Showing papers on "Insulator (electricity) published in 2004"

Gate Insulators in Organic Field-Effect Transistors

Abstract: In this paper, we review recent progress in the understanding of insulator/semiconductor interfaces in organic field-effect transistors (OFETs). We would like to emphasize that the choice of gate insulator is as important for high-quality OFET devices as the semiconductor itself, especially because of the unique transport mechanisms operating in them. To date researchers have explored numerous organic and inorganic insulator materials, some of them designed to improve the morphology of the organic semiconductor (OSC). Surface treatments, particularly on inorganic insulators, have been shown to influence significantly molecular ordering and device performance. In addition, the deposition technique used for the insulator and semiconductor layers has a further impact on the active interface. Dielectric related effects are reviewed here for a variety of polymeric and molecular semiconductors reported in the literature, with an emphasis on electronic transport. We also review in more detail experiences at Phil...

Spin-Hall insulator.

Abstract: Recent theories predict dissipationless spin current induced by an electric field in doped semiconductors. Nevertheless, the charge current is still dissipative in these systems. In this work, we theoretically predict the dissipationless spin-Hall effect, without any accompanying charge current, in some classes of band insulators, including zero-gap semiconductors such as HgTe and narrow-gap semiconductors such as PbTe. This effect is similar to the quantum-Hall effect in that all the states below the gap contribute and there occurs no dissipation. However, the spin-Hall conductance is not quantized even in two dimensions. This is the first example of a nontrivial topological structure in a band insulator without any magnetic field.

Silicon-on-insulator active pixel sensors

Abstract: Active pixel sensors are defined on double silicon on insulator (SOI) substrates such that a first silicon layer is selected to define radiation detection regions, and a second silicon layer is selected to define readout circuitry. The first and second silicon layers are separated by an insulator layer, typically an oxide layer, and the layers can be independently doped. Doping can be provided in the silicon layers of the SOI substrate during assembly of the SOI substrate, or later during device processing. A semiconductor substrate that supports the first and second layers can be removed for, for example, back side radiation detection, using a second insulator layer (typically an oxide layer) as an etch stop.

Service programmable logic arrays with low tunnel barrier interpoly insulators

Abstract: Structures and methods for in service programmable logic arrays with low tunnel barrier interpoly insulators are provided. The in-service programmable logic array includes a first logic and a second logic plan having a number of logic cells arranged in rows and columns that are interconnected to produce a number of logical outputs such that the in service programmable logic array implements a logical function. The logic cell includes a first source/drain region and a second source/drain region separated by a channel region in a substrate. A floating gate opposing the channel region and is separated therefrom by a gate oxide. A control gate opposes the floating gate. The control gate is separated from the floating gate by a low tunnel barrier intergate insulator. The low tunnel barrier intergate insulator includes a metal oxide insulator selected from the group consisting of PbO, Al 2 O 3 , Ta 2 O 5 , TiO 2 , ZrO 2 , Nb 2 O 5 and/or a Perovskite oxide tunnel barrier.

Insulator surface charge accumulation under impulse voltage

Abstract: The surface charge distribution under impulse voltage is measured using a static capacitance probe. A probe with very small charge leakage is designed. The condition of surface charge accumulation under impulse voltage is analyzed, and it is concluded that micro discharges in the gas near the insulator surface such as the corona caused by free and fixed metal particles is usually a prerequisite condition. The dynamic equation describing the relationship between surface charge density and the applied voltage is established, and the process of surface charge accumulation under impulse voltage is analyzed. Theoretical analysis and experimental results show that the decrease of wave front time of the impulse voltage can result in an increase of surface charge accumulation. A GIS spacer is used to investigate the influence of charge accumulation on the flashover characteristics. It is shown that the 50% impulse flashover voltage can be reduced by 23.4%, and the lower limit of the V-t characteristics can be lowered drastically if the polarity of the surface charge is opposite to that of the applied voltage.

Internally grounded filtering feedthrough

Abstract: A feedthrough device includes a conductive ferrule having an outer peripheral surface defining the outermost boundary of the feedthrough device, an insulator, a lead wire electrically isolated from the ferrule extending through the insulator, a filter capacitor adjacent the insulator through which the lead wire extends in conductive relation therewith, and a ground wire coupled to the ferrule and to the insulator within the outermost boundary of the feedthrough device. The ferrule has an inner peripheral surface defining an opening therethrough and each of the insulator and the filter capacitor has an outer peripheral surface proximate the inner peripheral surface, a counterbore in the outer peripheral surface of each of the insulator and filter capacitor, an end of the ground wire being received in the counterbore and brazed to the ferrule and insulator. Alternatively, an end of the ground wire is welded to the inner peripheral surface of the ferrule.

Method for manufacturing wiring and method for manufacturing semiconductor device

Abstract: The present invention provides a method for manufacturing a wiring and a method for manufacturing a semiconductor device, which do not require a photolithography step in connecting a pattern of an upper layer and a pattern of a lower layer. According to the present invention, a composition including a conductive material is discharged locally and an electric conductor to function as a pillar is formed on a first pattern over a substrate, an insulator is formed to cover the electric conductor, the insulator is etched to expose a top surface of the electric conductor, and a second pattern is formed on the top surface of electric conductor that is exposed.

Semiconductor memory and method of producing the same

Abstract: A semiconductor memory incorporates cylinder-type stacked capacitors. Each capacitor has a lower electrode and an upper electrode facing each other via a dielectric film. The lower electrode of each capacitor is supported by a beam-like insulator at a side portion of the electrode, the side portion being apart from a lower edge of the lower electrode.

Application of a corona onset criterion to calculation of corona onset voltage of stranded conductors

Abstract: The conditions under which corona first occurs for any set of electrodes are an important design consideration since corona can limit the performance of any given configuration of electrical conductors. Here, the 60 Hz ac corona onset voltage for a stranded wire in air is calculated. The criterion involves the characteristics, i.e. composition and pressure, of the gas in which the conductor is immersed and the electric field in the vicinity of the conductor surface. It is found that the calculated corona onset voltage agrees reasonably well with experimental data and that its behavior as a function of overall conductor radius and number of strands is as expected.

A new flashover dynamic model of polluted HV insulators

Abstract: In this work, a model based on field criterion has been developed to represent the flashover phenomenon, which occurs due to surface pollution on high voltage insulators, under ac voltage. The values of potential and electric field on an insulator surface have been determined using the finite element method (FEM). The open model of the insulator has been used for calculating the resistance in series with the arc, in addition to the values of the leakage current and the arc gradient. As a new approach, this dynamic model uses Lagrange multipliers for the solution of the pollution flashover problem. Both the impedance and the electric field criterion have been used for the propagation of arc on the surface. A computer program called NFDM (new flashover dynamic model) has been developed to achieve this. The results obtained from the program have been compared with theoretical and experimental results of other researchers.

Structure–property relationship in high-tension ceramic insulator fired at high temperature

Abstract: Ceramic insulators are widely used in microelectronic devices. In this paper, the mechanical and electrical properties of porcelain ceramic insulator fired at 1350 °C have been investigated along with microstructural characterization using scanning electron microscopy (SEM) in order to understand the structure–property relationship of ceramic insulator. The bending and the dielectric strength were measured on various samples fired at 1350 °C. The bending strength (757.3 kg/cm2) and the dielectric strength (28.36 kV/mm) was found short of the desired value. The microstructural features developed clearly describe why the dielectric strength and the bending strength are not up to the mark. EDAX analysis, X-ray fluorescence (XRF) and X-ray diffractometry (XRD) techniques were also done to support the results. XRD pattern shows 70% mullite and 20% quartz peak intensity and the XRF results shows 22.64% Al2O3 that indicates low mullite formation and hence it is confirmed that it is mullite, the crystalline phase, which contribute together with quartz particle to the dielectric and mechanical strength. SEM image shows large number of microcracks that also hinder the high electrical and mechanical properties of porcelain ceramic insulator.

Film bulk acoustic resonator and method for manufacturing the same

Abstract: A film bulk acoustic resonator, includes first to fourth insulator patterns disposed apart from each other. The third and fourth insulator patterns are disposed opposite the second and first insulator patterns in relation to the first and second insulating patterns, respectively. A bottom conductive layer is disposed above the first and third insulator patterns spreading from a region between the first and second insulator patterns to the third insulator pattern. A piezoelectric film is provided on the bottom conductive layer, disposed above the region between the first and second insulating patterns. A top conductive layer is facing the bottom conductive layer so as to sandwich the piezoelectric film, spreading from the region between the first and second insulator patterns to the fourth insulator pattern.

Aluminum conductive wire

Abstract: This invention provides an aluminum conductive wire. An electric wire, which has hitherto been used for automobile wiring, is mainly an electric wire produced by twisting an annealed copper wire or the like as specified in JIS C 3102 to prepare a conductive wire and covering this conductive wire with an insulator such as vinyl chloride. In recent years, however, an enhancement in performance and function of automobiles has led to an increase in control circuits of various types of electronic equipment, and a weight reduction, drawability in wire drawing, electrical conductivity, flex resistance, recycling efficiency and the like have been required of conductive wires. Despite this, any conductive wire satisfying these requirements has not been known. The aluminum conductive wire of this invention can satisfy the above requirements by twisting aluminum alloy wires comprising 0.1 to 1.0% by mass of Fe, 0.05 to 0.5% by mass of Cu, and 0.05 to 0.3% by mass of Mg, the total content of Cu and Mg being 0.3 to 0.8% by mass, with the balance consisting of aluminum and unavoidable impurities.

Current modulation of a hygroscopic insulator organic field-effect transistor

Abstract: We have fabricated solution processable polymer transistors with high conductivity, requiring only a few volts for obtaining good current modulation. The devices can be fabricated and operated in air and the operation is greatly enhanced in humid atmosphere. Devices reach an On∕Off ratio of about 600 and a subthreshold swing of 500mV per decade operating on voltages less than 2V. In this letter the mechanism behind the current modulation is investigated, and we show that the current is modulated through ion-assisted oxidation and reduction of the semiconductor by ions moving vertically in the insulator material to the transistor channel.

Multipin feedthrough containing a ground pin passing through an insulator and directly brazed to a ferrule

Abstract: A filtered feedthrough including a ferrule surrounding an insulator supporting one or more lead wires and at least one ground pin is described. The insulator defines a channel cutout extending from a first insulator side to a channel cutout bottom part way through the thickness of the insulator and in communication with the ferrule. An attached filter capacitor shunts electromagnetic interference from the lead wire to the ground pin, and the ground pin is in electrical communication with the ferrule by way of a ferrule-ground pin braze joint formed in the channel cutout.

Optimization of corona ring design for long-rod insulators using FEM based computational analysis

Abstract: The paper presents a method to optimize the location and the dimensions of the corona ring for transmission line composite insulators using finite element based software, FEMLAB. The procedure used to optimize the corona ring design, which handles more than one parameter, has been verified with examples that have an analytical solution or known optimal values. In this work the optimization is based on finding the maximum field along the insulator surface, such that this maximum field is well below the corona inception level. The design parameters of the ring diameter, diameter of the ring tube, position of the ring in its vertical plane, and the maximum field that cannot exceed the corona inception level have been used in the optimization process.

Organic thin-film transistors having inorganic/organic double gate insulators

Abstract: Bottom-contact organic thin-film transistors (BC OTFTs) based on inorganic/organic double gate insulators were demonstrated. The double gate insulators consisted of tantalum pentoxide (Ta2O5) with high dielectric constant (κ) as the first gate insulator and octadecyltrichlorosilane (OTS) with low κ as the second gate insulator. The devices have carrier mobilities larger than 10−2cm2∕Vs, on/off current ratio greater than 105, and the threshold voltage of −14V, which is threefold larger field-effect mobility and an order of magnitude larger on/off current ratio than the OTFTs with a Ta2O5 gate insulator. The leakage current was decreased from 2.4×10−6 to 7.4×10−8 A due to the introduction of the OTS second dielectric layer. The results demonstrated that using inorganic/organic double insulator as the gate dielectric layer is an effective method to fabricate OTFTs with improved electric characteristics.

Improvement of Characteristics of Organic Thin-Film Transistor with Anodized Gate Insulator by an Electrolyte Solution and Low-Voltage Driving of Liquid Crystal by Organic Thin-Film Transistors

Abstract: The characteristics of pentacene-based organic thin-film transistors (OTFTs) on plastic substrates with anodized gate insulators using different electrolyte solutions were investigated. The characteristics were significantly improved by using ammonium borate as the solution. The results show a good current-saturation characteristic, field-effect mobility of 0.51 cm2/Vs and a current on/off ratio of 105 at a low drain voltage of 3 V. To investigate the reason for the improvements, the structural and electrical characteristics of OTFTs and insulators were examined using various methods such as X-ray diffraction, atomic force microscope, capacitance-voltage measurement and secondary ion mass spectroscopy. From the results of these experiments, it was found that the orientation of pentacene was improved and the concentration of impurities in the insulator decreased in the case of ammonium borate. We also examined low-voltage driving of liquid crystal devices by the OTFT, targeting its application for flexible displays. Improvement of characteristics by the solution was also confirmed in the driving.

Coil component and fabricaiton method of the same

Abstract: A coil component (100) comprises a coil-containing insulator enclosure and a magnetic core (80). The coil-containing insulator enclosure can be obtained by enclosing a coil (30), except for end portions (12, 22) of the coil (30), with an insulator (50), wherein the insulator (50) comprises at least first resin. The magnetic core (80) is made of a mixture of a second resin (82) and powder, which comprises at least magnetic powder (84). The coil-containing insulator enclosure is embedded in the magnetic core (80).

High voltage circuit breaker with cooling

Abstract: A heat pipe (1) carries off heat-loss in an inner conductor (21) and extends from the inner conductor as far as an outer conductor (22). It also has an insulating hollow body (5) to form an electric insulating section (7). The heat pipe can run in an insulator (24) to support the inner conductor. An independent claim is also included for a method for cooling a heavy-duty circuit breaker's inner conductor stretched as an oblong and surrounded by an outer conductor in the form of a casing.

Electromagnet water heater

Abstract: The utility model provides an electro-magnetic water heater, which contains a heat receiving component, a heating used inductive loop, controlling circuit components, a cold water pipeline, a hot water pipeline and a shell. The controlling circuit components are composed of a power supply, a frequency conversion circuit, a controlling circuit and a protective circuit, the heat receiving component is at least one metal magnetism material cylinder whose outer surface is arranged with electricity and heat insulator sleeve. The two ends of the heat receiving component are communicated with the cold and the hot water pipelines respectively. The heating used inductive loop is an inductive loop using the electricity and heat insulator sleeve as bracket which is arranged on the outer surface of the metal magnetism material cylinder. The working electric current of the heating used inductive loop is a large power high frequency AC which is provided by the frequency conversion circuit among the controlling circuit components. The large power rectifier among the controlling circuit components and the frequency conversion power valve are provided with a water-cooled radiator. The idea is novelty, the structure is compact, the conduction residual heat of the water-cooled radiator is fully applied. The product adopting the technical proposal of the utility model is characterized in that high heating efficiency, large safety coefficient, small manufacturing difficulty and good popularization prospect are provided.

Domain structure of epitaxial CaHfO3 gate insulator films on SrTiO3

Abstract: Thin CaHfO3 films were grown on (100) and (110)-oriented SrTiO3 surfaces with the aim of obtaining an insulator film for epitaxial oxide device design. We show that films grown on the (100) surface of SrTiO3 have a multidomain structure, which increases film roughness and decreases the maximum breakdown field of the insulator. Single-domain films were obtained on the SrTiO3 (110) surface. These films had a breakdown field of 5 MV/cm and a dielectric constant of er=16 to 17 at room temperature.

Relativistic magnetron driven by a microsecond E-beam accelerator with a ceramic insulator

Abstract: Relativistic magnetron experiments performed on a six-cavity device have generated over 300 MW total microwave power near 1 GHz. These experiments were driven by the long-pulse electron beam from an accelerator with parameters as follows: voltage of *300 kV, current of 1-10 kA, and typical pulselength of 0.5 ms. This paper reports investigations of high-power microwave generation, mode competition, and pulse shortening for the relativistic magnetron with a ceramic insulator compared to a plastic insulator. The ceramic insulator improves the vacuum by a factor of ten (to 10/sup *7/ torr range) and flattens the voltage of the accelerator. Relativistic magnetron performance with the ceramic insulator shows increased microwave power and pulselength over the plastic insulator. Effects of RF breakdown in the extraction waveguide on peak microwave power and pulselength are also investigated by utilizing SF/sub 6/ in one or both of the extraction waveguides.

Method for producing printed wiring boards

Abstract: A method for producing printed wiring boards comprises the steps of perforating through holes at predetermined positions in an adhesive insulator sheet, filling the through holes with a conductive material such as a conductive paste or metal balls, transferring conductive wiring patterns that have been formed on surfaces of releasable supporting sheets onto the surfaces of the adhesive insulator sheet by heat and pressure. Simultaneously, interlayer via-connections are performed by means of the conductive material filled into the through holes.

The Energy of Electrons Emitted from Wearing Solid Surfaces

Abstract: The energy of electrons emitted during the scratching of solids by a diamond stylus was measured using a retarding-potential energy analyzer in a vacuum of 10-4–10-5 Pa. The solids tested were insulators, a semiconductor and a conductor. The insulators were normal sintered alumina (Al2O3), polymethylmethacrylate (PMMA) and glass, the semiconductor was n-type silicon (Si) and the metal was aluminum (Al). The energy of emitted electrons was distributed from low values to beyond 900 eV for the insulators and from low values to about 100 eV for the semiconductor, while that of metals could not be measured because the electron emission intensity was too low to be detected. The energy of the electrons emitted from metals was inferred from previous reports to be less than about 2 eV. These results lead to the conclusion that the electric field caused by tribocharging accelerates the electrons to give the energy of electrons increasing in the order of insulator > semiconductor > conductor. This is because electric resistivity is chiefly responsible for generating the surface potential—a function of both electric resistivity and dielectric constant.

Armature of rotary electrical device

Abstract: An improved armature construction in which a coil winding wiring board and cooperating insulator around which the coils are wound at least in part wherein the insulator and wiring board are interconnected by an attachment arrangement that automatically positions and retained components in the desired circumferential, axial and radial positions.

Molded three-dimensional insulator

Abstract: This invention provides a molded three-dimensional insulator that is suitable for use in an end cone region of a pollution control device. The invention also provides a method of making the insulator. The insulator includes ceramic fibers that have a bulk shrinkage no greater than 10 weight percent. The ceramic fibers contain alumina and silica and are microcrystalline, crystalline, or a combination thereof.

Semiconductor-on-insulator chip with -oriented transistors

Abstract: A semiconductor-on-insulator device includes a silicon active layer with a crystal direction placed over an insulator layer. The insulator layer is placed onto a substrate with a crystal direction. Transistors oriented on a direction are formed on the silicon active layer.