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Showing papers on "Schottky diode published in 1979"


Journal ArticleDOI
TL;DR: In this article, electric field effects on the thermal emission of traps in a diode have been studied and compared with experimental data on deep centers in GaAs, consistent with a thermal equivalent of the optical Franz-Keldysh effect.
Abstract: Electric field effects on the thermal emission of traps in a diode have been studied. Calculations were performed and compared with experimental data on deep centers in GaAs. The results are consistent with a thermal equivalent of the optical Franz‐Keldysh effect.

503 citations


Journal ArticleDOI
TL;DR: In this paper, the current-voltage characteristics of a two-terminal FET with ballistic electron transport were analyzed using an approach similar to the Shockley model, showing that very high drift velocities can be obtained at low voltages leading to high speed and low power consumption in possible applications in logic circuits.
Abstract: At low temperatures, a mean free path of electrons in semiconductors may exceed device dimensions. Current-voltage characteristics, potentials, electrical field, and carrier distributions are calculated for a two-terminal device under such conditions when the electron transport is ballistic. Current-voltage characteristics of a "ballistic" FET are analyzed using an approach similar to the Shockley model. It is shown that very high drift velocities can be obtained at low voltages leading to high speed and low power consumption in possible applications in logic circuits. For example, GaAs logic devices with characteristic dimensions about a micrometer or less at 77 K will be comparable with or better than Josephson tunneling logic gates.

273 citations


Journal ArticleDOI
TL;DR: In this article, surface analyses combined with barrier height studies indicate that barriers made with low-work-function metals (Yb, Mg, and Mn) are essentially Cu/Cu2O cells due to reduction of the Cu2O surface and subsequent interdiffusion phenomena.
Abstract: Surface analyses combined with barrier‐height studies indicate that Cu2O Schottky barriers made with low‐work‐function metals (Yb, Mg, and Mn) are essentially Cu/Cu2O cells due to reduction of the Cu2O surface and subsequent interdiffusion phenomena. The copper‐rich region essentially determines the barrier height. As a result, efficiencies of Cu2O Schottky‐barrier solar cells are usually less than 1%. It is concluded that to achieve significant increases in Cu2O cell efficiencies, MIS or heterojunction device structures must be utilized.

179 citations


Journal ArticleDOI
TL;DR: The photovoltaic properties of Schottky barier solar cells, made by dispersing particles of the x form of mental-free phthalocyanine in a binder polymer and sandwiching between NESA (SnO2/Sb) and aluminum electrodes, have been studied as discussed by the authors.
Abstract: The photovoltaic properties of Schottky barier solar cells, made by dispersing particles of the x form of mental‐free phthalocyanine in a binder polymer and sandwiching between NESA (SnO2/Sb) and aluminum electrodes, have been studied. A power conversion efficiency of over 6% for transmitted light at low power densities (0.06 W/m2) has been obtained for monochromatic irradiation at 670 nm. At peak solar power density (1400 W/m2) the extrapolated power conversion efficiency (η) for transmitted 670 nm irradiation decreases to 0.01%. The decrease in η with intensity was attributed to a space charge limitation due to nonlinear resistance. The devices exhibit Voc’s as high as 1.1 V, but are still limited by a field dependent quantum efficiency. Analysis of the action spectra of these devices revealed the formation of a thin photoactive depletion region (∼400 A) at the semiconductor/metal interface. These devices are capable of capturing 30% of the solar spectrum within the photoactive region. The effect of pig...

166 citations


Journal ArticleDOI
TL;DR: In this paper, the voltage dependence of the capacitance of a tetracene or Nesatron cell is investigated in an attempt to better understand the contradiction of conductivity measurements suggesting that many organic materials behave as insulators while photovoltaic properties of some of these same materials may be rationalized using the concepts of semiconductor physics.
Abstract: The study of the electrical properties of (metal 1‖ organic ‖metal 2) cells has not led to a consistent model of their origin. On the one hand, conductivity measurements suggest that many organic materials behave as insulators (low carrier concentrations) while photovoltaic properties of some of these same materials may be rationalized using the concepts of semiconductor physics, suggesting that the organic film has a high carrier concentration. In this paper the voltage dependence of the capacitance of a (Al‖tetracene‖Au or Nesatron) cell is investigated in an attempt to better understand this contradiction. The electrical properties of this cell are explained in terms of a model in which depletion layers are made from a high density of immobile trapped charge. The trapped charge can be mobilized by light and then evidence is found for a Schottky depletion region (∼2000 A thick) in the tetracene film.

142 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of the insulating layer on barrier height and carrier transport are delineated by an activation energy analysis, and a capacitance anomaly consistently noticed in MIS Schottky barriers is resolved by stipulating a non-uniform interfacial layer.
Abstract: The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of GaAs metal-insulator-semiconductor (MIS) Schottky barrier diodes are investigated over a wide temperature range and compared with MS diodes. The effects of the insulating layer on barrier height and carrier transport are delineated by an activation energy analysis. Excess currents observed at low forward and reverse bias have also been analyzed and their cause identified. A capacitance anomaly consistently noticed in MIS Schottky barriers is resolved by stipulating a non-uniform interfacial layer, and a self-consistent model of the GaAs MIS Schottky barrier is developed by analyzing I-V and C-V data of both MIS and MS diodes.

135 citations


Journal ArticleDOI
TL;DR: In this article, the authors derived the optimum doping profile of a lightly doped layer that introduces the minimum series resistance and sustains a given junction breakdown voltage, which applies to a one-dimensional Schottky diode and qualitatively to the collector or drain doping profiles of transistors.
Abstract: The optimum doping profile of a lightly doped layer that introduces the minimum series resistance and sustains a given junction breakdown voltage is derived. The theory applies to a one-dimensional Schottky diode and qualitatively to the collector or drain doping profiles of transistors. The minimum series resistance is found to be about 3.7 × 10-9 V\min{B}\max{2.6} Ω.cm2for an n silicon layer. The optimum doping profile can be closely approximated by a conventional uniformly doped n-n+structure.

118 citations


Patent
24 Oct 1979
TL;DR: In this paper, a gaseous glow-discharge process for coating a substrate with semiconductor material, a variable electric field in the region of the substrate and the pressure of the Gaseous material are controlled to produce a uniform coating having useful semiconducting properties.
Abstract: In a gaseous glow-discharge process for coating a substrate with semiconductor material, a variable electric field in the region of the substrate and the pressure of the gaseous material are controlled to produce a uniform coating having useful semiconducting properties. Electrodes having concave and cylindrical configurations are used to produce a spacially varying electric field. Twin electrodes are used to enable the use of an AC power supply and collect a substantial part of the coating on the substrate. Solid semiconductor material is evaporated and sputtered into the glow discharge to control the discharge and improve the coating. Schottky barrier and solar cell structures are fabricated from the semiconductor coating. Activated nitrogen species is used to increase the barrier height of Schottky barriers.

116 citations


Journal ArticleDOI
TL;DR: In this article, the Schottky barrier height of three iridium silicides IrSi, Ir2Si3, and IrSi3 was determined by combining TEM observations and I•V and C•V measurements.
Abstract: Direct correlations between iridium silicides and their Schottky barrier heights on Si have been studied by combining TEM observations and I‐V and C‐V measurements. It has previously been shown that three iridium silicides IrSi, Ir2Si3, and IrSi3 can be formed by annealing Ir films on Si at temperatures around 400, 600, and 960 °C, respectively. The Schottky barrier height of these silicides on 〈100〉 Si have been determined to be 0.93 eV (IrSi), 0.85 eV (Ir2Si3), and 0.94 eV (IrSi3). Along with the I‐V measurement, a computer fitting of current transport across Schottky diodes has been used to analyze the I‐V data so that the barrier height from nonideal diodes can be determined. The question of a parallel diode formed by a mixture of two phases at the contact area has also been addressed. It is shown that I‐V measurements, which are very sensitive to the presence of a lower barrier phase, tend to give a lower barrier height than a corresponding C‐V measurement since the latter depends on the major phase ...

106 citations


Proceedings Article
B.J. Sloan1
01 Jan 1979
TL;DR: The application of state-of-the-art bipolar I.C. device and process technologies to the fabrication of Schottky Transistor logic is discussed in this paper, where the performance and density of STL utilizing minimum features ranging from 5 µm to less than 1.5 µm is shown including minimum gate delays below.5 nsec and power-delay product below 50 femto-Joules.
Abstract: The application of state-of-the-art bipolar I.C. device and process technologies to the fabrication of Schottky Transistor logic is discussed. The special requirements of a dual Schottky barrier-height metal system is reviewed and the performance and density of STL utilizing minimum features ranging from 5 µm to less than 1.5 µm is shown including minimum gate delays below .5 nsec and power-delay product below 50 femto-Joules. An example of an STL circuit implemented with an automatically routed gate array is shown.

98 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the low-frequency excess noise in Schottky barrier diodes and empirically found that the 1/ε noise level decreases very rapidly if the ideality factor tends to unity.
Abstract: The low-frequency excess noise in Schottky barrier diodes has been investigated. In the ideal case where the saturation current is completely determined by thermionic emission of electrons, no 1/ƒ noise will be produced in the barrier. The presence of trap states in the depletion region can lead to generation-recombination noise. At sufficient high forward currents 1/ƒ noise can be generated in the series resistance of the Schottky diode. Deviations from the ideal diode, for example as a result of edge effects, produce 1/ƒ noise and increase at the same time the ideality factor. It is empirically found that the 1/ƒ noise level decreases very rapidly if the ideality factor tends to unity.

Journal ArticleDOI
TL;DR: In this article, a defect model was used to study the interfaces formed between metals and the semiconductors silicon and indium phosphide, showing that the interface electronic properties are dominated by chemical and metallurgical effects, which cast some doubt about the usefulness of S, the index of interface behavior often used to describe metal-semiconductor interfaces.
Abstract: Detailed studies, using a range of experimental techniques, are described of the interfaces formed between metals and the semiconductors silicon and indium phosphide. For contacts between Ag or Au and cleaved (111) Si the existence of thin adlayers of oxygen or chlorine at the interface makes little difference to the magnitude of the Schottky barrier formed, although the adlayers totally change the electronic structure of the free surface. Au, Ag, and Cu contacts on clean (110) surfaces of InP yield good Schottky barriers but exposure of the clean surface to oxygen, air or chlorine prior to deposition of the metal electrodes leads to low apparent barrier contacts at room temperature. Reactive metals such as Al, Fe, and Ni also yield low barrier contacts, at room temperature, when deposited on clean surfaces of InP. These results coupled with studies on other materials cast some doubt about the usefulness of the quantity S, ’’the index of interface behavior’’ often used to describe metal–semiconductor interfaces and on the existence of the much quoted covalent‐ionic transition. The present results on InP may be understood in terms of a defect model and details of this model are discussed. The interface electronic properties are dominated by chemical and metallurgical effects.

Journal ArticleDOI
TL;DR: In this paper, a new laser structure, the ''T''laser'' was monolithically integrated with a MESFET on a semi-insulating GaAs substrate, achieving direct modulation of the laser by means of the transistor.
Abstract: A new laser structure, the ’’T‐laser’’, has been monolithically integrated with a MESFET on a semi‐insulating GaAs substrate. Integration is achieved by means of a compatible structure in which the optically active layer of the laser also serves as the electrically active layer of the MESFET. Direct modulation of the laser by means of the transistor is demonstrated.

Journal ArticleDOI
TL;DR: In this paper, a defect mechanism responsible for pinning states within the band gap on the (110) surfaces of the III-V compounds is presented. But the defect mechanism is not considered in this paper.
Abstract: New evidence for a defect mechanism which is responsible for pinning states within the band gap on the (110) surfaces of the III–V compounds is presented. Investigations of column III metals on both n‐ and p‐type GaAs revealed a systematic difference in surface Fermi energy stabilization in the gap with p‐type samples pinning 0.25 eV below n‐type samples. Several current models and theories of Schottky barriers are discussed in terms of both the results given in this paper and previously reported data.

Journal ArticleDOI
01 Jan 1979
TL;DR: In this article, the transport properties of indium monoselenide have been measured in n-and p-type material and fabrication procedures for Schottky and p-n diodes are reported.
Abstract: The transport properties of indium monoselenide have been measured in n- and p-type material. Parameters for photoexcited carriers are given. Fabrication procedures for Schottky and p-n diodes are reported. Photovoltaic spectra are fitted with measured values of transport and optical parameters. InSe is shown to be a new material with attractive characteristics for solar energy conversion. Performance of InSe solar cells is discussed.

Patent
27 Jul 1979
TL;DR: In this article, a high frequency field effect transistor of gallium arsenide or other III-V semiconductor compounds has a preferentially etched trapezoidal groove structure in the top surface which creates parallel trapezoid semiconductor fingers that are wider at the top than at the bottom.
Abstract: A high frequency field effect transistor of gallium arsenide or other III-V semiconductor compounds has a preferentially etched trapezoidal groove structure in the top surface which creates parallel trapezoidal semiconductor fingers that are wider at the top than at the bottom. Schottky gates or junction gates are fabricated within the grooves surrounding the elongated fingers. The vertical conducting channels between the gates are narrow leading to a high blocking gain, and more contact area is available at the top of the device.

Journal ArticleDOI
TL;DR: In this article, the authors reported the electrical characteristics of InP Schottky diodes as a function of isochronous heating cycles from 120 to 340°C.
Abstract: Variations of barrier heights with heat treatment are observed on Au/(n‐type) InP Schottky diodes. The n‐type InP wafers used are vapor epitaxially grown ({100} face oriented) and have carrier concentrations in the range 4×1015 to 2×1016 cm−3. Before the deposition of the metal, the surfaces are chemically etched in a bromine‐methanol mixture. Electrical characteristics are reported as a function of isochronous heating cycles from 120 to 340 °C, using conventional Schottky barrier I‐V and C‐V analysis. The barrier heights are in the range 0.42–0.49 eV. Degradation characteristics and decreased barrier heights are observed after a 340 °C heat treatment in N2 with a residual O2 atmosphere. Distribution profiles of elemental species obtained by Auger electron spectroscopy associated with an Ar+‐ion‐beam sputtering show the interdiffusion between the metal and InP as a function of the heat treatment: out‐diffusion of In and O as a solid solution of In2O3 in the Au film and Au and O diffusion through the Au/In...

Journal ArticleDOI
TL;DR: In this paper, the diffusion length of p-type silicon implanted with 400 kV boron ions to a dose of 1014 B+ cm-2 and annealed to temperatures in the range 700-1000 degrees C was evaluated.
Abstract: The SEM operated on the EBIC model is used to evaluate the diffusion length in p-type silicon implanted with 400 kV boron ions to a dose of 1014 B+ cm-2 and annealed to temperatures in the range 700-1000 degrees C. The method is to fabricate a Schottky diode on the irradiated surface of the implanted sample, and then place the sample in the SEM in such a way so that the beam is incident normal to the sample surface partly covered with the Schottky diode metal film; the diffusion length is found by slowly scanning the beam away from the Schottky diode and analysing the resulting EBIC decay. It is found that the effect of the implantation is to reduce the diffusion length with reference to an unimplanted sample subjected to the same heat treatment. The reduction is approximately 53% at 700 degrees C, and as the annealing temperature increases it gradually decreases to approximately 21% at 1000 degrees C. This shows that the effect of the damage on the diffusion length decreases with increasing annealing temperature.

Journal ArticleDOI
TL;DR: Integrated Schottky logic (ISL) as mentioned in this paper is a new 200 mV voltage-swing LSI logic that can be made in standard Schottkey processes with a double-layer metallization.
Abstract: Integrated Schottky logic (ISL) is a new 200 mV voltage-swing LSI logic that can be made in standard Schottky processes with a double-layer metallization. It fills the gap between low-power Schottky TTL and I/SUP 2/L for those circuits where low-power Schottky TTL consumes too much power and takes up too much chip area, and when I/SUP 2/L does not attain the required speed. An ISL gate consists of a current source and a set of Schottky output diodes (wired AND gate). Minimum propagation delay times of 2.7 ns at 200 /spl mu/A/gate are obtained, with a speed-power product of 1.2 pJ. The packing density of ISL is 120 to 180 gates/mm/SUP 2/. The logic can be combined with ECL, I/SUP 2/L, and TTL on the same chip, and can also be made in analog processes.

Journal ArticleDOI
TL;DR: In this article, the Schottky diodes obtained by evaporation of platinum onto hydrogenated amorphous silicon (a 'Si':H) fabricated by glowdischarge decomposition of silane were studied as a function of several preparation parameters, namely, silane pressure, substrate temperature, and annealing temperature.
Abstract: We report on the open‐circuit voltage Voc and the forward‐current–voltage characteristic, J=Js(expqV/nKT−1), of Schottky diodes obtained by evaporation of platinum onto hydrogenated amorphous silicon (a‐Si :H) fabricated by glow‐discharge decomposition of silane. The diode characteristics were studied as a function of several preparation parameters, namely, silane pressure, substrate temperature, silane flow rate, annealing temperature. Rectifying behavior was obtained only for substrate temperatures between 200 and 300°C. Within this constraint, the preparation parameters have only a small effect on Voc but have large influences on n and Js. The factor n decreases towards ideality (n=1) as the silane pressure decreases, as the substrate temperature increases and with annealing of the Pt contact. The corresponding decrease of the concentration of polyhydride H sites with similar variations in the preparation parameters suggests that the recombination center responsible for nonideal value of n are associat...

Journal ArticleDOI
TL;DR: In this article, the electron emission spectrum is dominated by two levels near the middle of the silicon forbidden energy band with activation energies of ∼0.49 and 0.56 eV, and the defect density is shown to decrease monotonically with depth into the silicon substrate.
Abstract: Electronic defect levels in self‐implanted cw Ar‐laser‐annealed silicon have been measured by deep‐level transient spectroscopy. The electron emission spectrum is dominated by two levels near the middle of the silicon forbidden energy band with activation energies of ∼0.49 and 0.56 eV. These levels can be spatially resolved in the depletion layer of Schottky diodes due to a more rapid decrease with distance in the density of the shallower level. In samples receiving a 450 °C furnace anneal (after laser irradiation) an additional level appears at 0.28 eV; the defect density is shown to decrease monotonically with depth into the silicon substrate.

Journal ArticleDOI
TL;DR: In this article, the capacitance of a forward-biased Schottky diode was used to determine the energy distribution and relaxation time of interface states in ultrahigh vacuum contacts between chromium and silicon.
Abstract: By studying the capacitance of a forward‐biased Schottky diode it is possible to determine the energy distribution and relaxation time of interface states. This method is applied to contacts between chromium and silicon cleaved in ultrahigh vacuum. The presence in the silicon gap of interface states in equilibrium with the semiconductor and distributed in a set of energy bands is established. The characteristics of each band (energy position, density, and capture cross section) are identified. The origin of these states is discussed, and it is argued that they are characteristic of the silicon surface.

Journal ArticleDOI
TL;DR: In this paper, the microwave power gain, noise figure, maximum output power and power-added efficiency were measured and compared to those parameters measured on GaAs Schottky barrier gate devices of identical geometry.
Abstract: LPE GaAs and InP n-channel depletion mode insulated gate field effect transistors (MISFETs) having 4 μm gate lengths have been fabricated employing pyrolytic SixOyNz, pyrolytic SiO2 and an anodic dielectric for gate insulation. The microwave power gain, noise figure, maximum output power and power-added efficiency were measured and compared to those parameters measured on GaAs Schottky barrier gate devices of identical geometry. The results show that, at least at the microwave frequencies measured, power gain and noise are essentially the same in the GaAs Schottky gate FET and anodic MISFET devices while the maximum output power of a typical InP MISFET was greater than that of a representative GaAs Schottky device.

Journal ArticleDOI
TL;DR: In this article, the electrical conductivity, Hall effect and photoluminescence properties of single crystals of CuGaSe 2 have been investigated and it was found that the electrical and optical properties of this material depend on thermal treatment.

Journal ArticleDOI
TL;DR: In this paper, conversion Iosses for Schottky diode mixers in the submillimeter region were calculated, and the optimum mixer performance was shown to depend strongly upon operating frequency and upon diode diameter.
Abstract: Conversion Iosses, both intrinsic and parasitic, are calculated for Schottky diode mixers in the submillimeter region, and optimum mixer performance is shown to depend strongly upon operating frequency and upon diode diameter. The implications for high-frequency diode fabrication are discussed, and a comparison is made of the expected performance of GaAs, Si, and InSb Schottky diodes at frequencies up to 5 THz.

Journal ArticleDOI
TL;DR: In this paper, a modified photocapacitance technique was used to measure the optical and thermal transitions at the center of ZnSe. Butt et al. showed that keeping the depletion region of a Schottky diode constant during the measurements of transients highly compensated samples could result in larger signals than previously possible, allowing optical emission rates for both electrons and holes to be measured with higher accuracy and in a broader temperature region than in previous investigations.
Abstract: Emission and capture rates describing the optical and thermal transitions at the ’’Cu‐red’’ center in ZnSe have been investigated using a modified photocapacitance technique. By keeping the depletion region of a Schottky diode constant during the measurements of transients highly compensated samples could be used, resulting in larger signals than previously possible. This permitted optical‐emission rates for both electrons and holes to be measured with higher accuracy and in a broader temperature region than in previous investigations. The capture cross section of electrons σn was determined in the temperature range 77–200 K. σn increases with decreasing temperature and has a value of 1.4×10−19 cm2 at 77 K.

Journal ArticleDOI
TL;DR: In this paper, an estimate for the minimum (Bardeen limit) and maximum (Schottky limit) of the interface index, S, is calculated. And it is shown that current measurements on high S materials are near or at the maximum value for S.
Abstract: An estimate for the minimum (Bardeen limit) and maximum (Schottky limit) of the interface index, S, is calculated. It is shown that current measurements on high S materials are near or at the maximum value for S.

Patent
12 Mar 1979
TL;DR: Amorphous silicon Schottky barrier solar cells which incorporate a thin insulating layer and a thin doped layer adjacent to the junction forming metal layer exhibit increased open circuit voltages compared to standard rectifying junction metal devices as discussed by the authors.
Abstract: Amorphous silicon Schottky barrier solar cells which incorporate a thin insulating layer and a thin doped layer adjacent to the junction forming metal layer exhibit increased open circuit voltages compared to standard rectifying junction metal devices, i.e., Schottky barrier devices, and rectifying junction metal insulating silicon devices, i.e., MIS devices.

Journal ArticleDOI
TL;DR: In this article, the Schottky barrier at a CdS electrode in contact with various redox electrolytes has been measured at electronic equilibrium and the open-circuit photovoltage, V oc, has been found being linearly related to this quantity at constant illumination intensity.

Journal ArticleDOI
TL;DR: In this paper, a submillimeter-wave solid-state sources were developed with a frequency tripler and a frequency quadrupler driven by an 150 GHz band IMPATT oscillator, achieving an output power of -9.3 dBm at 447 GHz with a conversion loss of 20 dB.
Abstract: Submillimeter-wave solid-state sources have been developed with a frequency tripler and a frequency quadrupler driven by an 150-GHz band IMPATT oscillator. The tripler and quadrupler delivered an output power of -9.3 dBm at 447 GHz with a conversion loss of 20 dB, and -28 dBm at 589 GHz with a conversion loss of 39 dB, respectively. The frequency multiplication was performed by use of GaAs-Ni-Au schottky-barrier diodes with junction diameter of 1-3 mu m and hybrid integrated circuit techniques.