Showing papers on "Silicon dioxide published in 1976"

Correlations of the 4.77–4.28‐eV luminescence band in silicon dioxide with the oxygen vacancy

Abstract: A luminescence band observed at 4.77 eV (260 nm) in crystalline and at 4.28 eV (290 nm) in amorphous silicon dioxide has been found to correlate with optical and spin resonance measurements of oxygen vacancy concentrations in a series of irradiated samples. The 4.28‐eV (290‐nm) band has also been observed in the silicon dioxide layer of metal‐oxide‐semiconductor (MOS) devices. The intensity of the bands can be increased by chemical reduction in carbon monoxide vapor or decreased by heating in oxygen or water vapor. The 4.28‐eV (290‐nm) luminescence intensity in the MOS samples also seems to be related to the trapped positive charge in the silicon dioxide. These facts all support a model for the luminescence center as being the oxygen vacancy.

Pyrolytic deposition of silicon dioxide on semiconductors using a shrouded boat

Abstract: Silicon dioxide is pyrolytically deposited by the reaction of silane with oxygen on vertically mounted substrates in an evacuated system. A standard diffusion furnace equipped with a furnace tube which is vacuum tight is used. Injection tubes having multiple injection ports are positioned within the furnace tube to distribute the silane and the oxygen uniformly across a plurality of substrates which are positioned perpendicular to the furnace tube axis in a boat covered with a perforated shroud. The process is particularly useful in providing for the low temperature deposition of uniform layers of silicon dioxide on silicon wafers to be used in the fabrication of semiconductor devices.

Thin-Film Multilayer Capacitors Using Pyrolytically Deposited Silicon Dioxide

Abstract: Thin-film multilayer high-energy-density capacitors have been constructed using a pyrolytically deposited phosphosilicate glass as the dielectric material with aluminum as the electrode material. Other electrode materials such as gold, chromium, and silicon were studied to determine the best electrode for this application. A careful study was made of the behavior of the oxide with respect to the formation of microcracks and pin holes in order to eliminate those problems. It was found that the stresses in undoped SiO 2 were too great to permit its use in this application. Capacitors having an area of 1 cm2with up to 20 layers were constructed using a doped oxide with a P 2 O 5 concentration of from 7 to 10 percent.

Control of etch rate of silicon dioxide in boiling phosphoric acid

Abstract: The etch rate of silicon dioxide, particularly thermally grown silicon dioxide, in boiling phosphoric acid, can be controlled by deliberately adding additional silicate to the acid. For thermally grown silicon dioxide, the etch rate can be reduced from about 5A per minute with no added silicate, to about 0.5A/minute with 1 gram of added silicate to about 1 liter of acid.

Process for coating a synthetic polymer sheet material with a durable abrasion-resistant vitreous composition

Abstract: There is disclosed a process for improving the adhesion of an evaporable glass coating on a synthetic polymer sheet material by the application of a base vitreous coating of a mixture of silicon dioxide and silicon monoxide by evaporating silicon monoxide under vacuum in an oxygen atmosphere so that in addition to silicon monoxide, a silicon dioxide condensate is condensed on the outer surface of the sheet. An outer vitreous coating is subsequently applied over said base coating. The evaporative glass outer coating can be formed essentially from boron oxide and silicon dioxide containing less than 5% by weight of sodium oxide. The evaporative glass coating can also be of fused silica, or a boro-silicate glass sold under the trademark "Pyrex".

Method of treating a layer of silicon dioxide

Abstract: A layer of silicon dioxide such as used in an MOS gate dielectric, is treated, after growth, to prevent deleterious effects resulting from any mobile impurity ions therein. An ionic fluoride compound is applied to one surface of the layer of silicon dioxide. A corona discharge is then directed from a negative electrode of a pair of electrodes of opposite polarity onto the fluoride compound to drive the fluoride ions into the layer. The layer is then washed and annealed.

P+ Silicon integrated circuit interconnection lines

Abstract: An improved interconnecting line for an integrated circuit comprising a P+ silicon island having an optional first layer of silicon dioxide or a like material thereon and a second layer of silicon nitride or a like material adjacent the first layer, is provided. The line may be manufactured by improvements in the standard P channel MOS or MNOS processing method wherein the line is formed concomitantly with the island upon definition of the silicon. The line may be subsequently coated with silicon dioxide during formation of a gate oxide for a MNOS device and then coated with silicon nitride.

Process for thinning silicon with special application to producing silicon on insulator

Abstract: This disclosure relates to methods of producing thin layers of silicon as well as thin layers of silicon on insulating substrates such as silicon dioxide or polycrystalline silicon by forming either an n- layer of single crystal silicon over a p++ layer of single crystal silicon or a p- layer of single crystal silicon over an n++ layer of single crystal silicon and then removing either the n++ or p++ single crystal substrate, as the case may be, by utilizing an etch which will only etch the n++ or p++ region and will stop when the n- or p- region, as the case may be, has been reached.

Process for the production of finely divided silicon dioxide having a large specific surface

Abstract: Process for the production of finely divided silicon dioxide having a surface of more than about 380 m 2 /g BET which comprises converting a volatile silicon halide in an inert gas vehicle with a gas forming water upon combustion and oxygen gas or air in a flame, the quantity of oxygen being sufficient for the practically complete combustion of the combustible gas, and the quantities of oxygen or air and combustible gas being sufficient to produce a quantity of water which will at least suffice for the hydrolysis of the volatile silicon halide, said volatile silicon halide consisting essentially of trichlorosilane and said inert gas vehicle consisting for instance of nitrogen, carbon dioxide, noble gases or others the amount of trichlorosilane vapor being about 410-565 g trichlorosilane vapor per Nm 3 /h total gas, the molar ratio of trichlorosilane vapor to nitrogen being about 0.5:1 - 5:1, the molar ratio of hydrogen in the combustible gas to oxygen being about 0.5:1 - 1.3:1, and separating the resulting silicon dioxide from other reaction products. Finely divided silicon dioxide prepared according to this process is also provided. The finely divided silicon dioxide is useful as a thickening agent in liquid systems.

Two-phase continuous poly silicon gate CCD

Abstract: This invention provides the structure for a two-phase charge coupled storage device. Alternate regions of thicker and thinner silicon dioxide are grown upon a silicon substrate. These silicon dioxide regions are covered with a layer of deposited, undoped polysilicon. A layer of silicon dioxide is grown over the polysilicon. Ion implantation is applied to cause isolated regions of conductivity in the polysilicon. Then contact windows are cut in the upper most layer of silicon dioxide exposing the polysilicon therethrough and a metal coating is deposited in the contact windows. Two-phase signals are applied to the resulting electrodes to advance charges at the surface of the silicon substrate.

Temperature dependence of the absorption edge of vitreous silica

Abstract: During an investigation of the optical properties of high-purity vitreous silica (fused quartz), which is being developed by NASA as a reflective and ablative heat shield, some interesting properties of theoretical and experimental nature have become apparent which otherwise may have remained unnoticed. Of particular interest for the NASA application is the shift of the absorption edge toward longer wavelengths with increasing temperature. The results of studies of this shift and of the spectral dependence of the absorption edge are summarized in the present paper. Plots of the absorption edge and the absorption spectrum of fused quartz vs temperature are given and discussed.

Production of high purity hydrogen fluoride from silicon tetrafluoride

Abstract: Method and apparatus for the production of high purity hydrogen fluoride by the flame hydrolysis of silicon tetrafluoride and the deliberate cooling of the silicon dioxide and hydrogen fluoride reaction products without appreciable dilution to promote agglomeration of the silicon dioxide and permit separation of the hydrogen fluoride with substantially no contamination.

Powder for continuous casting

Abstract: A flux powder for use in the continuous casting of steels, particularly aluminum killed steels in the form of a mechanical mixture of components and has the following chemical analysis by weight % :- silicon dioxide 20 - 60, calcium oxide source 20 - 60, calcium fluoride 3 - 20, alkali metal carbonate 3 - 20, carbon source 4 - 20 and aluminum oxide 0 - 10. At least the inorganic components of the mixture are substantially pure, whereby the properties of the powder may be made substantially uniform and reproducible. The components preferably have a uniform grain size and calcium carbonate is disclosed as a calcium oxide source and natural graphite is a preferred carbon source.

Method of selective etching of materials utilizing masks of binary silicate glasses

Abstract: A method of etching a layer of material on the surface of a substrate of silicon dioxide utilizes an etch mask constituted of a binary silicate glass. The binary silicate glass is removed subsequent to the etching of the layer without affecting the substrate of silicon dioxide.

Method of selective aluminum diffusion

Abstract: A silicon substrate is coated with a mask comprised of the combination of a silicon dioxide layer and a layer of undoped polycrystalline silicon. Aluminum is then diffused through windows formed in the mask. The mask has proven effective for relatively deep aluminum diffusion.

Method for making vitreous silica

Abstract: Method and apparatus for making vitreous silica of high purity including producing a melt of liquid silicon in a first chamber, mixing the liquid silicon with carbon dioxide in an upper zone of a second chamber to produce silicon monoxide, mixing the silicon monoxide with oxygen in a lower zone of the second chamber producing silicon dioxide in gaseous form, condensing the silicon dioxide on the wall of the second chamber, and withdrawing the resultant tube of vitreous silica from the lower end of the second chamber. The apparatus is lined with silica to prevent introduction of impurities. The liquid silicon is produced by mixing hydrogen and trichlorosilane.

Method of selective growth of microcrystalline silicon

Abstract: An array of microcrystalline silicon pads for a vidicon target is selectively grown, by the hydrogen reduction of silicon tetrachloride, along surface portions of a silicon wafer exposed through openings in an overlying silicon dioxide layer. The method disclosed avoids the spurious irregular growth of silicon on the silicon dioxide layer between the adjacent silicon pads.

Process for producing an improved dielectrically-isolated silicon crystal utilizing adjacent areas of different insulators

Abstract: Thermoprocessing of integrated-circuit devices and ionizing radiation environments create electronic charges in dielectric isolation materials and in dielectric-semiconductor interface regions. These charges can produce serious alterations in the operating characteristics of the devices and integrated circuits. The deleterious effect of these charges may be greatly reduced by the disclosed process which produces a single-crystal silicon film dielectrically isolated from a polycrystalline silicon support by an underlying insulator of either silicon nitride or silicon dioxide, both of which may be grown by the process at selected locations on the same chip.

Polarity dependent oxide defects located using liquid crystals

Abstract: Liquid crystals have been used to study, non-destructively, the localized regions of high conductivity known to be present in thin layers of silicon dioxide grown thermally on n type silicon. The polarity dependence of the turbulence in the liquid crystals, together with the growth in the number of defects with time suggests that mobile impurity ions play an important role.

Semiconductor device manufacturing method

Abstract: PURPOSE:Voltage witstanding yield of mesa-type semiconductors is improved by removing silicon dioxide contaminated when structuring electrodes, with hydrofluoric acid solution and by forming a silicon dioxide with ghdrogen peroxide water.

The formation of silicon dioxide film

Abstract: PURPOSE:To form good quality silicon dioxide film on silicon substrate which does not contain naturally oxidized layer at the interface between silicon dioxide film and the substrate.

Silicon-insulator-polysilicon infrared imaging device and method of making same

Abstract: A layer of epitaxial silicon is grown on a silicon growth substrate, a thinayer of silicon dioxide or other suitable insulator is grown (in the case of silicon dioxide) or deposited (for other insulators) on the epitaxial layer, and a thick layer of polysilicon is grown on the dioxide layer. The silicon growth substrate is then removed, and the epitaxial layer is etched to form islands on the insulator layer. Some of the islands are doped to form an array of infrared sensitive detectors, and a large island is doped to act as CCD region. Electrical leads are fabricated, some to provide drive and output lines for the CCDs, other to provide connections of the detectors to respective CCDs, and yet others to provide common leads for the detectors.

Method for dispersing glass fibers for the preparation of glass filter media

Abstract: Beta Glass fibers are dispersed in a solution containing hydrochloric acidnd a hydrophobic fumed silicon dioxide treated with a silane thereby forming a slurry which is subjected to a sonic probe whereafter other glass fibers are mixed into said slurry and the mixture is formed into a glass fiber filter.

Correlations of the 4. 77 eV--4. 28 eV luminescence band in silicon dioxide with the oxygen vacancy. Final report 1 Jul 1975--30 Jun 1976

Abstract: A luminescence band observed at 4.77 eV (260 nm) in crystalline and at 4.28-eV (290 nm) in amorphous silicon dioxide has been found to correlate with optical and spin resonance measurements of oxygen vacancy concentrations in a series of irradiated samples. The 4.28 eV (290 nm) band has also been observed in the silicon dioxide layer of metal--oxide semiconductor (MOS) devices. The intensity of the bands can be increased by chemical reduction in carbon monoxide vapor or decreased by heating in oxygen or water vapor. The 4.28--eV (290 nm) luminescence intensity in the MOS samples also seems to be related to the trapped positive charge in the silicon dioxide. These facts all support a model for the liminescence center as being the oxygen vacancy. (auth)