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Showing papers on "Schottky barrier published in 1974"


Journal ArticleDOI
TL;DR: The photovoltaic and rectification properties of Al/Mg phthalocyanine/Ag sandwich cells are reported in this article, where a charge density of [inverted lazy s]1018/cm3 is estimated from C-V measurements.
Abstract: The photovoltaic and rectification properties of Al/Mg phthalocyanine/Ag sandwich cells are reported. At low voltages, the current in the forward direction varies exponentially with voltage. A charge density of [inverted lazy s]1018/cm3 is estimated from C‐V measurements. The short‐circuit photocurrent JscαFm (m [inverted lazy s]0.5), where F is the incident light intensity. The open‐circuit photovoltage Vocα logF as expected for a Schottky barrier or p‐n junction. The J‐V curve in the photovoltaic mode is characteristic of a cell with large series resistance. From the photovoltaic action spectra, the electron diffusion length is estimated to be [inverted lazy s]1.5×10−6 cm. The action spectrum is dependent on the direction of the incident radiation. A theory is presented which explains the results. The junction is attributed to a Schottky barrier of Vd ∼ 0.6 eV and width ∼ 2.5 × 10−6 cm estimated from C‐V measurement. The values determined from photovoltaic measurements are in agreement. The lifetime of ...

275 citations


Journal ArticleDOI
TL;DR: In this article, a thin highly doped layer at the surface of a semiconductor was used to increase the surface field of a Schottky barrier and reduce the barrier height by an amount insensitive to applied bias.
Abstract: A thin highly doped layer at the surface of a semiconductor has been used to increase the surface field of a Schottky barrier and reduce the barrier height by an amount insensitive to applied bias. The effective barrier height of Ni–Si barriers of this type made using ion‐implantation techniques has been reduced by an amount in the range 0–0.2 eV without significant degradation of the reverse characteristic.

167 citations


Journal ArticleDOI
TL;DR: In this article, the authors measured the emission and capture of majority carriers on the centres in the depletion layer of a p-n junction or Schottky barrier, and measured the change in charge state of the centres by measuring the reverse bias applied to the junction necessary to keep the junction capacitance constant.
Abstract: Measurements of emission rates and majority carrier capture cross-sections of Au, Pt, Pd and Rh centres in silicon are reported, and the activation energies associated with the different levels of these centres are determined. Where appropriate, our results are compared with values reported in the literature; other results have not been previously reported. The measurement depends on the emission and capture of majority carriers on the centres in the depletion layer of a p-n junction or Schottky barrier. The change in charge state of the centres is monitored by measuring the change in reverse bias applied to the junction necessary to keep the junction capacitance constant. The advantage of this technique, compared with the usual method of keeping the bias voltage constant and measuring the change in capacitance, is demonstrated.

131 citations


Journal ArticleDOI
TL;DR: In this article, the Schottky barrier diode has been characterized in terms of the height and thickness of the potential energy barrier arising from thermal equilibrium among charge carriers between dissimilar conductors.
Abstract: A typical medium-scale integrated (MSI) circuit requires hundreds of metal-semiconductor (M–S) junctions that are utilized for rectification, interconnection of device elements, and termination to external circuits. Comparison has been made between two metallization technologies, based upon the possible metallurgical reactions with Si: (1) nonreactive, such as evaporated aluminum, and (2) reactive, such as PtSi. Ohmic and rectifying contacts have been contrasted on the basis of the dominant current conduction mechanisms at the M–S interface. Current transport has been characterized in terms of the height and thickness of the potential energy barrier arising from thermal equilibrium among charge carriers between dissimilar conductors. Thermionic emission of electrons and holes provides the first illustration of conduction over a thick potential barrier (≫100 A), resulting in a rectifying contact (Schottky barrier diode). Thus, Schottky diode currents are exponentially dependent upon potential barrier height and inverse temperature. The contrasting illustration deals with a thin barrier (≪100 A) that conducts electrons and holes by quantum mechanical tunneling and forms ohmic contacts with resistance controlled only by contact size and underlying silicon resistivity. The final section covers two possible problems associated with silicon integrated circuit (SIC) fabrication. In the first example, a layer of oxide, too thin to be visible by optical interference (<500 A), can prevent proper contact formation. A method of observation, which makes use of hydrostatic surface tension, has been presented with experimental results on SiO2 films. Successive etching has revealed a detection limit of 11–13 A. The second deleterious phenomenon to be treated is the electrical degradation of Schottky barrier rectification associated with nonplanar penetration of metals into silicon. The destruction of the planar M–S interface could result from either undesired alloy eutectics or metallic precipitation.

84 citations



Patent
20 Jun 1974
TL;DR: In this article, an inert barrier layer of a refractory metal, such as Mo, Ti, W, Ta and alloys thereof, is deposited overlaying and in electrical contact with the metal silicide layer.
Abstract: In a Schottky diode of the type wherein a metal silicide layer interfaces with a silicon semiconductive body to form a Schottky diode, an inert barrier layer of a refractory metal, such as Mo, Ti, W, Ta and alloys thereof, is deposited overlaying and in electrical contact with the metal silicide layer An aluminum electrical connector electrode is deposited overlaying the barrier layer for intraconnecting the Schottky diode with other devices The refractory barrier layer prevents the aluminum from diffusing into or otherwise reacting with the metal silicide layer in such a way as to deleteriously affect the performance of the Schottky diode

72 citations


Journal ArticleDOI
TL;DR: An 8.1% efficient 1.5 cm2 Schottky barrier solar cell has been fabricated in this article using a layered barrier on 2 − Ω cm p-type silicon.
Abstract: An 8.1% efficient 1‐cm2 Schottky‐barrier solar cell has been fabricated in our laboratory using a layered Schottky barrier on 2‐Ω cm p‐type silicon. Reproducible results have been obtained on the layered structure which involves 44‐A Cr adjacent to the silicon to obtain good photovoltaic voltage and a 58‐A Cu overlayer to decrease cell resistance. The layered structure provides good control of barrier height, resistance, and optical transmission. Application of this approach should produce a 15% efficient Schottky solar cell and be readily applied to thin‐film silicon solar cells when high‐quality thin silicon films have been developed.

62 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the ionization coefficients of electrons (α) and holes (β) are not equal and that β>α. This result is in agreement with the variation of multiplication with bias voltage at different wavelengths observed for standard GaAs Schottky barrier diodes but contrary to the generally accepted belief that α=β.
Abstract: GaAs Schottky barrier avalanche photodiodes have been fabricated in which it is possible to achieve nearly pure hole and pure electron injection in the same device. Measurements of the multiplication characteristics of these devices show that the ionization coefficients of electrons (α) and holes (β) are not equal and that β>α. This result is in agreement with the variation of multiplication with bias voltage at different wavelengths observed for standard GaAs Schottky barrier diodes but contrary to the generally accepted belief that α=β.

57 citations


Journal ArticleDOI
TL;DR: In this article, a uniform Schottky barrier avalanche photodiodes with gains greater than 250, rise times less than 200 psec, and good quantum efficiencies at 1.06 μm have been fabricated in InxGa1−xAs alloys.
Abstract: Uniform Schottky barrier avalanche photodiodes with gains greater than 250, rise times less than 200 psec, and good quantum efficiencies at 1.06 μm have been fabricated in InxGa1−xAs alloys. The material used for these devices was grown epitaxially on GaAs substrates using an AsCl3–H2–Ga–In vapor‐phase system which permitted grading the epitaxial layers from GsAs to the desired composition.

51 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of an incremental electric field in the bulk semiconductor is deduced from a simple analytical treatment, and some qualitative features are shown for an electrostatically selfconsistent solution, initially without correlation and exchange forces, for the effect that electrons which tunnel from the metal of a Schottky barrier into the energy band gap of the semiconductor.
Abstract: Some qualitative features are shown for an electrostatically self-consistent solution, initially without correlation and exchange forces, for the effect of electrons which tunnel from the metal of a Schottky barrier into the energy band gap of the semiconductor. The effect of an incremental electric field in the bulk semiconductor is deduced from a simple analytical treatment. In covalent semiconductors most of the incremental electric field terminates in the semiconductor in a manner almost independent of the nature of the metal, i.e., the effective “metal” electrode exists inside the bulk semiconductor. This is not true for ionic semiconductors. When the “metal” electrode location is used as the origin for the image force, a normal square root of the field dependence of the Schottky image force lowering is predicted at low electric fields and a linear dependence is predicted at high electric fields, both as reported recently by Andrews. The model also predicts the order of magnitude of the very small ba...

48 citations


Journal ArticleDOI
TL;DR: Differential capacitance measurements on Schottky barrier contacts are used to determine energy levels for 29 different impurities implanted into silicon as mentioned in this paper. But their results do not account for the effect of implantations with low solubility, such as Nb, Ni, Ti, and Na.
Abstract: Differential capacitance measurements on Schottky barrier contacts are used to determinedeep energy levels for 29 different impurities implanted into silicon. Back-ground doping and deep levels are separated by making use of the sharply peaked implantation distribution. Donor or acceptor behavior is identified by the shape of the measured apparent charge profile. Energy levels measured for many impurities after annealing of the radiation damage agree with values known from literature. Other levels are caused by a non-thermal state of incorporation into the silicon lattice, e.g. for C, Si, and Ge, even after annealing of the radiation damage. Some impurities, e.g. Nb, Ni, Ti, and Na, show more than one state of incorporation, concentrations of which vary with the annealing conditions. Many implanted elements, especially those having a low solubility, e.g. Au, Be, Co, Se, etc., show strong out-diffusion and precipitation at the surface at annealing temperatures around 500°C.

Patent
28 Aug 1974
TL;DR: In this paper, a molecular beam technique for fabricating semiconductor devices from Group III(a)-V(a) compounds is described, in which an amorphous insulative layer is formed on selected portions of a monocrystalline substrate of the Group III-V-a material which is at least semi-insulating.
Abstract: Described is a molecular beam technique for fabricating semiconductor devices from Group III(a)-V(a) compounds. To form planar isolated devices, an amorphous insulative layer is formed on selected portions of a monocrystalline substrate of the Group III(a)-V(a) material which is at least semi-insulating. The amorphous layer may be formed by deposition of an oxide (e.g., SiO2), anodization of an oxide (e.g., native oxides) or by conversion of a surface layer of the substrate (e.g., by grit blasting). When a molecular beam containing Group III(a) and Group V(a) elements is directed at the surface, which is preheated to a temperature in the range of 450* to 675* C, monocrystalline Group III(a)-V(a) material grows on the exposed substrate whereas polycrystalline Group III(a)-V(a) material is simultaneously formed on the amorphous layer. The polycrystalline and monocrystalline surfaces are substantially coplanar. The polycrystalline material has a resistivity high enough to provide electrical isolation between active devices formed in the monocrystalline material. Examples of such active devices, which are also described, include beam-leaded Schottky barrier mixer diodes which have reduced parasitic capacitance and sealedjunction Schottky barrier IMPATT diodes. To form devices in which isolation is not required, the same procedure is followed except that neither the amorphous layer nor the substrate need be made of high resistivity material.

Journal ArticleDOI
TL;DR: The rate at which GaAs reacts with Pt has been determined at selected temperatures between 300 and 400 °C by measuring the movement of the original Pt Schottky barrier contact into the GaAs as discussed by the authors.
Abstract: The rate at which GaAs reacts with Pt has been determined at selected temperatures between 300 and 400 °C. The amount of GaAs reacted is determined by measuring the movement of the original Pt Schottky‐barrier contact into the GaAs. Data are presented which show the amount of GaAs reacted as a function of anneal time at several different temperatures. The reaction follows a parabolic rate law with activation energy of 1.6 eV. Some change in the electrical characteristics of the Schottky barrier is observed.

Journal ArticleDOI
TL;DR: The phenomenological rules governing the values of electrical barriers between metals, and semiconductors or insulators are reviewed in this article, and the success of a simple barrier model in accounting for the properties of the barrier is reviewed.
Abstract: The phenomenological rules governing the values of electrical barriers between metals, and semiconductors or insulators are reviewed. The barrier energies on ionic insulators are shown to vary strongly with metal electronegativity, while in the case of covalent semiconductors, the barrier energies are relatively independent of the metal. The barrier energy from the metal Fermi level to the conduction band of the semiconductor is shown to be approximately two thirds of the semiconductor band gap with certain exceptions. The success of a simple barrier model in accounting for the properties of the barrier are reviewed. The variation of barrier energy with electrical field is reported for Al-SiO2, Al-GaSe, and Al-GaAs and compared with simple theory including image-force lowering and field penetration into the metal. Transport through interfacial barriers is illustrated by discussing transport through metal-GaSe-metal structures and metal-InAs Schottky barriers.

Journal ArticleDOI
TL;DR: The photovoltaic properties and infrared response of epitaxial PbSe Schottky-barrier diodes are reported in this article, where the temperature dependence of zero bias resistance suggests that generation/recombination is the dominant transport mechanism.
Abstract: The photovoltaic properties and infrared response of epitaxial PbSe Schottky‐barrier diodes are reported. The temperature dependence of the zero‐bias resistance suggests that generation/recombination is the dominant transport mechanism. At 77 °K the devices are limited by the 290 °K background at f/0.6. With further reduction of the background they attain Johnson‐noise‐limited peak detectivities of 5×1011 cm Hz1/2 W−1. The diode quantum efficiencies are reflection loss limited and reach 70%.

Journal ArticleDOI
TL;DR: In this article, high-purity GaAs planar waveguides using a selective epitaxial growth process were used for detection in the 0.9-1.06-μm wavelength range.
Abstract: InxGa1−xAs Schottky‐barrier diodes for detection in the 0.9–1.06‐μm wavelength range have been incorporated in high‐purity GaAs planar waveguides using a selective epitaxial growth process. A quantum efficiency of 60% at 1.06 μm has been obtained for these detectors, and current gain has been observed.

Journal ArticleDOI
TL;DR: In this paper, the changes in the electron exchange and correlation potential are related to the collective excitation at the interface of a metal semiconductor junction, and the possible effects on the barrier formation are discussed.
Abstract: The changes in the electron exchange and correlation potential are related to the collective excitation at the interface of a metal semiconductor junction. They are shown to change discontinuously across the band gap, and the possible effects on the barrier formation are discussed. The possibility of surface superconductivity through exciton and plasmon exchange is considered briefly.

Patent
25 Jan 1974
TL;DR: In this article, metal-silicide-silicon Schottky barrier diodes are made by a process which yields the characteristic of low barrier height, in the region of 0.15 volt, suitable for use without dc bias as a detector at microwave frequencies.
Abstract: Metal-silicide-silicon Schottky barrier diodes are made by a process which yields the characteristic of low barrier height, in the region of 0.15 volt, suitable for use without dc bias as a detector at microwave frequencies. Low barrier height metals, such as palladium, platinum and hafnium are processed through heat treatment steps which reduce the barrier height below that which is typical of point contact diodes.

Journal ArticleDOI
TL;DR: Schottky barrier avalanche photodiodes have been fabricated on n-type high-purity epitaxial GaAs as mentioned in this paper, and the results indicate that the ratio of βp to αn is even larger than previous measurements have given.
Abstract: Schottky barrier avalanche photodiodes have been fabricated on n‐type high‐purity epitaxial GaAs These devices have their largest response at wavelengths beyond the usual absorption edge for high‐purity materials The absorption mechanism involves the Franz‐Keldysh shift of the absorption edge, and the higher response at the longer wavelengths can be explained by a much higher ionization coefficient for holes than for electrons The results indicate that the ratio of βp to αn is even larger than previous measurements have given

Journal ArticleDOI
TL;DR: In this paper, the performance of Au n-type SiC Schottky barrier diodes at room temperature was investigated and the forward currentvoltage characteristics were found to agree quantitatively with the theory based on thermionic emission with the barrier height modified by image force lowering.
Abstract: Results of the experimental study of Au n-type SiC Schottky barrier diodes at room temperature are presented. The diodes are fabricated by vacuum-evaporating gold on chemically etched n-type hexagonal (6H) SiC surfaces and exhibit excellent forward current vs voltage characteristics with the exponential factor n of about 1·07±0·02 for voltages between 0·35 and 0·85 V. The linear part of the characteristic, in a semi-logarithmic plot, extends over seven orders of magnitude in current. The forward current-voltage characteristics are found to agree quantitatively with the theory based on thermionic emission with the barrier height modified by image force lowering. The Schottky barrier height is determined from three independent techniques: differential capacitance vs voltage, photoresponse, and forward current vs voltage methods. The barrier height deduced from the three methods is about 1·40±0·05 V.

Journal ArticleDOI
TL;DR: In this paper, the Schottky barrier height of the gold-gallium arsenide system increases linearly with the thickness of an interfacial oxide layer, l. The predicted barrier height also varies with the amount of trapped surface charge, Qss.
Abstract: Two recent papers have dealt with the observation that the Schottky barrier height, Vb′, of the gold‐gallium arsenide system increases linearly with the thickness of an interfacial oxide layer, l. In this paper it is shown how this linear relationship can be derived by considering the cause to be the same as that of the flat‐band voltage shift in MOS devices. That is, charge trapped at the oxide‐semiconductor interface creates an image charge in the semiconductor bulk. The slope, dVB′/dl, predicted by this analysis is in good agreement with the 1.75×10−6V/cm value experimentally derived. The predicted barrier height also varies linearly with the amount of trapped surface charge, Qss.

Patent
Ingrid E. Magdo1
01 Nov 1974
TL;DR: In this paper, a Schottky barrier structure which is integratable with standard integrated circuits comprising a metal layer of Al 2 Pt in contact with a high resistivity semiconductor region is presented.
Abstract: A novel Schottky Barrier structure which is integratable with standard integrated circuits comprising a metal layer of Al 2 Pt in contact with a high resistivity semiconductor region. The structure is fabricated by first forming a platinum silicide layer on said silicon substrate and then applying a metallic layer comprising aluminum on said first layer, after which the structure is sintered at a temperature of at least 400° C. for at least an hour.

Patent
Ronald L. Bell1
08 Mar 1974
TL;DR: In this article, a long wavelength photoemitter, for example a III-V semiconductor, having a work function reduction activation layer thereon, with means for overcoming the energy barrier between the semiconductor conduction band edge and the vacuum comprising means for thermally energizing the photoexcited electrons in the conduction bands from a lower energy level therein to a higher "metastable" energy level in which they may reside for a sufficient time such that the electrons can pass with high probability from the elevated energy level into the vacuum over a energy barrier.
Abstract: A long wavelength photoemitter, for example a III-V semiconductor, having a work function reduction activation layer thereon, with means for overcoming the energy barrier between the semiconductor conduction band edge and the vacuum comprising means for thermally energizing the photoexcited electrons in the conduction band from a lower energy level therein to a higher "metastable" energy level in which they may reside for a sufficient time such that the electrons can pass with high probability from the elevated energy level into the vacuum over the energy barrier. In one embodiment, promotion of electrons to this higher energy level in the conduction band results from proper selection of the semiconductor alloy with conduction band levels favoring such room temperature thermal excitation. In another embodiment, a Schottky barrier is formed between the semiconductor emitter surface and the activation layer, by means of which an internal electric field is applied to the cathode resulting in high effective electron temperature for energy level transfer analogous to the intervalley electron transfer process of the Gunn effect. In yet other embodiments, composite semiconductor bodies are fabricated in which one region may advantageously be designed for efficient absorption of long-wavelength photons, and another for efficient operation of the promotion mechanism, which together assure a high quantum efficiency. Other properties of the biased promotion layer may be used to minimize emission of electrons which have been excited by purely thermal means, thus providing a low dark current, usually considered to be incompatible with long-wavelength infrared response.

Patent
06 Dec 1974
TL;DR: In this article, a gate metalization is applied to the FET channel region, and the gate is exposed to the bombardment of protons with sufficiently high energy to penetrate through the gate and enter the channel region.
Abstract: Disclosed is a new process for fabricating field effect transistors, and particularly enhancement mode and depletion mode Schottky-gate field effect transistors. The process includes the steps of forming a thin layer of gate metalization over the FET channel region, and this gate metalization is then exposed to the bombardment of protons with sufficiently high energy to penetrate through the gate metalization layer and enter the channel region of the FET and there produce deep level energy traps in the channel region. These traps serve to tie up carriers and create donor and acceptor vacancy complexes in the FET channel. This step has the effect of raising the resistivity of the FET channel and is used to make the FET device non-conducting with zero voltage on the gate metalization, i.e., an enhancement mode device.

Journal ArticleDOI
Shyam P. Murarka1
TL;DR: In this paper, the reverse bias voltage at currents of 10 μA, 100 μA and 1 mA were determined as a function of annealing time at 350°C for diodes metallized with AuPt and with Pt alone.
Abstract: The operating surface temperature for the Au/Pt/ n -GaAs Schottky barrier microwave devices is in the temperature range of 200–250°C. In order to determine operating lifetimes for these devices accelerated aging studies were performed. In this study the reverse bias voltage at currents of 10 μA, 100 μA and 1 mA were determined as a function of annealing time at 350°C for diodes metallized with AuPt and with Pt alone. Two distinct degradation mechanisms were observed. (a) Penetration of Au by diffusion through thin Pt films or by surface migration along edges or cracks in the Pt films resulted in rapid degradation of the devices. (b) The second degradation mechanism was observed in absence of Au and was found to be related to annealing ambient and the metallurgical interaction between Pt and GaAs. A decrease in the reverse bias voltage was observed due to the diffusion of oxygen from the interfacial oxide and from the ambient. Oxygen from the ambient diffused throug platinum into GaAs and was the cause of the final degradation of devices annealed in air. An increase in the reverse bias voltage occurred immediately after the initial decrease due to the interfacial oxide. This recovery has been attributed to the metallurgical interaction between Pt and GaAs which led to the formation of PtAs 2 at the interface and GaPt phases away from the interface.

Patent
18 Mar 1974
TL;DR: Schottky barrier detector arrays for detecting the infrared portion of the spectrum connected through enhancement mode field effect transistors to a charge coupled device for read out were used in this paper.
Abstract: Schottky barrier detector arrays for detecting the infrared portion of the spectrum connected through enhancement mode field effect transistors to a charge coupled device for read out. The system utilizes a voltage to charge conversion to provide an infrared camera device vidicon.

Journal ArticleDOI
TL;DR: In this article, the small-signal transmission line properties of Schottky contact lines with Al-and Au-Schottky contacts on n-type silicon are investigated.
Abstract: Schottky contact lines are a type of microstrip on semiconducting substrata. The strip forms a rectifying metal-semiconductor interface, the Schottky contact. Schottky contact lines show interesting small-signal and large-signal properties, so far unknown in microwave IC-technology, due to the voltage-dependent capacitance per unit length. In this paper the small-signal transmission line properties are investigated. Formulas for the characteristic impedance and the propagation constant are given. Particular account is taken of the effect of varying external d.c. bias. measurements performed on microstrip lines with Al- and Au-Schottky contacts on n -type silicon are given.

Patent
12 Jun 1974
TL;DR: In this paper, a Schottky barrier contact includes a thin layer of high carrier concentration impurities ion implanted over the contact surface of the semiconductor, which reduces the electronic barrier height, increases the tunneling component, and thus reduces the forward bias turn-on voltage of the diode.
Abstract: A Schottky barrier contact includes a thin layer of high carrier concentration impurities ion implanted over the contact surface of the semiconductor. This reduces the electronic barrier height, increases the tunneling component, and thus reduces the forward-bias turn-on voltage of the diode. The implanted layer has a carrier concentration at least ten times that of the semiconductor substrate, and a thickness smaller than the width of the inherent depletion region resulting from the internally generated electric field at the metal-semiconductor interface. An implanted layer of the opposite conductivity type raises the barrier height.

Patent
18 Jan 1974
TL;DR: In this article, the minimum charge density required in the insulating layer is determined by the density of the surface states, Qss, in the semiconductor, and the minimum Qss for silicon is about 5 × 1010 charges/cm2.
Abstract: Ohmic contacts to semiconductor surfaces are fabricated by a process which includes the formation of an adherent, uniform insulating film at the interface between the semiconductor surface and the metallization layer. The insulating film contains stationary charges of sign opposite to the sign of the conductivity of the semiconductor whereby image charges are introduced in the semiconductor. These image charges are located near the semiconductor surface and are of sufficient density to induce the formation of an accumulation layer. The minimum charge density required in the insulating layer is determined by the density of the surface states, Qss, in the semiconductor. Minimum Qss for silicon is about 5 × 1010 charges/cm2. The structure thus formed will present an electrical resistance resulting almost solely from the tunneling resistance of the insulating layer. Such a resistance is far smaller than the resistance one would observe in a structure consisting only of the semiconductor and metallization layer because the resistance of the structure is dominated by the resistance of the Schottky barrier formed at the metal-semiconductor interface. For example, just prior to metallization, an oxide-masked silicon wafer is subjected to argon ion bombardment for surface cleaning and activation, followed by oxygen ion bombardment for a time sufficient to form a uniform layer of silicon oxide having a thickness on the order of about 20 Angstroms. Subsequent metallization produces a specific contact resistance of about 5 × 10- 7 ohm-cm2 on a silicon region having a resistivity of 1.0 ohm-cm, without previous contact diffusion or subsequent metal-semiconductor annealing.

Journal ArticleDOI
TL;DR: In this article, surface acoustic waves on GaAs can be used to read the amount of charge stored on an isolated Schottky barrier, which can be controlled by the light intensity which illuminates a given electrode and allows one to monitor this light intensity.
Abstract: We show that surface acoustic waves on GaAs can be used to read the amount of charge stored on an isolated Schottky barrier. This charge can be controlled by the light intensity which illuminates a given electrode and our technique allows one to monitor this light intensity. We propose that the effect can be used in a panel array suitable for imaging.