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Showing papers on "Schottky diode published in 1990"


Book
01 Jan 1990
TL;DR: In this article, the authors describe a general process for wet etching photolithography and dry etching of a GaAs material and crystal properties, as well as general process techniques for cleaning and cleanliness.
Abstract: GaAs material and crystal properties GaAs devices general process techniques cleaning and cleanliness wet etching photolithography nonoptical lithography plasma processing equipment and plasma-assisted deposition dry etching plasma, RIE, RIBE, ion milling specific process types device isolation ohmic contacts schottky barriers and gate formation first-level metal, dielectric formation, second-level metal capacitors, inductors, and resistors.

266 citations


Journal ArticleDOI
TL;DR: On examine comment de tels resultats experimentaux sont modifies par les phototensions generees dans la region de courbure de bande, non seulement par les sources de lumiere ambiantes, mais aussi par les rayons X incidents eux-memes.
Abstract: Photoelectron spectroscopy is frequently used to study band bending in semiconductors due to charge stored in surface or interface states. This paper examines how such experimental results are modified by photovoltages generated within the band-bending region not only by ambient light sources, but by the incident x rays themselves. Recent experiments which have suggested dopant-dependent and reversible temperature-dependent band bending in the initial stages of formation of the metal-GaAs(110) interface are used as an example. It is shown here that the reported dependence derives from a photovoltaic effect.

195 citations


Proceedings ArticleDOI
11 Jun 1990
TL;DR: In this paper, a resonant synchronous rectifier which combines the fast switching of Schottky diodes with low conduction drop of MOSFET devices is discussed.
Abstract: A resonant synchronous rectifier which combines the fast switching of Schottky diodes with low conduction drop of MOSFET devices is discussed. The MOSFET devices are driven in a resonant fashion by the power circuit, resulting in partial recovery of the energy stored in the parasitic capacitances. Power loss in the resonant synchronous rectifier is determined as a function of various devices parameters and switching frequency. Contributions of conduction losses, gate-drive switching losses, and losses due to current circulating in the parasitic capacitances are discussed. The analysis indicates that, at megahertz range switching frequencies, a resonant synchronous rectifier has a significantly higher efficiency than either a PWM (pulse width modulation) synchronous rectifier or a Schottky diode rectifier. >

168 citations


Journal ArticleDOI
TL;DR: In this paper, Ni/n-CdF2 Schottky barrier type diodes were fabricated on unpolished CdF 2 surface, etched with 1 : HCl and showed an MIS structure with interface states and deep donor bulk defects.
Abstract: Current-voltage (I-V) and capacitance-voltage (C-V) measurements were performed in the temperature range 45–330 K on Ni/n-CdF2 Schottky barrier type diodes fabricated on unpolished CdF2 surface, etched with 1 : HCl. The diodes showed an MIS structure with interface states and deep donor bulk defects. Under forward bias and for T ⩾ 280 K, the electric current transport was controlled by the thermionic emission process. However, for T ⩽ 280 K, the current was controlled by thermionic field emission. The zero bias and zero temperature barrier height, φ0 = (0.67 ± 0.07) V was obtained from the I-V measurements and agreed very well with the value of φ0 = (0.60 ± 0.06) V, determined from the C-V data. The energy density of interface states estimated from the room temperature I-V measurements was ≈ 1012 cm−2 eV−1. The interface states were responsible for the non-ideal behavior of the forward I-V characteristics of the diodes. However, the non-linearity in the C−2vsV curves under reverse bias was introduced by the deep donor levels. From the C-V measurements under reverse bias, two deep levels with energies of EC - (0.7 ± 0.1) eV and EC - (1.0 ± 0.1) eV were detected.

157 citations


Patent
28 Aug 1990
TL;DR: In this paper, a multicellular FET structure with a Schottky barrier diode structure interspersed therewith with at least some of the FET cells being free of the barrier portions.
Abstract: A semiconductor power switching device comprises a multicellular FET structure with a Schottky barrier diode structure interspersed therewith with at least some of the FET cells being free of Schottky barrier portions. The ratio of Schottky barrier contact area to FET cell area in the overall device may be adjusted to tailor the device for operation at specific current densities.

156 citations


Journal ArticleDOI
TL;DR: In this paper, two types of TiO2-based oxygen sensors operating at different temperatures with different detection principles were studied, and it was shown that Pt/TiO2 Schottky diodes make extremely sensitive oxygen detection possible.
Abstract: We have studied two types of TiO2-based oxygen sensors operating at different temperatures with different detection principles At high temperatures, TiO2 devices can be used as thermodynamically controlled bulk defect sensors to determine oxygen over a large range of partial pressures Their intrinsic behaviour can be controlled by carefully directed doping with tri- or pentavalent cations At low temperatures, we find that Pt/TiO2 Schottky diodes make extremely sensitive oxygen detection possible The latter show reversible shifts of current-voltage curves, which are determined by interface states formed by chemisorbed oxygen

143 citations


Journal ArticleDOI
TL;DR: In this paper, the capacitance and current voltage characteristics of high barrier Yb/p-InP metal-insulator-semiconductor (MIS) and MS diodes were measured over a wide range of temperatures.
Abstract: High barrier Yb/p‐InP metal‐insulator‐semiconductor (MIS) and metal‐semiconductor (MS) junctions were fabricated by evaporation of Yb on InP:Zn substrates. The capacitance‐voltage (C‐V) and current‐voltage (I‐V) characteristics of these devices were measured over a wide range of temperatures. From the room‐temperature forward I‐V data, the values of 1.06 and 1.30 for the ideality factor (n) were obtained for the MIS and MS diodes, respectively. The higher value of n was attributed to an order of magnitude higher density of interface states in the MS junction than in the MIS diodes. The I‐V/T data over the temperature range 190–400 K, indicated that the forward current transport in the Yb/p‐InP MIS junction was controlled by the thermionic‐field emission (TFE) mechanism. The analysis of the reverse saturation current I0 in terms of the TFE model provided a value of 1.07±0.03 V for the zero bias, zero temperature barrier height (φ0) which was in close agreement with the value of φ0=1.03±0.04 V, provided by ...

142 citations


Proceedings ArticleDOI
08 May 1990
TL;DR: In this paper, solid-state sources have been developed for 330 and 500 GHz using cascaded varactor multipliers driven by a Gunn oscillator, achieving very high efficiency, achieving an output of 4 mW.
Abstract: Solid-state sources have been developed for 330 and 500 GHz using cascaded varactor multipliers driven by a Gunn oscillator. The 330-GHz source uses a cascade of two balanced doublers, achieving very high efficiency, and produces an output of 4 mW. The 500-GHz source uses a cascade of a balanced doubler and single diode tripler and produces 0.7 mW. The doubler output at 330 GHz has been used to drive a harmonic mixer at 660 GHz, and plans are to drive yet another doubler at 660 GHz, where an output of 0.1-0.2 mW is expected. The output may prove to be enough LO for a cooled Schottky diode mixer. The tripled power at 500 GHz is quite sufficient for operation of Schottky diode mixers at this frequency and should be adequate as a pump source for a low-power doubler at 1 THz, such as would be used with a superconductor-insulator-superconductor (SIS) mixer. >

121 citations



Journal ArticleDOI
TL;DR: In this paper, the femtosecond laser beam from a semiconductor was used to determine impurity doping concentration, carrier mobility, sign, and strength of the depletion field near the semiconductor surface.
Abstract: Ultrafast electromagnetic radiation induced by a femtosecond laser beam from a semiconductor provides determination of the impurity doping concentration, carrier mobility, sign, and strength of the depletion field near the semiconductor surface.

107 citations


Journal ArticleDOI
TL;DR: In this article, the transit-time limited frequency response of InGaAs interdigitated metal-semiconductor-metal (MSM) Schottky barrier photodetectors for 1.55-mu m wavelength incident radiation was investigated.
Abstract: Calculations are reported of the transit-time limited frequency response of InGaAs interdigitated metal-semiconductor-metal (MSM) Schottky barrier photodetectors for 1.55- mu m wavelength incident radiation. The response is examined for light which is incident from above and a two-dimensional simulation based on carrier drift is used. It is shown how the impulse response of the device changes as the interdigital spacing and the InGaAs layer thickness vary over the range typically assumed by practical detectors. The device bandwidths are also computed, and the tradeoff which occurs between high-speed performance and high quantum efficiency is studied. >

Journal ArticleDOI
TL;DR: In this article, it was shown that the electronic properties of Schottky contacts cannot be understood if one neglects spatial fluctuations of the Schittky barrier height, and that excess noise increases drastically when the standard deviation σs of the spatial distribution of barrier heights exceeds the critical threshold value of 2kT.
Abstract: Electronic properties of Schottky diodes depend sensitively on spatial inhomogeneities of the metal/semiconductor interface. We find that, contrary to previous theories for low‐frequency noise, the electronic properties of Schottky contacts cannot be understood if one neglects spatial fluctuations of the Schottky barrier height. Our systematic investigation of several silicide/silicon diodes yields as an empirical law that excess noise increases drastically when the standard deviation σs of the spatial distribution of Schottky barrier heights exceeds the critical threshold value of 2kT.

Journal ArticleDOI
TL;DR: In this paper, the authors used quantum-barrier-varactor (QBV) diodes in harmonic multipliers to achieve state-of-the-art results for Schottky-Vactor diode triplers.
Abstract: Experimental results are presented using quantum-barrier-varactor (QBV) diodes in harmonic multipliers. Output powers and tripler conversion efficiencies of more than 2 mW and 5%, respectively, were achieved between 210 and 280 GHz. In a crude experiment, an efficiency of more than 0.2% for the fifth harmonic was measured at 310 GHz. The values for the QBV diode as a tripler are comparable to state-of-the-art results for Schottky-varactor diode triplers. The experimental results agree well with theoretical calculations. >

Journal ArticleDOI
TL;DR: In this paper, a pn-diode micro-model representing forward and reverse recovery phenomena for power electronic simulation, especially simulations using SPICE2, was proposed to compensate the incompleteness of the diode model in current circuit simulation packages.
Abstract: A pn-diode micro-model representing forward and reverse recovery phenomena for power electronic simulation, especially simulations using SPICE2 is presented. The model is proposed to compensate the incompleteness of the diode model in current circuit simulation packages. In the forward recovery submodel, the diode bulk resistance modulation and its forward current dependence are included. In the reverse recovery submodel, the charge control equation for excess storage carriers is employed to simulate the detailed behavior. A procedure is described for extracting the model's physical parameters from data sheet information. The model is verified by a comparison of experimental results for several different tests with SPICE simulations. A discussion is given of extending the applicability of the micro-model to the simulation of p-i-n diode behaviour. >

Journal ArticleDOI
TL;DR: In this paper, a power DMOSFET structure with a monolithically integrated Schottky diode located under the source contact pad is described, which results in significantly improved internal diode switching characteristics with no degradation in the onstate resistance and drain-source breakdown voltage.
Abstract: A power DMOSFET structure with a monolithically integrated Schottky diode located under the source contact pad is described. In this structure the source contact metallization step is also used to fabricate an epitaxial drift region Schottky diode in parallel with the parasitic body p-n junction diode of the power MOSFET. Such a structure results in significantly improved internal diode switching characteristics with no degradation in the on-state resistance and drain-source breakdown voltage. The integral power MOSFET technology was used to fabricate 30- and 45-V vertical power DMOSFETs with a reduction in peak reverse current and stored charge of more than 25% as compared to a conventional power DMOSFET. The Schottky diode consumed less than 15% of the active transistor area. >

Proceedings ArticleDOI
08 May 1990
TL;DR: In this article, a planar Schottky diode with greatly reduced shunt capacitance for millimeter-and sub-millimeter-wave applications is described, where the dominant pad-to-pad shunt is minimized by replacing the substrate GaAs with a low-dielectric substitute.
Abstract: The design and fabrication of a novel planar Schottky diode with greatly reduced shunt capacitance for millimeter- and submillimeter-wave applications is described. The dominant pad-to-pad shunt capacitance is minimized by replacing the substrate GaAs with a low-dielectric substitute. This replacement substrate can be easily removed by the user after the device is soldered into the mixer circuit. This will yield the minimum possible pad-to-pad shunt capacitance. >

Journal ArticleDOI
12 Jul 1990-Nature
TL;DR: In this article, the authors describe the fabrication of diodes using a low-temperature chemical procedure, in which contact to the semiconductor is made by a layer of the conducting organic polymer, polyacetylene.
Abstract: Diodes formed from semiconductor/metal interfaces often display non-ideal electronic properties. For instance, silicon/metal (Schottky) diodes made from n-type silicon and a variety of contacting metals exhibit only small differences in their rectification properties, despite theoretical and practical expectations that changes in the metal should effect changes in device properties. Similarly, Schottky diodes formed on p-type silicon generally exhibit ohmic behaviour with poor rectification characteristics. This lack of electrical response to changes in the properties of the contacting metal phase is generally attributed to interfacial reactions that take place during the high-temperature thermal or electron-beam deposition of metals onto silicon. Here we describe the fabrication of diodes using a low-temperature chemical procedure, in which contact to the semiconductor is made by a layer of the conducting organic polymer, polyacetylene. Unlike conventional metals, the electrical properties of polyacetylene can be manipulated through choice of the polymer dopant. The resultant organic/inorganic interfaces behave more ideally than contacts with conventional metals, in that changes in the electrical properties of the conducting polymer exert a large and predictable effect on the electrical properties of the resulting semiconductor/polymer diodes.

Book ChapterDOI
Abstract: Conjugated polymers which can be processed to form thin, coherent films can be used as the active layers in semiconductor device structures. We have used the Durham precursor route to polyacetylene to fabricate a range of unipolar devices including Schottky barrier diodes, MIS diodes and MISFET’s. Although carrier mobilities are low, limited by thermally-activated transport between chains, these devices work well, and we find that these structures are remarkably free of surface states and bulk defect states with energy levels within the gap. The fundamental excitation of the trans-polyacetylene chain is the self-localised soliton-like kink defect in the bond alternation pattern along the chain; the soliton has associated with it an energy state at mid-gap of non-bonding pz character. We have been particularly concerned to demonstrate the formation of solitons from charges injected into the polyacetylene layer in these device structures, and have measured the changes in the optical properties that accompany soliton formation. For the MIS structures working in accumulation mode we find the ‘mid-gap’ transition from soliton level to the band edge at energies ranging between 0.55 eV (characteristic of the bulk) for polyacetylene on polymeric insulator layers to 0.8 eV when formed on silicon dioxide. We discuss this spread in energies in terms of the different surface structures at these different interfaces. We also show data for the characteristic vibrational excitations of the soliton, including both the IR-active translation modes and the Raman active amplitude modes.

Journal ArticleDOI
TL;DR: A region of anomalous negative capacitance has been observed with forward bias in Se−Tl Schottky evaporated layer structures as mentioned in this paper, which is due to an inductive contribution to the impedance that is believed to arise from high level injection of minority electrons into the bulk selenium.
Abstract: A region of anomalous negative capacitance has been observed with forward bias in Se‐Tl Schottky evaporated layer structures. The effect, which is more prevalent in diodes with lower series resistance, is due to an inductive contribution to the impedance that is believed to arise from high‐level injection of minority electrons into the bulk selenium.

Journal ArticleDOI
TL;DR: In this paper, the Schottky barrier height φB during contact formation was investigated for n-type β-SiC(100) for several metals with various physical and chemical properties, including Pd, Au, Co, Ti, Ag, Tb, and Al.
Abstract: Formation of Schottky barrier contacts to n‐type β‐SiC(100) was systematically investigated for several metals with various physical and chemical properties. The metals (Pd, Au, Co, Ti, Ag, Tb, and Al) were deposited onto oxygen terminated (∼1 monolayer) surfaces. Metal/β‐SiC interface chemistry and Schottky barrier height φB during contact formation were obtained by x‐ray photoemission spectroscopy; the corresponding electrical properties of thick contacts were characterized by capacitance‐voltage and current‐voltage methods. The metal/β‐SiC interface is unreactive at room temperature. X‐ray photoemission spectroscopy and electrical measurements demonstrate that these metal contacts exhibit a wide range of φB , 0.95–0.16 eV; within this range an individual contact φB value depends strongly on the metal work function in general accord with the Schottky–Mott limit.

Journal ArticleDOI
TL;DR: In this paper, it was shown that much of the recent photoelectron spectroscopy literature describing the onset of pinning in adsorbate-semiconductor systems at low temperature must be reinterpreted in light of surface photovoltaic effects.
Abstract: It is shown here that much of the recent photoelectron spectroscopy literature describing the onset of pinning in adsorbate-semiconductor systems at low temperature must be reinterpreted in light of surface photovoltaic effects. Two sources of surface charging are discussed, both of which are strongly enhanced at low temperature. The surface photovoltage resulting from separation of electron-hole pairs by the electric field in the depletion region is usually the dominant source of surface potential shifts, and causes flattening of the semiconductor bands. In addition, surface charging due to photoemission into the vacuum may reverse bias a p-type diode at low temperatures, causing increase band bending.

Journal ArticleDOI
TL;DR: The present results show that the barrier height and its temperature dependence are affected by the metal and deviate from the predictions of models of Schottky-barrier formation based on Fermi-level pinning in the center of the semiconductor indirect band gap.
Abstract: The Schottky-barrier heights of Cu and its silicide ${\mathrm{Cu}}_{3}$Si on both n-type and p-type Si(100) have been measured in the temperature range 95--295 K with the use of a current-voltage technique. X-ray photoemission spectroscopy, Rutherford backscattering, and glancing-angle x-ray diffraction were used to monitor the reaction between Cu and Si. Impurity-related energy levels in Si were determined using deep-level transient spectroscopy. Only one level was observed at \ensuremath{\sim}0.55 eV below the conduction-band edge upon copper deposition. Silicide formation was found to cause the disappearance of this level and also to have very little effect on the barrier height and its temperature dependence. For both the metal and the reacted silicide phase, the change in the n-type barrier height with temperature follows closely the change in the indirect energy gap in Si. The p-type barrier height does not exhibit a temperature dependence. These results suggest that the Fermi level at the interface is pinned relative to the valence-band edge. These results deviate from the predictions of models of Schottky-barrier formation based on Fermi-level pinning in the center of the semiconductor indirect band gap. Along with those Schottky barriers reported for metal-Si systems with a wide range in metal electronegativity, the present results show that the barrier height and its temperature dependence are affected by the metal.

Journal ArticleDOI
TL;DR: In this article, a model in which there is a range of barriers with a normal distribution was introduced, and the photoyield was calculated using the photo-emission model.
Abstract: Current-voltage-temperature ( I - V - T ) characteristics of p -type moderately doped PtSi Schottky barrier diodes have been measured as a function of temperature from 77 to 120 K. From thermionic emission theory, the saturation current at each temperature is plotted against inverse temperature. According to this theory, the slope should give the barrier height. However, the experimental data obtained do not correlate well with a straight line relationship. These effects are explained by introducing a model in which there is a range of barriers with a normal distribution. A mean barrier of 0.242 eV with a standard deviation of σ = 0.011 eV is obtained. Photoresponse measurements have also been performed at a temperature of 78.0 K to verify the I - V - T results and to test the distributed model. It is found that the cut-off wavelength for PtSi Schottky diodes is well beyond that predicted by a single barrier, giving further evidence for multiple barriers. To test the distributed model, the parameter extracted from the model, i.e. the spread of the barrier, σ is introduced into the photoemission model. The photoyield thereby calculated compares well with experimental results.

Journal ArticleDOI
TL;DR: Schottky diodes were formed using gold contacts to chemically cleaned boron-doped homoepitaxial diamond films as mentioned in this paper, and they incorporated ohmic contacts formed by annealing Au(70 nm)/Ti(10 nm) layers in air at 580 degrees C.
Abstract: High-temperature (500-580 degrees C) current-voltage (I-V) characteristics of gold contacts to boron-doped homoepitaxial diamond films prepared using a plasma-enhanced chemical vapor deposition (CVD) method are described. Schottky diodes were formed using gold contacts to chemically cleaned boron-doped homoepitaxial diamond films. These devices incorporate ohmic contacts formed by annealing Au(70 nm)/Ti(10 nm) layers in air at 580 degrees C. The experiments with homoepitaxial diamond films show that the leakage current density increases with the contact area. This implies that a nonuniform current distribution exists across the diode, presumably due to crystallographic defects in the diamond film. As a result, Au contacts with an area >1 mm/sup 2/ are essentially ohmic and can be used to form back contacts to Schottky diodes. Schottky diodes fabricated in this matter also show rectifying I-V characteristics in the 25-580 degrees C temperature range. >


Journal ArticleDOI
TL;DR: The application of core and valence level photoelectron spectroscopy to the study of semiconductor heterojunctions and metal-semiconductor interfaces (Schottky barriers) is outlined, with an emphasis on recent results and their explanation in terms of current theories.
Abstract: The application of core and valence level photoelectron spectroscopy to the study of semiconductor heterojunctions and metal-semiconductor interfaces (Schottky barriers) is outlined, with an emphasis on recent results and their explanation in terms of current theories. While the determination of transport barriers (valence band offsets and Schottky barriers) is stressed, the identification of chemical reactions at the interface is also discussed using several examples. Photoemission can precisely determine many important quantities in these junctions; also demonstrated, however, is the disturbing influence of the photoemission process itself through the creation of a surface photovoltage in metal-semiconductor interfaces, and its possible consequences for recent investigations of Schottky barrier heights in metal overlayers on low temperature substrates.

Patent
04 Sep 1990
TL;DR: In this paper, the Schottky electrode is formed of a thin film of a material selected from the group consisting of metals of Group 1, Group 2A, Group 3A, and lanthanoids, metal silicides, metal borides, and metal carbides of Group 4A.
Abstract: An electron emission element comprises a semiconductor substrate having a p-type semiconductor layer (3002) whose impurity concentration falls within a concentration range for causing an avalanche breakdown in at least a portion (3003) of a surface thereof, a Schottky electrode (3008) connected to said p-type semiconductor layer, means (3011) for applying a reverse bias voltage between the Schottky electrode and the p-type semiconductor layer to cause the Schottky electrode to emit electrons, and a lead electrode (3007), formed at a proper position, for externally guiding the emitted electrons. At least a portion of the Schottky electrode (3008) is formed of a thin film of a material selected from the group consisting of metals of Group 1A, Group 2A, Group 3A, and lanthanoids, metal silicides of Group 1A, Group 2A, Group 3A, and lanthanoids, metal borides of Group 1A, Group 2A, Group 3A, and lanthanoids, and metal carbides of Group 4A. A film thickness thereof is set to be not more than 100 A.

Journal ArticleDOI
TL;DR: In this paper, the structure and hydrogen gas sensing properties of a trench Pd-thin oxide-Si Schottky diode are compared with a planar one, and the sensitivity of the trench diode is thus higher than that of the planar diode under room-temperature operation.
Abstract: The structure and hydrogen gas sensing properties of a trench Pd‐thin oxide‐Si Schottky diode are studied and compared with a planar one. The trench diode possesses additional vertical surface area and a large number of interface traps induced by injected hydrogen ions. The additional vertical surface area enlarges the entrance of H2 molecules, and the generated middle traps enhance the carrier tunneling. Also, the generated shallow traps can catch the carrier to form a thin surface charge layer and lower the barrier. The sensitivity of the trench diode is thus higher than that of the planar diode under room‐temperature operation.

Journal ArticleDOI
TL;DR: It is concluded that an atomically abrupt interface between the semiconductor and the M(111) overlayers is formed and an alternative interface model is suggested considering n-type doping of the semiconductors interface due to intercalation of the adsorbed metal atoms.
Abstract: The interaction of Cu and Ag on the van der Waals (0001) face of p-type ${\mathrm{WSe}}_{2}$ has been investigated in relation to Schottky-barrier formation and Schottky solar cells using x-ray and uv photoelectron spectroscopy (XPS,UPS), low-energy electron diffraction (LEED), and surface photovoltage measurements. XPS and UPS results show the growth of a metallic overlayer for small coverages without detectable formation of any interfacial reaction layer. In addition, the LEED experiments indicate epitaxially grown (111) metal layers in the form of clusters. Therefore, we conclude that an atomically abrupt interface between the semiconductor and the M(111) overlayers is formed. The observed band bending obtained from binding-energy shifts corresponds to the work-function difference following the Schottky-Mott theory. However, the surface photovoltage measured at 300 and 100 K is not in good correspondence to the thermionic-emission model of Schottky barriers. Therefore, an alternative interface model is suggested considering n-type doping of the semiconductor interface due to intercalation of the adsorbed metal atoms.

BookDOI
01 Jan 1990
TL;DR: Ueber et al. as mentioned in this paper proposed an effective work function model for Schottky barrier formation at single-Crystal metal Semiconductor interfaces, which is based on the Mott Rule.
Abstract: 1. Preliminary Remarks.- 2. Conceptual Models.- 2.1 Schottky-Mott Rule.- 2.2 Interface States.- 2.3 Continuum of Metal-Induced Gap States.- 2.4 MIGS-plus-Defects Model.- 2.5 Charge Transfer at Interface.- 3. Computational Results.- 4. Experimental Data.- 4.1 Chemical Trend of the Slope Parameters.- 4.2 Correlations with Chemical Reactivity.- 4.3 Effective Work Function Model.- 4.4 MIGS-plus-Defect Model.- 4.5 Direct Observation of the Continuum of MIG States.- 5. Surface-Science Approach to Schottky Contacts.- 5.1 Growth Modes of Nonreactive Metals on Semiconductors.- 5.2 Surface Band-Bending as a Function of Metal Coverage.- 5.3 Unified Defect Model.- 6. Concluding Remarks.- References:.- Reprinted Articles.- Additional Reference.- Reprinted Articles.- Ueber die Stromleitung durch Schwefelmetalle, Pogg. Ann. (1874).- Zum Mechanismus der Richtwirkung in Kupferoxydulgleichrichtern, Physik. Z. (1929).- Halbleitertheorie der Sperrschicht, Naturwissenschaften (1938).- Note on the Contact between a Metal and an Insulator or Semiconductor, Proc. Camb. Phil. Soc. (1938).- Abweichungen vom Ohmschen Gesetz in Halbleitern, Physik. Z. (1940).- Surface States and Rectification at a Metal Semiconductor Contact, Phys. Rev. (1947).- Surface States and Barrier Height of Metal Semiconductor Systems, J. Appl. Phys. (1965).- Theory of Surface States, Phys. Rev. (1965).- Fundamental Transition in the Electronic Nature of Solids, Phys. Rev. Lett. (1969).- Density of States and Barrier Height of Metal-Si Contacts, J. Phys. C: Solid State Physics (1971).- Metal-semiconductor Junctions for (110) Surfaces of Zinc-blende Compunds, Phys. Rev. B (1976).- Electronic Structure of a Metal Semiconductor Interface, Phys. Rev. B (1976).- Ionicity and the Theory of Schottky Barriers, Phys. Rev. B (1977).- Chemical Trends in Metal-semiconductor Barrier Heights, Phys. Rev. B (1978).- Transition in Schottky Barrier Formation with Chemical Reactivity, Phys. Rev. Lett. (1978).- New and Unified Model for Schottky Barrier and III-V Insulator Interface States Formation, J. Vac. Sci. Technol. (1979).- Schottky Barriers: An Effective Work Function Model, AppL Phys. Lett. (1981).- The Foramtion of the Schottky Barrier at the V/Si Interface, J. Vac. Sci. Technol. (1982).- Formation of Ultrathin Single- Crystal Silicide Films on Si: Surface and Interfacial Stabilization of Si-NiSi2Epitaxial Strucutures, Phys. Rev. Lett. (1983).- Schottky Barrier Heights and the Continuum of Gap States, Phys. Rev. Lett. (1984).- Schottky Barrier Formation at Single-Crystal Metal Semiconductor Interfaces, Phys. Rev. Lett. (1984).- Reflection High-energy Electron Diffraction Study of the Growth of In on GaAs (110) at Different Temperatures, J. Vac. Sci. Tecnol. B (1986).- Direct Variation of Metal-GaAs Schottky Barrier Height by the Influence of Interface S, Se and Te, AppL Phys. Lett. (1985).- Interface Potential Changes and Scottky Barriers, Phys. Rev. B (1985).- Ruthenium-Induced Surface Staes of n-GaAs Surfaces, J. Vac. Sci. Technol. B. (1986).- Metallization and Scottky Barrier Formation, Phys. Rev. B (1986).- On the Present Understanding of Schottky Contacts , Festkorperprobleme (1986).- Role of Virtual Gap States and Defects in Metal Semiconductor Contacts Phys. Rev. Lett. (1987).- Initial Stages of Schottky Barrier Formation: Temperature Effects, J. Vac. Sci. Technol. B (1987).- Kinetics Study of Initial Stage Band Bending at Metal GaAs (110) Interfaces, J. Vac. Sci. Technol. B (1987).- The Schottky Contact in a Xe/Metal Interface Probed by Inverse Photoemission, Europhys. Lett. (1987).- Origin of the Excess Capacitance at Intimate Schottky Contacts, Phys. Rev. Lett. (1988).- Correlation between EfPinning and Development Metallic Character in Ag Overlayers on GaAs (110), Phys. Rev. Lett. (1988).- Direct Investigation of Subsurface Interface Electronic Structure by Ballistic-Electron-Emission Microscopy, Phys. Rev. Lett. (1988).- Chemical Trends in Schottky Barriers: Charge Transfer into Adsorbate Induced Gap States and Defects, Phys. Rev. B (1988).- The Advanced Unified Defect Model for Schottky Barrier Formation, J. Vac. Sci. Technol. B (1988).- Screening and Derealization Effects in Schottky Barrier Formation, J. Vac. Sci. Technol. B (1988).- Tight-Binding Model of Surface Donor-States Induced by Metal Adatoms on GaAs (110) Surfaces, Europhys. Lett. (1988).- Switching of Band Bending at the Nonreactive CsOx/GaAs (110) Interface, Phys. Rev. Lett. (1989).- Metallicity and Gap States in Tunneling to Fe Clusters on GaAs (110), Phys. Rev. Lett. (1989).