Showing papers on "Diode published in 1985"

Semiconductor Devices: Physics and Technology

Abstract: Preface. Introduction. PART I: SEMICONDUCTOR PHYSICS. Energy Bands and Carrier Concentration in Thermal Equilibrium. Carrier Transport Phenomena. PART II: SEMICONDUCTOR DEVICES. p-n Junction. Bipolar Transistor and Related Devices. MOSFET and Related Devices. MESFET and Related Devices. Microwave Diodes, Quantum-Effect, and Hot-Electron Devices. Photonic Devices. PART III: SEMICONDUCTOR TECHNOLOGY. Crystal Growth and Epitaxy. Film Formation. Lithography and Etching. Impurity Doping. Integrated Devices. Appendix A: List of Symbols. Appendix B: International Systems of Units (SI Units). Appendix C: Unit Prefixes. Appendix D: Greek Alphabet. Appendix E: Physical Constants. Appendix F: Properties of Important Element and Binary Compound Semiconductors at 300 K. Appendix G: Properties of Si and GaAs at 300 K. Appendix H: Derivation of the Density of States in Semiconductor. Appendix I: Derivation of Recombination Rate for Indirect Recombination. Appendix J: Calculation of the Transmission Coefficient for a Symmetric Resonant-Tunneling Diode. Appendix K: Basic Kinetic Theory of Gases. Appendix L: Answers to Selected Problems. Index.

1.54‐μm electroluminescence of erbium‐doped silicon grown by molecular beam epitaxy

Abstract: The feasibility of producing erbium‐doped silicon light‐emitting diodes by molecular beam epitaxy is demonstrated. The p‐n junctions are formed by growing an erbium‐doped p‐type epitaxial silicon layer on an n‐type silicon substrate. When the diodes are biased in the forward direction at 77 K they show an intense sharply structured electroluminescence spectrum at 1.54 μm. This luminescence is assigned to the internal 4f–4f transition 4I13/2→4I15/2 of Er3+ (4f11).

A dual-detector optical heterodyne receiver for local oscillator noise suppression

Abstract: The performance of a dual-detector optical heterodyne receiver was analyzed and compared with the performance of a conventional single-detector heterodyne receiver. The dual-detector receiver is found to offer two main advantages over the single-detector receiver-1) increased performance in the presence of local oscillator intensity fluctuations that might severely degrade single-detector receiver performance, and 2) decreased local oscillator power requirements. These two advantages are particularly important in a communication system which uses semiconductor laser diodes as local oscillators. Such lasers suffer from intrinsic wide-band intensity fluctuations and can also impose strict power constraints on receiver design. Based on the analysis, suggestions for the optimal design of a dual-detector heterodyne receiver are made. Also, several experiments were performed to demonstrate the improved performance of the dual-detector receiver-both for unguided- and guided-wave receivers.

A reciprocity theorem for charge collection

Abstract: It is shown that the current collected by a p‐n junction in presence of a unit point generation of carriers at a point P is the same (apart from the dimensions) as the excess minority‐carrier density at P due to a unit density of carriers at the junction edge. Use of this reciprocity relation may simplify the calculation of beam induced currents in semiconductor devices. The practical meaning of this property is illustrated in the case of a light‐emitting diode containing defects.

Characterization of interface states at Ni/nCdF2 Schottky barrier type diodes and the effect of CdF2 surface preparation

Abstract: Two Schottky diodes were fabricated by evaporation of nickel on to an n-type CdF2:YF3 semiconductor. Diode A was prepared on a slightly etched polished surface and diode B on an unpolished strongly etched surface. The current-voltage (I-V), capacitance-voltage (C-V), and conductance-voltage (G-V) characteristics were determined at room temperature. Both diodes showed non-ideal I-V behaviour with ideality factors 1.5 and 2.0, respectively and are thought to have a metal-interface layer-semiconductor configuration. Under forward bias, the admittance showed large frequency dispersion possibly caused by the interface states in thermal equilibrium with the semiconductor. Analysis of the C-V data in terms of Lehovec's model of an interface state continuum required the supposition of two time constants differing by 2 to 3 orders of magnitude. The characteristic parameters of the interface states (energy position, density, time constant and capture cross-section) were obtained for the values of the forward bias in the range 0.0 V ≦ V ≦ 0.2 V. The diode B is found to have the interface state densities about two orders of magnitude higher than the diode A which may be attributed to the different surface treatments. The C-V measurements at 100 kHz also indicated the presence of a deep donor trap about 0.6 eV below the conduction band edge in diode A.

Room Temperature Observation of Differential Negative Resistance in an AlAs/GaAs/AlAs Resonant Tunneling Diode

Abstract: A resonant tunneling diode having AlAs/GaAs/AlAs double barrier structure is designed to enhance the resonant tunneling current component and to suppress the excess current component which is believed to dominate the transport at high temperatures. Based on this design, a diode structure with optimized parameters is prepared by careful molecular beam epitaxial growth, in which the dopant incorporation into the well layer and the interface asperities are minimized. The AlAs/GaAs/AlAs diodes thus fabricated were found to exhibit differential negative resistance at room temperature for the first time.

Period doubling and chaos in a directly modulated laser diode

Abstract: It is shown theoretically that the directly modulated laser diode, with the modulation frequency of its injection current comparable to the relaxation oscillation frequency, exhibits period doubling route to chaos as the modulation index of current is increased. The effect of spontaneous emission factor on the chaotic behavior in the laser diode is also studied.

Resonant tunneling of two‐dimensional electrons through a quantum wire: A negative transconductance device

Abstract: A novel three‐terminal resonant‐tunneling structure is proposed in which the double potential barrier is defined within the plane of a two‐dimensional (2‐D) electron gas. The resonant tunneling of 2‐D electrons into a 1‐D ‘‘quantum wire’’ is controlled not only by a source‐to‐drain voltage but also by a gate potential. In addition to the negative differential resistance found in conventional resonant‐tunneling diodes, our device offers a negative transconductance. This feature is potentially useful for low‐power logic circuits.

Semiconductor memory device

Abstract: PURPOSE:To lower applied voltage on the memorization of informations without reducing the electrostatic dielectric resistance of polycrystalline silicon, and to eliminate possibility of which a diode is broken or a gate film is broken by forming a section thicker than other sections to one part of polycrystalline silicon used as a memory element and lowering the heat dissipation properties of the section. CONSTITUTION:A thick section 404 is formed to one part of low resistance polycrystalline silicon 401 for a wiring. Consequently, the heat dissipation properties of the thick section lower, and the internal temperature of high resistance polycrystalline silicon 402 in a thicker section more rises when flowing currents are the same. Conversely speaking, crystals in the high resistance polycrystalline silicon 402 can be changed by small currents. That is, crystals can be changed at voltage lower than conventional devices in which the thickness of polycrystalline silicon is uniform, and a resistance value can be reduced. As a result, informations can be memorized at low applied voltage. Accordingly, the possibility of the breaking of a diode for the countermeasure against static electricity or the breaking of a gate film or the like is reduced.

Power drift step recovery diodes (DSRD)

Abstract: Reverse recovery processes in diodes, leading to a high voltage rise rate, have been considered. A maximum voltage rise rate for silicon diodes as high as 2·10 12 v/s has been estimated. Power drift step recovery diodes for shaping 1 kV voltage steps with nanosecond fronts have been designed and investigated.

Schottky barrier diodes on 3C‐SiC

Abstract: Schottky barrier contacts have been made on n‐type 3C‐SiC epitaxially grown by chemical vapor deposition, and their characteristics were studied by the capacitance and photoresponse measurements. By evaporating Au onto chemically etched surfaces of 3C‐SiC, good quality Schottky barrier junctions have been obtained. The barrier height determined by the capacitance measurements is 1.15 (±0.15) eV, while the height by the photoresponse measurements is 1.11 (±0.03) eV. These values are about a half of the energy band gap Eg at room temperature.

Spectroscopy using thermionic diode detectors

Abstract: The basic principles of the thermionic diode technique and the potential of the detector in laser spectroscopy are discussed. Furthermore different types of set-ups, effective detection schemes and hints for the construction and preparation of thermionic diodes are given.

1/ f noise in p‐n junction diodes

Abstract: A survey is given of the recent literature on 1/ f noise in p‐n junction diodes. Two models for the explanation of 1/ f noise are discussed: Hooge’s model assuming mobility fluctuations and McWhorter’s model assuming number fluctuations. Relations for the magnitude of the 1/ f noise based on Hooge’s model are presented for several types of diodes: diffusion current dominated diodes, GR current dominated diodes, long and short diodes, and illuminated photodiodes. These relations are compared with experimental results obtained from diodes made of Si, GaP, and (HgCd)Te. The agreement between experiment and calculated relations is often found to be satisfactory, both for forward and reverse‐biased diodes and for illuminated diodes. 1/ f noise relations based on McWhorter’s model are scarce, moreover, they do not sufficiently describe the 1/ f noise in diodes.

A High-Power Backward-Wave Oscillator Driven by a Relativistic Electron Beam

Abstract: A high-power backward-wave oscillator (BWO) has been constructed that is driven by a relativistic electron beam (REB). A typical electron beam of 2-4 kA is accelerated across a diode potential of 650-800 kV and then guided through a section of corrugated transmission line by an axial magnetic field of 5-15 kG. Peak microwave powers of 100-200 MW have been observed in the circular TM01 mode at the predicted frequency of 8.4 GHz. The basic principles and parameters of operation will be discussed, along with the dependence of peak microwave power on applied axial magnetic field.

Radiant refrigeration by semiconductor diodes

Abstract: Dousmanis et al. [Phys. Rev. 133, A316 (1964)] demonstrated that GaAs light‐emitting diodes could produce a cooling effect if the quantum efficiency (ratio of photon flux to junction current) is very close to unity (e.g., >0.97). Here, it is pointed out that for narrow‐bandgap semiconductors, the quantum efficiency need not be so high to produce cooling. Also, for narrow‐bandgap semiconductors there is an additional cooling mode in which the reverse‐biased diode cools its radiant environment by absorbing infrared radiation. Maximum cooling rates per unit of junction area are on the order of n2σT4, where n is the index of refraction, σ is the Stefan–Boltzmann constant, and T is the temperature. For small cooling rates the efficiency for cooling can approach the limit imposed by the second law of thermodynamics.

Forward I‐V plot for nonideal Schottky diodes with high series resistance

Abstract: In this work we present an extension of Norde’s forward I‐V plot. This modified method allows us to obtain reliable values for three different parameters (n, R, and Is) in nonideal Schottky barrier diodes with high series resistance.

Room‐temperature operation of GaAs/AlGaAs diode lasers fabricated on a monolithic GaAs/Si substrate

Abstract: Room‐temperature operation has been achieved for GaAs/AlGaAs heterostructure diode lasers fabricated on a monolithic GaAs/Si substrate. These devices, which incorporate a large optical cavity structure grown by molecular beam epitaxy directly on a Si wafer, have exhibited threshold currents as low as 775 mA and power outputs as high as 27 mW/facet in pulsed operation.

Analysis of a Resonant Transistor DC-DC Converter with Capacitive Output Filter

Abstract: Resonant dc-dc converters offer several advantages over the more conventional PWM converters. Some of these advantages include: 1) low switching losses and low transistor stresses; 2) medium speed diodes are sufficient (transistor parasitic, inverse-parallel diodes can be used, even for frequencies in the hundreds of kilohertz); and 3) ability to step the input voltage up or down. This paper presents an analysis of a resonant converter which contains a capacitive-input output filter, rather than the more conventional inductor-input output filter. The switching waveforms are derived and design curves presented along with experimental data. The results are compared to the inductor-input filter case obtained from an earlier paper.

Operation of individual diode lasers as a coherent ensemble controlled by a spatial filter within an external cavity

Abstract: Five diode gain elements (diode lasers with one facet antireflection coated) have been controlled to operate coherently with each other by a spatial filter placed between the antireflection coated facet and the mirror of an external cavity which provides the feedback for laser operation The locking of the lasers is relatively insensitive to phase adjustment in each laser path Locking has occurred with lasers whose output wavelength when operating individually differed by 60 A It is expected that the maximum tolerance to wavelength difference is much larger because lasers used were selected so simple individual temperature control could bring them into wavelength coincidence These results point to the feasibility of placing well over a thousand diode lasers in an external cavity with coherent output

A theory of the Hooge parameters of solid-state devices

Abstract: Handel's theory of quantum 1/f noise is applied to the Hooge parameters of bipolar transistors and various types of FET's. Very low values for the Hooge parameters α Hn and α Hp for electrons and holes are obtained. For several cases the experimental data seem to agree with the predicted theoretical limit whereas in other cases the mobility 1/f noise is masked by other noise sources. In good GaAs devices the predicted quantum limit for α Hn is reached within a factor 5-10. The theory is also applied to the Hg 1-x Cd x Te materials and devices. Because of the very low effective masses involved, the theory predicts values as high as 2 × 10-4-2 × 10-5, depending on x . What remains presently unexplained are the high values of α H for semiconductor resistors and long p-n diodes.

Electron and ion kinetics and anode plasma formation in two applied Br field ion diodes

Abstract: Two magnetically insulated ion diodes that utilize a radial applied‐B field are described Both diodes generate an annular beam that is extracted along the diode axis The first diode operated at 12 MV and 600 kA for 25 ns and generated a 300‐kA ion beam The second operated at 300 kV, 100 kA and generated 15 kA of ion current The first diode was used to study diode performance as a function of inner and outer anode‐cathode gaps, the applied‐B field, and transmission line current ratios The second diode was used to study anode plasma formation The diodes were operated below Bcrit, resulting in electron leakage to the anode, especially near the outer cathode A definition of Bcrit applicable to extraction diodes is given and methods of improving ion production efficiency in these diodes are suggested The strong correlation of ion production with visible light emission suggests, however, that the electron loss played an important role in anode turn‐on The breakdown of neutral gas desorbed by electron

Time‐resolved proton focus of a high‐power ion diode

Abstract: An improved understanding of the factors that control the axial focus of applied‐B ion diodes was obtained from time‐resolved diagnostics of ion‐beam trajectories. This resulted in a new selection of anode shape that produced a proton focus of 1.3‐mm diameter from a 4.5‐cm‐radius diode, which is a factor of 2 improvement over previous results. We have achieved a peak proton power density of 1.5±0.2 TW/cm2 on the 1‐TW Proto I accelerator. The radial convergence of this proton beam, defined as the ratio of the anode diameter to focused beam FWHM, is 70. Time‐resolved information about virtual cathode evolution, the self‐ and applied‐magnetic‐field bending, and the horizontal focus of the beam was also obtained. In addition, the diffusion of the magnetic field into the anode plasma is estimated by measuring the horizontal focal position as a function of time. Finally, we discuss the effects of gas cell scattering on the beam focus.

A virtual‐cathode reflex triode for high‐power microwave generation

Abstract: Microwave generation by a relativistic electron beam injected through a screen or foil into a cylindrical waveguide is investigated. The electron beam is generated by a field‐emission diode with an anode‐cathode gap of ∼1 cm. The electron density exceeds the space‐charge limit for the beam, which forms a virtual cathode inside the waveguide. The instability of the virtual cathode causes oscillations which couple to bunched reflexing electrons trapped in the potential well. Frequency locking between the oscillating virtual cathode and the reflexing electrons is found to generate a much purer, narrowband microwave output. Using diode mismatch to increase the beam impedance is shown numerically to be a useful technique to improve the microwave generation efficiency and spectral purity. The peak conversion efficiency is calculated to be 2.2% at 7 GHz. The numerical results are compared to experimental results, and the agreement is within 8% in frequency and 25% in peak power. Experimentally, we describe the q...

The DSI diode—A fast large-area optoelectronic detector

Abstract: Fast double-Schottky-interdigitated diodes have been fabricated by evaporating Al-Schottky contacts on lowly doped n-GaAs (n=1014cm-3), These detectors have a relatively large light-sensitive area of 400 µm2. Rise and fall times are in the order of 10 ps. The external quantum efficiency is 25 percent at λ = 820 nm. The frequency response of the diodes is essentially flat up to 18 GHz, which is the limit of the measuring equipment.

Depletion mode thin film semiconductor photodetectors

Abstract: A depletion mode thin film semiconductor photodetector comprises a crystalline silicon thin film on an insulating substrate with a source region, a drain region and a thin film light sensing channel region formed therebetween. A gate oxide formed over the channel region and a gate electrode formed on the gate oxide. A p-n junction located parallel to the surface of the substrate and within the thin film functioning as a space charge separation region in the channel. The lower portion of the channel region is a p region extending to the substrate and the upper portion of the channel region is a n region extending to the gate oxide. The channel region functions as a fully depleted channel when the photodetector is operated in its OFF state providing for high dynamic range and large photocurrent operation. The depletion mode thin film semiconductor photodetector with n+ source and drain regions function as an ohmic contacts to the channel n region forming a thin film transistor. The thin film transistor photodetector has high photoconductive gain at low light intensities when the n channel region is fully pinched off by an applied gate voltage to the gate electrode which is sufficiently negative as compared to the threshold voltage of the photodetector. When the drain region is replaced by a p+ region functioning as an ohmic contact to the channel p region, a depletion mode gated diode is formed. When the channel region is extended to include a plurality of linearly spaced gate electrodes formed on the gate oxide region with an input diode formed adjacent to the first of such gate electrodes and an output diode formed adjacent to the last of such gate electrodes, the photodetector functions as a charge coupled device.

Ytterbium‐doped InP light‐emitting diode at 1.0 μm

Abstract: Light‐emitting pn junction diodes have been realized in ytterbium‐doped InP. The p‐type epitaxial layers, which contained the dopant ytterbium (Yb), were grown by liquid phase epitaxy on (100) oriented n+‐type InP substrates. Ohmic contacts were alloyed, and the diodes biased in forward direction. At 77 K, emissions were observed at 1.38 eV (0.90 μm) and 1.24 eV (1.00 μm) due to near band‐edge electron hole recombination and transitions between the spin‐orbit levels 2F5/2→2F7/2 of Yb3+(4f13), respectively. The dependence of the electroluminescence intensity with applied voltage is presented. The external quantum efficiency was determined to be 8×10−4 at 77 K.

Point contact diode at laser frequencies

Abstract: Dramatic improvements in the stability of the metal‐insulator‐metal point contact diode has been achieved by the use of blunter whisker tips. The optimum values for tip radius and diode resistance were experimentally determined. Both sensitivity and high‐speed response of W‐NiO‐Ni point contact diodes were investigated at different laser frequencies and mixing orders as a function of tip radius, resistance, and coupling. The tip radii were changed by more than an order of magnitude, and surprisingly, the sensitivity and the harmonic generation up to 88 THz were not significantly affected. A conical antenna was found to be superior to the conventional long‐wire antenna at wavelengths shorter than 10 μm. Responsivity measurements as a function of the diode resistance showed evidence for two different physical mechanisms responsible for the operation of the diode.

Intracavity nearly degenerate four‐wave mixing in a (GaAl)As semiconductor laser

Abstract: Intracavity nearly degenerate four‐wave mixing has been demonstrated by injecting a low intensity probe beam of frequency ω−δω inside a (GaAl)As semiconductor laser operating above threshold at the pump frequency ω. Conjugated reflectivities as high as 5000 together with a 25% energy conversion efficiency are reported with only a few milliwatt pump power. Additional peaks related to the ac stark effect have been observed at a detuning which depended on the pump power. This process could be useful for the study of instabilities occurring in lasers as well as for optical amplification in laser diodes.