underlayer

    Fei QIN  Yukio NOZAKI  Kimihide MATSUYAMA  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    189-192

    High-quality Fe3O4 thin films have been fabricated onto metallic underlayers of Cr/Cu and Al by rf-magnetron sputtering at low substrate temperatures (<573 K). The measured saturation magnetizations Ms are 462 emu/cm3 for Al (50 nm)/Fe3O4 (200 nm) and 422 emu/cm3 for Cr (45 nm)/Cu (300 nm)/Fe3O4 (200 nm), which are markedly enhanced compared with that for the reference sample deposited directly on a glass substrate, and practically comparable to the bulk value of 477 emu/cm3. Highly conductive transport with an order-disorder change of the Verwey transition was observed in the current-perpendicular-to-plane geometry. The order of decrease in coercive field was achieved by exchange coupling with an overlaid NiFe layer.

  • Thermal Stability of W2N Compound Barrier in W/W2N/poly-Si Gate Electrode Configuration

    Atsushi NOYA  Mayumi B. TAKEYAMA  

     
    LETTER-Electronic Materials

      Vol:
    E86-C No:11
      Page(s):
    2332-2335

    A high temperature performance of a W2N compound barrier in the model electrode configuration of W/W2N/poly-Si was examined. The stacked electrode was fairly stable upon annealing at 850 for 1 h. In this electrode configuration, the decomposition and outdiffusion of nitrogen, which were observed in the electrode with a WNx barrier incorporating nitrogen atoms at the interstitial sites in the bcc W lattice, were completely suppressed. We interpreted that the obtained excellent high temperature performance was attributed to the strong chemical interaction forming chemical bonds between nitrogen and W atoms in the W2N compound barrier.

  • Equivalent Circuit Model of InAlAs/InGaAs/InP Heterostructure Metal-Semiconductor-Metal Photodetectors

    Koichi IIYAMA  Junya ASHIDA  Akira TAKEMOTO  Saburo TAKAMIYA  

     
    PAPER-Lasers, Quantum Electronics

      Vol:
    E86-C No:11
      Page(s):
    2278-2282

    One-dimentional equivalent circuit model of a heterostructure InAlAs/InGaAs/InP metal-semiconductor-metal photodetector is discussed. In this photodetector, InGaAs is used as an optical absorption layer and the InAlAs is used for Schottky barrier enhanement. The measured S11 parameter deviates from equi-resistance lines on the Smith chart, indicating the equivalent circuit is different from the conventional equivalent circuit using a series resistance, a depletion region capacitance and a depletion region resistance. The difference is due to band discontinuity at the heterojunctions, and we propose a equivalent circuit taking account of the band discontinuity. The band discontinuity is expressed by parallel combination of a resistance and a capacitance. The measured S11 parameter can be fitted well with the calculated S11 parameter from the proposed equivalent circuit, and we can successfully extract the device parameters from the fitted curve.

  • Three-Dimensional (FD)2TD Analysis of Light-Beam Diffraction from Phase-Change Optical Disks with Land/Groove Recording Structures

    Toshitaka KOJIMA  Hisashi HOTTA  Yuji ASANO  

     
    PAPER

      Vol:
    E86-C No:9
      Page(s):
    1861-1867

    The present paper deals with the frequency-dependent finite difference time domain ((FD)2TD) method analysis of the light-beam diffraction from a land/groove recording phase-change (PC) disk model with a metal (Al or Au) reflective layer in order to improve the conventional analysis for PC optical disk models with a perfectly conducting reflective layer. The diffracted fields are numerically calculated for both recorded and non-recorded states of the recording layer, and the comparison of the detected signal characteristics between two states is discussed. The crosstalk between the recording marks on lands and grooves are evaluated and the optimum groove depth is examined for Al,Au and perfectly conducting layer models.

  • High-Temperature Superconducting CPW Bandpass Filters Using Meander-Line Parallel-Circuited Resonators

    Atsushi SANADA  Takahiro HAMAMURA  Ikuo AWAI  

     
    PAPER

      Vol:
    E86-C No:8
      Page(s):
    1729-1736

    A compact high-temperature superconducting (HTS) bandpass filter (BPF) using coplanar waveguide (CPW) meander-line parallel-circuited resonators is proposed for microwave receiver applications. The design theory is presented based on a conventional filter theory with J-inverters. Also, analytical and numerical studies of the meander-line resonator are carried out in terms of equivalent circuit values, the resonant frequency, and the unloaded Q. Two- and four-stage 0.05 dB ripple Chebyshev BPFs at 2 GHz with relative bandwidth 60 MHz are fabricated with the metalorganic deposition (MOD)-derived YBCO films on LaAlO3 substrates and their performance are demonstrated. The measured frequency characteristics and the unloaded quality factors agree well with the theoretical and numerical results and the validity of the design theory is confirmed.

  • Improvements of Crystal Orientations of Wurtzite-Type GaN Thin Films Grown on Metal Surfaces

    Yuichi SATO  Toshifumi HISHINUMA  Susumu SATO  

     
    PAPER-Emerging Technologies

      Vol:
    E86-C No:6
      Page(s):
    1002-1006

    Gallium nitride (GaN) is one of the wurtzite-type materials and has semiconducting properties. Crystallinities of GaN thin films are usually poor when they are directly grown on polycrystalline metal-foils which are expected as substrates for realizing novel giant microelectronic devices. Improvements of crystal orientations of GaN thin films grown on such polycrystalline metal-foils are tried by using several kinds of intermediate layers. Aluminum nitride (AlN), GaN, silicon dioxide (SiO2) and Si are chosen as materials for the intermediate layers. The crystal orientations of GaN thin films grown by inserting the SiO2 and Si intermediate layers with adequate thicknesses are markedly improved, while those grown on the AlN or GaN intermediate layers are not improved. These differences are not caused by the kinds of the materials used for the intermediate layers but by differences in their crystallinities.

  • Metal Nanostructure of Metal/Organic Interface Causing Photocurrent Multiplication Phenomenon

    Masahiro HIRAMOTO  Ichiro SATO  Masaaki YOKOYAMA  

     
    LETTER-Electronic Devices

      Vol:
    E85-C No:6
      Page(s):
    1253-1255

    Metal nanostructure of organic/metal interface showing photocurrent multiplication phenomenon more than 105-fold was investigated. Au films deposited on organic films were revealed to be a gathering of nanoparticles and the multiplication rate can be tuned by the particle size. Spatial gaps formed between Au sphere and organic surface, which provide the hole accumulation sites (structural trap), was concluded to be indispensable for the photocurrent multiplication.

  • Uniform Raised-Salicide Technology for High-Performance CMOS Devices

    Hitoshi WAKABAYASHI  Takeshi ANDOH  Tohru MOGAMI  Toru TATSUMI  Takemitsu KUNIO  

     
    PAPER

      Vol:
    E85-C No:5
      Page(s):
    1104-1110

    A uniform raised-salicide technology has been investigated using both uniform selective-epitaxial-growth (SEG) silicon and salicide films, to reduce a junction leakage current of shallow source/drain (S/D) regions for high-performance CMOS devices. The uniform SEG-Si film without pits is formed by using a wet process, which is a carbon-free oxide removal only using a dilute hydrofluoric acid (DHF) dipping, prior to the Si-SEG process. After a titanium-salicide formation using a conventional two-step salicide process, this uniform SEG-Si film achieves good S/D junction characteristics. The uniform titanium-salicide film without bowing into a silicon is formed by a smaller Ti/SEG-Si thickness ratio, which results in a low sheet resistance of 5 Ω/sq. without a narrow-line effect. Furthermore, the drive current is maximized by this raised-salicide film using a Ti/SEG-Si thickness ratio of 1.0.

  • Interconnection of Stacked Layers by Bumpless Wiring in Wafer-Level Three-Dimensional Device

    Akinobu SATOH  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1746-1755

    This paper describes the wafer-level, three-dimensional packaging for MEMS in which sensors, actuators, electronic circuits and other functions are combined together in one integrated block. Si wafers with built-in MEMS functions were integrated with no change in thickness to ensure mechanical strength and improve heat dissipation. In the entire process of three-dimensional integration, Si wafers were processed at temperatures below 400C to prevent degradation of their built-in functions. A description is made of the low-temperature oxidation technology developed by us, which makes through-holes of high density and high aspect ratio in Si wafers with built-in functions by the Optical Excitation Electropolishing Method (OEEM) and forms an oxide film on the hole walls simply by replacing electrolyte. Next, a description is presented of the bumpless interconnection method which fills through-holes of stacked layers with metal by the molten metal suction method and of the electrocapillary effect as a countermeasure to prevent the filler metal from dropping out of holes under its own weight.

61-80hit(132hit)