Showing papers on "Thin film published in 1974"

A new ferroelectric memory device, metal-ferroelectric-semiconductor transistor

Abstract: The ferroelectric field effect has successfully been demonstrated on a bulk semiconductor (silicon) using a thin ferroelectric film of bismuth titanate (Bi 4 Ti 3 O 12 ) deposited onto it by RF sputtering. A new memory device, the metal-ferroelectric-semiconductor transistor (MFST); has been fabricated. This device utilizes the remanent polarization of a ferroeletric thin film to control the surface conductivity of a bulk semiconductor substrate and perform a memory function. The capacitance-voltage characteristics of the metal-ferroelectric-semiconductor structure were employed to study the memory behavior. The details of the study together with a preliminary results on the MFST are presented.

Direct resolution of surface atomic steps by transmission electron microscopy

Abstract: Long exposure dark-field micrographs have been imaged in weak but finite reflections from evaporated (III)-Au films normally considered forbidden on structure factor grounds. Contrast features in the forbidden reflection images are attributed to single atomic steps in film thickness, and are used to determine the roughness of the (III)-Au surface in detail. The technique provides a powerful general method for studying thin film surfaces.

Applications of Ion Beams to Metals

Abstract: I. Implantation Modification of Superconductivity.- Superconductivity of Palladium and Pd-Alloys Charged with H or D by Ion Implantation at Helium Temperatures.- Ion Implantation in Superconducting Thin Films.- Ion Implantation in Superconducting Niobium Thin Films.- Superconducting Properties of the Dilute Magnetic Alloys Pb-Mn, Sn-Mn and Hg-Mn Obtained by Ion Implantation.- Ion Irradiation and Flux Pinning in Type II Superconductors.- II. Ion Induced Surface Reactions.- The Use of Ion Beams in Corrosion Science.- The Effects of Ion Bombardment on the Thin Film Oxidation Behavior of Zircaloy-4 and Zr-1.0 Nb.- Ion Implantation and Backscattering from Oxidized Single-Crystal Copper.- Movement of Ions During the Anodic Oxidation of Aluminum.- Friction and Wear of Ion Implanted Metals.- III. Thin Films and Interfaces.- Ion Beam Studies of Metal-Metal and Metal-Semiconductor Reactions.- Rutherford Scattering Studies of Diffusion in Thin Multilayer Metal Films.- Analysis of Compound Formation in Au-Al Thin Films.- Thin Film Interdiffusion of Chromium and Copper.- Ion Backscattering Study of WSi2 Layer Growth in Sputtered W Contacts on Silicon.- Reactions of Thin Metal Films with Si or SiO2 Substrates.- Ion Beam Induced Intermixing in the Pd/Si System.- IV. Alloying and Migration in High Fluence Implants.- Precipitation During Ion Bombardment of Metals.- Radiation Damage and Ion Behavior in Ion Implanted Vanadium and Nickel Single Crystals.- Sb-Implanted A? Studied by Ion Backscattering and Electron Microscopy.- The Changes in Electrical Properties of Tantalum Thin Films Following Ion Bombardment.- Implantation and Diffusion of Au in Be: Behavior During Annealing of a Low-Solubility Implant.- Anomalous Room Temperature Diffusion of Ion-Injected Ni in Zn Targets.- Study of Li-6 Implanted into Niobium.- V. Implanted Atom Location.- Lattice Location of Impurities Implanted into Metals.- High Substitutional Fractions in Cold Implantations of Xe and Te in Iron as Shown by Mossbauer Effect Measurements.- Valence Determination and Lattice Location via Mossbauer Spectroscopy of Gd151 Implanted into Iron.- Combined Lattice Location and Hyperfine Field Study of Yb Implanted into Fe.- Effect of Radiation Damage on Lattice Location and Hyperfine Interactions of Impurities Implanted in Iron.- Determination of Unique Site Population in Various In Implanted Non-Cubic Metals using Angular Correlations and the Nuclear Electric Quadrupole Interaction.- The Location of Displaced Manganese and Silver Atoms in Irradiated Aluminum Crystals by Backscattering.- Lattice Location Studies of 2D and 3He in W.- Location of He Atoms in a Metal Vacancy.- Simulation of Inert Gas Interstitial Atoms in Tungsten.- VI. Ion Lattice Damage.- Ion Damage Effects in Metals as Studied by Transmission Electron Microscopy.- Transmission Electron Microscopy Study of Implantation Induced Defects in Gold.- Transmission Electron Microscope Studies of Defect Clusters in Aluminium Irradiated with Gold Ions.- Dechanneling from Damage Clusters in Heavy Ion Irradiated Gold.- Heavy Ion Damage in Thin Metal Films.- Formation of Interstitial Agglomerates and Gas Bubbles in Cubic Metals Irradiated with 5 keV Argon Ions.- Observation of Ion Bombardment Damage in a Ni (100) Crystal by Helium Ion Injection.- VII. Ion Implanted Gas Buildup.- Helium Implantation Effects in Vanadium and Niobium.- Effect of He+ and D+ Ion Beam Flux on Blister Formation in Niobium and Vanadium.- Depth Distribution and Migration of Implanted Helium in Metal Foils using Proton Backscattering.- Blistering of Niobium due to Low Energy Helium Ion Bombardment Investigated by Rutherford Backscattering.- Radiation Damage and Gas Diffusion in Molybdenum Under Deuteron Bombardment.- Radiation Blistering After H+, D+ and He+ Ion Implantation into Surfaces of Stainless Steel, Mo, and Be.- VIII. Voids and Implantation Simulation of Neutron Damage.- A Review of Ion Simulation of High Temperature Neutron Damage and Void Formation.- Ion Radiation Damage.- 4 MeV Iron Atom Bombardment of Iron.- Flux (Dose Rate) Effects for 2.8 MeV 58Ni Irradiations of Pure Ni.- Heavy Ion-Induced Void Formation in Pure Nickel.- The Temperature Dependence of Irradiation Induced Void Swelling in 20% Cold Worked Type 316 Stainless Steel Irradiated with 5 MeV Nickel Ions.- Author Index.

Catalysts for electroless deposition of metals on comparatively low-temperature polyolefin and polyester substrates

Abstract: A method for the metallization of a nonconductive surface with gold, nickel or copper whereby on a nonconductive, relatively low temperature surface (such as a polyester or a polyolefin) a thermosensitive coordination complex of palladium (or platinum) is deposited from a solvent; the complex has the general formula LmPdXn wherein L is a ligand or unsaturated organic radical, X is a halide, alkyl group or a bidentate ligand and m is an integer from 1 to 4 and n is from 0 to 3; bis-benzonitrile palladium dichloride complex is an appropriate illustration; the palladium complex is applied in a thin film from a suitable nonaqueous solution solvent such as xylene, toluene or a chlorobenzene onto the surface of the nonconductive material and that thin film is thermally decomposed, such as by an infrared irradiation; the method in the preferred embodiment can be practiced without the necessity of surface etching or similar chemical conditioning of the polyester, polyamide, polyvinyl chloride, or polyolefin substrate prior to the catalytic coating; circuit element intermediates of said substrates are also disclosed.

Ferromagnetism near surfaces and in thin films

Abstract: The ferromagnetic order is modified near the surface of a magnetic crystal. This modification is studied most clearly in magnetic thin films consisting of only a few atomic layers. Some essential features of the theoretical description are reported as a basis for the discussion of experiments. The main experimental problem is the preparation of flat single crystal films; the real structure of the best available films is discussed. Their magnetic properties are compared with theoretical predictions. Furthermore, methods and results are reported for probing the magnetic properties of surfaces, by their interaction with low energy electrons.

Simulation of structural anisotropy and void formation in amorphous thin films

Abstract: We have computer simulated the structure of thin amorphous films grown from a vapor. Our hard‐sphere model shows that structural anisotropy and voids are a natural occurrence of the deposition process. The amount of unfilled space (voids) and the anisotropy have been studied as a function of the angle of incidence of the vapor stream upon the substrate.

Quantitative electron microprobe analysis of thin films on substrates

Abstract: Monte Carlo simulation procedure is developed for kilovolt electron beam scattering and energy loss in targets consisting of thin films on thick substrates. Such calculations have direct application to the nondestructive quantitative chemical analysis of ultrathin films in the electron microprobe (an electron probe x-ray microanalyzer), utilizing characteristic x-ray fluorescence. Angular elastic scattering is calculated in the electron trajectory simulation with the screened Rutherford expression for cross section, and energy loss between elastic scattering events is calculated with the continuous-slowing-down approximation of Bethe. The contribution to x-ray fluorescence from the film due to backscattered electrons from the substrate is accounted for. For elemental films, the Monte Carlo simulation predicts intensity ratios ki for characteristic x-rays from the film, referenced to standards of thick elemental samples. No film standards are required, and the mass thickness of any elemental film on any substrate can be determined from theoretical calibration curves. The model has been verified by measurements on films of Si, Cu, and Au on Al203 over wide ranges in E0, and t. For alloy films, calibration curves are generated and graphically iterated to provide independent analysis of weight fractions Ci and total mass thickness pt. Films of Mnx,Biy, and Cox,Pty, were successfully analyzed with pt ≤ 100 µg/cm2.

Stress waves generated in thin metallic films by a Q-switched ruby laser

Abstract: Investigation results on stress waves generated by Q-switched ruby laser irradiated thin metal films under confinement, studied over a wide range of film materials and film thicknesses, are reviewed. The results indicate that the dependence on these parameters is much weaker than is predicted by heat transfer estimations commonly used to describe the interaction of laser irradiation with unconfined bulk-solid surfaces.

Multiple‐pass thin‐film silicon solar cell

Abstract: A technique is described by which light entering a thin film is ``trapped'' in the sense of having to traverse the film a number of times. It is shown that the use of this technique in silicon provides a solar cell with good carrier collection efficiencies even with Si only ∼2 μm thick and with ∼10‐nsec lifetime.

Method of manufacturing thin-film field-emission electron source

Abstract: A method of manufacturing a thin-film field-emission electron source which is of a sandwich structure of a substrate - metallic film-insulating film - metallic film and which has at least one minute cavity and a field-emitter of, for example, a conical shape within the cavity, comprises the steps of (i) forming on a substrate a first layer of metallic film pattern for current supply, (ii) depositing a second layer film made of an electron emissive material onto the entire area of the substrate provided with the first layer, and thereafter subjecting the second layer film to a mesa etch by a photoetching process, to form a conical emitter on the first layer film, (iii) forming a third layer made of an insulating material, the third layer having a height substantially equal to the level of a tip portion of the emitter, (iv) forming a fourth layer of metallic film pattern as an accelerating electrode, and (v) etching the third layer, so as to expose the extremity of the emitter. According to the manufacturing method, a thin-film field-emission electron source can be readily produced merely by the combination between the standard evaporation techniques and etching techniques.

Alignment of nematics and smectics on evaporated films

Abstract: We discuss the alignment of nematics and smectics on substrates where an obliquely evaporated thin film has been previously deposited. In the planar samples, the surface anchoring energy is substantially larger than with the traditional rubbing technique. We can also uniformly align the liquid crystals obliquely, in particular by coating the evaporated film by a surfactant.

Tubular solar cell

Abstract: High efficiency, low cost solar energy conversion is facilitated by using tubular photovoltaic solar cells situated at the focus of a line-generated paraboloidal reflector. Advantageously, each solar cell comprises a pair of concentric glass tubes that are hermetically sealed at the ends. A photovoltaic junction is formed over the entire inside surface of one of the concentric tubes. For example, this may comprise an inner electrically conductive film, contiguous layers of Cu2 S and CdS forming a heterojunction, and an outer film of optically transparent but electrically conductive material. The conductive films provide electrical connection to the junction via external contacts that are symmetrically disposed at the ends of the tubular cell. In other embodiments the photovoltaic junction is formed in a crystalline silicon layer that is grown in situ on one of the glass tubes. Techniques for promoting oriented semiconductor crystalline growth are disclosed. These include providing minute crystalline islands in a metal matrix to serve as growth centers, surface alignment using a wavy layer deposited at an acute angle onto the glass substrate, surface seeding and normalization growth atop a fluid-like thin film deposition substrate.

Thin film electrochemical electrode and cell

Abstract: A thin film polarographic oxygen sensor, in which a number of thin film microcathodes are deposited in holes in a thin film layer of silicon dioxide formed on a silicon substrate. A single thin film anode layer is deposited on the insulating layer and is insulated thereby from the cathodes. Preferably the microcathodes and the anode are located in a well in the thin film insulating layer, the well being filled flush to its surface with electrolyte, and having a thin film polymer filter membrane deposited thereover. Contacts to the anode and cathodes may be punched through a thin film insulating layer on the back of the wafer, the cathode contact being thereby connected to the substrate, and the anode contact being insulated from the substrate by an encircling thin film layer of silicon dioxide and extending through to the anode metallization layer. With appropriate choice of electrode, electrolyte and membrane materials, the cell may also be used as a pH sensor, a CO 2 sensor, a specific ion sensor, or to detect or sense other substances in solution. Single electrode units may also be formed by depositing thin film electrode materials on appropriate substrates.

Laser‐generated pulsed atomic beams

Abstract: The irradiation of thin films of solid material by a moderate energy (0.5 J/pulse) Q‐switched ruby laser beam has been used to produce intense pulses of neutral atoms and molecules in the 1 to 10 eV energy range. For a given total laser beam energy, both the flux and energy range of atoms within the pulse can be varied within limits by adjusting the energy density of the laser light at the target surface. As observed at a distance of 60 cm from a thin BiF3 compound target, the flux of 5 eV fluorine atoms from a typical burst was estimated to be about 1.3×107 atoms/cm2/sec. For the same burst, the flux integrated over the 1 to 10 eV range yields a value of ∼2×1013 atom/cm2. Similar results were obtained with aluminum and uranium thin films.

ac electron tunneling at infrared frequencies: Thin‐film M‐O‐M diode structure with broad‐band characteristics

Abstract: A high‐speed diode element consisting of a metal‐metal‐oxide‐metal electron‐tunneling junction is formed by thin films deposited on a substrate. These junctions are integrated with deposited narrow resonant antenna structures which couple the junction to incident radiation. Broad‐band characteristics from radio and microwave frequencies to the infrared region are shown. Frequency mixing and the possibility of utilizing large numbers of elements simultaneously are also demonstrated.

Quantum size effects in metal particles and thin films by an extended RPA

Abstract: The RPA is extended in the framework of linear response theory to allow for the treatment of a finite free electron gas. The dielectric function taking quantum size effects into account, is calculated and shown to be finite in the limit of small wavevectors. The theory is applied to a simple free electron model for a small metal particle and analytical expressions are obtained for the electronic polarizability of a thin film and for the optical properties in the plasma resonance region.

Method of forming doped dielectric layers utilizing reactive plasma deposition

Abstract: A doped oxide layer is formed on a semiconductor substrate utilizing reactive plasma deposition. Impurity doped thin film oxide deposits are formed by reacting suitable source gases in an RF plasma at low pressures and temperatures. Passing an dopant compound in vapor form with a suitable carrier gas, in combination with a flow of silicon hydride and an oxide vapor flow, provides a solid film of doped silicon dioxide on a surface when the gases are subjected to an RF discharge. The method features low temperature processing which is particularly advantageously utilized in providing a doped oxide layer as a diffusion source for a Group III-V substrate.

Structural investigations of amorphous transition element films I. Scanning electron diffraction study of cobalt

Abstract: Thin films of cobalt, prepared in ultra-high-vacuum at 4 K and examined in situ by scanning electron diffraction, are shown to be amorphous with a radial distribution function similar to that obtained theoretically by serial deposition of atoms in the computer-simulated model developed by Bennett. The effects of removal of lossy electrons (by velocity filtering), subtraction of substrate background, and multiple scattering on the diffraction profile are investigated and discussed.

Tungsten metallization for LSI applications

Abstract: It is shown that MOS–LSI devices can be satisfactorily metallized with tungsten thin films using the rf-diode sputtering technique. The apparatus used consisted of a roots-blower and a Vacion pumped belljar system equipped with an 8-in. diam CVD W-cathode and a W-substrate table (anode) to which a dc bias could be applied. The control substrates were oxidized silicon wafers in which the back-oxide was removed to facilitate proper application of the bias. The effect of sputtering power (200–400 W) and of substrate bias (−200−+250 V) was studied on the deposition rate, substrate temperature, and various properties of the film such as electrical resistivity, stress, impurity concentration, constitution, and microstructure. The present process of W-film depostition has been found to offer several advantages. Low-power and low-voltage operation results in high quality MOS-compatible W-films. Substrate heating during the sputter deposition is kept to a minimum, thereby eliminating any undesirable metallurgical ...

Resistivity of Permalloy thin films

Abstract: Data on resistivity at room temperature in polycrystalline and single‐crystal Permalloy (80 Ni‐20 Fe) thin films are analyzed in terms of grain boundary scattering and the dc size effect, respectively

The growth and structure of semiconducting thin films

Abstract: In this review silicon and gallium arsenide are considered as typical examples of elemental and compound semiconductors respectively, and an account is given of the nucleation, growth and structure, both crystallographic and electrical, of autoepitaxial films of these materials. Some discussion of preparative techniques is first provided to illustrate the basic principles of thin film growth, but experimental details are not included. The use of modern methods of surface physics to assess the influence of the substrate surface on nucleation and subsequent growth behaviour is discussed, particularly with reference to results obtained using low energy electron diffraction. Auger electron spectroscopy and molecular beam techniques. Finally, the way in which studies of autoepitaxial growth have been extended to include growth on other substrates is considered.

Combination moisture resistant and antireflection plasma polymerized thin films for optical coatings.

Abstract: The technique of plasma polymerization under vacuum conditions at ~0.1 Torr has been employed to produce highly moisture resistant, thin polymer films on hygroscopic alkali metal halide crystal materials. The polymer film is fluorocarbon in nature. In addition to the moisture resistance, the films also exhibit antireflection properties and have only one absorption band over the range 25,000–250 cm−1 centered at 1200 cm−1.