Showing papers on "Thin film published in 1968"
623 citations
TL;DR: In this paper, it was shown that the reversible switching is not due to a phase change of the dielectric, but rather due to an anodized titanium dioxide (TiO 2 ).
Abstract: Thin films of anodized titanium dioxide can be made to switch between three distinct conductivity states. Some electrical properties which characterize these states are given in the temperature range 4·2°K to 500°K. It is concluded that the reversible switching is not due to a phase change of the dielectric.
308 citations
TL;DR: In this article, the loss tangent and permittivity of vacuum- baked dielectric films of anodized aluminium oxide and evaporated silicon oxide, in the frequency range 10 -2 -10 7 Hz and temperature range 77-600 °K, were reported.
231 citations
TL;DR: In this article, it was shown that boron-nitride films of up to 6000Aa thick have been deposited on a variety of substrates at 600 °-1000 °C by a reaction between diborane and ammonia in hydrogen or inert carrier gas.
Abstract: Clear, vitreous films of boron nitride up to 6000Aa thick have been deposited on a variety of substrates at 600 °–1000 °C by a reaction between diborane and ammonia in hydrogen or inert carrier gas. Deposition rate may be readily adjusted to 50–1000 Aa/min. Most samples were made at either 600° or 800°, with some attendant variation in film properties. The 600° material contains some residual B‐H bonding. The film is essentially amorphous to electron diffraction. The refractive index is 1.7–1.8, the 1 MHz dielectric constant ~ 3 1/2, the dielectric strength , and the The band gap is 3.8 ev and the phonon temperature in the neighborhood of 2000°K. For semiconductor junction protection boron nitride has no advantage over silicon nitride. 600° deposition directly on Si has produced surface charges as low as , but there are room‐temperature drifts, and high‐field conduction also. BN deposited at 800° on Si is electrically similar to silicon nitride. Etching of BN film also presents the same problems as does silicon nitride. BN is not as good a barrier against sodium ion permeation. Attack by atmospheric moisture over a long period has varied from insignificant to extensive conversion to orthoboric acid.BN film on Si dopes the substrate with boron at temperatures above 900 °C in inert ambient. Uniform junction depths are produced. D‐C conductivity in 500–4000Aa films has been studied from room temperature to 270 °C. With fields ≥ 106 v/cm BN film shows stable, nonohmic conductivity which is independent of polarity. The 25 °C d‐c conduction is describable over at least seven decades of current by , , where , . The 600°‐deposited BN is the more conductive and can carry indefinitely. is linear, and the slope of the curve is in good agreement with the theoretical value for a Frenkel‐Poole conduction mechanism. Possible use of BN as a thin film varistor is discussed.
225 citations
TL;DR: In contrast to the standard nucleation theory, in which thermodynamic (macroscopic) variables are used, the present theory uses atomic variables as discussed by the authors, which leads to a system of stochastic equations.
164 citations
TL;DR: In this paper, the optical constants of bulk materials and thin films have been conveniently determined employing an automatic curve-fitting procedure to obtain a classical oscillator fit to reflectance and/or transmittance data.
Abstract: The optical constants of bulk materials and thin films have been conveniently determined employing an automatic curve-fitting procedure to obtain a classical oscillator fit to reflectance and/or transmittance data. The method compares favorably in convenience and accuracy with a Kramers–Kronig analysis of bulk reflectivity spectra and is a better technique than the R,T or T,T methods presently used to analyze spectro-photometric data of thin films.
159 citations
TL;DR: In this article, it was shown that the writing magnetic field can be reduced to less than 10 Oe by using a memory plane consisting of discrete squares of MnBi and erasing of a spot a few microns in diameter in a 1000 A thick film with a 4 μsec pulse from a 13 mW Gaussian laser beam.
Abstract: Thin films of MnBi possess many unusual physical properties and are particularly suitable for memory applications using laser Curie‐point writing and magneto‐optical readout. Films prepared on mica substrates have the easy direction of magnetization perpendicular to the film plane. They typically have a specific Faraday rotation of 5×105 deg/cm, and an absorption coefficient of 3.8×105 cm−1 for 6328 A wavelength, permitting a readout rate of 109 bits/sec at 1 mW laser power level using available detectors. Curie‐point writing and erasing of a spot a few microns in diameter in a 1000 A thick film with a 4 μsec pulse from a 13 mW Gaussian laser beam have been achieved. For a 106 bits/cm2 packing density, heating at adjacent spots is negligible. Calculations show that the writing magnetic field can be reduced to less than 10 Oe by using a memory plane consisting of discrete squares of MnBi. Analytical and experimental results as well as memory design considerations are presented.
144 citations
TL;DR: In this article, the concentration of conduction electrons is changed by a heat treatment between ne = 1017 and 1020 cm−3 (T = 300°K), indicating an intense scattering at charged imperfection centres which are due to a considerable intrinsic lattice disorder.
Abstract: Thin films of n-conducting In2O3 are prepared by reactive sputtering. The concentration of conduction electrons is changed by a heat treatment between ne = 1017 and 1020 cm−3 (T = 300°K). Concentration and temperature dependence of the electron mobility indicate an intense scattering at charged imperfection centres which are due to a considerable intrinsic lattice disorder. The intrinsic absorption is also influenced by this disorder.
Dunne, n-leitende In2O3-Schichten wurden durch reaktive Kathodenzerstaubung hergestellt. Durch Tempern konnte die Konzentration der Leitungs-Elektronen in weiten Grenzen (ne = 1017 bis 1020 cm−3 bei T = 300°K) variiert werden. Betrag und Temperaturabhangigkeit ihrer elektrischen Beweglichkeit lassen auf eine starke Streuung an ionisierten Storstellen-hervorgerufen durch eine erhebliche Eigen-Fehlordnung-schliesen. Durch diese Fehlordnung wird auch die Eigenabsorption beeinflust.
133 citations
Patent•
24 Oct 1968TL;DR: In this paper, a thin film inductor for use with miniaturized integrated circuits is fabricated by forming a first level of parallel metal strips on a substrate and then forming an insulating layer over the strips.
Abstract: Thin film inductors for use with miniaturized integrated circuits are fabricated by forming a first level of parallel metal strips on a substrate and then forming an insulating layer over the strips. A bar of magnetic material is disposed along the center portions of the metal strips and a layer of insulation is deposited over the bar of magnetic material. A second level of parallel metal strips is then formed over the layer of insulation and is connected between opposed ends of adjacent ones of metal strips at the first level to form a continuous flattened coil around the bar of magnetic material. In other embodiments of the invention, the bar of magnetic material may be omitted, or may be disposed outside the continuous flattened coil formed by the metal strips.
124 citations
TL;DR: It has been shown experimentally that it is possible to excite rare earth and transition metal ions included in a II-VI compound matrix as fluoride molecules by direct, hot-electron impact as mentioned in this paper.
Abstract: It is shown experimentally that it is possible to excite rare‐earth and transition metal ions included in a II‐VI compound matrix as fluoride molecules by direct, hot‐electron impact. Electron‐hole pairs in the matrix are unnecessary and even undesirable. AC excitation of a thin film structure has given external power conversion efficiency of about 10−4 at several optical frequencies including the 5480‐A line of Tb3+.
Patent•
26 Dec 1968
TL;DR: In this article, a beam gun is provided having an anode and a cathode and is supplied with current of such magnitude as to cause an arc discharge to occur between the anodes and cathode to emit the beam.
Abstract: According to the present disclosure, a deposition process comprises emitting a beam of particles consisting of atoms and ions of source material, each particle having a kinetic energy between about 10 and 100 electron volts. The particles are deposited onto an object to coat the object with a thin film of source material. A beam gun is provided having an anode and a cathode and is supplied with current of such magnitude as to cause an arc discharge to occur between the anode and cathode to emit the beam.
TL;DR: In this article, the thermal strain energies of thin films bonded to substrates of different thermal expansion coefficients will experience ''thermal strains'' when their temperature is changed, and the corresponding strain energies for crystals having various crystallographic orientations relative to the surface of the film were made for a number of fcc and bcc metals.
Abstract: Thin films bonded to substrates of different thermal expansion coefficients will experience ``thermal strains'' when their temperature is changed. Calculations of these thermal strains and the corresponding strain energies for crystals having various crystallographic orientations relative to the surface of the film were made for a number of fcc and bcc metals. Results are given for the (111), (200), (220), (311), (331), (420), (422), (511), (531), (442), (620), and (533) orientations of the fcc metals Cu, Au, Ag, Al, Ni, Pb, and Pd. They are basically similar for all fcc metals studied with the (100) orientation having the lowest strain energy and the (111) orientation the highest. For the bcc metals Cr, Fe, Nb, Mo, Ta, V, and W, calculations were made for the (110), (200), (211), (310), (222), (321), (411), (420), (332), (510), (431), (521), (530), (433), and (442) orientations. Neglecting W, which is isotropic, it was possible to classify the bcc metals into two groups depending upon whether the (100) o...
TL;DR: In this article, a short list of the best materials for low loss and high capacitance capacitors is drawn up for thin-film dielectrics in thin-filtered capacitors.
TL;DR: The optical absorption spectra of single crystals and thin films of MoO 3 have been measured in the temperature range 150 to 340 °K with polarized light and the temperature dependence of the absorption edge was found to be linear from 340 to 150 °K, with a temperature coefficient of 6.2 x 10 -4 and 9.3 x 10 −4 eV/°K for E || C and E ⊥ C, respectively as mentioned in this paper.
Abstract: The optical absorption spectra of single crystals and thin films of MoO 3 have been measured in the temperature range 150 to 340 °K with polarized light. At room temperature, the absorption spectrum of a single crystal consists of two peaks at λ 4130 and λ 3930 A with E || C and only one absorption peak at 4250 A with E ⊥ C followed by a rapid rise in absorption. The temperature and frequency dependence of the absorption coefficient in the edge over a range of absorption magnitudes 10 2 -10 5 cm -1 are described by expressions of the form K(v, T) = K 0 exp[— (β/kT) (E 0 — hv )]. The temperature dependence of the absorption edge was found to be linear from 340 to 150 °K with a temperature coefficient of — 6.2 x 10 -4 and — 9.3 x 10 -4 eV/°K for E || C and E ⊥ C , respectively. The corresponding temperature coefficients in thin films are — 2.7 x 10 -4 and —4.0 x 10 -4 eV/°K for E|| and ⊥ to the film surface, respectively. Measurements have been made of the refractive indices of a single crystal and thin films. Ultraviolet irradiation of a thin film of MoO 3 produces a broad colour centre band having a maximum at 8700 A. Several absorption peaks are resolvable in polarized light. On cooling down to 150 °K, the peak position shifts to shorter wavelength by 400 A (4.67 x 10 -4 eV/°K). An e. s. r. signal with g = 2.001 ± 0.005 has been observed in the colour film. The electrical conductivity has been measured on single crystals and polycrystalline samples in the temperature range 25 to 500 °C, and the activation energies are found to be 1.83 ± 0.01 eV (intrinsic) and 0.29 to 0.70 eV (extrinsic). Photoconductivity has been measured in single crystals and thin films as a function of photon energy, temperature, and irradiation intensity. Trapping plays a significant role in the conduction phenomena. The thermal activation energies associated with different trapping levels were determined from the photoconductive decay curves and the electrical glow peaks measurements and were found to be in the range 0.16 to 0.64 eV.
Patent•
31 May 1968
TL;DR: A thin film piezoelectric filter comprises a plurality of coaxially disposed resonators, each having a different but overlapping frequency-amplitude characteristic as discussed by the authors, separated from one another by a selectively transmissive structure such that high-frequency acoustic waves produced in a first resonator are coupled in part to an adjacent resonator.
Abstract: A thin film piezoelectric filter comprises a plurality of coaxially disposed resonators; each having a different but overlapping frequency-amplitude characteristic The individual resonators are separated from one another by a selectively transmissive structure such that high-frequency acoustic waves produced in a first resonator are coupled in part to an adjacent resonator
TL;DR: In this paper, plane waveguide modes excited on thin dielectric films in the visible spectrum are described and photographs of the modes of the first six orders, taken at the exit edge of the film, are shown.
Abstract: -Plane waveguide modes excited on thin dielectric films in the visible spectrum are described and photographs of the modes of the first six orders, taken at the exit edge of the film, are shown. Photographs are also presented of interference patterns between separately excited modes, Measurement techniques based on the mode properties are discussed and the application of thin film techniques to integrated optical data processors is proposed.
Patent•
20 Jun 1968TL;DR: In this article, high resistivity, low temperature coefficient of resistance films are formed by evaporating a molybdenum or tungsten source in a low-pressure atmosphere, e.g. 5 X 10 4 4 torr, of a nitrogen bearing gas, a carbon bearing gas or an inert gas and depositing a resistor film atop a preferably unheated dielectric substrate.
Abstract: High resistivity, low temperature coefficient of resistance films are formed by evaporating a molybdenum or tungsten source in a low-pressure atmosphere, e.g. 5 X 10 4 torr, of a nitrogen bearing gas, a carbon bearing gas or an inert gas and depositing a resistor film atop a preferably unheated dielectric substrate.
TL;DR: In this paper, the authors used dynamical diffraction to measure the sign of the stress in a thin film and/or a substrate, which is used to detect stress buildups and stress reversals connected with processing procedures, in particular with planar semiconductor devices.
Abstract: X‐ray stress topography of thin films deposited on single‐crystal substrates is established. This method permits a nondestructive rapid analysis of the stress environment of film‐crystal interfaces. It is based on dynamical diffraction phenomena that occur at such interfaces. This technique is principally useful for the measurement of the sign of the stress in film and/or substrate. It is used to detect stress buildups and stress reversals connected with processing procedures, in particular, with those of the planar semiconductor device technology. It is also an elegant way to measure the adhesion properties of thin films deposited on single‐crystal slices as large as 2 in. in diameter. Dynamical diffraction phenomena of film‐crystal interfaces are discussed in terms of the Penning and Polder theory and shown to be caused through tie‐point migration. Topographical x‐ray contrast of film‐crystal interfaces is interpreted in terms of Bragg plane curvature. Relations between lattice curvature and film stress are given.
TL;DR: In this article, the thickness dependence of the thermal emf of thin-film copper thermocouples at room temperature and above was investigated and it was shown that when the thickness of both elements comprising the thermocouple is greater than ∼1200 A, the thermal response time of the thermouples as measured with a pulsed laser beam heating source is less than 10−6 sec.
Abstract: The thickness dependence of the thermal emf of thin‐film copper—constantan thermocouples at room temperature and above shows nearly bulklike behavior when the thickness of both elements comprising the thermocouple is greater than ∼1200 A. The thermal response time of the thermocouples as measured with a pulsed laser beam heating source is less than 10‐6 sec. The thickness‐dependent contribution to the thermopower of copper films is deduced from the thermal emf data on thermocouples formed with a thick constantan film and compared with the size‐effect theory based on the free‐electron model. The marked thickness dependence observed yields anomalously high dependence (an order‐of‐magnitude higher) of the mean free path on the energy of electrons. This result is tentatively ascribed to the thermopower behavior of a transition layer formed by diffusion of the two components of the thermocouples.
TL;DR: In this article, a simple sliding experiment with hardened steel sliders on flat polytetrafluoroethylene was carried out and the sliding tracks were examined with the electron microscope by means of surface replicas and thin film extractions.
TL;DR: In this article, the structure of vanadium dioxide films was determined by x-ray diffraction, reflection electron diffraction and electron microscopy of carbon replicas of the film surfaces.
Abstract: Reactively sputtered vanadium dioxide films have been analyzed to determine the relation between their electrical and structural properties. The structure of the thin films was determined by x-ray diffraction, reflection electron diffraction, and electron microscopy of carbon replicas of the film surfaces. The various substrates which were evaluated for thin film VO2 deposition were amorphous glass, glazed ceramic, and single-crystal sapphire and rutile. Electrical conductivity measurements were made to correlate film perfection with the conductivity ratio between the semiconducting and metallic states. Films deposited on amorphous substrates such as glass and glazed ceramic are polycrystalline in structure with small grain size. Conductivity ratios of approximately 102 were observed with a very broad transition region centered at 68 °C. These films, in addition to VO2, exhibit an extra x-ray line at d = 2.25, tentatively identified as VO1.87. On sapphire substrates, highly textured films were obtained wh...
TL;DR: The preparation and characterizing properties of thin polymer films are discussed with particular emphasis on recent developments in such areas as ultraviolet surface photolysis, electron bombardment, gaseous electrical discharge, and special chemical processes.
Abstract: Polymer dielectric films, ranging in thickness from less than 100 A to several microns, have become increasingly useful for basic investigations of surface phenomena and thin film electrical conductivity and for thin film electronic device and circuit development. The preparation and characterizing properties of thin polymer films are discussed with particular emphasis on recent developments in such areasa s ultraviolet surface photolysis, electron bombardment, gaseous electrical discharge, and special chemical processes. Previously unpublished data on certain aspects of polymer dielectric films are presented, and present and potential applications are briefly reviewed.
TL;DR: In this article, a thin-film, heated-element probe is calibrated to measure fluctuating skin friction, mounted flush with the surface of a flat plate which is oscillated in its own plane, in the direction of the air stream.
Abstract: A thin-film, heated-element probe is calibrated to measure fluctuating skin friction. The probe is mounted flush with the surface of a flat plate which is oscillated in its own plane, in the direction of the air stream. The relationship between fluctuating heat transfer from the film and fluctuating skin friction is discussed theoretically using Lighthill's (1954) technique.
IBM1
TL;DR: In this article, a combination of optical and spectroscopic techniques have been used to evaluate and compare various glass films with regard to composition, structure, and water and chemical stability.
TL;DR: In this article, the authors have made measurements in uniformly superheated water at pressures from 0·5 to 1·2 atm which supplement the data of Dergarabedian and of Hooper and Abdelmessih, both of whom worked at 1 atm.
TL;DR: In this paper, the temperature coefficient of resistance of a thin-film resistor depends on the mismatch in the thermal expansion coefficient between the film and its substrate, and the effect can be quite significant for typical thin films.
Abstract: The temperature coefficient of resistance of a thin‐film resistor depends on the mismatch in the thermal expansion coefficient between the film and its substrate This Letter presents a calculation of this effect and shows that the effect can be quite significant for typical thin films
TL;DR: In this paper, the effects of humidity, heating rate, and particle size on oxidation of the dichalcogenides are presented, and a table summarizing these oxidation characteristics together with information from the literature on crystal structures, electrical resistivities, and densities.
Abstract: Thermogravimetric oxidation data are presented for fifteen refractory metal dichalcogenides. Interpretation of these data is supported by oxidation thermograms of the chalcogens and the refractory metals and by X-ray diffraction analysis of the oxidized products. The effects of humidity, heating rate, and particle size on oxidation of the dichalcogenides are presented. Thermogravimetric analysis is shown to be helpful in detecting impurities, such as unreacted elements, in commercial samples. Some dichalcogenides are shown to retain the same relative oxidation stability, when bonded in thin films with a ceramic, as for pure powder samples. A table is presented summarizing these oxidation characteristics together with information from the literature on crystal structures, electrical resistivities, and densities. Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Chicago, Illinois, October 17–19, 1967.
TL;DR: In this paper, the growth rate of polyacrylonitrile thin films is proportional to the monomer vapor pressure and discharge voltage, and non-ohmic characteristics of the electrical conduction are observed in the filed higher than 3×104 V/cm, and agree with the theoretical expression of the modified Pool-Frenkel effect.
Abstract: Semi- and photo-conductive thin films of polyacrylonitrile with the thickness of a few microns of less are prepared by the silent electric discharge in acrylonitrile monomer vapor followed by the heat-treatment at temperatures of 150°C to 500°C. The growth rate of the films deposited under the discharge is proportional to the monomer vapor pressure and the discharge voltage. The electrical resistivity and its activation energy decrease and the spectral responses of both the photocurrent and the optical absorption shift toward longer wavelength as the heat-treatment temperature rises. Non-ohmic characteristics of the electrical conduction are observed in the filed higher than ~3×104 V/cm, and agree with the theoretical expression of the modified Pool-Frenkel effect. The energy depth of the trap estimated from the thermally stimulated current measurement is ~0.5 eV.