Showing papers on "Breakdown voltage published in 1985"

Method of making high breakdown voltage semiconductor device

Abstract: A multiple-zone junction termination extension region is formed adjacent a reverse-blocking junction in a semiconductor device to increase the breakdown voltage of such device. A single mask is used to form the multiple-zone JTE region, with the mask having different patterns of openings in the different zones of the mask. Adjacent openings are maintained with a center-to-center spacing of less than 25 percent of the depletion width of the reverse-blocking junction in a voltage-supporting semiconductor layer adjoining the reverse-blocking junction at the ideal breakdown voltage of the junction. As a consequence, the resulting non-uniformities in doping of the various zones of the JTE region are negligibly small. An alternative JTE region is finely-graduated in dopant level from one end of the region to the other, as opposed to having multiple zones of discrete doping levels.

The δ-Doped Field-Effect Transistor

Abstract: A new Schottky-gate FET grown by molecular-beam epitaxy is presented. A V-shaped potential well with a 2D electron-gas is generated in the epi-layer by implementation of a δ-function like doping profile. The δ-doped FET is scaled down to its ultimate physical limit normal to the crystal surface. The advantages of the new device are high gate-breakdown voltage, high transconductance due to the proximity of the electron channel to the crystal surface, and high electron concentration in the channel. Current-voltage and capacitance-voltage measurements reveal a large breakdown voltage and a narrow impurity and carrier distribution.

Zener diode looping element for protecting a battery cell

Abstract: A special zener diode is disclosed which is shunted across each cell in a series connected string of battery cells. In response to a cell failure which causes a cell to open circuit, all battery current is routed through the zener diode looping element. This current causes a permanent state change of the looping element thereby causing the looping element to become a permanent short circuit. Thereby, the failed cell is effectively removed from the circuit. Another embodiment is disclosed whereby the zener diodes are used to ensure uniform full charge among all of the cells in the battery. The zener diodes are chosen to have a breakdown voltage slightly higher than the optimal maximum battery voltage. A special charger is used which lowers the charging rate when the zener breakdown voltage is approached, so that the zener will not be destroyed from excess current during charging.

Halo doping effects in submicron DI-LDD device design

Abstract: The design of DI-LDD submicron channel devices is investigated, specifically focusing on the halo optimization for punchthrough and threshold falloff protection. Two dimensional numerical analysis is used to demonstrate the tradeoff between breakdown voltage and improved short channel threshold falloff as the halo concentration is increased. For a given halo doping level, there is a maximum permitted drain voltage for each channel length which is limited by avalanche breakdown, drain induced threshold lowering and punch-through. A window of useful halo doses is established from 5\times10^{16} to about 8\times10^{17} below which there is no significant improvement of the device and above which there is an unacceptable level of device degradation. A maximum V ds versus channel length curve for the polysilicon gate DI-LDD MOSFET is obtained which implies that power supply voltage must be scaled by approximately the same factor as channel length for this type of device.

Observation of Prebreakdown and Breakdown Phenomena in Liquid Hydrocarbons II. Non-Uniform Field Conditions

Abstract: The prebreakdown and breakdown processes have been recorded in n-hexane toluene and Marcol 70, both in a pure state and with selected impurities. The study was carried out using a point-plane geometry. A low ionization potential additive had only a small effect on the breakdown voltage or the streamer propagation speed but did significantly alter the shape of the prebreakdown streamer when the needle was positive, an anode. For a negative needle, a cathode, chemical impurities affected the breakdown voltage. The significance of these findings is discussed in detail.

Ozone generator with a ceramic-based dielectric

Abstract: In modern ozone generators high power densities can be achieved using ceramic-based dielectrics and suitable gap widths and double cooling. By constructing the dielectric layer from dielectric powders of different grain size and binding with artificial resin, the long-term breakdown voltage of the dielectric layer can be increased to such an extent that they fulfil the operating requirements.

A new programmable cell utilizing insulator breakdown

Abstract: A new programmable cell called the Breakdown-of-Insulator-for-Conduction cell (BIC cell) has been proposed and developed. A BIC cell utilizes the electrical breakdown of an insulator for programming. A highly refined thin insulator, with a delta-function type of breakdown voltage distribution, is employed in the BIC cell. This cell can be programmed within 1 µsec, making it possible to realize the shortest programming time for PROM cells reported so far Programmed cell resistance is around 1×102ohms. Since a BIC cell has a stacked-cell structure, a PROM cell can be formed simply by merging a BIC cell with a MOSFET. Then, a PROM cell array can be formed from these cells. A programming method for a PROM cell array is discussed below.

Low temperature sintered ceramic capacitor with high DC breakdown voltage, and method of manufacture

Abstract: @ A monolithic ceramic capacitor having a higher DC breakdown voltage per unit thickness of the dielectric ceramic body than heretofore. The major ingredient of the ceramic is expressed as {(Ba1-x-yCaxSry)O}k(Ti1-zZrz)O2, where x, y, z and k are numerals in the ranges specified herein. To this major ingredient is added a minor proportion of a mixture of boric oxide, silicon dioxide and at least one metal oxide selected from among BaO, SrO and CaO, in specified ranges of proportions. For the fabrication of capacitors having dielectric bodies of the above composition, the moldings of the mixture of the major ingredient and additives in the specified proportions are sintered to maturity in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (1000-1200 °C.) that the moldings can be cosintered with base metal electrodes buried therein.

Static induction transistors optimized for high-voltage operation and high microwave power output

Abstract: An optimized static induction transistor (SIT) design utilizing local oxidation in a self-aligned geometry is described. Devices with 10.5- and 7-µm pitch (gate-to-gate spacing), which have been optimized with respect to epitaxial layer thickness and resistivity, have attained a combination of operating frequency and breakdown voltage which is much higher than devices made with other technologies. The 10.5-µm pitch SIT's have a blocking voltage of 170 V with 6-dB gain at 225 MHz and 10-dB gain at 900 MHz. Typical multicell power devices have demonstrated 110-W output power at 225 MHz with 65-percent drain efficiency and 25 W at 900 MHz with 40-percent drain efficiency, operated at voltages in excess of 100 V de bias. The 7-µm pitch SIT's have a blocking voltage of 140 V and the same power gain performance at 225 and 900 MHz as the 10.5-µm pitch devices, but with higher effiency and a higher maximum frequency of operation. Typical multicell power devices of this type have achieve 110-W output power at 225 MHz with 70-percent drain efficiency and 25 W at 900 MHz with 55-percent drain efficiency operated at 90 V de bias.

Spacer Flashover in Compressed Gases

Abstract: Surface flashover studies of cylindrical spacers are carried out in SF6-N2 and other SF6-gas mixtures in a uniform field. In the presence of the spacer, the value of the surface flashover voltage is typically found to be lower than the corresponding breakdown own voltage of the gas gap without the spacer. It is experimentally found that this reduction in the breakdown voltage depends to a large extent on the dielectric constant of the spacer material, the type of end-contact between the spacer and the electrode surface, the surface condition of the spacer, the content of SF6 in the gas mixture, and the gas pressure. re. From these experimental results, an empirical expression is developed for the first time to predict in compressed gases. The calculated values of the flashover voltage show a good agreement with the measured values of the author as well as with those previously published in the literature.

High field effects in MOSFETS

Abstract: "High field effects", such as hot-carrier effects and dielectric breakdown, which most significantly affect VLSI reliability are discussed. This paper describes: 1) the hot-carrier injection mechanism and modeling; 2) degradation characteristics: low voltage and low temperature hot-carrier effects, the influence of new processes and materials, degradation modeling, and the TDDB vs. hot-carrier phenomena; 3) hot-carrier resistant device structures and dielectrics, and the additional device breakdown phenomena (drain sustaining and gate-assisted surface breakdown); 4) new power supply voltage and the influence of hot-carrier effects on circuit noise and VLSI design methodology. These effects in MOSFETs inherent to device down-scaling impose the most stringent constraints on submicron MOS VLSI design, even after the power supply voltage is reduced to ∼ 3V.

A microwave power double-heterojunction high electron mobility transistor

Abstract: A microwave power high electron mobility transistor (HEMT) has been developed and tested in the K -band frequency range. The HEMT has a unique configuration of a selectively low-doped (AlGa)As/GaAs/(AlGa)As double heterojunction resulting in both capability of high-current density and high gate breakdown voltage. The structure showed electron mobility of 6800 cm2/V.s and two-dimensional (2-D) electron density as high as 1.2 × 1012cm-2at room temperature. An output power of 660 mW (550 mW/mm) with 3.2-dB gain and 19.3-percent power added efficiency was achieved at 20 GHz with 1-µm gate length and 1.2-mm gate periphery. A similar device with 2.4-mm gate width produced an output power of 1 W with 3-dB gain and 15.5-percent efficiency. These results offer microwave high power capability in a double-heterojunction HEMT (DH-HEMT).

Method for the manufacture of semiconductor devices with planar junctions having a variable charge concentration and a very high breakdown voltage

Abstract: The invention relates to a method for the manufacture of high voltage semiconductor devices with at least one planar junction with a variable charge concentration. The method consists in doping with impurities of a same type, in a region of monocrystalline semiconductor material, a first zone, and then a second zone which comprises the first, and so on, and in carrying out a subsequent heat treatment so as to provide a planar junction with a stepped profile and a concentration of impurities which decreases from the center to the periphery in a predetemined range. In this way the intensity of the surface electric field, when the junction is reverse biased, is reduced as a result of which it is possible to provide planar junctions having very high breakdown voltages of some thousands of volts.

Surge voltage protective circuit arrangements

Abstract: A circuit arrangement for protecting a load connected across a supply against surge voltage includes a gas-filled arrester connected in parallel with a semiconductor arrester across the load. A firing circuit is provided which is responsive to the breakdown of the semiconductor arrester to apply a voltage between a trigger electrode in the gas-filled arrester and another electrode within the gas-filled arrester to reduce the breakdown voltage of the discharge gap of the gas-filled arrester. The arrangement is operative for protection against surge voltages between the supply lines, and also between each line and earth.

Field effect transistor with a high voltage breakdown capacity, and method for its production

Abstract: 1. Field effect transistor with high breakdown voltage in which a source region and a drain region (2, 3) of a first conductivity type are incorporated in a semiconductor body (1) of a second conductivity type, in which a gate (5) separated from the semiconductor body (1) by a thin insulating layer (4) is provided, and in which are source-side connection region (6) and a drain-side connection region (7) are present which belong to the first conductivity type, are situated between the source region (2), the drain region (3) and a zone (Z) of the semiconductor body covered by the gate (5) and have a lower doping concentration and also a substantially lower penetration depth than the source region and the drain region, characterized in that the drain-side connection region (7) has a lower doping concentration than the source-side connection region (6).

Semiconductor device having an annular region for improved voltage characteristics

Abstract: The breakdown voltage of a p-n junction operated under reverse bias in at least one mode of operation of a semiconductor device is increased by providing at least one annular region forming an auxiliary p-n junction within the spread of a depletion layer from the reverse-biased junction. A passivating dielectric layer with an overlying electrically resistive layer extends over the semiconductor body surface between the active device region forming the p-n junction and a surrounding region of the body portion located beyond the (outer) annular region. The resistive layer is connected to these regions but is insulated from the annular regions by the dielectric layer. A stable high breakdown voltage can be obtained by providing the resistive layer with conductive connection means at the or each annular area which overlies the annular region(s). The conductive connection means, which may be for example annular metal areas or annular highly-doped parts of the resistive layer, is more highly conductive than the resistance of adjacent parts of the resistive layer and provides an electrical connection between these adjacent parts so that a potential variation which corresponds approximately with that along the underlying semiconductor body surface (including the annular regions) can be obtained along the resistive layer.

Effect of lateral curvature on the breakdown voltage of planar diodes

Abstract: The effect of lateral radius of curvature on the breakdown voltage of planar diodes is investigated. It is shown that, this effect should be incorporated while estimating the breakdown voltage in most of the situations, especially in power integrated circuits.

Introduction to VLSI Silicon Devices: Physics, Technology and Characterization

Abstract: 1. Resistances and Their Measurements.- 1.0 Introduction.- 1.1 Resistance.- 1.2 Resistivity.- 1.3 Current Density.- 1.4 Electric Field, Mobility, Conductivity and Resistivity.- 1.5 Carrier Concentrations.- 1.6 Sheet Resistance and Techniques for its Evaluation.- 1.7 Line Width and Mask Alignments.- 1.8 The Spreading Resistance Technique.- Summary of Important Equations.- References.- 2. PN Junctions.- 2.0 Introduction.- 2.1 Description of PN Junction.- 2.2 Fabrication of A PN Junction.- 2.3 Characteristics of the PN Junction at Thermal Equilibrium.- 2.4 Forward Biased PN Junction.- 2.5 Reverse Biased PN Junction.- Summary of Important Equations.- References.- 3. The Bipolar Transistor.- 3.0 Introduction.- 3.1 Transistor Action.- 3.2 A Typical Bipolar Process Sequence.- 3.3 Injection Parameters, Wide Base Region.- 3.4 Injection Parameters, Narrow Base Region.- 3.5 The Schottky Barrier Diode.- 3.6 Maximum Transistor Voltage Limitations.- 3.7 High-Current Transistor Characteristics.- 3.8 High-Frequency and Switching Behavior.- Summary of Important Equations.- References.- 4. The MIS CV Technique.- 4.0 Introduction.- 4.1 The Insulator Capacitance.- 4.2 The Ideal MOS System.- 4.3 Description and Analysis of an Ideal Cv-Curve.- 4.4 The Real MIS Structure.- 4.5 Methods to Evaluate CV-Plots.- Summary of Important Equations.- References.- 5. Surface Effects on PN Junctions.- 5.0 Introduction.- 5.1 Ideal Structure without Applied Bias.- 5.2 Ideal Structure with Applied Bias on the Gate.- 5.3 Effect of Insulator Charge and Work-Function Difference.- 5.4 Body-Effect or Substrate Bias Sensitivity.- 5.5 Reverse Current.- 5.6 Effect of Gate Bias on the Junction Breakdown Voltage.- 5.7 Injection of Hot Carriers into the Insulator.- 5.8 Surface Effects on the Junction Forward Characteristics.- Summary of Important Equations.- References.- 6. Insulated-Gate-Field-Effect-Transistor (IGFET).- 6.0 Introduction.- 6.1 Principle of Operation.- 6.2 Fabrication Techniques.- 6.3 Current-Voltage Characteristics, Long and Wide Channel, Uniform Substrate.- 6.4 Non-Uniform Substrate Profile.- 6.5 Second-Order Effects, Device Limits and Design Considerations.- 6.6 Types of IGFETs and Applications.- 6.7 CMOS.- Summary of Important Equations.- References.- Universal Physical Constants.- Conversion Factors.- The Greek Alphabet.

Ion production rates in SF 6 and the relevance thereof to gas-insulated switchgear

Abstract: Breakdown of SF 6 is of commercial interest as a result of the large amounts of SF 6 -insulated switchgear installed world wide and is of technical interest as a result of the excellent dielectric strength of the gas caused by its high electronegativity. Previous studies in the area of positive surge breakdown area have centered on the concept of “critical volume”. The basic idea has been that probability of breakdown depends on the volume stressed above the minimum breakdown voltage and the electron production rate [1-2]. These concepts are semi-empirically based and have been derived under relatively homogeneous field conditions. As such, one has no reason to think that the concepts have any fundamental or universal validity.

Relativistic Hartree condition for magnetrons: Theory and comparison with experiments

Abstract: The Hartree voltage UH is derived for a cylindrical magnetron in the relativistic limit with and without an axial current. This voltage corresponds to the breakdown voltage of the magnetron in the presence of a rotating perturbation field. In general, UH is less than the cutoff voltage UI for magnetic insulation in the absence of a perturbation field. Comparisons with a number of different experiments at zero axial current indicate that the maximum microwave power occurs for voltages slightly larger than UH, but well below UI. With axial current, two different Hartree voltages are derived, UHA and UHB

Power performance of microwave high-electron mobility transistors

Abstract: The large-signal performance of 0.25-µm gate-length high-electron mobility transistors (HEMT's) operating at 15 GHz is reported. At a drain voltage of 5 V, an output power of 135 mW (0.34 W/mm) has been obtained with 8-dB associated gain and 37-percent power-added efficiency. Furthermore, in class C operation a power-added efficiency of 57 percent has been measured. These results are attributed to high transconductance (300 mS/mm), high gain (12-dB maximum stable gain at 18 GHz), low knee voltage (1.25 V), relatively high full channel current (280 mA/mm at V_{ds} = 2 V), and good RF drain-source breakdown voltage (9 V).

Lateral bidirectional notch FET with gates at non-common potentials

Abstract: Lateral FET structure is disclosed for bidirectional power switching, including AC application. A notch extends downwardly from a top major surface to separate left and right source regions and left and right channel regions, and direct the drift region current path between the channels around the bottom of the notch. Split gate electrodes in the notch proximate the channels control bidirectional conduction, and are at non-common potentials in the OFF state to increase breakdown voltage. Self-shielding of the gates is also disclosed to further increase OFF state breakdown voltage.

Extended corona stabilisation in SF6/Freon mixtures

Abstract: Some results are reported of static and impulse corona onset and breakdown voltage measurements in 10 mm point-plane gap in SF6 mixture containing 0.5% and 1% by volume of Freon 113. It is found that the corona inception voltage in the mixture is higher than for pure SF6 over the pressure range investigated (up to 4 bar) and that the corona stabilisation peak is greatly extended. Measurements of the minimum impulse breakdown voltage have shown that the improved stabilisation is associated with an increase in the leader propagation voltage in such mixtures. The results are of significance in connection with particle-triggered breakdown in commercial compressed-gas-insulated cables and sub-station equipment.

Zener diode structure

Abstract: A zener diode structure for integrated circuits is disclosed. The device includes a pair of parallel zener diodes connected back to back with a third zener diode. The anode of one of the parallel diodes is connected to the anodes of the other two diodes through a parasitic resistance. The zener breakdown junctions of two of the diodes are well below the surface of the device thereby reducing any adverse affect of stray surface charges and ultraviolet radiation. Further, the doping levels of the opposing diodes are selected to reduce drift in the breakdown voltage due to variations in operating temperature of the device.

Buried recombination layers with enhanced n-type conductivity for silicon power devices

Abstract: The concentration profile of defect centres induced by proton irradiation, which had been proposed as a technique for production of recombination layers in silicon, is investigated using DLTS and spreading resistance. After irradiation and annealing additionally a buried shallow donor doped layer is observed. Comparison with α-irradiated samples suggests the interpretation as proton-containing centres. The buried n-layer may vary the breakdown voltage of power devices. It could be regarded as being favourable for GTO thyristors.

Modeling of self-breakdown voltage statistics in high-energy spark gaps

Abstract: A model which incorporates the influence of electrode surface conditions, gas pressure, and charging rate on the voltage stability of high energy spark gaps is discussed. Experimental results support several predictions of the model; namely, that increasing the pressure and the rate of voltage charging both produce a broadening of the self‐breakdown voltage distribution, whereas a narrow voltage distribution can be produced by supplying a copious source of electrons at the cathode surface. Experimental results also indicate that two different mechanisms can produce this broadening, both of which can be taken into account with the use of the model presented. Further implications of the model include changes in the width of the self‐breakdown voltage probability density function as the primary emission characteristics of the cathode are modified by, for example, oxide or nitride coatings and/or deposits from the insulator. Overall, the model provides a useful and physically sound framework from which the pr...

Semiconductor device having high breakdown voltage

Abstract: A semiconductor device includes a semiconductor substrate having at least three semiconductor layers of alternately different conductivity types between a pair of principal surfaces. A pair of main electrodes are kept in low-resistance contact with the outermost ones of the semiconductor layers. A surface-passivation insulating film is provided on an exposed surface of the semiconductor substrate. A resistive material sheet is provided on the insulating film and connected electrically to semiconductor layers having their potentials substantially equal to the main electrodes.

Effect of Dielectric Materoals on Surface Breakdown in Vacuum and Analysis by Electron Trajectory Simulation

Abstract: To study and analyze the effect of surface insulation in case of a solid insulator used in actual vacuum interrupters, prebreakdown currents, breakdown voltages and Vb-t characteristics were measured with two different dielectric materials (glass and ceramics). It has been found that the breakdown voltage with a solid insulator is lower than without it, and that this fact is closely associated with prebreakdown current. In other words, glass provides a higher surface breakdown strength than ceramics because the prebreakdown current of glass is lower than that of ceramics. Electron trajectory analysis has revealed that the above-mentioned phenomenon is caused by the presence of a critical field strength of 8.9 kV/mm at one or more points on the electrode and a prebreakdown current of the order of 10-11 A. Although the prebreakdown current for the critical field strength of 8.7 kV/mm remains too low to cause electrical breakdown, it can be predicted that the level readily increases by some million times, reaching the order of 10-4 A at the time of a breakdown. This is the result of the contribution of secondary electron avalanches on the surface of the-solid insulator.