Abstract: Annealing a titanium-rich carbide film deposited on silicon produces, in a single processing step, both a stable titanium silicide contact and a titanium carbide diffusion barrier between the silicide and a subsequently formed overlying layer of aluminum. Reliable low-resistance contacts to VLSI devices are thereby provided in a cost-effective fabrication sequence. Other metallization systems, comprising a silicide and a diffusion barrier to aluminum formed in a single processing step, are also described.

Abstract: Semiconductor devices with resistor regions, capable of operating at higher temperatures, and having improved bond pull strength are obtained by using a single layer (e.g. Ni--Cr) to act as a combined resistive layer and barrier layer. When placed in the contact windows between the semiconductor (e.g. Si) and the interconnect metallization, (e.g. Al) and Ni--Cr layer acts as a diffusion barrier to prevent interdiffusion of silicon and aluminum and contact alloying punch-through. When placed elsewhere on the device the Ni--Cr layer also serves as thin film resistor material. Wire bond pull strength is improved by placing an adhesion layer (e.g. polysilicon) beneath the portion of the resistive barrier layer underlying the bonding pads. The polysilicon layer rests on the insulator (e.g. SiO 2 ) covering the semiconductor substrate.

Abstract: The modification of a diffusion barrier by the deposition of one or more inorganic species within the pores and on to the surfaces of said diffusion barrier to form an immobilized crystalline lattice barrier or molecular grid having substantially uniform permeability and to select and separate different ionic species, giving a high efficiency of separation with a low energy input. The diffusion barrier is characterized by one or more units, each incorporating a tubular housing with a bundle of porous hollow fibres therein, arranged in the axial direction of the housing. The inorganic crystalline lattice is exemplified by barium sulphate (BaSO 4 ) formed by the interdiffusion of barium hydroxide (Ba(OH) 2 ) and sulphuric acid (H 2 SO 4 ) solutions, or, alternatively, co-precipitated aluminium hydroxide (Al(OH) 2 ) and barium sulphate (BaSO 4 ) formed by the interdiffusion of barium hydroxide (Ba(OH) 2 ) and aluminium sulphate (Al 2 (SO 4 ) 3 ) solutions. These immobilized inorganic diffusion barriers are used for selective separation of small molecules (e.g. with a molecular weight of less than 1000 daltons) and provide means for the more effective separation of ionic species. A method is also provided for the low cost removal of ions from molasses, to enhance fermentation efficiency and to improve its usefulness as a stock feed supplement, or it may be followed by other treatments to reduce and/or remove higher molecular weight substances, such as proteins and waxes, to produce sugar syrups and caramel substitutes.

Abstract: The low resistivity and refractory nature of titanium carbide makes it potentially useful as a diffusion barrier in thin film metallization schemes. In the present investigation, deposition and properties of thin titanium carbide films have been investigated. The films were deposited by reactive radio frequency sputtering in methane–argon mixtures on a variety of substrates. The effects of methane to argon ratio, total sputtering pressure, and power on the film deposition rate, composition and properties were determined. There were interactive effects of these parameters on the composition and properties of these films. Resistivity increased with carbon content; for Ti/C≥1 it was ∼200 μΩ cm. Stress that was compressive was maximum in the nearly stoichiometric TiC film. Grain size was small in all films, especially so in carbon rich films. All stoichiometric titanium carbide films were resistant to HF solutions. Films with TiC/≥1 dissolved easily in ethylene dinitrilo tetra acetric acid (EDTA) solution.

Abstract: A low resistive, electrically and mechanically stable three level metallization scheme has been developed TiSi2 was adopted as a low contact resistance material to silicon, and TiN was selected as a diffusion barrier between the silicide and the A1 interconnect layer. The Ti/TiN bilayer was deposited by magnetron sputtering. It is shown, using RBS and X-ray diffraction that the deposited Ti reacts to form TiSi2, and the upper titanium nitride layer transforms to a stoichiometric compound TiN. Furthermore, it is demonstrated that TiN acts as a diffusion barrier between TiSi2 and aluminium up to 550°C and that the onset for interdiffusion occurs at 600°C. Finally, the interposition of a third sacrificial Ti layer between the nitride film and the aluminium top layer is shown to prevent intermixing between the A1 layer and Si even after a prolonged heat treatment at 600°C.

Abstract: : During the pitting of magnesium and other metals in halide solutions, a film of halide salt of the metal forms on the corroding surface. This salt film plays a major role as a diffusion barrier for water and prevents repassivation by oxide. Properties of magnesium chloride layers were determined on corroding high-purity magnesium shielded electrodes or one-dimensional pits. Electrical transient experiments showed that the salt film thickness is proportional to applied anodic potential and that conduction is by the high field mechanism. Water diffusion rate decreases with film thickness. (Author)

Abstract: The interactions of reactively sputtered titanium carbide (TixC) films with Si, SiO2, Ti, TiSi2, and Al have been studied using Auger electron spectroscopy, x‐ray diffraction, and four‐point probe resistance. The TixC films react with Si leading to silicide phases that are not observed when pure Ti reacts with Si. The interaction of TixC with Si is delayed to higher temperatures with increasing carbon content. For x≤1, no interaction is observed even after 900 °C‐30 min anneal. For x≥1, the silicide formation leads to phase separation with TiSi2 near the silicon substrate plus an outer titanium carbide layer, which, like all other TixC films investigated, is found to be an effective diffusion barrier to Al penetration up to 500 °C. For x≤1, no interaction with SiO2 is observed up to 900 °C. However, Ti‐rich films interact with SiO2 to form titanium oxide. The stoichiometric film adheres to Ti and TiSi2 much better than to Si and SiO2. It does not react with Ti or TiSi2 up to 750 °C. At 900 °C TiC is unsta...

Abstract: Solar cells having a semiconductor body composed of amorphous silicon which is deposited on a substrate coated with aluminum at least on one of its surfaces, with a diffusion barrier layer composed of titanium nitride positioned between the aluminum layer and the semiconductor body. The aluminum layer and the titanium nitride layer can be produced by high frequency sputtering while the semiconductor body can be produced by a glow discharge deposition.

Abstract: : During the pitting of magnesium and other metals in halide solutions, a film of halide salt of the metal forms on the corroding surface. This salt film plays a major role as a diffusion barrier for water and prevents repassivation by oxide. Properties of magnesium chloride layers were determined on corroding high-purity magnesium shielded electrodes or one-dimensional pits. Electrical transient experiments showed that the salt film thickness is proportional to applied anodic potential and that conduction is by the high field mechanism. Water diffusion rate decreases with film thickness. (Author)

Abstract: Metallic contacts to compound semiconductor devices which employ a native oxide for passivation are provided. The metallic contacts of the invention comprise at least two metal layers: a first layer making non-rectifying contact with the semiconductor surface and providing a diffusion barrier and a second layer thereon comprising an easily oxidizable metal. A low resistivity metal layer may optionally be interposed between the two metal layers for improved conductivity. The metallic contact is formed prior to passivation. The diffusion barrier layer prevents diffusion of potentially deleterious materials into the semiconductor, while exposed portions of the oxidizable metal form an insulating oxide during anodic passivation in an electrolyte. The insulating oxide prevents disruption of the electric field distribution in the electrolyte, thereby eliminating passivating oxide and device non-uniformities commonly encountered in the formation of prior art metallic contacts and providing more uniform semiconductor oxide thickness.

Abstract: Diffusion barrier for electrolysis furnaces for the preparation of aluminium by electrolysis of alumina dissolved in a fluoride melt. The diffusion barrier comprises a material which reacts with sodium fluoride to form compounds which are solid at the operation temperature of the furnace.

Abstract: According to the invention, the moderator material is coated or encased with a material as diffusion barrier for hydrogen. In a manner known per se in this regard, the moderator material is a metal hydride which is used in the form of granules, small spheres, rods or plates, which are coated or enclosed with the diffusion barrier. For the metal hydride, use is made in particular of a stable hydride of the titanium group or of the alkali metals or alkaline earth metals. Oxides or enamels are very well suited as diffusion barriers.

Abstract: PURPOSE:To obtain a metal nitride thin film of low specific resistance and small internal stress easily, by a method wherein negative D.C. bias is applied to a substrate and hydrogen is added to nitrogen/argon mixing gas. CONSTITUTION:A chamber 1 is evacuated and hydrogen gas is introduced therewithin through a gas inlet port 8 until attaining a prescribed partial pressure. Nitrogen is introduced until attaining a prescribed partial pressure, and then argon is introduced until attaining total pressure of prescribed value. Discharging is started and a metal nitride thin film is deposited. Prescribed D.C. bias voltage is applied to a substrate 6 from a bias power source 7. In this constitution, a metal nitride thin film having low specific resistance and small internal stress can be obtained easily. If the thin film is used as part of electrode of IC, for example, as a diffusion barrier, parts being execellent in heat-resisting property and reliability can be obtained in high yield.

Abstract: 1. A steel connecting element having a galvanic outer layer of metal and a non-galvanic diffusion barrier layer present on the element body under the outer layer characterized in that the diffusion barrier layer (3) comprises a mechanically carried metal layer applied by cold welding.

Abstract: The performance of TiN as a diffusion barrier in Au/TiN/InP structures has been studied and compared with Cr and Pt under identical conditions. In order to sensitively monitor interdiffusion, a novel SEM-EDX technique has been used to determine interdiffusion coefficients and activation energies in the temperature range 250–700°C. Extensive intermixing for Cr and Pt was indicated by the SEM-EDX technique and this was confirmed by Auger depth profiling. In addition the heterogeneous formation of the brittle intermetallic phase Au4 in was detected by XRD, and marked the catastrophic failure of the metallization due to delamination. These interfacial reactions and copious interdiffusion may be controlled by a TiN diffusion barrier which remains impervious for periods in excess of 24h at 500°C.

Abstract: A minimal corrosion resistor structure and deposition technique for superconductive circuits, with mutually protective niobium oxide passivation ring, gold corrosion barrier film and titanium resistive layer. Niobium has an intrinsic oxide of Nb 2 O 5 , which must be removed from a contact area designated by an opening in photoresist; the development process leaves a photoresist overhang. The gold corrosion barrier film deposition is sharply focused to form an area corresponding to the opening in the photoresist. An unfocused plasma oxidation step, which follows the gold deposition, grows an extrinsic Nb 2 0 5 passivation ring about the gold. The titanium resistive metal is then deposited with a wider focus than that of the gold corrosion barrier film, through the same opening, the titanium resistive metal layer deposits over the edge of the gold, encapsulating the gold with a diffusion barrier.

Abstract: PURPOSE:To reduce the thickness of an Au film to one third or below of that of the film of the conventional type in use by a method wherein Au is plated using Rh as an under-layer. CONSTITUTION:Rh hardly forms an intermetallic compound with Au, while it effectively performs the function as a diffusion barrier such as Fe, Ni and the like, and the Rh itself is hardly oxidized. Therefore, when the Rh is used as an under layer for an Au plating, the thickness of Au plating of approximately 1.5mum required heretofore can be reduced to 0.5mum or thereabouts. Accordingly, the discoloration by heat, the exfoliation of chips, the unsatisfactory junction and the like can be removed, thereby enabling to obtain the package of high quality at a low cost.