Abstract: An electromegasonic wafer cleaning system is disclosed that is extremely important, if not essential, in the fabrication of advanced microelectronic devices having a line width or feature size of from 0.05 to 0.10 micron. A unique synergistic combination is provided wherein piezoelectric transducer means are operated at a tolerable power level, such as from 1 to 2 watts per square centimeter, to minimize the risk of harm to the extremely delicate microcircuits and wherein the face of each wafer is negatively charged to a temperate voltage, such as from 5 to 20 volts, sufficient to cause effective removal of colloidal or sub 0.4-micron contaminant particles. This unique wafer cleaning system supersedes and replaces the standard megasonic-assisted RCA-type wet wafer cleaning systems which have never been able to eliminate or provide efficient purging of harmful sub 0.1-micron particles.

Abstract: An effective electropurge process and apparatus for wet processing of semiconductor wafers applies electrical charges to the wafer surface with an ample voltage sufficient to provide an effective field intensity which can substantially eliminate intolerable sub-0.05 micron “killer” defects when making highly advanced microchips with a feature size or line width less than 0.15 micron. The process can be used with frequent voltage reversal for automated wet-batch cleaning operations using cassettes that hold 10 to 50 wafers at a time and in various other operations involving megasonic transducers, mechanical brush scrubbers, laser cleaners and CMP equipment. The electropurge process is primarily intended for Fab plants where large wafers with a diameter of 200 to 400 mm require 250 to 350 steps including many dry layering, patterning and doping operations and at least 30 wet processing steps.

Abstract: Cup-shaped porous silica preforms suitable for manufacture of large 24-inch crucibles used in Czochralski crystal-growing furnaces are produced by a unique electrophoretic casting process using a high-purity aqueous silica slip or slurry having a predetermined particle-size distribution, an average particle size of from 6 to 10 microns and a solids content of from 80 to 85 percent by weight. The slurry contains an electrolyte, such as ammonium hydroxide, has a pH of from 7.5 to 8.5, and can be wet milled at a pH of at least 7 in such manner as to provide the micronized silica particles with excellent electrophoretic mobility, thereby providing a superb process for economical mass production of large pure silica preforms using safe voltages, such as 20 to 40 volts. The electrophoretic casting apparatus can be of the type shown in FIGS.

Abstract: A mega stadium-convention center complex is disclosed comprising an impressive pyramid building with a 670-foot pinnacle and a base covering more than 20 acres. The complex contains a 60,000-seat football stadium with a central playing field located more than 180 feet above the ground. The four-sided pyramid can be clad in tinted reflective glass or the like and has 8 or more floors below the playing field that provide several million square feet of floor space for a variety of different business and entertainment facilities. The pyramid roof structure above the stadium and the playing field is adjustable and convertible and includes more than a dozen narrow retractable roof panels or strips and associated guide rails.

Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.

Abstract: The application discloses a number of unique sintered quartz glass products together with new silica compositions and processes for making and using such products. Nitrided clear and opaque nitrided quartz products are disclosed having incredible physical properties resulting from the incorporation of very small, but effective, amounts (e.g., 25 ppm or more) of chemically bound nitrogen. Opaque quartz glass heat shields with remarkable resistance to transmission of infrared radiation are disclosed which can have a high bubble population density, such as 80 to 120 per mm2. These heat shields make possible remarkable improvement in the performance of tube furnaces and other reactors used in processing silicon wafers and other electronic components.

Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.

Abstract: Unique cristobalite-seeded quartz glass crucibles and cores admirably suited for Cz crystal growing and D.S. metal casting are formed by slip casting using a slurry containing a quartz refractory composition comprising silica particles with an average particle size of from 1 to 10 microns and a minute but effective amount of micronized dispersible particles of a unique crystallization aid, such as basic aluminum acetate, which provides the glass with at least 0.005 percent by weight of evenly dispersed metallic ions. The metallic ions provide the quartz glass with nucleation sites so that heating of the glass to a temperature of from 1200.degree. C. to 1250.degree. C. permits formation of a high concentration of evenly dispersed cristobalite nuclei in the glass without causing excessive devitrification prior to cooling of the seeded glass. The desired nucleation sites can also be provided by using micronized particles of alpha quartz or alpha cristobalite.

Abstract: A high-density silica glass article with excellent thermal shock characteristics is formed from a high purity vitreous silica containing an aluminum compound as a crystallization aid and having a dense concentration of cristobalite muclei. The aluminum compound is aluminum oxide, aluminum hydroxide, an aluminum salt, or other aluminum-oxide precursor.A refractory silica glass crucible made according to the invention has remarkable advantages in a Czochralski crystal-growing process. The entire crucible can be crystallized during the initial melt down in the Cz furnace to provide a cristobalite inner surface which effectively resists attack by the molten silicon to minimize contamination problems during crystal growing.Another embodiment of the invention relates to a unique drawn silica glass with good flexural strength having fibrous oriented veins of cristobalite embedded in a matrix of vitreous silica and having remarkable resistance to deformation at temperatures of 1500.degree. C.

Abstract: A process is disclosed for high speed automatic production of ply stock in which tire cord fabric on a first conveyor is cut by a bias cutter to form panels which are spliced at the side of said conveyor and then pulled transversely onto a second conveyor. During each cycle a cut panel is advanced by the first conveyor to a stationary transfer position where its uncut side portion is overlapped by the trailing side portion of an adjacent panel in a stationary splicing position on the second conveyor.

Abstract: A universal cement composition is disclosed suitable for both natural and synthetic rubber based tire compounds which solves the tack and cured adhesion problems heretofore encountered at the tread splice region of radial and bias/belted tires. The composition disclosed contains 75 to 90 parts by weight ("wt") of a cis-polybutadiene elastomer, 10 to 25 parts by wt of natural rubber, 5 to 30 parts by wt of a phenolic tackifying resin, and 40 to 80 parts by wt of a fine reinforcing carbon black and has an AMEDA carbon black dispersion rating of from 96 to 99 percent.

Abstract: A simple economical multistage vulcanization process is disclosed for producing premium anomaly-free tires wherein the inner liner or curing bladder is supplied with dead end water and steam sequentially in several stages at high pressures which assure thorough diffusion of entrapped air. The internal steam pressure is 250 to 300 psig in stage I to effect rapid heat transfer, the internal water pressure in stage II is from 300 to 450 psig, and the internal steam pressure is 250 psig or higher in the first part of stage III. The overall cycle time for curing radial passenger car tires in "Bag-O-Matic" presses is reduced one minute or more by using internal steam pressures from 250 to 300 psig in stage I and III and reducing the steam pressure near the end of stage III to boil off the residual water.

Abstract: A tractor tire is disclosed having widely spaced lug pairs with a symmetrical Y-shaped footprint, each lug pair having inclined transverse lugs and an elongated longitudinal nose portion at the peripheral centerline providing a central lug projecting in the direction of tire rotation and overlapping the trailing end portions of the next adjacent lug pair. The unique lug arrangement minimizes vibration to improve safety during operation on the highway while retaining the characteristics required for effective off-the-road (OTR) performance on soft ground.

Abstract: A profound improvement in the properties and capabilities of elastomeric polyurethane joint sealing compositions is achieved by incorporating a fibrillated polyolefin of high surface area which is rendered compatible by combining it with effective stabilizing cofillers, such as titanium dioxide, calcium carbonate, carbon black, fibrous talc, serpentine, kaolin, or various other metal silicate fillers. Such cofillers are capable of improving compatibility and stabilizing the sealant mixture so that unacceptable sweat out or exudation of liquid is prevented and so that the outer surface of the applied sealant has an acceptable surface quality after curing.

Abstract: A simple inexpensive modification of existing tire molds used in old steam dome vulcanizing presses provides remarkable versatility and permits curing of truck and farm tractor tires at higher temperatures with higher internal water pressures to reduce curing times 5 to 10% or more while improving tire quality. A thin, flat heat exchanger with outstanding heat transfer characteristics is readily provided on each mold half by welding a flat outer disc and spacers to the mold to form an annular steam chamber of narrow cross section in direct communication with the outer mold face and the vent passages.

Abstract: Partially devitrified silica cores with exceptional high temperature strength are disclosed for foundry use in sand casting of ferrous alloys. Precision cored holes of small size and long length, which heretofore could not be cast accurately or had to be machined because of limitations in existing core technology, are formed using accurately machined extruded porous silica cores fired to eliminate combustibles and partially devitrified (e.g., 15 to 30%) to develop a strong crystalline phase bond that resists viscous flow at a temperature of 1500.degree. C. and to increase the refractoriness of the vitreous silica grains, whereby the permeability and thermal shock resistance are such that the core can be heated very rapidly by molten steel to above 1500.degree. C. without spalling, cracking, sagging, breaking, or loss of integrity and without gas holes, scabs, fissures or other serious casting defects.

Abstract: A profound improvement in the properties and capabilities of elastomeric polyurethane joint sealing compositions is achieved by incorporating a fibrillated polyolefin of high surface area which is rendered compatible by combining it with effective stabilizing cofillers, such as titanium dioxide, calcium carbonate, carbon black, fibrous talc, serpentine, kaolin, or various other metal silicate fillers. Such cofillers are capable of improving compatibility and stabilizing the sealant mixture so that unacceptable sweat out or exudation of liquid is prevented and so that the outer surface of the applied sealant has an acceptable surface quality after curing.

Abstract: A unique process is disclosed for modifying an automobile engine to improve fuel economy and reduce harmful exhaust emissions by introducing water and an oxidizing agent, such as hydrogen peroxide, when the engine is under load. The carburetor of a standard engine is adjusted to provide a very lean air-fuel mixture and to increase the air-fuel ratio substantially (e.g., 10 to 20 percent). The amount of hydrogen peroxide injected into the engine depends on the rate of fuel flow and may be regulated by the throttle valve or intake manifold pressure. Means are provided for maintaining a supply of hydrogen peroxide including a high pressure mixing tank containing water and hydrogen peroxide and a pair of removable oxygen tanks for a continuous supply of oxygen to the tank.

Abstract: A porous high-silica core is disclosed for use in directional solidification casting processes having exceptional thermal stability at temperatures above 1650.degree. C. and containing mineralizers which promote the formation of cristobalite. The cores may be made by mixing at least 75 parts of essentially pure fused silica particles with 1 to 25 parts of activating particles containing a mineralizer, such as an alkali metal or alkaline earth metal compound, may be fired at a temperature of 1000.degree. to 1300.degree. C. until they contain 35 percent or more of cristobalite and may then be cooled to room temperature. They may thereafter be incorporated in a shell mold in accordance with the "lost-wax" process and preheated with the shell mold at a temperature of 1300.degree. to 1600.degree. C. to provide a cristobalite content of 60 to 85 percent or more within a short period of time, such as 10 to 30 minutes, and before a molten superalloy is allowed to flow into the mold.