Showing papers on "Thin film published in 1971"
TL;DR: The purpose of this paper is to review in some detail the important development of this new and fascinating field, and to caution the reader that the technology involved is difficult because of the smallness and perfection demanded by thin-film optical devices.
Abstract: Integrated optics is a far-reaching attempt to apply thin-film technology to optical circuits and devices, and, by using methods of integrated circuitry, to achieve a better and more economical optical system. The specific topics discussed here are physics of light waves in thin films, materials and losses involved, methods of couplings light beam into and out of a thin film, and nonlinear interactions in waveguide structures. The purpose of this paper is to review in some detail the important development of this new and fascinating field, and to caution the reader that the technology involved is difficult because of the smallness and perfection demanded by thin-film optical devices.
1,060 citations
TL;DR: Ion beam deposition of insulating carbon thin films on room temperature substrates, considering transparency, index of refraction, insulating capacity, glass scratching ability, etc. as discussed by the authors.
Abstract: Ion beam deposition of insulating carbon thin films on room temperature substrates, considering transparency, index of refraction, insulating capacity, glass scratching ability, etc
1,046 citations
TL;DR: In this article, a new dipping technique is described for producing uniform thickness low-defect-density magnetic garnet films suitable for bubble-domain devices, based on the observation that melts having the appropriate flux and garnet composition can be supercooled over a large temperature range and will remain super-cooled, permitting the growth at constant temperature of epitaxial magnetic nanoparticles.
Abstract: A new dipping technique is described for producing uniform‐thickness low‐defect‐density magnetic garnet films suitable for bubble‐domain devices. The technique is based on the observation that melts having the appropriate flux and garnet composition can be supercooled over a large temperature range and will remain supercooled, permitting the growth at constant temperature of epitaxial magnetic garnet films.
236 citations
TL;DR: In this article, the crystal structure of tantalum nitrides was examined by X-ray and electron diffraction techniques and the following seven phases were identified: TaN~0.05 (cubic, β-phase), Ta2N (hexagonal, γ-phase, δ-TaN(hexagonal), e-TaNs (hexagon), Ta5N6, Ta4N5, and Ta3N5 (tetragonal or monoclinic).
Abstract: The crystal structure of tantalum nitrides is examined by X-ray and electron diffraction techniques and the following seven phases are identified: TaN~0.05 (cubic, β-phase), Ta2N (hexagonal, γ-phase), δ-TaN (hexagonal), e-TaN (hexagonal), Ta5N6 (hexagonal), Ta4N5 (tetragonal) and Ta3N5 (tetragonal or monoclinic). Thin films of Ta nitrides for electron diffraction study were prepared by nitriding thin evaporated films of tantalum in ammonia and nitrogen. By heating thin films of Ta3N5 in vacuum, the phase transformations occur successively as follows: Ta3N5→Ta4N5→Ta5N6→e-TaN→Ta2N. The stucture of each nitride form is discussed.
145 citations
TL;DR: By properly choosing the film thicknesses at both sides of the step, one can obtain an unusually large positive or negative wavelength dispersion of the refraction or, if desired, achromatic refraction.
Abstract: We consider thin film light guides consisting of a transparent film of high refractive index deposited on a substrate of lower index. The propagation of light in such a two-dimensional transmission medium can be described within the limits of geometrical optics by an effective index of refraction N. Its value depends on the film thickness. Therefore, a light beam in the thin film guide is refracted or totally reflected at a step of film thickness. We discuss these phenomena (Snell’s law) and demonstrate them experimentally, using ZnS films on glass as guides. As applications, we show a thin film prism and thin film lenses for guided light beams. By properly choosing the film thicknesses at both sides of the step, one can obtain an unusually large positive or negative wavelength dispersion of the refraction or, if desired, achromatic refraction.
136 citations
TL;DR: In this article, a technique for the preparation of pinhole-free glass films on porous substrates is described, and the permeabilities of He, Ne, Ar, Kr, and D2 are reported.
Abstract: A technique for the preparation of pinhole‐free glass films on porous substrates is described. The permeabilities of He, Ne, Ar, Kr, and D2 and the diffusivities of Ne, Ar, and D2 in the films are reported. The temperature range studied for He, Ne, and D2 was 25–500°C, while the range for Ar and Kr was 650–920°C. Activation energies reported for the permeabilities are: He, 5.22 kcal/mole; Ne, 9.13 kcal/mole; Ar, 25.2 kcal/mole; Kr, 44 kcal/mole; and D2, 8.32 kcal/mole. Activation energies reported for diffusivities are: Ne, 9.55 kcal/mole; Ar, 28.7 kcal/mole; and D2, 9.26 kcal/mole. A technique of nonlinear least squares curve fitting for the calculation of diffusion coefficients is described, and various interpretations of the temperature dependence of the diffusivity preexponential factor are discussed.
131 citations
TL;DR: In this article, a theoretical and experimental description of laser machining of thin bismuth films with glass and mylar as substrates using a lowest-order transverse mode argon laser with an average power output capability of 20 milliwatts was given.
Abstract: A theoretical and experimental description of laser machining of thin metallic films is given. Calculations are carried out for the temperature rise of a thin film in response to a pulse of incident light energy and for the dependence of the temperature rise on the different thermal constants of the substrate and film and on the illumination conditions. Experiments have been conducted on the pulsed machining of thin bismuth films with glass and mylar as substrates using a lowest-order transverse mode argon laser with an average power output capability of 20 milliwatts. A fast intracavity acoustooptical modulation system produced optical pulses with durations controllable from 25 ns to several ms. The pulse repetition rate could be varied from a single pulse up to several MHz. The peak power depended on the duty cycle but was limited to 2 watts for low duty cycles. Experiments were done with both front and back illumination. (In back illumination the laser beam is incident on the film through the substrate.) For optimal machining conditions in which the optical beam diameter is adjusted to produce the maximum diameter of transparent area for a given pulse energy, less than 50 percent of the removed material left the surface of the substrate. The remainder was displaced so as to leave some areas free of bismuth while the thickness of bismuth in other areas was increased. With a pulse duration of 25 ns and a 600-A-thick bismuth film on mylar, the peak power required to machine a 6-µm-diameter spot was about 0.7 watt. Variable amplitude light pulses produced by the intracavity modulation system with a 1-MHz repetition rate and duration of 25 ns were used to write images on a 600-A-thick bismuth film, deposited on a mylar substrate, by deflecting the laser beam in raster fashion over the surface of the bismuth film. The average laser power output was 20 mW. The film area was 8 × 10 mm2. Both positive and negative continuous-tone images were recorded. The images consisted of an array of 1200 by 2000 completely independent spots of varying diameter and a spot density of 4 × 106/cm2. Images of documents which were originally of size 8½ × 11 inches showed a limiting resolution of over 175 lines per inch when magnified to the original size.
129 citations
Patent•
10 May 1971
TL;DR: A REDUCIBLE GAS SENSOR COMPRISING an ELECTROCHEMICAL CELL including a CATHODE, ANODE and an ELECTROLYTE of a rare Earth FLUORIDE is described in this article.
Abstract: A REDUCIBLE GAS SENSOR COMPRISING AN ELECTROCHEMICAL CELL INCLUDING A CATHODE, AN ANODE AND AN ELECTROLYTE OF A RARE EARTH FLUORIDE. THE CELL PROVIDES ANBIENT REDUCIBLE GAS WITH INGRESS TO THE ELECTROLYTE AND THE CONDUCTIVITY OF THE ELECTROLYTE IS ACCORDINGLY MODIFIED, THUS PROVIDING THE CELL WITH A MEASUREABLE CHARACTERISTIC INDICATIVE OF AMBIENTCONCENTRATION OF THE GAS. A RUGGED MINIATURE SENSOR, ADAPTED FOR USE IN PHYSICALLY DISTRUBED ENVIRONMENTS AND PREFERABLY SELF-POWERED, IS FORMED BY THIN FILM DEPOSITION OF THE CELL ELEMENTS.
126 citations
IBM1
TL;DR: In this paper, the results of experiments conducted with the goal of understanding the mechanism of this effect are presented, where the relationships between lifetimes and the mode of preparation, the composition, and the heat treatment of the samples are explored.
Abstract: Copper additions reduce the rate of electromigration in aluminum thin film conductors subjected to dc currents of high density. The results of experiments conducted with the goal of understanding the mechanism of this effect are presented. The relationships between lifetimes and the mode of preparation, the composition, and the heat treatment of the samples are explored. The lifetimes of copper bearing aluminum conductors vary in the same way, with respect to temperature and current density, as conductors made of pure aluminum. Data obtained with an electron microprobe on samples which have failed electrically, after prolonged exposure to current, show the coincidence of crack formation and copper depletion in the surrounding area. Analysis along the length of current stressed samples, also with the microprobe, indicates that under the effect of current, copper atoms migrate at a considerably faster rate than aluminum atoms. Gold and silver additions in aluminum do not have the same effect as copper additions. It is believed that this difference is due to variations in adsorption of different atomic species on aluminum grain boundaries.
120 citations
TL;DR: In this article, the superconducting transition temperature, the critical magnetic field Hc, and the room temperature conductivity have been measured as a function of thickness d. The results indicate that films as thin as 30 A act essentially as uniform layers in which the crystal size is approximately equal to the film thickness.
Abstract: Thin films of aluminum have been produced in the thickness range of 1000–30 A in small area samples with photoetched edges. The superconducting transition temperature Tc, the critical magnetic field Hc, and the room‐temperature conductivity have been measured as a function of thickness d. The results indicate that films as thin as 30 A act essentially as uniform layers in which the crystal size is approximately equal to the film thickness. The transition temperature was found to vary linearly with d−1. Hc (T) was measured from Tc to 0.4°K. For thickness from 1000 to 200 A, Hc∼d−3/2, as expected from the Ginzburg‐Landau theory. For d <200 A, Hc is paramagnetically limited to about 49 kOe = 19.6Tc, slightly above the Clogston limit.
110 citations
TL;DR: In this article, the authors measured the average value of the self-diffusional mass transport parameter, Λdv, for a considerable number of dislocations making angles, θ, with respect to b over the range at least 20° ⪯ θ ⪩ 80°.
TL;DR: The versatility of rf sputtering and related processes often allows one to tailor the properties of thin films in ways not always available with other methods of film deposition as discussed by the authors, and effects that occur at the target, in the gas discharge, and at the substrate are reviewed in the context of their over-all effect on the physical and chemical properties.
Abstract: The versatility of rf sputtering and related processes often allows one to tailor the properties of thin films in ways not always available with other methods of film deposition. Effects that occur at the target, in the gas discharge, and at the substrate are reviewed in the context of their over-all effect on the physical and chemical properties of thin films. Special emphasis is placed on the effects of substrate temperature and the bombardment of substrates by various energetic species. Techniques involving controlled bombardment of substrates (deposition with rf-induced substrate bias) are considered in detail.
TL;DR: In this article, a unified treatment for switching and breakdown events, which occur in the range of fields of a few to more than 107 V/cm, is given, showing that the mechanisms of thermal events and electronic ones in semiconductor junctions are understood, but that the mechanism of insulator breakdown requires clarification.
TL;DR: In this paper, an analysis of the evolution of the temperature profile in the VO2 film is given, where the authors show that the I-V characteristic of thin-filament thin-film devices has been investigated.
Abstract: Filaments have been observed in VO2 coplanar thin‐film devices and their I‐V characteristic investigated. An analysis of the evolution of the temperature profile in the VO2 film is given.
TL;DR: In this paper, a comparison between the semiconducting properties of thin silicon films epitaxially grown, by chemical vapor deposition processes, on single crystal sapphire and spinel is examined.
TL;DR: In this paper, an improved ion thinning apparatus, suitable for preparing electron microscope foils of inorganic nonmetallic samples (ceramics, minerals, rocks), is described, along with a resume of conditions for its optimum operation.
Abstract: Details of an improved ion thinning apparatus, suitable for preparing electron microscope foils of inorganic nonmetallic samples (ceramics, minerals, rocks), are described, along with a resume of conditions for its optimum operation. Problems of surface topography and radiation damage associated with the ion thinning process are also briefly discussed.
TL;DR: Barium titanate (BaTiO3) was deposited onto Pt foil, and onto thin-film Pt and Pt-Rh electrodes on sapphire, and counterelectroded to complete metal-dielectric-metal structures.
Abstract: Barium titanate (BaTiO3) was deposited onto Pt foil, and onto thin-film Pt and Pt-Rh electrodes on sapphire, and counterelectroded to complete metal-dielectric-metal structures. Dielectrics (5000–60 000 A) were deposited at substrate temperatures from 23 ° to 1000 °C, some fired in air at temperatures to 1400 °C after deposition, the films providing a wide range of dielectric constants (16–1900). Onset of BaTiO3 crystal growth was detected at 500 °C, a reduced BaTiO3 detected at 1000 °C, and constant Ba/Ti ratios measured over the deposition temperature range. Capacitance increase with temperature was essentially linear, with the fired dielectrics showing minimum slope. Tanδ varied from 0.005 for amorphous films to 0.065 for films with highest dielectric constants, with related dielectric strengths of 1.8×106 to ≈0.15×106 V/cm, respectively. Substrate, electrode, and process limitations for capacitor fabrication are defined.
TL;DR: In this paper, a method to prepare thin films of MnBi by vapor deposition followed by a fast annealing process is described, and uniform and reproducible MnBi films suitable for magnetooptic applications can be obtained using this technique.
Abstract: A method to prepare thin films of MnBi by vapor deposition followed by a fast annealing process is described. Uniform and reproducible MnBi films suitable for magneto‐optic applications can be obtained using this technique. Upon quenching from above 360°C, the high‐temperature phase can be preserved at room temperature. The stability of this crystallographic phase has been evaluated and an activation energy of 1. 08 eV associated with the phase transformation from the quenched high‐temperature phase to the normal low‐temperature phase is determined.
TL;DR: In this article, negative resistance and memory effects occurring in formed thin insulating films are described and new experimental results for zinc sulphide thin film devices are shown not to be a constant voltage for maximum current.
Abstract: Negative resistance and memory effects occurring in formed thin insulating films are described and new experimental results for zinc sulphide thin film devices are presented. Contrary to previous work the voltage for maximum current is shown not to be a constant. The switching time of the devices is interpreted in terms of an activation energy. Previous theories are shown to be unsatisfactory and a theory based on the thermal rupture of conducting filaments and applicable to all such formed devices is presented.
TL;DR: In this article, a systematic study of the d.c. breakdown strength of thin ionic films of barium stearate is reported in the thickness range (25-2000 A).
Patent•
26 Feb 1971
TL;DR: In this article, the authors present a process for the construction of a polygonal surface with an adhoc movie and a solution of a precurved solvent-soluble, further-CURABLE ORGANOPOLYSILOXANE.
Abstract: PROCESS, AND THE ARTICLE PRODUCED THEREBY, FOR PROVIDING A UNIFORMLY AND TENACIOUSLY ADHERED, HARD, ACETONE-RESISTANT AND MAR-RESISTANT COATING ON ARTICLES HAVING A SOLID POLYCARBONATE OR ACRYLIC SURFACE. THE PROCESS INCLUDES PRIMING THE POLYMERIC SURFACE WITH AN ADHESION PROMOTING, THERMOSETTABLE ACRYLIC BY FORMING A THIN FILM THEREON, THEN COATING THE PRIMED SURFACE WITH A SOLUTION OF A PRECURED SOLVENT-SOLUBLE, FURTHER-CURABLE ORGANOPOLYSILOXANE IN AN ORGANIC SOLVENT AND THEREAFTER EVAPORATING THE SOLVENT AND FINALLY CURING THE ORGANOPOLYSILOXANE TO A THERMOSET CONDITION. THE SOLVENT-SOLUBLE, FURTHER-CURABLE ORGANOPOLYSILOXANE IS PRODUCED BY HEATING METHYLTRIALKOXYSILANE, PHENYLTRIALKOXYSILANE OR MIXTURES THEREOF AND WATER IN THE PRESENCE OF AN EFFECTIVE CATALYTIC AMOUNT OF A HYDROLYSIS CATALYST, E.G., HCL, AT A SUFFICIENT TEMPERATURE AND FOR A TIME SUFFICIENT TO FORM A PARTIAL CONDENSATION PRODUCT, CONCENTRATING THIS PRODUCT BY HEATING TO REMOVE SOME ALKANOL BY-PRODUCT AND WATER AND THEREAFTER PRECURING THE PRODUCT BY HEATING BELOW THE GEL POINT THEREOF.
TL;DR: The relationship between frequency shift and incremental deposit thickness was found to agree with theoretical predictions as discussed by the authors, which is unexpected since differences in the elastic constants of film material and quartz and/or changes of the oscillatory behavior could lead to deviations.
Abstract: Quartz-crystal oscillators were operated in conjunction with film thickness monitors which convert the shift of the period of oscillation into indicated film thickness t. Films exceeding 125 kA of Cu (>415 kA of Al equivalent) were deposited on individual crystals. The deposit on glass slides simultaneously exposed to the deposition process was weighed. Up to the largest masses investigated, the indicated thickness of the deposit was linearly proportional to the deposit thickness on the slides. This result is unexpected since differences in the elastic constants of film material and quartz and/or changes of the oscillatory behavior could lead to deviations. Furthermore, the effective oscillating area of various crystals was only slightly larger than that of the deposit. The relationship between frequency shift and incremental deposit thickness was found to agree with theoretical predictions.
TL;DR: In this paper, the operation and characteristics of a ring laser formed by a singlemode light-guiding thin film are described, where the rhodamine 6G doped polyurethane film is coated on the surface of a cylindrical glass rod.
Abstract: We report the operation and characteristics of a ring laser formed by a single‐mode light‐guiding thin film. The rhodamine 6G doped polyurethane film is coated on the surface of a cylindrical glass rod. This geometry establishes feedback for laser oscillation around the circumference of the rod. A nitrogen laser serves as pump source.
TL;DR: In this paper, it was shown that NbN thin superconductor (NbN) films exhibit the highest current densities of any presently known superconductuctor in all fields from zero up to the limit of their measurement capability (210 kOe).
Abstract: Previous results indicated that NbN thin films possess critical current and field characteristics significantly superior to that of bulk NbN having a similar Tc. Further measurements made on NbN films, with thicknesses between 50 A and 8 μ, now show that, at 4.2°K, certain of these films exhibit the highest current densities of any presently known superconductor in all fields from zero up to the limit of our measurement capability (210 kOe). In addition, anomalously high current and field values have been measured in very thin (<300 A) films. These thinner films show no depressions in Jc (measured at 4.2°K) or in Hc2 (O) values despite decreases in Tc from almost 16°K (in the thicker films) down to 11°K.
TL;DR: In this article, the results reported by Routledge and Stowell for computer simulation of thin film nucleation and growth can be derived analytically and extended to cover both three-dimensional and two-dimensional island growth when complete condensation conditions are valid.
TL;DR: Aromatic hydrocarbon films display field-induced switching between two impedance states when a mobile electrode material such as gallium-indium alloy is employed as mentioned in this paper, and the switching mechanism involves the formation of conducting filaments.
Abstract: Field-induced switching between two impedance states has been observed in both pure and doped organic thin films. Aromatic hydrocarbon films display this phenomenon reproducibly when a mobile electrode material such as gallium-indium alloy is employed. Controlled doping of the hydrocarbons with electron acceptors leads to reproducible switching characteristics which are not electrode dependent. For the doped films, activation energies of conduction typical of bulk charge-transfer complexes characterize the low impedance states whereas the activation energies of the high impedance states are typical of organic insulating films. It is suggested that the switching mechanism involves the formation of conducting filaments.
TL;DR: In this article, a model of magnetic anisotropy in epitaxial films is proposed and shown to be in good agreement with experimental domain observations, and a typical sample of a domain diameter of 8 μ is observed in a 6μ-thick film at a bias field of 25 Oe.
Abstract: The properties of cylindrical domains in wafers of bulk single crystals of various magnetic oxides have been extensively studied and described in recent months. Mobile cylindrical domains have been produced in single‐crystal thin films of gallium‐substituted yttrium iron garnet. The deposits are formed by chemical vapor deposition onto nonmagnetic garnet substrates greater than 1 cm2 in area. A model of magnetic anisotropy in epitaxial films is proposed and shown to be in good agreement with experimental domain observations. In a typical sample, a domain diameter of 8 μ is observed in a 6‐μ‐thick film at a bias field of 25 Oe. From the domain translational velocity of 5600 cm/sec, a cylindrical domain mobility of 1500 cm/sec Oe has been calculated. A fractional change in cylindrical domain diameter of −0.07%/°K has been measured at 300°K. Annealing at 1570°K for several hours did not alter the Neel temperature or the optical transmission spectrum.
TL;DR: In this article, two new phases of niobium nitride, Nb4N5 and Nb5gN6, were identified on thin films by electron diffraction.
Abstract: Two new phases of niobium nitride, Nb4N5 and Nb5gN6, were identified on thin films by electron diffraction. The specimens were prepared by nitriding the evaporated thin films of niobium in ammonia. The structures of these two nitrides are isomorphous with those of Ta4N5 and Ta5N6, respectively. The Nb4N5 phase belongs to the tetragonal system with lattice parameters, a = 6.87 3 A and c = 4.29 8 A , while the Nb5N6 phase is based on the hexagonal structure having lattice parameters, a = 5.19 3 A and c = 10.38 0 A . By heating Nb5N6 in vacuum at high temperature, successive phase changes were observed: Nb5N6→δ′-NbN→δ-NbN→Nb4N3→Nb2N.
TL;DR: In this paper, a backscattering analysis has been employed to study the phenomenon of low-temperature migration of Si through thin films of Au and Ag evaporated in vacuum on substrates of single crystal Si.
Abstract: The method of backscattering analysis has been employed to study the phenomenon of low-temperature migration of Si through thin films of Au and Ag evaporated in vacuum on substrates of single crystal Si. The Si begins to migrate at lower temperatures (≈200 °C) through Au, which has a low-temperature eutectic with Si, than it does through Ag (≈400 °C), which has a higher eutectic point. Migration of Si is also studied through double layers of Au with superimposed Ag, and vice versa. It is concluded that the interface between the Si substrate and the film plays a leading role in this process of low-temperature migration.
TL;DR: Ion migration direction in thin Ag, Cu and Au films under direct current effect from resistance radioactive tracer measurements and scanning electron micrographs was studied in this article, where the authors showed that the current effect on the migration direction of the ion migration was negligible.
Abstract: Ion migration direction in thin Ag, Cu and Au films under direct current effect from resistance radioactive tracer measurements and scanning electron micrographs