Abstract: In the practice of this disclosure, rare earth disilicide low Schottky barriers (≲0.4 eV) are used as low resistance contacts to n-Si. Further, high resistance contacts to p-Si (Schottky barrier of ≳0.7 eV) are also available by practice of this disclosure. A method is disclosed for forming contemporaneously high (≳0.8 eV) and low (≲0.4 eV) energy Schottky barriers on an n-doped silicon substrate. Illustratively, the high energy Schottky barrier is formed by reacting platinum or iridium with silicon; the low energy Schottky barrier is formed by reacting a rare earth with silicon to form a disilicide. Illustratively, a double layer of Pt/on W is an effective diffusion barrier on Gd and prevents the Gd from oxidation.

Abstract: A method and an apparatus are provided for performing growth of compound thin films by alternately repeating separate surface reactions of the substances comprising the compound. A carrier gas affects a diffusion barrier between the surface reaction steps to be separated from each other. The gas phase diffusion barrier is also applied to separate the source regions (12) of different reacting vapors both from each other and from the surface reaction zone.

Abstract: The use of a molybdenum diffusion barrier between a copper layer and a magnesium oxide dry etch mask to obtain and insure adhesion between the two.

Abstract: In electrical circuitry, and particularly superconducting circuitry including Josephson tunnelling devices, it is often necessary to provide solder contacts to electrical lines, where the electical lines would be destroyed if there were interdiffusion between the lines and the solder. To avoid this problem, a laterally extending metallic layer is used as a diffusion barrier between the solder land and the electrical line which can be a superconducting line. The diffusion barrier is comprised of a refractory metal which has a first portion electrically contacting the solder land and a second, laterally displaced portion, electrically contacting the electrical line. An insulating protective layer on the diffusion barrier layer separates the solder land and the electrical line. In a specific embodiment, the superconducting electrical line is comprised of an alloy of lead while the diffusion barrier is comprised of niobium, and the solder alloy is a low melting point alloy, typically comprised of indium, bismuth, and tin.

Abstract: Single mode optical fibre for operation in the wavelength range 1.5 to 1.7 microns is made by depositing a cladding glass layer and then a core glass layer upon the bore of a silica substrate tube. The bore of the coated tube is then collapsed to form a solid cross-section optical fibre preform. The cladding glass has an index matching that of silica and either contains no oxide of phosphorus or the minimal amount to provide a low enough deposition temperature and high enough deposition rate to provide an acceptably low diffusion of hydroxyl groups from the material of the substrate tube. Optionally the deposition of the cladding may be preceded by the deposition of a diffusion barrier layer which may contain a higher proportion of oxide of phosphorus.

Abstract: To improve the adhesion of a nickel layer to a valve metal layer in a thin film electronic circuit, a boundary layer is created between the valve metal and the nickel layer. The boundary layer is created by oxidizing the valve metal surface and applying the nickel layer by cathode sputtering with sufficiently high energy to cause nickel-ion migration into the valve metal oxide layer. The so-formed boundary layer improves the mechanical adhesion of the nickel layer to the valve metal layer and also prevents penetration of solder to the valve metal layer since the boundary layer acts as a diffusion barrier.

Abstract: PURPOSE:To improve the memory retaining property with a charge diffusion barrier film in the second gate insulating film for charge storage provided on a gate insulating film presenting a tunnel phenomenon of the charge. CONSTITUTION:An Si4N3 film 51 is piled on an extremely thin SiO2 film 4 and immersed in a specified mixed solution of H2SO4 and H2O2 to form an extremely thin SiO2 film 42. By the same procedure, an SiO2 film 42 serving as charge diffusion barrier in the second gate insulating film comprising Si3N4 films 51-53. With this structure, a relatively large positive voltage is given the gate electrode 6 to trap electrons in the Si3N4 film with implantation of ions from the substrate 1. As the electron diffusion in the Si3N4 film is made between the centers of trapping in the film, the film makes possible tunneling of the electrons trapped, but provides a barrier after the removal of voltage. Therefore, after the implantation of charge, there is little change in the threshold voltage thereby ensuring an excellent memory retaining property.

Abstract: A thermionic cathode (figure 1) comprises an emitter (3) comprising a matrix (4) of tungsten impregnated with an alkaline earth activator The matrix is coated with a coating (5) of about 20-30 % osmium fully alloyed with tungsten formed by cosputtering osmium and tungsten onto the matrix A diffusion barrier (6) of osmium may be interposed between the matrix 4 and coating (5) (figure 2) and, optionally, osmium may be diffused into the matrix (4) Alternatively the whole matrix may comprise a mixture of about 20-30 % osmium fully alloyed with tungsten (figure 3) Alternative to osmium and tungsten may be used, and various modifications may be made, and other methods of making the emitter may be used In particular the proportion of osmium may be about 40 %

Abstract: A method for providing a barrier against copper diffusion into a zirconium alloy tube which is lined with copper for the purpose of increasing the resistance of the tube to stress corrosion induced by fission products when the tube is used to fuel a nuclear reactor. The method involves the deposition of a copper lining on the zirconium alloy tube and the subsequent exposure of the lined tube to a substance such as steam, water, nickel oxide or carbon dioxide or another material which has the ability to oxidize the zirconium without oxidizing the copper. Thus, a zirconium oxide layer is developed between the zirconium alloy tube and the copper lining thereon.

Abstract: PURPOSE: To improve surface characteristics such as corrosion resistance, electrical connecting property, solderability or the like by interposing the intermediate plating layer of a specific metal or an alloy between a noble metal plating layer and stainless steel. CONSTITUTION: After the surface of stainless steel is activated, an intermediate layer comprising one or more of Zn, Cd, Sn, In or an alloy thereof is formed by plating. If necessary, on said plated layer, further, a secondary intermediate layer comprising one or more of Ni, Co or an alloy thereof is provided and noble metal plating such as Au, Ag, Pt or the like is applied thereon. Because said first intermediate layer is less noble than stainless steel in an electrolytic corrosion system, said stainless steel is subjected to cathode corrosion proofing. Further, the secondary intermediate layer prevents deterioration of the noble metal acting as a diffusion barrier. Therefore, the resultant noble metal plated stainless steel is suitable for a material for an electronic and an electric parts. COPYRIGHT: (C)1982,JPO&Japio

Abstract: Process and apparatus for recovery of hydrogen-reduced metals from aqueous salt solutions at a porous hydrophobic catalytic barrier (2). Previously, the prior art provided a diffusion barrier between a hydrogen anode and a cathode to prevent metal deposition on the hydrogen catalyst anode surface. This disclosure provides direct metal production at the catalytic barrier (2) by feeding hydrogen (5) at one surface of the barrier and recovering metal from a second solution contacting surface of the barrier (9). Metal reduction and deposition occur in the absence of an external electric circuit.

Abstract: Solder, copper, and silver are evaluated as conductor layer metals for silicon solar cell metallization on the basis of metal price stability and reliability under operating conditions. Due to its properties and cost, copper becomes an attractive candidate for the conductor layer. It is shown that nickel operates as an excellent diffusion barrier between copper and silicon while simultaneously serving as an electrical contact and mechanical contact to silicon. The nickel-copper system may be applied to the silicon by plating techniques utilizing a variety of plating bath compositions. Solar cells having excellent current-voltage characteristics are fabricated to demonstrate the nickel-copper metallization system.

Abstract: The formation of diffusion barrier materials on SiC filaments is discussed. The filaments possess a carbon-rich surface layer and, consequently, are difficult to wet by molten Al and tend to react with the molten metal, degrading filament strength. Characterization of the filament with various CVD barrier materials is reported.

Abstract: Circuit connection for electrical circuitry, and particularly superconducting circuits including Josephson tunnelling devices, wherein solder lands can be used to make electrical connection to electric lines without interdiffusion between the lines and the solder. To avoid the interdiffusion problem, a laterally extending metallic layer (18) is used as a diffusion barrier between the solder land (28) and the electrical line (M) which can be a superconducting line. The diffusion layer is comprised of refractory metal and has a first portion electrically contacting the solder land and a second, laterally displaced portion, electrically contacting the electrical line. An insulating layer (22) on the diffusion barrier layer separates the solder land and the electrical line. In a specific embodiment, the diffusion barrier is comprised of niobium, and the solder is a low melting point alloy, typically comprised of indium, bismuth, and tin.

Abstract: Single mode optical fibre for operation in the wavelength range 1.5 to 1.7 microns is made by depositing a cladding glass layer (51) and then a core glass layer (52) upon the bore of a silica substrate tube (50). The bore of the coated tube is then collapsed to form a solid cross-section optical fibre preform. The cladding glass has an index matching that of silica and either contains no oxide of phosphorus or the minimal amount to proved a low enough deposition temperature and high enough deposition rate to provide an acceptably low diffusion of hydroxyl groups from the material of the substrate tube. Optionally the deposition of the cladding may be preceded by the deposition of a diffusion barrier layer which may contain a higher proportion of oxide of phosphorus.

Abstract: Prodn. of solderable thin film conductor tracks on a substrate involves the deposition of a Cr base layer, followed by a Cu oxide barrier layer by reactive deposition in an O2 atmos. and finally a Cu conductor track layer. The process is used in the mfr. of an integrated laminated or hybrid circuit with elements, esp. thin film resistors, on an electrically insulating substrate. Costs are reduced, since the use of a noble metal as diffusion barrier film is avoided.

Abstract: A study of the localized pitting attack of 20% Cr/25%Ni stainless steel and a similar alloy containing a dispersion of titanium nitride particles has been made over the temperature range 1023 to 1173 K. Pitting is initiated when localized spoiling of the protective chromic oxide film occurs. Rapid oxidation of the chromium-depleted substrate then proceeds with the formation of an iron-rich oxide mound on the alloy surface and spinels containing nickel, chromium, and iron within the pit itself. A silica layer which, in general, remains on the alloy surface acts as a diffusion barrier during this stage of the reaction. With increasing depth of attack the local chromium concentration in the alloy at the base of the pit attains a critical value (∼16%) for a protective chromium oxide film to reform; the pitting attack then effectively ceases, although a a subsequent slow rate of growth continues through the protective film at the base. The observed maximum depth of pitting as a function of time is consistent with the parabolic variation predicted by the proposed mechanism. There is no significant difference in the kinetics of attack between the alloys examined.