Showing papers on "Diode published in 1972"

Surface breakdown in silicon planar diodes equipped with field plate

Abstract: The distribution of the electrical potential around the edge of the field plate in a silicon planar diode has been solved by means of a computer. The breakdown voltage related to this region has been derived as a function of impurity doping in silicon and of oxide thickness. If the oxide layer is not thick enough, avalanche breakdown voltage is often considerably lower than the value allowed by the material. The effect of Q ss has been found to be negligible. Breakdown voltage vs. gate voltage measurement on gated diodes and avalanche light emission support an edge breakdown mechanism. Breakdown voltage on field plated diodes matches rather well with the calculated values. It normally drifts towards higher values and during this walkout a hot carrier current is collected by the field plate. The field plate current is fairly proportional to avalanche current and increases with bulk doping. A new planar diode structure suitable for a BV up to 900 V has been designed. The discharge voltage in air between field plate and equipotential ring (EQR) is shown to be correlated with the actual field at the edge.

Thin‐MIS‐Structure Si Negative‐Resistance Diode

Abstract: We have realized a high‐switching‐speed Si S‐shaped negative‐resistance diode having a thin MIS structure where the thickness of the SiO2 layer is less than 100 A. It has a p‐n‐I (insulator)‐M (metal) structure in contrast with a Shockley diode. The threshold and sustaining voltages are about 20 and 2–3 V, respectively. The regenerative nature of this device may be related to the minority carrier injection into the interface between the n layer and the insulating layer, and electron trapping in the interface states.

Thermally Stimulated Capacitance (TSCAP) in p‐n Junctions

Abstract: High‐frequency small‐signal capacitances of semiconductor junction vs temperature, from the initial conditions of filled and emptied traps in the junction depletion region, are used to determine the trap concentration and the thermal activation energies of trapped electrons and holes. Illustrations are given for silicon N + P diodes doped with gold impurity or irradiated with 1‐MeV electrons, showing the room‐temperature annealing for the latter.

Principles of electronic instrumentation

Abstract: Direct Current Circuits. Capacitors and Inductors. Alternating Current Circuits I. Alternating Current Circuits II. Diodes and Some Applications. Test Equipment and Measurement. Transducers. Transistors. Operational Amplifiers. Waveform Generators. Digital Basics. Digital Circuitry. Microprocessor Basics. Digital and Analog I/O. Noise.

Liquid crystal display mounting structure

Abstract: A LIQUID CRYSTAL DISPLAY MOUNTING STRUCTURE WHEREIN THE ELECTRICAL CONTACTS ON THE BACK SIDE OF A LIQUID CRYSTAL DISPLAY PANEL ARE HELD IN PRESSURE CONTACT WITH A FLAT FLEXIBLE CABLE WHICH PROVIDES ELECTRICAL CONNECTION TO A MATRIX OF DIODES WITHIN A PAIR OF DIODE BOATS OR HOLDERS; INTERCONNECTIONS BETWEEN THE DIODES AND OTHER CIRCUITS ARE PREVIDED BY ETCHED CIRCUIT BOARDS.

Reproducible Liquid‐Phase‐Epitaxial Growth of Double Heterostructure GaAs–AlxGa1−xAs Laser Diodes

Abstract: Highly uniform GaAs–AlxGa1−xAs double heterostructure (DH) wafers have been reproducibly grown, and when fabricated into DH laser diodes yield diodes whose current threshold densities Jth lie within ±5% of each other. Other laser parameters such as lasing wavelength and external differential quantum efficiency ηD also show the same uniformity. The DH wafers can be reproducibly grown so that these parameters lie within ±10% from wafer to wafer. The methods used to achieve these results employ a well‐designed sample holder, minimization of contaminants into the system, reproduction of oven gradients from run to run, and careful temperature control and temperature reproducibility. Using these techniques, we have been able to grow DH wafers, whose active layers are as thin as 0.14 μm. When fabricated into laser diodes, 200 mW of continuous power output has been obtained at room temperature.

Intensity control for light-emitting diode display

Abstract: A plurality of light-emitting diode elements which are unmatched in light output at the lower portions of their forward current ranges and which form an integrated illuminated visual display are activated by a power supply arrangement which applies to each diode element a series of independent power pulses of sufficient power to activate each diode element to saturation and into light-emitting condition in a frequency range which appears to the human eye to be steady illumination, the power supply arrangement being provided with a control feature for selectively varying the duration of the power pulses in order to vary the apparent intensity of the illuminated display, and also provided with current limiting means to limit the current passed by each diode element, during each power pulse and its activation thereby, to a given upper range of forward current in which the light-emitting diode element light outputs are substantially matched and in which optimum light emission efficiency is achieved.

Lead frame for light-emitting diodes

Abstract: A lead frame strip for light-emitting diodes containing a plurality of lead pairs, one lead of each pair having a portion in a plane perpendicular to the plane of the strip containing an integral reflective cavity in which the light-emitting diode die is mounted.

Neutron Production and Collective Ion Acceleration in a High-Current Diode

Abstract: New measurements demonstrate that neutrons produced in a high-current pulsed diode with deuterium-bearing electrodes are of beam-target origin. During a brief portion of a 70-nsec, 2-MV, 50-kA pulse, positive ions from the anode and cathode plasmas were observed to be accelerated toward the anode rather than the cathode as dictated by the externally applied field. Energetic deuterons were observed, behind a small aperture in the anode, which were the source of neutrons produced with Li or C anodes.

Variable capacitance device

Abstract: This specification discloses variable capacitance devices which vary their capacitances under the influence of DC bias voltages or radiations. One embodiment comprises a PN junction diode, a dielectric thin film deposited on the surface of said junction diode at which the junction terminates and a conducting electrode deposited on the dielectric thin film, in which the area of an equivalent plate electrode formed in said junction diode is varied by changing the thickness of a depletion region. In another embodiment, a nonlinear resistance layer deposited on the dielectric thin film is employed. As a DC voltage as applied to the nonlinear resistance layer is increased, the lateral conductivity of the nonlinear resistance layer increases and the area of the equivalent plate electrode facing the conducting electrode is increased. A further embodiment employs a thin film transistor or a MIS transistor to vary the area of the equivalent plate electrode provided therein.

Very‐Low‐Current Operation of Mesa‐Stripe‐Geometry Double‐Heterostructure Injection Lasers

Abstract: Mesa‐stripe‐geometry double‐heterostructure lasers which operate at low‐current level have been fabricated. Lasers of this geometry are made by etching the heterostructure layers, leaving a stripe region with a width ranging from 10 to 40 μm. The current‐spreading effect inherent in stripe‐geometry lasers is eliminated in this structure. As a result of the small active region and the low‐threshold current density, a significant reduction of total threshold current has been realized. The lowest‐threshold current is 50 mA in pulsed operation, and 75 mA in dc. The thermal resistance of the diode of this structure is nearly as low as that of the stripe‐geometry laser.

Resonant-cap structures for IMPATT diodes

Abstract: A series of measurements at 10 GHz giving the performance of IMPATT diodes obtained when varying the parameters of a cap circuit are presented. The results indicate that, with correctly chosen parameters, the circuit is suitable for operation over a 40% bandwidth.

Performance of GaAs Surface-Barrier Detectors Made from High-Purity Gallium Arsenide

Abstract: Gallium arsenide surface barrier diodes have been fabricated from high purity level materials. These devices have an Au surface barrier having a depletion layer thickness of from 70?mto 1 mm and an area of from 3mm2-27mm2. These devices have been operated as ?-particles, / s-ray, and ?-ray spectrometers and detectors. The best energy resolutions taken with a GaAs detector made from liquid phase epitaxial GaAs wafer were 20keV (fwhm) and 8 keV for 5.486 MeV ?-particles from 241Am and 115 keV conversion electrons from 57Co at room temperature, respectively. For room temperature applications, a simple charge sensitive preamplifier was constructed using two FETs and one OP amp. The combination of a encapsulated GaAs detector and two small semiconductor thermoelements (electrical cooling device) was studied to make a simple X-or ?-ray spectrometer. A special tiny GaAs detector was also fabricated as in vivo s-ray counting detector in biomedical applications. The energy per electron-hole pair (?) in GaAs was measured at 4.35 + 0.02 eV for ?-particles with a linear variation with bandgap energy (Eg) of 2.53 over a temperature range of 1950°K to 330°K, and 4.57 eV for conversion electrons (115keV) at 300°K, respectively. The ? vs Eg relationship was also investigated for Ge, Si, GaAs and CdTe using experimental values and led to ? = 2. 596 Eg + 0.714 (eV) with correlation coefficient of 0.999 at 300°K. The related problems for intrinsic material constant (?) are discussed for several semiconductor materials.

Radiance of small-area high-current-density electroluminescent diodes

Abstract: Optical power radiated into a solid angle per unit area of emitting surface (radiance) is a basic measure of the usefulness of an electroluminescent device to be used as a communications-system source. Dc radiance values from about 20 to more than 100 W/sr/cm2have been obtained for various small-area GaAs and AlGaAs diodes operated at current densities that yielded an operating half-life of at least several thousand hours. These radiance values are two to three orders of magnitude larger than those obtained with relatively large-area commercial light-emitting diode (LED) indicator lamps.

Cathodoluminescence assessment of GaAs1−x Px for light emitting diodes

Abstract: The room temperature cathodoluminescence (CL) properties of selenium doped epitaxial layers of GaAs1−xPx, in the composition range 0·35 < x < 0.45, have been examined as a function of the Hall electron concentration. Material selected for this investigation had less than 2 per cent of the total CL emission in the i.r. For a fixed alloy composition the CL intensity is shown to increase with increasing electron concentration, while for a fixed electron concentration the intensity decreases with increasing GaP content. These results have been correlated with the electroluminescent efficiencies of zinc diffused diodes fabricated from the same material. It is shown that CL provides a rapid and reliable means of assessing the composition and emitting efficiency of epitaxial layers for use in the fabrication of light emitting diodes.

Generation of infrared radiation in a metal-to-metal point-contact diode at synthesized frequencies of incident fields - A high-speed broad-band light modulator.

Abstract: This letter reports for the first time the detection of infrared radiation emitted from a metal‐to‐metal point‐contact diode as the result of mixing the frequencies of the radiation fields applied to the diode.

Battery charging system

Abstract: A circuit for preventing the buildup of a generating system when it is inadvertently connected in a reverse polarity employs a resistor-diode series combination which is connected between the field winding of a generator that charges the battery and one terminal of the battery When the battery is connected with a correct polarity, current flows through the field winding of the generator in one direction and no current flows through the diode since the diode is reverse biased However, when the battery is connected with a reverse polarity, the diode is forward biased and current flows through the diode and its series resistor, and through a parallel combination of field discharge diodes and the field winding The reverse current in the field will prevent the excitation necessary to build up a voltage output

Yellow‐light‐emitting ZnSe diode

Abstract: Yellow‐orange luminescence peaking at 5900 A was obtained from the aluminum‐doped ZnSe diode. The external quantum efficiency of 0.1% has been attained at 300 °K. Brightness levels of 200 fL have been measured at an input power of 100 mW.

Electroluminescence in reverse-biassed zinc selenide Schottky diodes

Abstract: Schottky diodes consisting of a metal layer in contact with an n-type ZnSe crystal are electroluminescent when biassed in the reverse direction. Electrons tunnel from the metal into the semiconductor, are accelerated in the depletion layer field and then impact-ionize luminescent centres. Experiments confirming each of these mechanisms are described. A simple theory is propounded to give a quantitative understanding of the processes and of the performance of the diodes as light sources.

Enhancement of breakdown properties of overlay annular diodes by field shaping resistive films

Abstract: Breakdown voltage of oxide masked and passivated overlay annular diodes are limited in magnitude and stability by locally high fields in the surface junction region. Topologically, it is demonstrated that these high field regions are influenced by both the overlay radius of curvature and the overlay to annular ring spacing. Breakdown voltages approaching bulk values are achieved only with much reduced average surface fields, requiring excessive area. The use of a highly resistive but essentially ohmic film over the oxide in the high field surface region can shape and homogenize the surface fields. The use of 2000 A polycrystalline silicon layers with sheet resistances in excess of 10 10 Ω/□ for the field shaping element is shown experimentally to lead to reduced surface spacings for a given breakdown voltage and less tendency for surface arcing.

p‐n Junction Photodiodes in PbTe Prepared by Sb+ Ion Implantation

Abstract: n‐p junction photovoltaic detectors in PbTe have been fabricated using Sb+ ion implantation to create the n‐type layer. At 77 °K, 15‐mil square diodes have had zero‐bias resistances as high as 15 MΩ for a resistance‐area product of 2.1×104 Ωcm2. Peak detectivities at 4.4 μm in reduced background as high as 1.6×1012 cmHz1/2/W were observed. Diode quantum efficiencies were typically 40% at 4.4 μm.

Detection of the Gaseous Pollutant Sulfur Dioxide Using Current Tunable Pb 1− x Snx Te Diode Lasers

Abstract: Current tunable semiconductor lasers of Pb1−xSnxTe have been used to investigate the ir spectrum of sulfur dioxide at high resolution near 1130 cm−1. The diode lasers emit radiation in a line of width <10−5 cm−1 thus providing much higher resolution than has been possible with the best grating spectrometer. The effects of self-broadening and broadening by nitrogen to a pressure of 760 Torr are presented, and some characteristics of the laser source such as stability and reproducibility are discussed.

Transit‐Time Oscillations in BARITT Diodes

Abstract: A new mechanism of microwave power generation, obtained in metal‐semiconductor‐metal structures with significantly lower noise than Impatt diodes is described. The two metal contacts to the semiconductor form a ``double Schottky barrier'' diode. Carriers are thermionically injected over the forward‐biased barrier and drift through the depleted semiconductor to be collected by the reverse‐biased barrier. When the transit time of the carriers is roughly three‐quarters of the desired microwave period, the structure is shown to have a small‐signal microwave negative resistance. Combining the ideas of thermionic injection over a barrier and transit time, we suggest the acronym BARITT (BARrier Injection Transit Time) for the device. The small‐signal impedance and noise measure of the device are calculated using several approximations to the actual space‐charge distribution and transport properties of this device. A minimum negative Q of about 21 and noise measures significantly less than that of Impatt diodes are predicted. Initial experimental observations of microwave oscillations are given, and reasonable agreement with theory is obtained. In general, the theory predicts well the magnitude of the small‐signal negative resistance with a somewhat smaller bandwidth than observed. The experimental small‐signal amplifier noise measure of 15 dB is verified with practical values as low as 8 dB predicted.

Average energy to form electron‐hole pairs in GaP diodes with alpha particles

Abstract: The energy required to form an electron‐hole pair in gallium phosphide has been measured using GaP p‐n junction diodes made from high‐purity‐level GaP materials. The values of eGaP for several GaP diodes for alpha particles ranged from 6.35 to 6.75 eV, with an average value of 6.54 ± 0.13 eV at 300°K. This value is smaller than that obtained by Goldstein and is very close to the value of 6.56 eV calculated from the experimental relationship e = 2.596Eg + 0.714 (eV), which was derived previously from the experimental values of e for Ge, Si, GaAs, and CdTe.

On diode thermometers

Abstract: Forward voltage vs. temperature characteristics are presented for 3 groups of silicon planar p-n junction diodes for the 4–300°K temperature range. Group ‘intrinsic’ characteristics are obtained at temperatures above about 40°K and existing diode theory appropriate for high level injection is successfully applied. Comparison of experimental results with theory permits the determinations of the zero temperature energy gaps of silicon (as well as germanium and gallium arsenide). The values thus obtained are in good agreement with values obtained by other methods. At temperatures below about 40°K, the forward voltage increases more rapidly with decreasing temperature. Deviations are noted among diodes within the same group as well as between groups. This low temperature ‘extrinsic’ characteristic is attributed to carrier freezeout effects at impurities which by increasing the junction width, convert the p-n junction to a p-i-n junction. Confirmation of this hypothesis is found by the current dependence as a function of temperature as well as by the decrease of capacitance with temperature. The role of the impurities in the semiconductor in controlling the slope in the intrinsic range and the sensitivity and deviation from linearity in the extrinsic range is discussed.