Abstract: The present invention relates to a method for the reactivation of phosphomolybdic acid based catalysts used for the conversion of saturated and unsaturated aldehydes to acids. The method comprises the step of feeding an oxide of nitrogen over the deactivated catalyst at a temperature of from about 100.degree. C. to about 400.degree. C. The method can be employed in the reactor by terminating the feed of reactant to the reactor, adjusting the reactor temperature as may be necessary to one suitable for reactivation and sweeping the reactor with a gas. Alternatively, the catalyst can be removed from the reactor for reactivation. Reactivated phosphomolybdic acid based catalysts are also disclosed. These catalysts have a ratio of molybdenum to phosphorus of 3:1 to 15:1 and are prepared by the process of feeding an oxide of nitrogen over the catalyst at a temperature of from about 100.degree. C. to about 400.degree. C.

Abstract: The present invention relates to a method for the activation of PMA based catalysts by treating the catalyst precursor with a nitrogen-containing compound such as an oxide of nitrogen gas or a nitrogen acid such as nitric or nitrous at a temperature of from about 125.degree. C. to about 400.degree. C. The method can be employed in a reactor by loading the catalyst precursor, adjusting the reactor temperature to one suitable for activation and optionally sweeping the reactor with an inert gas followed by the treating step. The method herein permits faster, lower temperature catalyst activation than when air activation is employed giving higher oxidative conversion yields and prolonged catalyst life.

Abstract: An aluminum-transition metal Schottky barrier contact, and methods of fabrication thereof are disclosed. In one preferred embodiment, the junction is comprised of an aluminum-tantalum intermetallic layer abutting a silicon substrate. Alternate embodiments utilize an intermetallic compound of a metal selected from the group of tantalum, zirconium, hafnium, niobium, titanium and nickel in combination with aluminum. The preferred embodiments can be fabricated by evaporation of a layer of a metal selected from the above mentioned group followed by evaporation of a layer of aluminum on a silicon substrate, after which an annealing step is utilized which creates the desired intermetallic compound in a layer abutting the silicon surface. Alternatively, the junction can be created by hot or cold sputtering of a preselected intermetallic compound of one of the metals with aluminum directly upon the silicon substrate, followed by deposition of a conductive layer such as aluminum.

Abstract: Thin film structures comprising a layer of aluminum and a material having a tendency to interact with aluminum are separated by an intermediate layer of aluminum having a high aluminum oxide content. The intermediate layer prevents said interaction by acting as a diffusion barrier.Preferred embodiments are directed to silicon semiconductor metallization structures, including Schottky barrier contacts, which comprise a bottom layer of tantalum, or other transition metal, or a metal silicide in contact with a silicon substrate, an intermediate layer of aluminum having a high aluminum oxide content and a top layer of aluminum. The intermediate layer functions as a diffusion barrier between aluminum and the metal, metal silicide or silicon.

Abstract: In a conductor pattern for integrated circuits, the use of barrier layers of TiW and selected transition metals between gold and a silicon substrate, with the transition metal containing a supplemental barrier region or stratum of an intermetallic formed between it and the gold. Also comprehended is the use of a platinum silicide layer between the TiW layer and silicon for Schottky Barrier Diodes.

Abstract: A method for forming thin film patterns in the fabrication of integrated circuits utilizing a lift-off mask in an inverse vertical relationship with the desired metal film. The method involves the preliminary blanket deposition of the metal in-point, followed by a coating of a patterned lift-off mask over which is blanket coated a dry-etch resistant material with subsequent removal of the lift-off mask, and dry etching of the exposed metal film. In one embodiment the dry-etch mask can comprise a diverse metal layer when a dry-etch ambient is employed which is passive to the diverse metal. In another embodiment, where dry etch ambients are employed which are corrosive to the diverse metal which is desired in the final structure, it can be covered with a blanket layer of any convenient dry-etch resistant material, such as magnesium oxide, prior to removal of the lift-off mask.

Abstract: A process for polymerizing alpha-olefins in the presence of a Ziegler-type catalyst wherein at least one of dichloroethane, dichloropropane and chlorine gas is added to the process after the polymerization has been initiated. This invention is especially useful when the olefin is propylene and the catalyst is a titanium trichloride complex.

Abstract: Thin film structures comprising a layer of aluminum and a material having a tendency to interact with aluminum are separated by an intermediate layer of aluminum having a high aluminum oxide content. The intermediate layer prevents said interaction by acting as a diffusion barrier.Preferred embodiments are directed to silicon semiconductor metallization structures, including Schottky barrier contacts, which comprise a bottom layer of tantalum, or other transition metal, or a metal silicide in contact with a silicon substrate, an intermediate layer of aluminum having a high aluminum oxide content and a top layer of aluminum. The intermediate layer functions as a diffusion barrier between aluminum and the metal, metal silicide or silicon.

Abstract: A low barrier Schottky Barrier Diode (SBD) utilizing a metallurgical diffusion barrier between a transition metal barrier contact and an aluminum base land pattern to prevent interaction therebetween. The diffusion barrier comprises a discretely formed layer of an intermetallic of the transition metal and aluminum.

Abstract: A method for carrying out reactions of the Friedel-Crafts type, such as alkylation, acylation, polymerization, sulfonylation and dehydrohalogenation. The reactions are catalyzed by arene-metal tricarbonyl complexes and when the reaction vessel contains aromatic substrates the catalyst may be generated in situ from a metallic hexacarbonyl. The arene-metal tricarbonyl catalyst is more selective than conventionally employed Friedel-Craft catalysts in that it yields generally para isomers with little of the ortho variety and very little if any of the meta variety when the aromatic substrate is reacted with organic halide. It is also possible to form the arene-metal tricarbonyl catalyst outside of the reaction vessel and then proceed by adding it to the vessel containing the substrate and the organic halide as is the case with dehydrohalogenation reactions wherein there are no aromatic rings available, the substrate in that instance being aliphatic.

Abstract: Catalysts containing tungsten, phosphorus, vanadium, molybdenum, and promoted with at least one of the elements selected from the group selected from Sn, As, Cu, Ce, B, Cr, Fe, Ni, Co, U, Mn, Ag, Ru, Rh, Cd, Sr, In, Zn, and La have been found to be especially effective for the oxidation of unsaturated aldehydes to form the corresponding unsaturated acid.

Abstract: Methacrylic acid or acrylic acid are produced by the oxidation of methacrolein or acrolein, respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, arsenic, at least one element selected from the group consisting of Ag, Rh, Ru, and Au, oxygen, and optionally, at least one of Cd, Pt, Tl, Pd, Al, Ge, Cu, Ni, alkaline earth metal, NH.sub.4 and Cl.

Abstract: An aluminum-transition metal Schottky barrier contact, and methods of fabrication thereof are disclosed. In one preferred embodiment, the junction is comprised of an aluminum-tantalum intermetallic layer abutting a silicon substrate. Alternate embodiments utilize an intermetallic compound of a metal selected from the group of tantalum, zirconium, hafnium, niobium, titanium and nickel in combination with aluminum. The preferred embodiments can be fabricated by evaporation of a layer of a metal selected from the above mentioned group followed by evaporation of a layer of aluminum on a silicon substrate, after which an annealing step is utilized which creates the desired intermetallic compound in a layer abutting the silicon surface. Alternatively, the junction can be created by hot or cold sputtering of a preselected intermetallic compound of one of the metals with aluminum directly upon the silicon substrate, followed by deposition of a conductive layer such as aluminum.

Abstract: Methacrylic acid or acrylic acid are produced by the oxidation of methacrolein or acrolein, respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, arsenic, at least one element selected from the group consisting of U, Ti, Nb, Re, Pb, Zn, and Ga, oxygen, and optionally, at least one of Cu, a rare earth element, Ag, Ta, In, Th, Cd, Tl, alkaline earth metal, NH.sub.4, Cl, Ni, Al and Ge.

Abstract: Methacrylic acid or acrylic acid is produced by the oxidation of methacrolein or acrolein respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum and phosphorus, promoted with chromium or at least one element selected from the group consisting of thallium, rubidium, cesium, potassium, titanium, and arsenic, or a mixture thereof, wherein at least part of the molybdenum employed in the preparation of the catalyst is supplied in the form of molybdenum trioxide. The oxidation of methacrolein in the presence of a catalyst wherein all the molybdenum employed in the preparation of the catalyst has been supplied by molybdenum trioxide gives especially desirable high yields and selectivities to methacrylic acid.

Abstract: Use of a rare gas in combination with oxygen or nitrogen to sputter etch unreacted platinum after formation of a platinum silicide contact structure for the formation of a Schottky Barrier diode in a silicon semiconductor substrate.

Abstract: Maleic anhydride is produced by the oxidation of n-butane, n-butenes, 1,3-butadiene or mixture thereof with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, arsenic, oxygen, and at least one element selected from the group consisting of Sn, rare earth metal, Zr, Rh, Mn, Re, Ru, Cu, Pb, Zn, Ti and Cr, Nb, Al, Ga, and alkaline earth metal.

Abstract: Methacrylic acid or acrylic acid are produced by the oxidation of methacrolein or acrolein, respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, bismuth, copper, oxygen, optionally a halogen selected from the group consisting of chlorine, bromine or iodine, and optionally, at least one element selected from the group consisting of Fe, Cr, Ni, Mn, Sb, Te, Rh, and Pd.

Abstract: Coated catalysts having an inert support material with an outer surface and a coating of active catalyst containing molybdenum, phosphorus, arsenic, copper and oxygen have been found to be especially effective catalysts for the production of unsaturated acids from the corresponding unsaturated aldehydes, for example, methacrolein is oxidized to methacrylic acid using these catalysts. The catalysts give a very low exotherm, very high single pass yields of the desired acid and reduce the undesirable byproducts.

Abstract: Maleic anhydride is produced by the oxidation of n-butane, n-butenes, 1,3-butadiene with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, bismuth, copper, oxygen, and a halogen selected from the group consisting of chlorine, bromine or iodine.