Showing papers on "Silicon oxide published in 1973"

Process for fabricating MNOS non-volatile memories

Abstract: The switching speed of an MNOS field effect transistor is increased by a heat treatment in an ammonia rich atmosphere during processing. The transistor has an insulated gate structure comprising a layer of silicon nitride deposited on a layer of silicon oxide. After the formation of the silicon oxide layer and immediately prior to the formation of the silicon nitride layer on a surface thereof, the surface of the silicon oxide layer is heat treated in an ammonia enriched atmosphere to remove substantially all remaining oxygen atoms and molecules absorbed on the surface.

Method of manufacturing semiconductor devices in which silicon oxide regions inset in silicon are formed by a masking oxidation, wherein an intermediate layer of polycrystalline silicon is provided between the substrate and the oxidation mask

Abstract: The manufacture of semiconductor devices, particularly silicon ICs, employing isolating inset oxides is described. To prevent formation of a projecting oxide beak under an oxidation masking layer, a layer of polycrystalline silicon is provided under the oxidation mask instead of the usual silicon oxide.

Erasable floating gate device

Abstract: A metal-oxide-semiconductor (MOS) floating gate storage device is disclosed which includes a pair of spaced-apart regions (source and drain) disposed in a substrate below a floating gate which is completely surrounded by silicon oxide. The gate extends laterally to a third diffused region in the substrate. The floating gate which provides non-volatile storage for an electric charge is charged through avalanche injection and electrically discharged through the third region.

Method of etching silicon oxide to produce a tapered edge thereon

Abstract: A method of etching away a selected portion of silicon oxide from a body of silicon oxide and tapering the edge of the remaining silicon oxide that delineates the selected portion comprises the steps of (a) delineating the selected portion with a coating of a photoresist on a surface of the body, and (b) etching away the selected portion with a composite solution that contains both an etchant for the silicon oxide and a component for lifting only the edge of the photoresist from the interface between the photoresist and the silicon oxide at the delineation of the selected portion.

Reduction of silicon dioxide by means of carbon in electric furnace

Abstract: Silicon and silicon-containing alloys are produced in an electric furnace by reduction of silicon oxide with carbon wherein reaction gases pass through a portion of the charge rich in carbon to enhance furnace operation. According to the present invention, at least a major amount of the reaction materials of silicon dioxide and carbon are separated from each other in the furnace and as a result the reaction gases will pass through a portion of the charge rich in carbon which tends to react with the silicon and silicon oxide gas and hold these materials in the furnace. Better control of the course of reaction is achieved and inexpensive raw materials may be utilized in the process.

Properties of nonvolatile semiconductor memories by using silicon clusters in the gate insulator

Abstract: Nonvolatile memories are now focused by many people. One of the most popular structure of the memories is an MNOS (metal-silicon nitride-silicon oxide-semiconductor) structure. However the structure has poor memory retention when B-T (80°c,-10V) stress is applied to the sample. The developed structures are MNCOS and MNCNOS (metal-over silicon nitride-silicon clusters-under silicon nitride-semiconductor), in which the silicon clusters are the small polycrystalline silicon particles having a compressed hemisphere. As the clusters act as trap centers of both holes and electrons, the trapping efficiency of censers increases, and the thicker silicon oxide film (tox= 50 - 60 A) is able to use for the better memory retention. The memories can operate more than ten years under the BT (-10V, 80°c) stress condition.

Monolithic acoustic surface wave amplifier device and method of manufacture

Abstract: A monolithic acoustic surface wave amplifier device is provided by heating a piezoelectric substrate in vacuum and then depositing a thin barrier layer of silicon oxide on the piezoelectric substrate. A thin film of a III-V semiconductor is deposited on the thin barrier layer, the semiconductor film overcoated with a thin film of silicon oxide and the device completed by annealing in argon.

Method of making silicon semiconductor devices utilizing enhanced thermal oxidation

Abstract: A silicon oxide layer is formed on a phosphorus doped surface region of a silicon semiconductor body by steam treatment, there being an enhanced growth rate of the silicon oxide on the phosphorus doped region enabling, for example, the provision of a low temperature steam treatment, and/or the production, possibly within an aperture in an already provided silicon oxide layer less than 3000A thick, of a thin silicon oxide layer, so that impurity concentration gradients within the semiconductor body are not caused to change by a significant extent and the surface concentration of phosphorus within the region is not significantly depleted.

Silicon nitride on silicon oxide coatings for semiconductor devices

Abstract: A method of manufacturing a semiconductor device wherein a silicon nitride film covers the exposed surfaces of an oxide film and the exposed major surface of a semiconductor body, and wherein holes are formed by chemical etching only in the portion of said silicon nitride film directly contacting said major surface, thereby obtaining precise etching of the insulating covering.

Mill for grinding minerals

Abstract: Grinding elements containing 30 to 70% by weight of zirconium oxide, 0.1 to 5% by weight of aluminum oxide and 5 to 20% by weight of silicon oxide, process of grinding and mills containing the grinding elements.

Catalytically active substance for the conversion of higher hydrocarbons comprising Co, La, Ni, and U

Abstract: This invention relates to a catalytically active substance for the conversion of higher hydrocarbons into gas mixtures, such as those containing carbon monoxide, methane and/or hydrogen, for use in combustion engines, such as the internal combustion engine of an automobile. The catalytically active substance uses a catalyst comprised of oxides of the metals lanthanum, cobalt, nickel and uranium; and an oxidic catalyst carrier for this catalyst. The carrier comprises a metal oxide selected from the group consisting of aluminum oxide, magnesium oxide, silicon oxide, zirconium oxide and titanium oxide. Preferably, the carrier is in the form of one or more porous sintered blocks on which the catalyst has been impregnated.

The predominant role of the surface films in the emission of electrons from reverse-biased p-n junctions in silicon carbide

Abstract: The emission current from a reverse-biased p-n junction in SiC is known to be proportional to the surface component of the junction current, which in turn appears to be related to the junction voltage by a power law It is suggested that the surface current crosses the p-n junction not in surface microplasmas in the SiC but along paths in a thin surface film of silicon oxide heavily doped with carbon atoms from the SiC lattice It is postulated that, during the thermal activation required to develop emission, changes occur in the structure of the oxide film which facilitate the ionization of the carbon inclusions to give a high donor density in the region of the reverse bias field These ideas are shown to give a selfconsistent picture of the conduction and emission processes occurring in SiC cathodes and explanations of several observed phenomena are given