Showing papers on "Breakdown voltage published in 1971"

Electrical Breakdown of Long Gaps in Sulfur Hexafluoride

Abstract: The electrical discharge characteristics of SF6 are discussed theoretically in relation to the field dependence of the ionization coefficient a and the electron attachment coefficient The results are compared with the characteristics of air. A simple theoretical formulation of breakdown or corona inception voltages of gaps in SF6 is derived. The formulation has been examined by experiments on several electrode configurations. At low pressures of less than 4 atm, the agreement of the theoretical and the experimental results is fairly good. The breakdown voltage decreases from the theoretical estimation at higher pressure.

Dielectric Breakdown in Electrolytic Capacitors

Abstract: Starting with the known but unexplained fact that high‐voltage electrolytic capacitors need operating electrolytes of high resistivity, breakdown (sparking) voltages of aluminum and tantalum anodes have been examined. If interfering side reactions are eliminated, breakdown voltage increases linearly with the logarithm of electrolyte resistivity and is insensitive to variations in electrolyte composition and to changes in temperature between 65°C and 95°C.

A review of laser-triggered switching

Abstract: A review of laser-triggered switching (LTS) is given. The theory of the laser-induced voltage breakdown of as gas-filled spark gap is considered and the theory is compared with observations wherever possible. Included in the review are: voltages ranging from a few kilovolts to more than 3 MV; dielectric media of vacuum, gas, liquid, and solid; delay as low as 1 ns and jitter as low as 0.1 ns.

Temperature dependence of breakdown voltage in silicon abrupt p-n junctions

Abstract: Temperature dependence of breakdown voltage in silicon abrupt p+-n junctions has been calculated using a modified Baraff theory [1]-[3] and measured experimentally from 77°K to 500°K, with substrate doping from 1015cm-3to 1018cm-3. Experimental data are in good agreement with the results of theoretical calculations. These results strongly substantiate the validity of the modified Baraff theory which has been pointed out by Sze and Crowell.

Field effect semiconductor device

Abstract: A field effect semiconductor switching device of high breakdown voltage and large current capacity having negative resistance characteristics which are controllable by an electric field.

Design considerations of hyperabrupt varactor diodes

Abstract: This paper describes the design calculations and fabrication techniques used to produce hyperabrupt varactor diodes. The computation consists of determining, the doping profile, the capacitance as a function of applied voltage, the breakdown voltage, and the series resistance; allowance is made for the nonlinear variation of mobility with doping density. Fabrication of the retrograded region was accomplished by diffusion from a doped-oxide source. Two groups of diodes were fabricated. The first group had a breakdown voltage V B of 95 V at 1 µA, a capacitance ratio of 12 over a voltage range of 1 to 40 V ( C_{P1}/C_{P40}=12 ), and a quality factor Q of 60 at an operating level of 3 V and 100 MHz. The corresponding values for the second group were V B =45 V ( C_{P1}/C_{P40}=4 ) and Q =210. The capacitance tracking capability of these diodes was found to be within 2 percent. These measurements showed excellent correlation with calculated results.

Gate protection of MIS devices

Abstract: Gate shorts caused by electrical breakdown of the gate dielectric are a major yield and reliability problem for MOS transistors and integrated circuits. Diodes or diffused resistors with breakdown voltages of about 40 V can be used to protect the gate from high voltage transients or static discharges. This paper provides a uniform approach to gate protection. It is shown theoretically that in order to obtain effective gate protection: the protecting device should have a low dynamic resistance in breakdown; the breakdown voltage of the protecting device should be above, but close to, the maximum gate operating voltage; and protection by a diffused resistor in series with the gate is much more effective than by a diode in parallel with the gate. It is shown experimentally that, compared to the widely used fieldplate-induced breakdown, breakdown due to reach-through to a highly doped substrate provides: a dynamic resistance that is almost two orders of magnitude lower; reasonable control of the breakdown voltage; much better protection against simulated static discharges. Since under pilot line conditions no adverse effects on performance or yield have been observed, reach-through breakdown devices seem to improve gate protection decisively without any coincident disadvantages.

Planar mesa Schottky barrier diode

Abstract: Planar silicon technology has been used to fabricate mesa Schottky barrier diodesh with high breakdown voltages. This method proves to be superior to alternate methods used to increase the breakdown voltage of Schottky diodes. The processing techniques and characteristics of mesa Schottky diodes are described in this paper.

Overvoltage protection arrangement for power converters

Abstract: A controlled rectifier is connected in multiple across a nonregulated d.c. source which supplies operating energy to a transistorized d.c. to d.c. converter apparatus. Also connected across the source, oppositely poled, is a Zener diode with a reverse breakdown voltage greater than the normal source voltage but less than the breakdown potential which damages the transistors in the voltage regulator portion of the converter. A gating signal is applied to the controlled rectifier if Zener diode breakdown occurs due to a sustained increase in source voltage. A fuse interrupts the leads from the source when the resulting high current flows through the controlled rectifier and protects the transistors from damage. Another Zener diode is connected, with reverse polarity, across the connections between the regulator and inverter portions of the converter. Its reverse breakdown voltage is selected just above the normal regulated output voltage, but low enough to protect the transistors in the inverter circuits. This second Zener diode also supplies a gating signal to the controlled rectifier, if breakdown occurs, to protect against an overvoltage due to a fault in the regulator circuits. Additional Zener diodes may be used in similar manner to protect against overvoltage faults at other points in the converter apparatus.

A new technology for high-power IC

Abstract: The paper describes a new fabrication technology for a monolithic high-power linear IC. It is based on a novel process for controlling the epitaxial growth of single crystal regions and very fine polycrystalline regions on an IC substrate essentially in accordance with the specified mapping of the IC pattern. Polycrystalline regions are used in areas of isolation and collector lead paths which must be diffused deeply, and contribute to the most important characteristics required for the high-power IC, i.e., higher breakdown voltage and lower saturation resistance. A power capability far beyond any known in this field has been achieved. A typical example of the output power rating for an IC designed for use in a low-frequency SEPP-type power amplifier is 20-watts rms continuous service, and the total harmonic distortion content is less than 8 percent at 1 kHz at 40-volts source voltage.

The effect of temperature on the operation of an IMPATT diode

Abstract: Some experimental results on the temperature dependence of an IMPATT oscillator are reported. Theoretical results for the effect of temperature upon the small-signal admittance of a Read diode are compared with the experiments.

Channel Shortening in MOS Transistors during Junction Walk‐Out

Abstract: The walk‐out of the breakdown voltage of the junctions of p‐channel MOS transistors was found to be accompanied by an increase in the transconductance. An explanation for this relationship is offered here in terms of electron injection into the gate oxide near the junctions, and subsequent trapping there. The rate of junction walk‐out depends not only on the total injected negative charge, but also on the value of the injection current itself, increasing at higher injection currents. The ratio of the injection current to the total junction current is found to decrease with increasing breakdown voltage.

On the emitter degradation by avalanche breakdown in planar transistors

Abstract: Avalanche breakdown of the emitter-base junction of planar transistors results in a decrease of the current gain at low current levels. This phenomenon was studied in transistors with a relatively low-doped (epitaxial) base region. By a voltage applied to a field plate above the e-b junction the breakdown at the interface can be better controlled in these transistors than in double-diffused transistors. The experiments show that the degradation is homogeneous along the perimeter of the e-b junctions and is not caused by local heating by the reverse current. Apparently, carriers produced by the avalanche breakdown obtain sufficient energy from the breakdown field to create interface states and to introduce charge in the oxide. An estimate of the damaged area allowed a calculation of the initial introduction rate of charge in the oxide. This rate was three orders of magnitude higher than the initial formation rate of interface states. Finally, the construction of a stable transistor is described.

Breakdown voltage of cylindrical Gaussian P- N junctions

Abstract: Avalanche breakdown voltage data are presented for silicon planar p - n junctions in a form appropriate for use in the design or evaluation of impurity diffusion processes of the predeposit/drive-in type. Breakdown voltage is computed for a junction with an assumed Gaussian impurity density distribution and plane-cylindrical geometry, and is related to the amount of predeposited impurity, junction depth and background impurity density of the processed slice. Comparison is made between such data for Gaussian junctions and corresponding data for a one-sided step junction. Data are also presented for specific examples of fabrication processes, showing the influence of changing the parameters that control the predeposit and drive-in cycles; designing the process and evaluation of the resulting device structures are discussed in the context of breakdown voltage. Experimental results obtained for fabricated device samples show good agreement with the breakdown voltage predicted theoretically in terms of the Gaussian model.

Electrical surge diverting connector

Abstract: An electrical connector which provides lightning protection by facilitating arcing of electrical surges over the end of an insulator and cooperating conductive surface employing dielectric to stimulate arc-over and thus substantially reduce breakdown voltage.

New Method for Breakdown Voltage Determination in p‐n Junctions

Abstract: The triggering behavior of small‐area uniform avalanche diodes may be used to measure the breakdown voltage. The diode is biased at sufficiently high reverse voltage that pulses of current appear and the relative probability of a generated electron or hole triggering an avalanche is determined by measuring the pulse rate. Performing the measurements over a range of bias and extrapolating the pulse rate to zero yield the breakdown voltage to within a few millivolts.

The electrical behaviour of abrupt ion implanted and diffused P+N junctions

Abstract: Results are reported of measurements of the properties of diodes formed by ion implantation, and for comparison boron diffused P+N diodes of similar area close by on the same chip. The four group III acceptor impurities were implanted separately to a dose of 5 × 1015 ions/cm2 at room temperature into similar samples of suitably masked silicon. Boron ions were also implanted at liquid nitrogen temperature and 450°C. Annealing was limited to a maximum temperatare of 550 °C. Measurements have been made of sheet resistance, forward and reverse I-V characteristics (from 10−9 amps/cm2), reverse breakdown voltage, noise, minority carrier storage time and junction series resistance. The bulk properties of boron implanted diodes were found to be reproducible. The introduction of recombination centres by implantation is the major factor influencing variation in these properties between one implantation condition and another. Changes in surface oxide conditions probably affect reverse leakage currents and b...

Minimized temperature coefficient voltage standard means

Abstract: To minimize the change in breakdown voltage of the series connection of one or more reverse biased diodes and one or more forward biased diodes with change in temperature, bulk semiconductive material is connected in series with a reverse biased diode or may be made part of the forward or reverse biased diode, or may be added to the material thereof.

GaAs Schottky diodes with near-ideal characteristics

Abstract: The I-V characteristics of some GaAs Schottky-barrier IMPATT diodes are found to be nearly ideal at operating temperatures (∼200°C). Fabricated on epitaxial n-type substrate with platinum contacts, the diodes use a truncated cone shape to avoid soft breakdown. The breakdown voltage and its temperature dependence are close to calculated values for one-sided abrupt junctions.

Anodic Oxides of Ta–Al Alloy Films

Abstract: The anodic oxides formed on two Ta alloy films with 23 at. % Al and 45 at. % Al are compared with anodic Ta2O5. The alloy films were obtained by cosputtering Ta and Al. A number of the oxide properties investigated depend on the Al concentration. The refractive index and dielectric constant vary as predicted for a homogeneous mixture of Ta2O5 and Al2O3, while the differential field strength and breakdown voltage increase in proportion to the Al2O3 content. For the anodization conditions and the electrolyte used in this study, the refractive index, dielectric constant, and differential field strength are independent of anodization voltage, and the stoichiometry of the two alloy compositions studied is maintained in the oxides.

Influence of corona discharges on the breakdown voltage of airgaps

Abstract: Measurements with rod-rod and rod-plane gaps result in a large scatter in the values of breakdown voltage at certain gap distances. The scatter in the figures depends on the change of the corona mode. The transition in predischarges at certain gap distances results in two different breakdown voltages. It is shown that this scatter can be observed with all investigated voltage shapes (alternating and direct voltages, lightning and switching surges). The paper also deals with the possibilities of influencing the scatter of the values of breakdown voltage.

Schottky barrier type semiconductor device with improved backward breakdown voltage characteristic

Abstract: A semiconductor device having a Schottky barrier junction formed in the bottom of a polygonal recess on a surface of a semiconductor substrate comprises an undercut in the recess beneath an insulating mask formed on the substrate, and a metal passing through the mask and extending to the bottom of the recess for forming said junction. The undercut provides an enclosed spacing encircling the junction portion of said metal and said semiconductor, thereby improving the backward breakdown voltage characteristic therein.

Germanium nonscanned infrared image converter

Abstract: Infrared image converters using nickel and gold doped germanium have been built. These devices provide image brightness up to 1 fL and resolution of 25 line pairs/cm. The devices are within a factor of 100 and 10, respectively, of "seeing" 2-5 µm radiation from an ambient temperature (∼ 300 ° K) scene. Copper doped germanium was also studied, but was found to have a low breakdown voltage rendering it unuasble for these devices.

Characteristics of impulse breakdown of standard rod gaps under controlled-atmosphere conditions

Abstract: The effect of humidity, polarity and irradiation on the 1/50μs impulse voltage breakdown and time lag of standard rod gaps has been determined for a range of spacings from 5cm to 30cm and a range of humidities from 1g/m3 to 24g/m3. An anomalous condition is reported for a 5cm unirradiated gap under positive impulses in which the slope of the humidity characteristic is opposite to that normally obtained. It is shown that, although the time lag is independent of humidity, the probability of breakdown in the sigmoid region is not independent of humidity.

Effect of a Grounded Cylinder Enclosure on the Breakdown Gradient of Rod Gaps in SF6

Abstract: Potential gradient at the surface of the electrode is the most important factor in the breakdown of SF6 gas as reported in a companion paper. Hence the breakdown voltage may be predicted from the potential gradient at the surface of the electrode with technically acceptable accuracy.

Use of tests at elevated temperatures to accelerate the life of an m.o.s. integrated circuit

Abstract: Assurances of a long service life will often be demanded of m.o.s. integrated circuits used in telecommunication equipment. An attempt has accordingly been made to identify failure risks and devise life-prediction procedures by accelerated testing, ambient temperature being the primary stress variable. The test vehicle, manufactured on a volume production line, had a simple circuit configuration permitting direct access to its constituent transistors and allowing each of them to be operated under different electrical conditions. The parameters monitored included threshold voltages, both of the transistors and of a spurious device, gain factors, transistor resistances (in the conduction mode), leakage currents and protective-diode breakdown voltage. The most significant response was obtained from the transistor threshold voltages, which change substantially but in a manner consistent both with the electrical operating conditions and with known physical theories of charge instability in the m.o.s. system. It is suggested that at least the drift of transistor threshold voltage is amenable to a life-prediction procedure, and it is shown how the results could be exploited for procurement-specification purposes.

The mechanism of breakdown of ambient air in long uniform-field gaps

Abstract: Measurements of pre-breakdown ionization currents in uniform-field gaps in filtered atmospheric air have been undertaken for values of the parameter pd (pressure × gap length) up to 10 500 Torr cm, corresponding to a maximum breakdown voltage of 350 kV. Over the whole range investigated, the spatial growth of ionization in the gaps was found to be in accordance with the generalized Townsend equation, the main source of secondary electrons being due to the photoelectric effect at the cathode. For given values of Es/p, where Es is the breakdown field stress, there is good agreement between the values of ds (sparking distance) obtained by experiment and those predicted by the Townsend breakdown criterion.