Showing papers on "Barrier layer published in 1993"

High dielectric constant capacitor and method of manufacture

Abstract: A high storage capacity capacitor for a semiconductor structure includes a barrier layer formed on a polysilicon electrode, a lower electrode, a dielectric layer, and an upper electrode. The dielectric material is formed of a high dielectric constant material such as BaSrTiO 3 . In order to protect the barrier layer from oxidation during deposition of the dielectric layer and to provide a smooth surface geometry for depositing the dielectric layer, conducting or insulating spacers are formed on the sidewalls of the barrier layer and lower electrode. A smooth dielectric layer can thus be formed that is less susceptible to current leakage. In addition, the insulating spacers can be formed to completely fill a space between adjacent capacitors and to provide a completely planar surface.

Copper transport in thermal SiO2

Abstract: The transport of copper in silicon dioxide thermally grown on single crystalline silicon was studied by capacitance techniques, secondary ion mass spectroscopy (SIMS) analysis, and Rutherford backscattering spectrometry (RBS). Metal/oxide/silicon (MOS) capacitors were used to study the penetration of copper into the oxide as a function of temperature and applied electric field. The role of a titanium layer between the copper and the oxide was also studied. Bias‐thermal stress (BTS) studies of MOS structures were conducted at 150°C to 300°C with an electric field of 1 MV/cm for times ranging between 10 min and 168 h. It is shown that without bias a relatively small amount of copper reaches the silicon/silicon dioxide interface, with a maximum surface concentration of about 1017 cm−3 that drops exponentially with depth in the oxide. The high‐frequency (100 kHz) capacitance vs. voltage (CV) characteristics of the MOS devices changed drastically when a positive bias was applied to the gate and copper reached the silicon/silicon‐dioxide interface. The penetration time for copper through the oxide was characterized as a function of the temperature. The copper drift velocity, mobility and diffusivity in the oxide were determined and the copper profiles in the capacitors were characterized by SIMS. The activation energy for the diffusivity and mobility models was found to be . Devices without a barrier layer, which were stressed under a positive electric field, showed high copper concentration in the oxide, up to 1021 cm−3. At high temperatures and long stress times a significant amount of copper was also found in the silicon substrate. A titanium layer thicker than 5 nm acted as effective barrier even after 30 h of BTS at 300°C.

Study of interface resistances in epitaxial YBa2Cu3O7−x/barrier/YBa2Cu3O7−x junctions

Abstract: We have measured interface resistances in YBa2Cu3O7−x/barrier/YBa2Cu3O7−x junctions with different barrier materials in an edge junction geometry. CaRuO3, La0.5Sr0.5CoO3, Y0.7Ca0.3Ba2Cu3O7−x, YBa2Cu2.79Co0.21O7−x, and La1.4Sr0.6CuO4 have been employed as the epitaxial barrier materials. We observe interface resistances of the order of 1×10−8 Ω cm2 when we use CaRuO3 and La0.5Sr0.5CoO3 barriers. These two barrier materials are cubic perovskites. However, in the case of the layered barrier materials, the measured interface resistances are smaller than 1×10−10 Ω cm2. Our study suggests that the oxygen disorder at the YBa2Cu3O7−x surface, due to stress created by the thermal expansion mismatch between YBa2Cu3O7−x and the barrier, may be the origin of the interface resistances, and that the magnitude of this stress can change the resistance by orders of magnitude.

Effect of local flaws in polymeric permeation reducing barriers

Abstract: Thin polymeric coating layers are often used to improve the barrier properties of packaging structures and container walls. We study how local flaws in the coating layers affect the overall permeation properties of such systems. We find that many small ‘‘holes’’ in a barrier layer are much more effective in compromising the system barrier properties than a few large ‘‘holes’’ with the same total area.

Value document and embossing foil for the production thereof

Abstract: A value document and an embossing foil for the production thereof comprise a security feature in the form of a combination of a magnetic layer and a security layer which has an optical-diffraction effect. The security layer structure that has the optical-diffraction effect is provided with a reflective metal layer. To prevent damage to the reflective metal layer by particles of the magnetic layer, the metal layer is made of suitably resistant metal and/or a barrier layer is provided between the metal layer and the magnetic layer.

Barrier layers and aluminum contacts

Abstract: In the manufacture of high temperature deposited aluminum contacts onto silicon substrates wherein a barrier layer of titanium nitride is used, the improvement wherein the titanium nitride contains oxygen. The improved contacts are made by depositing a titanium-containing layer onto a silicon substrate, performing a first, high temperature nitrogen anneal in vacuum to form a low resistance TiSi x contact to the silicon, and performing a second, lower temperature anneal in vacuum using a mixture of nitrogen and oxygen to add oxygen to the titanium nitride layer. This oxygen-containing titanium nitride layer provides an improved barrier to a subsequently deposited high temperature deposited aluminum layer.

Thin film transistor having a lightly doped drain and an offset structure for suppressing the leakage current

Abstract: A thin film transistor wherein generation of a leakage current is prevented to improve the operation stability thereof and a method for manufacturing the same. A polysilicon layer is formed on an insulating layer. A gate insulating layer is formed on the polysilicon layer. A gate electrode having a barrier layer formed thereon is formed on the gate insulating layer. The sidewall surface portion of the gate electrode is anodic oxidized to form a metal oxide layer on the sidewall of the gate electrode. A lightly doped drain region having a lower impurity concentration than that of source and drain regions of the thin film transistor or an offset region wherein no impurity is doped is formed in a portion of the polysilicon layer under the metal oxide layer. The thin film transistor may be manufactured by a low temperature process, and leakage current is suppressed when a reverse bias voltage is applied. Therefore, the operation stability of the thin film transistor is improved.

Manufacture of electroluminescent devices

Abstract: In an electroluminescent device which comprises a layer of a semiconductive conjugated polymer between positive and negative charge carrier injecting electrodes, a barrier layer is arranged between the layer of semiconductive conjugated polymer and the charge carrier injecting layer for negative charge carriers. The barrier layer protects the layer of semiconductive conjugated polymer from for example mobile ions released by the reactive charge carrier injecting layer. The barrier layer can in some circumstances also itself be light-emissive.

On the Formation of Voids in Anodic Oxide Films on Aluminum

Abstract: A mechanism is proposed for the formation of voids at triple points between grains in the anodic oxide formed on aluminum and for the growth of porous films. The proposed mechanism involves the condensation of cation and/or metal vacancies below regions in the barrier film (triple points) that are characterized by high cation vacancy diffusivity, due to the high degree of lattice disorder. Vacancy condensation causes local decohesion of the barrier layer from the substrate, thereby inhibiting the growth of the layer into the metal in these regions. The lower film growth rate, relative to the surrounding areas, accounts for the observation that the voids subtend protrusions of the metal into the film

Double-heterojunction lattice-matched and pseudomorphic InGaAs HEMT with delta -doped InP supply layers and p-InP barrier enhancement layer grown by LP-MOVPE

Abstract: The design and fabrication using low-pressure metalorganic vapor phase epitaxy (LP-MOVPE) of a HEMT on InP substrate that only uses InP and In/sub x/Ga/sub 1-x/As as layer materials are reported. Lattice-matched (x=0.53) and strained (x=0.68) channels and a double-heterojunction design were used in this investigation. The DC performance of the 0.8- mu m devices at 300 and 77 K was excellent for both cases. Improvements of 9 and 22% in g/sub mext/ with the strain were measured at the same temperatures, in accordance with theoretical predictions. The approach described may serve as a very useful alternative, especially in MOVPE growth, to InAlAs containing structures because it eliminates many of the troublesome effects such as kinks, deep levels, interface states, high output conductances, and gate leakage, which are to a large extent attributed to impurity-Al interactions. The use of lattice-mismatched InGaAs as channel layer increases the conduction band offset to InP, the DH structure improves both confinement and current, and the p-InP barrier layer results in sufficiently high quasi-Schottky barriers. >

Technique to fabricate a container structure with rough inner and outer surfaces

Abstract: The present invention provides a method for forming conductive container structures on a supporting substrate of a semiconductor device, by: forming an insulating layer over parallel conductive lines and existing material on the surface of the supporting substrate; providing openings into the insulating layer, the openings forming vertical sidewalls in the insulating layer that resides between two neighboring conductive lines and thereby exposing an underlying conductive material; forming a sacrificial layer that makes contact with the underlying conductive material; forming a barrier layer overlying and conforming to the sacrificial layer; forming insulating spacers on the vertical sidewalls of the barrier layer; removing portions of the barrier layer and the sacrificial layer that span between the insulating spacers to thereby expose a portion of the underlying conductive material; removing the insulating spacers and thereby exposing the barrier layer; forming a conductive layer that conforms to the exposed barrier layer, makes contact to the underlying conductive material and forms multiple containers; forming a filler material in the container; removing portions of the conductive layer, the barrier layer and the sacrificial layer down to an upper portion of the insulating layer, thereby forming individual the container structures; removing the insulating layer, thereby exposing the sacrificial layer surrounding the outer surfaces of the container structures; and removing the sacrificial layer, the remaining barrier layer and the filler layer, thereby exposing the outer and inner surfaces of the container structures.

An RBS study of interdiffusion across a brominated Si( 111) /Cu interface with and without a barrier layer

Abstract: Cu thin films have been deposited on Si(111) substrates with two different initial conditions. In one, the substrates had a top native oxide layer, and in the other the native oxide layer was etched in hydrofluoric acid and the etched surface was treated with a bromine-methanol solution prior to the surface being exposed to atmosphere. This Br-treatment is known to saturate surface dangling bonds on an Si(111) surface. Vacuum annealing of the Cu/Si samples, followed by Rutherford backscattering spectrometry (RBS) measurements showed the onset temperature of interdiffusion to be ∼ 220°C for the Si(111) substrate treated with bromine-methanol solution whereas the onset temperature of interdiffusion was found to be between 600°C and 700°C for Si(111) surfaces with native oxide on top. This shows that the native oxide layer works like a diffusion barrier. The effect of an interposed TiNx layer on the diffusion behaviour has also been investigated. A thin layer ( 600°C) for the Cu/SiO2/Si(111) suggests that SiO2 introduces the highest barrier for Cu-Si interdiffusion among all the barrier combinations studied here. At annealing temperatures above the onset temperature of interdiffusion copper silicides are formed. RBS simulations have been used to study the compositions of the reacted films.

Photographic support material comprising an antistatic layer and a heat-thickening barrier layer

Abstract: A base for a photographic element is provided which comprises a support having disposed thereon a vanadium pentoxide antistatic layer and an overlying barrier layer of a heat-thickening polyacrylamide polymer having hydrophilic functionality, and a method for preparing it.

Metallization process for good metal step coverage while maintaining useful alignment mark

Abstract: A new method of metallization of an integrated circuit is described. Semiconductor device structures are fabricated in and on a semiconductor substrate. At least one contact opening to the semiconductor substrate and at least one lithography alignment cross mark opening structure are formed. A barrier layer is preferably sputtered within the contact openings and over the semiconductor device structures. A cold aluminum seed layer is sputtered over all surfaces of the contact openings. Next, a hot aluminum flow layer is provided to obtain the desired step coverage of the contact openings. A second cold aluminum layer is then sputtered onto the hot aluminum layer to define the edges of the wide lithography alignment marks while maintaining good contact opening coverage.

Electrophotographic sensitive body

Abstract: PURPOSE:To enhance sensitivity by forming a carrier multiplying layer between a first conductive electric charge injection barrier layer and a second barrier layer. CONSTITUTION:The first conductive charge injection barrier layer 14, a photoconductive layer 12, and the second barrier layer 15 are successively laminated on a conductive substrate 11, and when this laminate is irradiated with light, light carriers generated in the photoconductive layer 12 transfer toward the layer 14. This layer 14 comprises a layer changing from a narrow forbidden band to a wide forbidden band, and a layer having energy level difference between the widest forbidden band in the wide forbidden bands and the following the narrowest forbidden band in the narrow forbidden bands, and stepback structure. When this energy level difference is equal to the ionization energy of the carriers or higher than this, transferred carriers are ionized and multiplied, and arrived at the surface of the photosensitive body to neutralize charge.

Rare earth coating process for aluminum alloys

Abstract: A method is provided by which a corrosion-resistant barrier layer composed of a rare earth oxide coating incorporated in an oxide film is developed on the surface of a metal for the purpose of improving the corrosion resistance of the metal. The method is particularly suitable for forming a corrosion-resistant barrier on an aluminum alloy, in which the corrosion-resistant barrier layer is composed of a cerium oxide coating incorporated with a uniform aluminum oxide film which has been formed on the aluminum alloy. The corrosion-resistant barrier layer exhibits a broader passivation range as compared to chromium conversion coatings typically used in the art. Simultaneously, the method of this invention avoids the environmental hazards associated with chromium conversion processes, making the method more suitable for manufacturing operations. Furthermore, the method of this invention does not employ hazardous compounds, making the process suitable for a manufacturing environment.

Hydrohalocarbon resistant refrigerator liners

Abstract: The present invention is directed to a refrigeration cabinet comprising an interior liner, a foam insulation derived from an HHC blowing agent and an outer wall. The interior liner comprises a styrene-based inner layer, an adhesive layer, and a barrier layer. The adhesive layer comprises an ethylene copolymer grafted with an anhydride or carboxylic acid moiety, and a styrene-based polymer or copolymer. The barrier layer comprises an ethylene vinyl alcohol copolymer.

Group II-VI compound semiconductor light emitting devices and an ohmic contact therefor

Abstract: Group II-VI compound semiconductor light emitting devices which include at least one II-VI quantum well region of a well layer disposed between first and second barrier layers is disclosed. The quantun well region is sandwiched between first and second cladding layers of a II-VI semiconductor material. The first cladding layer is formed on and lattice matched to the first barrier layer and to a substrate of a III-V compound semiconductor material. The second cladding layer is lattice matched to the second barrier layer. The quantum well layer comprises a II-VI compound semiconductor material having the formula AxB(1-x)C wherein A and B are two different elements from Group II and C is at least one element from Group VI. When the second cladding layer has a p-type conductivity, a greaded bandgap ohmic contact according to the present invention can be utilized. The graded bandgap contact can be a single continuously graded II-VI p-type region or a plurality of cells with each of the cells having first and second thin layers of first and second p-type II-VI semiconductor materials respectively. Another embodiment of the present invention discloses a monolithic multicolor light emitting element capable of emitting four colors and a method for fabricating same. The monolithic multicolor element includes four II-VI semiconductor light emitting devices formed on a single III-V substrate.

Tamper-evident tape having discontinuous barrier layer

Abstract: Disclosed is a tamper-evident tape for applying over the flap or other opening in cellulosic substrates such as paper products, corrugated containers, cardboard boxes, shipping cartons and the like, which tape will provide evidence of tampering with its contents over a wide temperature range from above to below the Tg of the adhesive layer adhering the tape to the substrate. The tape has a transparent backing layer carrying on one side thereof a discontinuous layer of deposits of a transparent barrier material which is bonded to the backing layer and which prevents bonding of an underlying colored layer to the backing layer in areas where the barrier material is present.

X-ray optical element including a multilayer coating

Abstract: In one aspect, the invention involves an optical element in an x-ray imaging system. The element comprises a substrate overlain by a multilayer coating. The multilayer coating comprises plural first and at least second material layers in alternation. This coating is soluble in at least one etchant solution at an etching temperature less than 100° C. The optical element further comprises a barrier layer intermediate the substrate and the multilayer coating. The barrier layer is relatively insoluble in the etchant solution at the etching temperature. In a second aspect of the invention, the optical element comprises a substrate and a multilayer coating as described above, and further comprises a release layer that underlies the multilayer coating. The release layer comprises a material that is relatively soluble in at least one etchant solution at an etching temperature less than 100° C. In contrast to release layers of the prior art, the inventive release layer comprises germanium.

Method for forming an aluminum contact through an insulating layer

Abstract: A method for forming an aluminum contact through an insulating layer includes the formation of an opening. A barrier layer is formed, if necessary, over the insulating layer and in the opening. A thin refractory metal layer is then formed over the barrier layer, and aluminum deposited over the refractory metal layer. Proper selection of the refractory metal layer and aluminum deposition conditions allows the aluminum to flow into the contact and completely fill it. Preferably, the aluminum is deposited over the refractory metal layer without breaking vacuum.

Transport properties of YBa2Cu3O7−δ/Y0.3Pr0.7Ba2Cu3O7−δ/YBa2Cu3 O7−δ Josephson junctions

Abstract: YBa2Cu3O7−δ/Y0.3Pr0.7Ba2Cu3O7−δ /YBa2Cu3O7−δ Josephson junctions have been prepared by a multistep laser ablation process using an improved shadow mask technique. Junctions with barrier layer thicknesses larger than 12 nm exhibit current‐voltage characteristics which are close to those predicted by the resistively shunted junction (RSJ) model. Under microwave irradiation, clear Shapiro steps, which could be well described by the RSJ model, occur in the current‐voltage curves. From the exponential decrease of the critical current density with increasing barrier layer thickness, an order parameter decay length ξn of 21±4 nm at T=4.2 K has been determined for Y0.3Pr0.7Ba2Cu3O7−δ. The increase of the junction resistance with decreasing temperature indicates that the barrier layer dominates the junction properties.

Multilayer conduit having a polyester layer

Abstract: A multilayer polymer hose or pipe conduit which contains at least one barrier layer of polyester, which acts as a barrier to fuel being carried thereby In a preferred form of the invention, the hose or conduit has an inner polyamide protective layer, an outer polyamide protective layer, an adhesion promotor layer between the barrier layer and the inner protective layer, and another adhesion layer between the barrier layer and the outer protective layer

Multi-layer polyamide-based packaging casing

Abstract: The biaxially stretch-oriented multi-layer tubular packaging casing for packaging pasty products, in particular the artificial sausage casing, includes a barrier layer having a reduced permeability to oxygen, an outer layer and an inner layer. The barrier layer comprises a partially aromatic polyamide and/or copolyamide, the outer and inner layers an aliphatic polyamide or copolyamide or a polymer mixture of at least one of the two compounds.

Method for forming a contact of a semiconductor device

Abstract: A method for forming contact of a semiconductor device which prevents residues of a conductive material due to high steps on an insulating layer between metal lines, and minimizes contact area, includes the steps of forming an impurity diffusion region on a predetermined portion of an isolation region on a substrate, forming a first insulating layer on the surface of the substrate, forming a first conductive pattern and a second insulating pattern on the upper portion of the first insulating layer, forming a barrier pattern on the upper portion of the second insulating pattern, forming a third insulating layer on the upper portion of the barrier pattern and the first insulating layer, and etching the third insulating layer to expose the upper portion of the barrier pattern, forming a photoresist pattern for contact mask on the surfaces of the barrier pattern and third insulating layer, etching the third insulating layer and first insulating layer exposed by the photoresist pattern to form a contact hole having a lower surface being the impurity diffusion region, forming a spacer along the sidewall of the contact hole, and forming a second conductive layer on the upper portion of the substrate having the contact hole and barrier layer, and patterning the second conductive layer.

Foamed core-reclaim multi layer sheet having improved resistance to barrier film delamination

Abstract: Disclosed is a multi-layer sheet in a which a foamed thermpolastic core layer is extrusion coated with a multi-resin reclaim-containing layer, and an EVOH or acrylonitrile barrier layer is laminated to the multi-resin layer. The multi-resin layer is formulated to contain at least about 5 weight percent, and preferably about 8 to about 16 weight percent, based on the weight of the layer, of an adhesive resin to reduce the tendency of the barrier layer to delaminate from the multi-resin layer over time. The preferred adhesive is EMA.

Peelable vacuum skin package with barrier foam tray

Abstract: A package for a product includes a support member having a barrier film disposed thereon and supporting the product; web structure for enclosing the product and the support member, the web structure including a first web and a second web sealed to the first web for enclosing the product wherein the second web includes a non-barrier layer sealed to the first web and a peelable barrier layer; and tab structure for initiating peel of the peelable barrier layer from the non-barrier layer at a location where the non-barrier layer is sealed to the first web whereby peeling of the peelable barrier layer does not cause peeling of the barrier film disposed on the support member.

Oxygen barrier container

Abstract: An oxygen barrier laminate structure (10) for producing an aseptic, oxygen barrier packaging or container comprising a substrate (12) having an inner surface and an outer surface, a first low density polyethylene layer (14) coated on the outer surface of the substrate, a multi-layer oxygen barrier coextrusion (20) coated interior to the substrate and a second, thick, low density polyethylene layer (32) coated on the multi-layer coextrusion. An optional extra low density polyethylene layer (16) may be added on the inside of the substrate. A photic barrier layer may also be employed.