Showing papers on "Barrier layer published in 1979"

Solid state electrically conductive laminate

Abstract: A unitary, composite laminated article comprises an electrically insulating top layer and an electrically insulating bottom layer. Applied to the inner surfaces of each of these layers is a barrier layer substantially impermeable to moisture and water vapor. A substantially continuous electrically conductive layer of substantially uniform thickness is interposed between the barrier layers. The electrically conductive layer is comprised mainly of carbon and is capable of emitting electromagnetic radiation when an electric current is passed therethrough. In contact with the electrically conductive layer is electrical conductor means. The top layer and bottom layer are sealed together to thereby form an enclosed laminate. The electrically conductive layer exhibits very stable resistivity. The use of the article as a radiant heating device and a method for its manufacture are provided. The device is especially useful for personal comfort heating and as a heat source in commercial, residential and industrial establishments.

Barrier Layers Against Diffusion

Abstract: SummaryTests have been carried out on copper and brass substrates which have been electroplated with a number of different barrier layers and then with an excess of matt tin. These samples have been heat treated to simulate accelerated storage and operation periods and observations made on the resulting intermetallic compound layers between the substrate and the tin coating. The results indicate the suitability of each barrier layer for altering the rate of growth of substrate-tin intermetallics and also the ability of the barrier to inhibit the diffusion of, specifically, zinc to the surface of the coating. On the basis of lowest barrier/coating reaction rates, iron appears by far the best choice for a barrier layer.

Surface Barrier Effects in Wool Dyeing Part I ‐ The Location of the Surface Barrier

Abstract: The properties of the surface layer on wool fibres which limits the rate of dye uptake have been examined. The removal of the barrier layer by mechanical means and its degradation by surface reduction using tri–butyl phosphine have been studied using the rate of dyeing as a parameter. The chemical properties of the barrier layer suggest that it is a cystine–rich component of the cuticle layer system, either the exocuticle or its ‘a’ layer sub-system.

Laminate structure for collapsible dispensing container

Abstract: A collapsible dispensing container for packaging preparations containing hard-to-hold ingredients such as acetic acid. The container comprises a deformable tubular body and a thermoplastic head fused thereto. The wall of the tubular body is made of a plurality of laminations, including a sealant core film which prevents product migration and delamination. The wall of the tubular body comprises, from the inside of the tubular body toward the outside thereof, overlying layers of ethylene-acrylic acid copolymer, the sealant core film and an outer thermoplastic (e.g., polyethylene) layer bonded to the outer layer of the sealant core film by another layer of ethylene-acrylic acid copolymer. The sealant core film comprises a metallic foil (e.g., aluminum) layer bonded to said inner ethylene-acrylic acid layer, an intermediate biaxially oriented corona treated polyester barrier layer bonded to said metal foil layer by a polyester adhesive layer or other suitable adhesive and an outer layer of ethylene-vinyl acetate or narrow molecular weight distribution (MWD) polyethylene bonded to the outer surface of said barrier layer by another polyester adhesive layer or other suitable adhesive. All layers are coextensively bonded to each other along their entire respective surfaces to insure against product migration and delamination at the metal foil interface.

Improved solder interconnection between a semiconductor device and a supporting substrate

Abstract: A ball limiting metallurgy pad structure for a semiconductor device solder bond interconnection comprising: a conductive layer that is adherent to the semiconductor device passivating layer, a relatively thick layer of a material having a high thermal conductivity, a barrier layer that protects the high conductivity layer by physically preventing any interaction or alloying with the subsequent layers, and a layer of a material that is solder wettable.

CdTe Schottky barrier photovoltaic cell

Abstract: Photovoltaic cell comprises thin film cadmium telluride in ohmic contact with a smooth conductive substrate, preferably comprising a cadmium surface, through a cadmium-rich layer at the interface with the substrate, the cell further including a rectifying barrier layer. Preferably, the film is electrodeposited on the substrate surface with specific materials and process conditions. Preferably also, the film or cell is subsequently treated to enhance its barrier layer interface function.

Mass-transport separator for alkaline nickel-zinc cells and cell

Abstract: A mass-transport separator for use in alkaline nickel-zinc cells which coises a barrier layer of a microporous membrane which contains a laminate of a material having a hydrogen overpotential in alkaline solution which is lower than that of zinc, the barrier layer being sandwiched between two protective layers of microporous polyolifin material.

Method of forming a printed circuit

Abstract: A readily etchable printed circuit board is provided which comprises a resinous substrate having bonded to at least one surface thereof a composite metal structure. This metal structure includes a layer of copper foil having opposed first and second surfaces and a thin layer of nickel having opposed first and second surfaces with one of the surfaces of the copper foil being bonded to one of the surfaces of the nickel layer and the opposite opposed surface of the nickel layer being bonded to the resinous substrate with the nickel layer containing an effective amount of sulfur to render the copper foil and the nickel barrier layer mutually etchable, i.e., etchable by the same etchant. The preferred amount of sulfur ranges from about 0.05 to about 10.0 weight percent.

Improvements in or relating to methods of forming coatings, coatings so formed and articles coated thereby

Abstract: A bitumen primer layer (5) is applied to a base sheet material (1) and while the bitumen primer layer (5) is still wet a layer of a barrier material (6) of a consistency composition and thickness is applied to the primer layer (5) such that the bitumen primer layer (5) does not bleed through the barrier layer (6) and the barrier layer (6) adheres to the bitumen primer layer (5). A coating of stone chips (8) is then applied to the barrier layer (6) in a manner such that the stone chips (8) are partially embedded at least in the barrier layer (6) so that the stone chips (8) are held in position on curing of the bitumen primer layer (5) and barrier layer (6) but the stone chips (8) are not completely covered by the barrier layer (6).

GaInAsP/InP Double-heterostructure lasers

Abstract: Double-heterostructure (DH) diode lasers based upon very thin epitaxial layers of Ga x In 1-x As y P 1-y grown on and lattice-matched to oriented InP substrates are disclosed. A preferred method for fabricating such lasers involves the successive growth, on an InP substrate, of an InP buffer layer, the GaInAsP active layer and an InP top barrier layer using liquid phase epitaxy techniques to grow these layers from supercooled solutions. Stripe geometry lasers can be fabricated from these materials which emit in the 1.1-1.3 μm range and are capable of cw operation for extended periods at room temperature.

TP-A2 barrier height enhancement in heterojunction Schottky-barrier solar cells

Abstract: Significant enhancement of the open-circuit voltage (V oc ) for GaAs Schottky-barrier solar cells has been achieved by inserting a thin AlGaAs barrier layer between the GaAs and metal surface layer. The maximum V oc measured at 1 SUN AM1 for one of these structures is 0.88 V (compared to ≤ 0.5 V for conventional GaAs Schottky-barrier cells). At this illumination, a peak conversion efficiency of 10.5 percent was measured without antireflective (AR) coating from a structure of Au/Al 0.5 Ga 0.5 As/GaAs. High efficiency for this structure is achieved by minimizing the hole barrier to photogenerated carriers at the AlGaAs/GaAs interface. The model proposed for this type of structure indicates that AlGaAs composition, layer thickness, and GaAs doping density are the device parameters most strongly controlling cell performance.

Barrier layer FET - mfd. by under etching bottom mask layer to cover barrier layer surface

Abstract: A barrier layer FFT is produced by using a mask over the channel to impart a high impurity concentration to the source and drain regions. The bottom mask layer is underetched until it covers only the surface of the intended barrier layer and the source and drain contacts are applied. The top mask layer is removed and the bottom layer replaced by a mask representing a negative image (window) of the latter in which the barrier layer is deposited. The distance between source/drain and gate contacts can thereby be minimised and extremely low contact resistance between channel area and source/drain contacts can be achieved.

Josephson junction devices

Abstract: A Josephson junction device consists of a barrier layer (12) between layers (10. 11) of superconductive material. The minimum size of the device is determined by its inductance which is inversely related to the circulating supercurrent density. so that for compactness this current density requires to be high. Reliability in manufacture requires that the barrier layer should not be excessively thin, and in order to obtain critical damping, the barrier capacitance must be kept low. so that the barrier material should not have a high dielectric constant. The present invention provides a Josephson junction device with a barrier which can support large circulating supercurrent densities without being excessively thin. which can readily be manufactured, and, if required, readily doped, and which has a relatively low dielectric constant. The barrier of a device according to the invention is of hydrated amorphous semiconductor material, the semi- conductor being silicon, germanium or a silicon germanium alloy. The barrier layer may be deposited by sputtering in a atmosphere containing hydrogen, and it may be doped with phosphorus, arsenic or antimony in manufacture. The device may include a control line (18).

Interdiffusion and Degradation of Si/Cr/Pt/Ag IMPATT Diode Metallization

Abstract: Interdiffusion and degradation of Cr/Pt/Ag multiple metallization layers for silicon IMPATT diode applications have been studied experimentally using Rutherford backscattering analysis, secondary ion mass spectrometry, and scanning electron microscopy. Diffusion coefficients for grain boundary diffusion and grain boundary‐assisted bulk diffusion of Pt in Ag and the corresponding activation energies have been determined. The effect of time on grain boundary diffusion showing rapid initial growth and eventual saturation of solute (Pt) in Ag grains has been studied in detail and its effect on device failure caused by the possible depletion of the Pt barrier layer is discussed. Samples annealed in air showed substantial degradation of the Ag layer due to chlorine contamination. The Cr/Pt interface has been found to be stable up to 400°C but annealing at or above 500°C caused considerable mixing between Si, Cr, and Pt.

Tunnel-junction type josephson element and manufacture thereof

Abstract: PURPOSE:To obtain the titled element withstanding the repeated cycles covering normal temperature and a super-low temperature by a method wherein the first and the second super-conducting material layers are composed of the probeskite type oxide shown by BaPb1-XBiXO3 and a barrier layer is composed of a probeskite type oxide containing Ba or Sr. CONSTITUTION:The first belt-shaped super-conducting material layer 2 is formed on a substrate 1 and a tunnel-junction type Josephson element is obtained by bonding the second super-conducting material layer 4 on the end section of said layer 2. To be more precise, the substrate 1 is covered by the first super-conducting material layer 1 consisted of a probeskite type oxide shown by BaPb1-XBiXO3 (0.05<=X<= 0.3) by performing a sputtering and a subsequent heat treatment while the substrate 1 is being cooled, and a barrier layer 3 consisted of a probeskite type oxide of SrPb1-XBiXO3 (0<=X<=0.3) is formed on the end section of the layer 1, while it is being cooled. The second super-conducting material layer 4 is similarly provided on said layer 3.

Barrier layer FET on insulating substrate - has series of insular gate zones connected to common gate terminal and extending through whole layer thickness

Abstract: The FET has an SC layer of a first conduction type and a gate zone of the opposite conduction type embedded in it. This gate zone consists of several separate regions connected to the same gate terminal. The regions lie in one plane and divide the SC layer into a source and a drain zone. The SC layer is a thin layer (2) grown on an insulating substrate, and the separate gate regions consist of a series of insular zones (3-5), extending from the surface of the layer (2) through its whole thickness. They have on their surfaces a contacting layer (10) is formed on the surface of the region to provide connection to the common gate terminal.

Infrared detector cell - pref. based on cadmium mercury telluride or lead tin telluride semiconductors with getter layers

Abstract: The surface (al) of the semiconductor (a), and/or the metal contacts (b) covering surface (al) are at least partly covered with a getter layer (c) Layer (c) is pref a silicon oxide, a silicon nitride, polycrystalline Si, or a mixt of these substances, and layer (c) pref includes getter doping elements from gps III or V of the periodice system, esp P, As or B Layer (c) pref covers the side of semiconductor (a) opposite the light entry window, or both side and in the window, where layer (c) has an appropriate refractive index Layer (c) is pref formed in an evacuated plasma reactor fed with a mixt of SiH4, N2, residual O2, and a gas contg the dopant, layer (c) being formed at 20-300 degrees C A passivating layer (d) of ZnS may be used on the cell Used esp for photoconductors with no barrier layer junciton; or photodiodes with a barrier layer The semiconductors (a) must be driven at very low temp (77 degrees K), and the invention provides a getter layer (c) increasing the sensitivity and working life of the cell

TEM Investigation of Effects of a Barrier Layer on Damage to 1.064µ AR Coatings

Abstract: Silica/titania 4 layer AR coatings on BK-7 glass, with and without a half-wave silica barrier layer, have been damaged at 1064μ by 150 ps laser pulses The damage sites have been examined by TEM replica techniques at a magnification of 70,000 The size of the damage sites appears to be "quantized" Most sites consist of a 1μ nucleus which leads to a 3μ crater in a fully developed site The mechanical properties of the films appear to play a role in the morphology of the damage sites The titania layers seem to fracture while the silica layers seem to melt or tear A series of micrographs of near threshold damage sites shows the development of the sites from a rupture which appears to occur at or near the substrate surface Evidence of heating in the substrate is also present, although it is difficult to pinpoint the exact starting point of the damage mechanism

Capacitance diode with particular doping profile

Abstract: A capacitance diode includes an epitaxial layer of a first conductivity type provided on a substrate in which a doping profile is formed in the epitaxial layer by controlled doping during the epitaxial layer growth, and a surface zone of the second conductivity type which forms a p-n junction with the epitaxial layer. According to the invention, the doping profile in the epitaxial layer varies according to the equation ##EQU1## wherein x is the distance from the p-n junction in μm, x o is the width of the barrier layer in μm at a voltage -U D across the p-n junction, U D is the diffusion voltage of the p-n junction, and k, n and β are constants. As a result of this doping profile, a very low frequency deviation is obtained which does not change sign.

Road construction for high flood risk arid zones - has air-proof sealed barrier layer above base and below covering layer

Abstract: The road structure is for deserts or other dry areas subject to flooding It has a covering layer above a support layer on a water-protected base layer A barrier layer (4) is provided above the base layer (1) and below the covering layer (6) This is sealed off so as to be impermeable to air It is drawn down at the sides to below the depth of the base layer being protected Its middle part may lie between support layer (3) and covering layer

Surface facing esp. ornamental wallpaper - has barrier layer of fleece between adhesive and decorative front layers

Abstract: A surface facing or cladding material is intended as decorative wallpaper and is composed of an outer, visible layer of textile, synthetic leather, leather, non-woven or the like and a backing or invisible layer to be glued to the wall. The structure is composed of a relatively thin, flexible non-woven or fleece (as backing layer) which prevents the passage of suspended or dispersed or dissolved adhesives from the adhesive layer into the front or facing layers. The layer next in front of this barrier layer is of plastics foam and this is followed by a dimensionally stable outer layer. More specifically, the elastics plastics foam has a thermoplastics character and bonds to the outr visible layer and to the fleece without damage to them when heat is applied. When the wallpaper is hung, not only does the backing layer bond firmly to the wall but the ornamental facing layers remain securely bonded to it. The formation of bubbles and gaps within the layers of the ornamental paper, such as occur with previous arrangements, is eliminated.

Gold-plated article

Abstract: For electrolytic gold-plating of a metal article, a barrier layer made of tungsten/cobalt or tungsten/nickel alloy is first deposited by electrolysis of a neutral bath containing sodium tungstate, cobalt or nickel sulphate, ammonium citrate and aminotrimethylphosphonic acid as chelating agent. This barrier layer effectively counteracts the diffusion of the base metal into the gold coating, the thickness of which is less than 1.25 mu , when the gold-plated article is heated.

Photosensitive, self-developing reprographic material - contg. metal salt layer and spiro-pyran layer, forming image by merocyanine dye formation

Abstract: A reprographic material comprises a support coated with a photosensitive compsn. comprising a first layer contg. a metal salt MX2, (where M is Fe, Zn, Co, MN or Cu and X is Cl, Br, I, stearate or thiocyanate) and a second layer contg. spiropyrans, benzothiazolinic, benzoxazolinic, thiazolidinic, oxazolidinic, thiazinic or oxazinic cpds. Pref. an intermediate heat sensitive barrier layer is placed between the two layers.

Cadmium sulphide photovoltaic cell - has a cadmium sulphide bi:layer, the second layer deposited at a lower temp. than the first

Abstract: Cell comprises a substrate; a first Cd sulphide layer; a second Cd sulphide layer deposited at a temp. at least 20 degrees C , pref. 30-60 degrees C , and esp. about 50 degrees C the deposition temp. for the first Cd sulphide layer; and a barrier layer, pref. of Cd sulphide. Esp. in solar cells; use of a Cd sulphide layer improves cell efficiency.

Semiconducting properties of anodically formed layer on antimony

Abstract: Results of photopolarization, photoconductivity and double layer capacity measurements for the sytem Sb/oxide layer/electrolyte have been given. On the basis of the above measurements it has been concluded that anolic layers on antimony as examined are semiconductors of n -type, band gap E g =3 eV and donor density N D ≈10 17 cm −3 . The dependence of photovoltage on barrier layer thickness of the Schottky type calculated on the basis of experimental results, also supports the above conclusion, that is, the minimum thickness in which significant photo-effect still appears is of the order of magnitude 10 −5 cm, which seems plausible with respect to the expected of light absorption coefficient.

Centrifugal casting of bimetallic tubes - using nickel barrier layer to prevent carbon diffusion between metal layers

Abstract: In the centrifugal casting of bimetallic tube blanks by successive casting of a base layer with flux and a cladding layer, a layer of Ni, in amt. 2-3% (by wt. of the base layer), is cast on the surface of the base layer when it has cooled to about 100-200 degrees C below its solidus temp. and then the cladding layer is cast onto the Ni layer, the Ni content of the cladding metal being 11-18% of that in the cladding layer after casting. From the start of casting the Ni, the rotational speed of the mould is controlled to be 30-40% of its starting speed. The method allows tubes of length to-dia. ratio >8-10 to be cast in different steel types, and gives a base layer/cladding weld joint of improved notch ductility without post-treatment. This improvement is due to the presence of Ni which acts as a diffusion barrier for C.

Barrier-layer capacitor and process for the production thereof

Abstract: A barrier layer capacitor and a process for producing that capacitor: A central reduction layer formed of ceramic material is produced with a rectangular cross-section. A reoxidation layer is formed on all of the surfaces and is removed from one of the surfaces. Grooves are formed in opposite surfaces, including the one from which the reoxidation layer has been removed. A metal layer is applied around the entire capacitor body, except on the surface from which the reoxidation layer has been removed. Narrow strips are removed from the metal layer on the sides adjacent the surface without the reoxidation layer and at a location slightly away from that reoxidation layer free surface. On the reoxidation layer free surface, a connection coating is applied which extends up to the unremoved portion of the solderable metal coating. The capacitor may be cut from an elongated bar. The bar from which the capacitor may be cut may be the width of two capacitors and it may be separated along the line running through the center into two individual capacitors. In that event, the ceramic bar has a longitudinally extending borehole therethrough which becomes the conductor receiving grooves upon separation of the bar into two pieces.