Showing papers on "Insulator (electricity) published in 1969"

Flashover voltage of high-voltage insulators with uniform surface-pollution films

Abstract: Contamination on the surface of high-voltage outdoor insulators can lead to the formation of quasistable gas discharges, which burn in series with the resistive contaminative film. Under certain conditions, these discharges may grow to cause a complete flashover. In this paper, a model for the case of a discharge burning on a rectangular polluted strip is introduced; solution of Laplace's equation in two dimensions enables accurate values for the series resistance of the pollution film to be calculated, and a numerical method is used to calculate a factor which accounts for the change in resistance due to heating. Application of the flashover criterion di/dx > 0 to this model yields results which are in good agreement with experiment. The model can also be applied to axisymmetric insulators with complex shapes by replacing the practical insulator by its `equivalent cylinder' Good agreement is obtained between the calculated flashover voltages and those measured by the VDE 0448 test method.

Semiconductor device, method, and memory array

Abstract: This disclosure relates to a semiconductor device which has a first electrical state prior to the application of a particular voltage to at least one conductor thereof and a second, different, irreversible electrical state after the voltage was applied to the selected conductor. A method of forming an electrical contact is also disclosed which is achieved by breaking down a portion of the insulator of the semiconductor device by the application of a voltage to a conductor located on the insulator thereby permitting electrical contact to the semiconductor by the conductor. Additionally, a memory array is disclosed which permits a write-once, read-only function or operation by using an insulator breakdown technique to change semiconductor devices of the array from a first electrical state to a second, irreversible and different electrical state.

Breakdown of Gases Below Paschen Minimum: Basic Design Data of High-Voltage Equipment

Abstract: For the region pd<(pd)min, breakdown characteristics U2 = f(pd) are presented for both the noble and the more important molecular gases He, Ne, A, Kr, Xe, N2, H2, NH3, air, CO2, O2 (and Hg), particularly giving the probability of breakdown on which they are based, so that they can be used for dimensioning the relevant equipment. The design of vessel and electrode geometry which were introduced to determine these characteristics, and which have been tested up to a peak voltage of several hundred kilovolts, made it possible to study and describe the shape of the breakdown and flashover voltages relative to one another at pressures down to high vacuum (region of vacuum breakdown). They also provide an overall picture of the constructional facilities existing within the four following regions of ultimate stress, in which the breakdown voltage is determined by the ultimate electrical stressing of 1) the electrode surface (vacuum breakdown), 2) the insulator inside wall (internal flashover), 3) the insulator outside wall (external flashover), and 4) the gas path (Paschen breakdown). To express the probability of breakdown between 100 percent certainty (W = 1) and complete freedom from breakdown (W = 0), Poisson's formula may be used for the various breakdown mechanisms, i. e., for values of pd close to the respective kink and in the kinked part of the lefthand leg of the Paschen curve (regions 1-4 in Fig. 2), the value ?being proportional to the peak value of the applied voltage U.

Non-equilibrium C-V and I-V characteristics of metal-insulator-semiconductor capacitors

Abstract: The C-V characteristics of metal-insulator-semiconductor (MIS) structures exhibit considerable departure from their quasi-equilibrium behavior under the application of large depleting voltages. The deviation is the result of d.c. current flowing through the insulator, so that steady state non-equilibrium conditions exist in the semiconductor. The primary effects are a lowering of the high frequency capacitance below its quasi-equilibrium minimum value C ∞ , a deviation of the I-V characteristics of the structure from those of the insulator and the development of a large voltage drop across the semiconductor. The low and high frequency capacitances coincide in this non-equilibrium range. The non-equilibrium properties have been observed for deposited films of Si 3 N 4 , SiO 2 , and Al 2 O 3 . Experimental data are presented for films of pyrolytically deposited Si 3 N 4 on p - and n -type silicon substrates, in the dark and for various levels of illumination. A model is developed in which current in the semiconductor occurs through the generation of carriers in the depletion region, and bulk diffusion of carriers in the case of illumination, and where the insulator current proceeds through the Poole-Frenkel mechanism. Agreement between theory and experiment is obtained, and the possible use of the non-equilibrium effect in determining the minority carrier lifetime of the substrate is indicated.

Semiconductor memory apparatus with a multilayer insulator contacting the semiconductor

Abstract: An electronic memory apparatus is disclosed in which the memory element is an insulated gate field effect transistor (IGFET) whose gate contains a metal electrode located on top of two parallel layered insulators, such as silicon oxide and zinc sulfide. The memory of a signal voltage applied to the gate electrode is provided by the phenomenon of tunneling of electrical charges between the metal electrode and the interface between the two insulator layers. These charges are trapped at this interface until a voltage of opposite sign is applied which is sufficient to discharge (''''erase'''' ) the trapped charges at the interface. Nondestructive readout of the presence or absence of these trapped charges is afforded by monitoring the sourcedrain current in the transistor.

Method of insulating multilevel conductors

Abstract: The present invention relates to a method of forming a thin stratified pinhole-free silicon dioxide insulator layer between multilevel conductors. Silicon dioxide films within the stratified pinhole-free silicon dioxide insulator layer are made from single drops of colloidal silicon dioxide liquid dispersion. These silicon dioxide films are stacked to form a stratified pinhole-free highly insulative silicon dioxide layer between the upper and lower conductors. The thinness of the stratified pinhole-free silicon dioxide insulator layer allows shallow contact windows to be formed therein. A shallow contact window allows reliable electrical contact therethrough between an upper conductor and a lower conductor.

Characterization, Control, and Use of Dielectric Charge Effects in Silicon Technology

Abstract: The charge behavior of dielectric films on silicon is particularly important in device and integrated circuit technology because of surface effects. Models for ionic migration, fixed-interface charge, and injection trapping are reviewed for insulators used in silicon technology: thermally-grown silicon dioxide and chemical vapor-deposited silicon dioxide and silicon nitride. The distinctive characteristics of insulator charge related to these mechanisms are applied in the case of reactively sputtered SiO2 and Ta2O5. Ion migration and injection-trapping behavior are found under certain conditions of preparation for both materials. A degree of interface charge control is indicated in the study of sputtered silicon dioxide. More work is needed to establish the future utility of these materials.

Thermally conductive electrical insulator for electron beam collectors

Abstract: A beam collector for an electron beam tube includes a hollow metallic beam collector surrounded by a metallic sheath forming a portion of the vacuum envelope of the tube. An electrical insulator structure is disposed in the annular space intermediate the beam collector and the surrounding sheath. The insulator structure includes an array of electrical insulator members with a first array of flexible metallic frame structures joined to said sheath and projecting inwardly to the insulator members. A second array of flexible metallic frame structures are joined to the collector and project outwardly therefrom to the insulators. The flexible frame structures are joined to the insulator members in electrical insulative relation with respect to each other and provide parallel thermally conductive paths for conduction of thermal energy from the collector to the sheath, while allowing for thermal expansion and contraction of the collector.

Electroacoustic semiconductor device employing an igfet

Abstract: An electroacoustic semiconductor device, comprising a direct-coupled piezoelectric transducer with interdigitated electrodes, and an insulated gate field-effect transistor fabricated on a layer of semiconductor material having a surface insulating coating, a part of which serves as the gate insulator of the transistor. An input signal applied to the interdigitated electrodes causes the transducer to launch a surface acoustic wave along the insulating coating, with a resultant change in gate electrode insulator thickness, thus controlling current flow between source and drain electrodes.

Electrical testing of dielectric layers, exhibiting voltage dependent capacitance, with linear ramp voltages

Abstract: In order to test a dielectric layered structure exhibiting a voltage dependent capacitance, a metal-insulator-semiconductor (M-I-S) structure for example, a linear ramp (sawtooth) voltage is applied across the structure initially in thermal equilibrium, but at a temperature below which the insulator allows ionic impurities to become mobile. The profile of current vs. time, which thereby flows through the structure, constitutes a signal which can be rapidly electronically processed to yield information about the quality and properties of the structure.

Theory and experiments on an electroluminescent device constructed in the metal-insulator&#8212;Semiconductor geometry

Abstract: A simple model is analyzed to quantitatively describe the operation of a new electroluminescent device constructed in the metal-insulator-semiconductor geometry to which an alternating voltage is applied. Expressions for the average emission intensity, power dissipation, and power efficiency are derived in terms of the operating conditions and material parameters for both the insulator and the semiconductor. From these results the optimum operating conditions for the device are determined and several quantitative criteria for evaluating promising insulators and semiconductors are discussed. Supporting results for devices constructed from GaP with TiO 2 for the insulator are given.

Electric resistance heater with a tension coil spring

Abstract: In an electric resistance heater having a heating element extended between spaced insulators, improved means for supporting the insulators at variably spaced distances to maintain nominal tightness in the heating element, including a support rod, and a coil spring secured at a first portion over the rod and having a second portion confined axially within an opening in one insulator operable thereby to bias the insulators apart

Resin-bonded glass-fibre outdoor h.v. insulators

Abstract: The pollution performances of a number of organic insulator materials have been studied, and, although materials have been found which withstand tracking, the erosion caused by sparking results in lowered pollution flashover voltages.An investigation of the mechanical characteristics of a resin-encapsulated glass fibre-loop in tension has shown that curing stresses can substantially reduce the ultimate strength, which is dependent on the modulus of elasticity of the resin and the shear strength of the glass-resin interface. To protect the glass component from moisture for a reasonable lifetime, a layer of 10–20mm of epoxy resin is shown to be needed.A study of the mechanical, electrical, manufacturing and economic problems of different types of insulator leads the authors to conclude that there are good prospects for suspension and tension insulators of resinbonded glass fibre.

Electrical connectors and attachments

Abstract: A conductor tape according to this disclosure comprises a first insulator layer having an adhesive for attaching the insulator to a wall surface. Conductors are attached to the opposite surface of said first insulation layer, and a second insulation layer overlaps the conductors. A metallic layer, such as a steel ribbon, is disposed over the second insulation layer. Spacers may be provided at regular intervals along the length of the tape to separate the conductors from the first insulator layer so that a connector lip of an electrical attachment may be wedged between the first insulator layer and the conductors to make electrical contact with the conductors to supply the attachment with electrical energy.

Furnace apparatus for blocking sodium ions

Abstract: The present invention relates to a processing apparatus for growing and annealing a silicon dioxide insulator layer to obtain a mobile positive ion free silicon dioxide insulator layer. A mobile positive ion free silicon dioxide insulator layer is required in order to make a stable insulated gate field effect transistor. The processing apparatus comprises a nonoxidizing high-melting-point platinum metal film coated quartz furnace tube, potential means for placing a positive potential upon the platinum metal film coating of the platinum metal film coated quartz furnace tube to repel mobile ions therefrom, heater means for heating the interior of the quartz furnace tube, and gas means for passing oxygen gas through the platinum metal film coated quartz furnace tube. A silicon wafer may be oxidized in said processing apparatus to form a relatively mobile positive ion free silicon dioxide insulator layer of an insulated gate field effect transistor upon the silicon wafer. The silicon dioxide insulator layer is relatively uncontaminated by mobile positive ions which exist to the outside of the platinum metal film coated quartz furnace tube. A silicon wafer which previously has been coated by a silicon dioxide insulator layer may be processed to remove mobile ions within the silicon dioxide insulator layer. Mobile positive ions are repelled by the positive potential applied to the platinum metal film away from the outside of the quartz furnace tube, and mobile positive ions of the silicon dioxide insulator layer within the platinum metal film coated quartz tube are removed by the flowing oxygen gas due to the low-vapor pressure of the mobile positive ions.

Method of forming a camera tube diode array target by masking and diffusion

Abstract: Silicon diode array vidicon targets characterized by a silicon oxide insulator disposed between P-type conductivity regions forming discrete diodes within an N-type conductivity wafer have been made substantially immune to burn-in by the utilization of a 0,1 to 3 micron thick electrically conducting glass layer to leak charge formed on the insulator to the adjacent P-type conductivity regions of the target. Preferably the electronically conducting glass is an alkaline earth metal borate glass containing an oxide of a metal, e.g., iron, vanadium, cobalt, etc., providing ions of both a higher valence state and a lower valence state within the glass to permit regulation of the resistivity of the glass layer during fabrication of the bulk glass. To inhibit crazing of the glass layer while providing superior contact between the glass and the surface of the target, the glass layer is R.F. sputter deposited atop the target employing a sputtering atmosphere, e.g., argon, nitrogen, oxygen, selected to provide the desired resistivity in the deposited glass layer.

Experimental determination of the ratio of injected hole current and total current in silicon nitride

Abstract: In a metal-Si3N4-nSi structure, the net minority-carrier generation rate is equal to the hole injection rate into the insulator under balanced conditions. The generation rate has been determined experimentally, giving the ratio of the injected hole current and the total current in the Si3N4 film.

Radio interference from high-voltage insulators under direct-voltage conditions

Abstract: A laboratory investigation into the radio interference arising from electrical discharges on porcelain pin insulators and string insulator units (cap-and-pin type) under high, direct-voltage conditions is described. The effects of the magnitude and polarity of the applied voltage, the surface conditions of the insulators, and the relative humidity of the air, have been studied and phenomena compared with those observed under alternating-voltage conditions. Measurements have been made in the frequency range 0.15–30 MHz, and details of the techniques adopted are given. It has been shown that radio interference is much lower with direct voltages than with alternating voltages of the same peak value.

Solid-state storage device

Abstract: A solid-state storage device in the form of an insulated gate field effect tetrode. A depletion region is created in the channel so that an electric field emanating from one gate can penetrate the channel and attract high energy charge carriers into traps in the insulator. The charge carriers enter the insulator by surmounting the Schottky barrier at the semiconductor-insulator interface.

Thermal considerations in the performance and design of high voltage power line insulators

Abstract: In 1967 the author with I. McCausland and S. B. Girvan 1 offered an empirical relationship between the voltage gradient E over an insulator surface and the final steady surface resistivity ρ SE attained under its influence. The relationship, found from a great number of tests on clean or uniformly contaminated rectangular or tubular glass specimens, was ρ SE = ρ SO (1 + A.E2)(i) where ρ SO was the initial value of surface resistivity before the application of voltage and A was a constant for a given surface and humidity.

Insulated gate fet with selectively doped thick and thin insulators

Abstract: An insulated gate field effect transistor is described having a thin insulator under the gate and a thick insulator under source and drain connections. The insulator over the source and drain is impurity doped, which impurity is diffused into the semiconductor body to form the source and drain. However, the insulator under the gate is a mask against diffusion of the said impurity.

Insulator means for lithium-chlorine high temperature battery

Abstract: SUBSTANTIALLY ENVIRONMENTALLY INERT ELECTRICAL INSULATORS AND INSULATED CONDUCTORS FOR USE IN THE LI$LICL$CL2ELECTROCHEMICAL SYSTEM. THE INSULATORS AND CONDUCTORS ARE COMPOSITES HAVING CL2-INERT AND LI-INERT BARRIERS WHICH SHIELD VULNERABLE COMPOSITES FROM CHLORINE OR LITHIUM ATTACK. SPECIFIC MATERIAL DISCLOSED INCLUDE COMBINATIONS OF ALUMI- NUM NITRIDE, CARBON, GRAPHITE, MOLYBDENUM, KOVAR AND STAINLESS STEEL.

Effect of thermal instability on ultra-high frequency performance of insulated-gate field-effect transistors

Abstract: A theory is derived which relates the device characteristics, in particular the ultra-high frequency performance of field-effect transistors (FETs) to thermal properties. The method of successive approximation is used to simultaneously calculate device temperature and power developed in the channel. FET's are thermally stable only when the device temperature under operating conditions does not contribute significantly to the carrier concentration which is difficult to achieve in modern devices where either high mobility materials and/or small channel lengths are used. The influence of semiconductor-, insulator-, and substrate-material, geometry and thermal properties upon thermal stability and ultra-high frequency performance are discussed. The theory is applied to InAs on glass-, Silicon on Sapphire-, and GaAs on Sapphire-FET's and the high frequency performance of these devices under thermal constraints is determined.

Capacitive-insulating and connector assembly for transformers and the like

Abstract: Two conductors connected respectively to low and high potential windings of a transformer are led through an insulating bushing in the transformer housing. The conductors are concentrically disposed and capacitive insulators are disposed respectively between the two conductors and between the outer conductor and the bushing. The two insulators and the outer conductor are integrated into a single unit in which the inner insulator controls the full potential between the conductors predominately in radial direction but, as well, partially in axial direction. The outer insulator controls the potential both radially and axially.

High voltage electrical insulator

Abstract: 1,139,050. Moulding insulators. DOULTON & CO. Ltd. 22 Nov., 1967 [29 Nov., 1966], No. 53421/66. Heading B5A. [Also in Division H2] An insulator (1, Fig. 1, not shown) for supporting overhead power lines, is made by casting an epoxy resin body (4) around a prestressed glass fibre loop (3), the tensile load on the loop (3) being progressively reduced during curing of the resin so that the extension of the loop decreases at the same rate as the contraction of the resin, which may include plasticizers. The body (4) may include an encapsulated strengthening member, e.g. a solid or tubular porcelain or glass fibre member.