Showing papers on "Breakdown voltage published in 1981"

Power-limiting breakdown effects in GaAs MESFET's

Abstract: State-of-the-art GaAs MESFET'S exhibit an output power saturation as the input power is increased Experiments indicated that this power saturation is due to the combined effects of forward gate conduction and reverse gate-to-drain breakdown This reverse breakdown was studied in detail by performing two-dimensional numerical simulations of planar and recessed-gate FET's These simulations demonstrated that the breakdown occurs at the drain-side edge of the gate The results of the numerical simulations suggested a model of the depletion layer configuration which could be solved analytically This model demonstrated that the breakdown voltage was inversely proportional to the product of the doping level and the active layer thickness

Free Conducting Particles in Compressed Gas Insulation

Abstract: This paper presents an electrostatic study of free conducting particles that contaminate com pressed gas-insulated high voltage apparatus and transmission lines Analytical and numerical techniques are used to describe the effect of the particle charge and the magnitude of the ambient electric field on the field intensification on and near the particle surface The electrostatic force acting on filamentary and spherical particles as they lift off one electrode and move towards the other, is also analyzed The techniques developed in this study enable the construction of a breakdown voltage profile which describes the instantaneous voltage required to break down the insulation as the particle moves between electrodes

High performance submicron metal-oxide-semiconductor field effect transistor device structure

Abstract: A novel metal-oxide-semiconductor (MOS) field effect transistor having enhanced oxide thickness at the edge of the gate electrode and having metal silicide regions in the gate electrode and source and drain areas. The enhanced oxide thickness improves interconnect-to-interconnect breakdown voltage in multilevel interconnect devices as well as minimizing gate overlap of source and drain. The metal silicide regions reduce series resistance and improve device speed and packing density.

Planar type semiconductor device with a high breakdown voltage

Abstract: A planar type semiconductor device with a high breakdown voltage has a diffusion region (2) of P type formed in a semiconductor layer (1) of N type, at least one guard ring region (7a, 7b) of P type provided surrounding the diffusion region, and an insulating film (3) covering a given portion on a surface of the semiconductor layer of N type. The planar type semiconductor device is further comprised of a first field plate (9a) kept at the potential equal to that of the diffusion region, and a second field plate (9b) which is provided on the insulating film outside a guard ring region and is kept at the potential equal to that of the guard ring region.

Characteristics in InGaAs/InP avalanche photodiodes with separated absorption and multiplication regions

Abstract: Improved characteristics of compound semiconductor avalanche photodiodes with separated absorption and multiplication regions (SAM) are discussed. Temperature dependences of dark current and breakdown voltage show that the tunneling current in the narrow energy gap layer can be suppressed in InGaAs/InP APD's with the SAM structure. Dark currents above punch-through voltages, at which the depletion layer reaches the InP-InGaAs heterointerface, are caused by the generation-recombination process in the InGaAs and at the heterointerface. Dark currents near breakdown depend on the n-layer thickness and are strongly affected by the electric field strength in the ternary layer. Tunneling currents are dominant in diodes with thin n-InP layers, while the generation-recombination processes in the InGaAs layers are dominant in those with a thick n-InP layer. The dark current was as low as 7.8 \times 10^{4} A/cm2at M = 10 when the interface electric field strength is reduced. A maximum multiplication factor of 60 was observed for the 6 \times 10^{-7} A initial photocurrent. Rise time and full width at half maximum in a pulse response waveform were 100 and 136 ps, respectively, at M = 10 .

Statistical Property of Breakdown Between Metal Electrodes in Vacuum

Abstract: The statistical property of breakdown voltage of vacuum gaps ( 2 x 10-6 Torr) was studied experimentally using parallel plane copper electrodes in the gap length of 3 mm to 20 mm. The results are summarized by expressing the cumulative probability of breakdown as a function of applied voltage and the gap length. It was found that the 50% breakdown voltage for the electrode with uniform field is expressed by the relation V - i. The 50% breakdown voltage for the electrode with non-uniform field is lower than the voltage derived from the relation V - 'i. It is shown that the breakdown property in the nonuniform field can be explained as well as in the uniform field by introducing the concept of effective area of the electrode surface.

Breakdown Characteristics of Moving Transformer Oil

Abstract: As a result of investigating breakdown characteristics of moving oil, it has become clear that the breakdown voltage of ac and dc for moving oil is higher than that for stationary oil by 10-15 % at a moving velocity of 5 cm/s region; the former voltage becomes almost equal to the latter voltage in the region of 25 cm/s, and the former is reduced to lower than 90 % of the latter when the moving velocity exceeds 100 cm/s. However, for impulse voltage, the breakdown voltage of moving oil is the same as that of stationary oil.

Streamer Breakdown Criterion for Compressed Gases

Abstract: The streamer breakdown criterion for computing the uniform field breakdown voltages is examined for gaps filled with Air, N2 and SF6. The critical avalanche size is obtained for these gases for different values of the parameter pd and it is shown that this size depends upon the type of the gas, its pressure, and the gap length. Furthermore, the amount of error introduced in the breakdown voltage calculations is computed by assuming a critical avalanche size of 108 electrons as a condition for the streamer formation. he results are discussed briefly.

Particle-Initiated Breakdowns in Compressed Gas Insulation Under Time-Varying Voltages

Abstract: The need is growing for an analytical model to describe the performance of particle-contaminated compressed gas insulation. The model should take into account the wide practical variety of particle shapes and sizes, insulation configurations, applied voltage magnitudes and wave forms, and gas pressure. This work introduces 'Breakdown Voltage Profile' as an attempt in that direction. The profile offers a description of the instantaneous breakdown voltage as a function of the location of a given particle within the gaseous insulation. The profile explains and, in turn, predicts such characteristics as critical particle position and free-particle and fixed-particle breakdown voltages. When properly combined with the particle moving trajectory under a transient (impulse) or steady state voltage, the profile enables the determination of the critical voltage magnitudes.

InGaAs/InP separated absorption and multiplication regions avalanche photodiode using liquid- and vapor-phase epitaxies

Abstract: Heterostructure planar InGaAs/InP avalanche photodiodes, which consist of a vapor-phase epitaxial InP avalanche multiplying layer and a liquid-phase epitaxial In 0.53 Ga 0.47 As optical absorption layer, were fabricated. Dark current, multiplication, spectral response, and pulse response characteristics are reported. Diodes were prepared by InGaAs liquid-phase epitaxy on an InP substrate, followed by InP vapor-phase epitaxy. The vapor-phase epitaxy was adopted in the InP growth to avoid ternary layer melting encountered in the liquid-phase process. Cd diffusion was carried out in the InP layer to form a p-n junction. A uniform multiplication factor of 5.5 was observed without a guard ring. The quantum efficiency was 70 percent in the 1-1.6 \mu m wavelength region without antireflection coating. Dark current density was as low as 1.5 \times 10^{-4} A/cm2at 90 percent of breakdown voltage. A fast rise time of 100 ps was observed.

Electrical Breakdown Properties of Soil

Abstract: The electrical breakdown characteristics of small-scale soil samples subjected to voltage pulses have been measured. The threshold breakdown field for these samples with a water content of 4.5 percent by volume is about 2.7 to 3.0 MV/m. The delay time from application of the voltage to breakdown varied from about 30 ns at the highest available voltages to milliseconds close to the threshold field. The postbreakdown I-V characteristics of the samples are strong functions of the amount of current that can be supplied by the pulser/circuit combination. The breakdown process in the test soils appears to be due to air ionization in the voids between the soil particles. A semiempirical mathematical model for the postbreakdown I-V characteristics, based on a competition between air ionization and a recombination (quenching) process, gives good correlation with the experimental results.

Static induction thyristor

Abstract: A static induction thyristor having a mesh like gate region in front of the cathode, and between the gate region and the cathode a high resistance region having effective impurity concentration of 10 11 cm -3 -5×10 14 cm -3 is interposed, and the voltage gain decided by the gate length, gate interval and the gate-to-anode distance is made 10 or more so that the forward voltage drop is small, providing high speed switching ability and a large reverse breakdown voltage

The Voltage Breakdown Characteristics of Miniature XLPE Cables Containing Water Trees

Abstract: This paper presents the results of 60 Hz, dc, and impulse voltage breakdown tests on miniature XLPE cables containing water trees. To produce the water trees, the cables were immersed in water and subjected to high voltage at a frequency of 1 kHz for periods up to 1000 h. The dc and impulse breakdown voltages of virgin cable were similar and about twice the peak value of the ac breakdown voltage. The breakdown voltages decreased by up to 90% of their original values with time of ageing and also with ageing voltage. For well-developed water trees in the insulation, the ac and dc breakdown strengths were similar. The number and lengths of the water trees also increased with time of ageing and voltage. The breakdown voltages were almost independent of the tree density but decreased significantly with increasing tree length. The effects of ageing temperature and drying out of the cable prior to breakdown testing are also reported.

Tunneling currents in In0.53Ga0.47As homojunction diodes and design of InGaAs/InP hetero-structure avalanche photodiodes

Abstract: Tunneling currents in InGaAs homojunctions were studied from measurements of temperature dependence of breakdown voltage, current-voltage characteristics, tunneling effective mass, and noise spectrum. Zener emission dominates the reverse current prior to avalanche breakdown in the carrier concentration region of >10 15 cm −3 and restricts the avalanche gain in InGaAs homojunctions. An InGaAs/InP hetero-structure having a p-n junction in the InP layer was studied to reduce dark currents caused by Zener emission. A design chart to aid in the realization of a high performance APD is discussed.

Mis semiconductor device

Abstract: PURPOSE:To restrict the parasitic transistor operation by a method wherein the P layer without N-P-N constitution is independently provided in a part of substrate surface to be connected to the N region on the substrate with the low breakdown voltage specified between the P layer and the N layer substrate. CONSTITUTION:An N Si substrate 1 to be the drain side, N epitaxial layer 2, P region 3 to be the channel region, N region 4 to be the source side, gate insulating film 5, polycrystal Si layer 6 to be the gate, Al film 7 to be the source electrode shortcircuiting the regions 4 and the breakdown preventive P layer 8 diffusingly formed on the N layer surface along the outside of gate are respectively provided. Then the Al film 9 coming into contact with the P layer 8 is connected to the Al film on the source side. The avalanche breakdown voltage of P-N junction J3 between P layer 8 and N layer 2 must be made lower than that of the junction J1 by means of making the depth d2 of the P layer 8 deeper than the d1 of the P region 3 of MOSFET.

VDMOS Power Transistor Drain-Source Resistance Radiation Dependence

Abstract: Data on the effects of neutron and gamma radiation on the drain-source resistance characteristics of power VDMOS transistors are presented. The change in resistance with neutron exposure is related to the resistivity of the drain material, which in turn can be related to the drain-source breakdown voltage. A device with a 450-V rating experienced a factor of 13 increase in resistance on exposure to a neutron fluence of 1014/cm2 whereas one with a breakdown voltage of 150 V experiences no increase in resistance. Threshold voltage shifts of about 2 V occurred at a gamma dose of 105 rad(Si) without bias and was accelerated by positive gate bias. All of these data are consistent with the predictions of a simple model for the dependence of drain-source resistance on gate voltage and drain resistivity. This model illustrates a general separability of neutron and gamma effects on power VDMOS devices. The systems implications for using this type device in a radiation environment are briefly addressed.

Low-leakage, high-efficiency, reliable VPE InGaAs 1.0-1.7 µm photodiodes

Abstract: High-quality InGaAs vapor-grown photodetectors for the 1.0-1.7 µm spectral region with a 100 µm diameter active area, ∼10-30 nA leakage current, 65-75 V breakdown voltage, 60-80% quantum efficiency, < 0.5 ns pulse rise time, < 1 pW/Hz1/2noise equivalent power and stable leakage current at 60°C for over 4000 hours are described.

Dielectric strength of SF6 at elevated temperatures

Abstract: The dielectric strength (ie breakdown voltage Uc of a 2 mm gap) of pure SF6 and its relaxation properties at p=100 kPa were measured for T=500-1800K Two temperature regions with approximately constant values of UcT were found

Method of making depthwise-oriented integrated circuit capacitors

Abstract: A depthwise-oriented capacitor comprises a cluster of separate, parallel, narrow elongated oppositely-doped conductive regions extending depthwise into a semiconductor substrate, for example, in an integrated circuit. The conductive regions can be parallel plates, but are preferably column shaped. The conductive regions are formed by ion implanting or diffusing a dopant into the substrate in a direction aligned with a crystallographic channel thereof to facilitate maximum ion penetration. P-type regions form one pole of the capacitor and N-type regions interspersed among the p-type regions form the opposite pole. Doping concentrations within the regions are sufficient to establish metal-like electric field boundary conditions. The bulk of the substrate containing the conductive regions is either near-intrinsic or semi-insulative so that the semiconductor material between the conductive regions is substantially nonconductive. The oppositely-doped regions are spaced closely enough together that the intervening nonconductive region is depleted of free carriers over the operational voltage range of the capacitor but sufficently separated that the depleted breakdown voltage of the nonconductive region is not exceeded. The conductive regions are arranged in a regular geometrical pattern, for example, at the vertices of a hexagonal or square honeycomb pattern, so that the nearest neighbors of each conductive region of one dopant type are of the opposite dopant type. Surface conductors interconnect at least the conductive regions of one dopant type while the oppositely-doped conductive regions are interconnected either by surface conductors or by doped conductors in the bulk of the substrate. The surface conductors are link-trimmable to vary capacitance incrementally after fabrication. Changes in capacitance values can be effected during manufacture without mask alterations by controlling the depth of penetration of the conductive regions.

Field terminating structure

Abstract: An improved field terminating structure for a semiconductor device provides a well defined voltage gradient in the vicinity of a p-n junction to reduce the electric field near the junction and increase the junction breakdown voltage. The structure includes one or more MOS-type field effect transistors operably connected to one of the regions of the junction. A portion of the potential difference applied across the junction corresponding to the threshold voltage of each transistor is distributed across the surface of the device near the junction.

Correlations between Nondestructive and Destructive Tests on High-Voltage Coil Insulations for Rotating Miachines

Abstract: The correlations between results of nondestructive and destructive tests on high-voltage coil insulations for rotating machines were investigated and the following findings were obtained. Breakdown voltage on application of a commercial line voltage (50 Hz) is correlated to the voltage at which a partial discharge bridges the insulation layer. Breakdown voltage on application of a direct voltage is correlated with the discharge magnitude, dielectric constant and dielectric loss tangent corresponding to void discharge in the insulation layer. Breakdown under an impulse waveform voltage is in some respects similar to that under commercial frequency but, because of the short duration of voltage application, it is correlated with the magnitude of electrical resistance, and this correlation is related to the ease with which the bridge phenomenon of discharge in the insulation layer propagates. Thus, the correlation between breakdown voltage and electrical characteristics in nondestructive tests varies with the voltage waveform involved. In tapewound laminated structures, as in micaceous insulatopms, breakdown occurs along the lap of tape, so that characteristic phenomena of the breakdown process for various voltage waveforms combining mutually correlated characteristics, are observed.

Mechanical Degradation of High Voltage Rotating Machine Insulation

Abstract: Several kinds of insulation systems, which were developed for high voltage coil insulation for motors and generators, are examined for insulation damage caused by mechanical stresses. Tests have been carried out on electrical properties under bending stress, i. e. the critical deformation characteristics which are defined as the maximum deformations able to withstand a fixed proof voltage, the fatigue characteristics under repeated bending stresses, and the voltage life characteristics under bending stress. Breakdown voltage, BDV, decreases with an increase of bending stress. Moreover, a remarkable increase of the base tan6 value, tan6o, and tan6 tip-up can be seen due to the delamination of mica-splittings, especially in the case of the insulation using mica splitting. An insulation system in which a flexible binder is used has a far greater critical deformation. The decrease of residual breakdown voltage RBDV, and the increase of tan6o and tan6 tip-up are seen at less repeated bending stress in the insulation system with mica-splitting tapes than in the insulation system with only mica-paper, because of the weakness of mica-splittings under repeated bending stress. Effects of the temperature on the repeated bending fatigue characteristics from -55 to 1550C are greatly influenced by the binder of the mica tape and/or the impregnating resin. Moreover, voltage life under a static bending stress becomes extremely short beyond a certain stress. Lastly, experimental equations are proposed for estimating the relationship between RBDV and the numbers of repeated bending cycles, and the voltage life under a static bending stress.

High breakdown voltage semiconductor device

Abstract: A semiconductor device having a semiconductor layer 3 of a first conductivity type which is situated on a substrate region 4 of the second opposite type. Present within an island-shaped region 3A of the layer 3 are a surface-adjoining active zone 8 of the second conductivity type, for example the base zone of a bipolar transistor or the channel region of a field effect transistor, and a juxtaposed highly doped contact zone of the first conductivity type. The thickness and the doping concentration of the layer 3 are so small that the layer is depleted up to the surface 2 at a reverse voltage across the p-n junction 5 of the layer 3 and the substrate region 4 which is lower than the breakdown voltage. According to the invention, a highly doped buried layer 8 is present between the layer 3 and the substrate region 4 and extends at least below at least a portion of the active zone 8, the shortest distance between the edge of the buried layer 11 and the edge of the contact zones 9 being at least equal to (2V.sub.B /E.sub.c) where V B is the breakdown voltage of the p-n junction 5, and E c is the critical field strength above which avalanche multiplication occurs. As a result of this the effect of lateral current concentrations (Kirk effect) is avoided, while a high breakdown voltage is maintained.

GaAlAs/GaAs heterojunction microwave bipolar transistor

Abstract: A GaAlAs/GaAs heterojunction bipolar transistor has been developed and tested. A double base structure was adopted to facilitate critical selective etching problems. An emitter-collector breakdown voltage VCEO as high as 80 V was achieved. Maximum frequency of oscillationfmax of 850 MHz and a cutoff frequency fT of 1.6 GHz were realised. The current-gain/temperature curve shows that the transistor can be operated at temperatures up to 350°C.

Breakdown experiments in air and nitrogen above 1500K

Abstract: The breakdown voltage in nitrogen and air was studied at temperatures between 1400 and 4500K at a pressure of a few atmospheres in a shock tube. The measurements were carried out in the physically clean situation behind the reflected shock wave. Below a certain temperature the character of breakdown is dielectric; above this limit the character changes into a thermal one (ohmic heating). The transition occurs in nitrogen at about 2500K and in air at 3100K. The influence of gas relaxation on breakdown was also considered.

Low specific on-resistance 400V LDMOST

Abstract: A readily integratable high voltage lateral DMOS (LDMOST) has been developed which has both as low or lower specific on-resistance and lower input capacitance as compared to the same breakdown voltage vertical transistors. The LDMOST has been designed for a reverse breakdown voltage V DSS = 400V. The active area of the device is 2 mm2and the drift region length is 26µm. The value of R on A for this transistor is 5.6Ω mm2(R on = 2.8Ω). The fabrication technology is compatible with that used for bipolar and MOS IC fabrication.

Influence of the electrode surface condition on the breakdown of liquid helium

Abstract: AC breakdown strength of liquid helium (4.2 K) in the gap range from 0.5 mm to 3 mm is studied with various electrode materials. The electrodes are spheres 50 mm in diameter and the materials are niobium, steel and brass. The breakdown strength varies from 15 kV/mm to 55 kV/mm, depending on the condition of the electrode surface. This includes roughness as well as nicrocracks and oxide layer. The statistical distribution of 10 to 20 individual breakdown values is found to give a normal Gaussian function against the logarithm of the voltage. Plots of the breakdown voltage versus gap distance give a linear relation in all cases.

Distributorless ignition system for multicylinder internal-combustion engines

Abstract: An ignition system of the type incorporating, instead of the usual distributor, high-voltage rectifier diodes connected between the secondary winding of an ignition coil and respective spark plugs. In response to voltages developed in the secondary winding in its opposite directions the diodes function to cause discharges at the spark plugs in the firing order of the engine. Each diode is composed of a multiplicity of laminated silicon rectifier diode chips each having a reverse breakdown voltage in the range of 400-850 volts. The reverse breakdown voltage of each diode is 1.1 to 1.8 times the maximum discharge voltage of the spark plugs. Thus constructed, the diodes can well withstand overvoltages that may develop in the secondary circuit of the ignition system.