Showing papers on "Silicon dioxide published in 1979"

Selective Etching of Silicon Dioxide Using Reactive Ion Etching with CF 4 ‐ H 2

Abstract: Highly selective etching of silicon dioxide relative to both silicon and resist has been obtained by reactive ion etching substrates which are loaded onto an rf cathode and exposed to a low pressure discharge of a etching gas mixture. Silicon dioxide‐to‐silicon etch rate ratios as high as 35 to 1 have been measured and silicon dioxide‐to‐resist etch rate ratios have been found to exceed 10 to 1. The use of reactive ion etching is important in achieving these high etch ratios; the low operating pressure of between 2.7 and 5.3 Pa and the exposure of substrates to bombardment by energetic ions tend to inhibit polymerization on the substrates. As a result, it is possible to use the greater concentrations which are required for high etch rate ratios.

The Deposition of Silicon Dioxide Films at Reduced Pressure

Abstract: Films of silicon dioxide have been deposited on silicon substrates by decomposing tetraethoxysilane (TEOS) at 700°–750°C in a reduced pressure CVD reactor. The deposition rate is 200–300 A/min. The thickness uniformity is better than ±1% over a deposition zone capable of holding 100 wafers. The step coverage is conformal, the defect density is very low, and the film stress is compressive and low. The refractive index, infrared spectrum, and film density appear normal for deposited silicon dioxide. The addition of phosphorus compounds causes the deposition rate to increase and the thickness uniformity to degrade. Consequently, this reaction is not suitable for depositing phosphorus‐doped films for integrated circuit applications; however, this reaction appears to be a very good process for depositing undoped films of silicon dioxide.

Process for making large area isolation trenches utilizing a two-step selective etching technique

Abstract: A method for making wide, deep recessed oxide isolation trenches in silicon semiconductor substrates. A semi-conductor substrate is selectively etched to produce a spaced succession of narrow, shallow trenches separated by narrow silicon mesas. Silicon oxide is chemical-vapor-deposited on the horizontal and vertical surfaces of the etched structure to a thickness equalling the width of a desired silicon oxide mask. The mask is used for etching multiple deep trenches in the substrate, the trenches being separated by thin walls of silicon. The thickness of the walls is uniformly equal to and determined by the thickness of the deposited silicon oxide mask. The deposited silicon oxide is reactively ion etched away from the horizontal surfaces, leaving the oxide only on the sidewalls of the shallow trenches. The silicon is deeply etched, using the remaining oxide as a mask. Boron is ion implanted and the resulting structure is thermally oxidized sufficiently to completely oxidize the silicon under the deposited oxide mask and to oxidize the silicon surfaces at the bottoms of the trenches. The remaining trench volume is filled in with chemical-vapor-deposited silicon dioxide.

Planar deep oxide isolation process utilizing resin glass and E-beam exposure

Abstract: A planar deep oxide isolation process for providing deep wide silicon dioxide filled trenches in the planar surface of a silicon semiconductor substrate, said process comprising the steps: (a) forming deep wide trenches in the planar surface of the silicon substrate; (b) forming a thin layer of silicon dioxide on the planar surface of the silicon substrate and the exposed silicon surfaces of said deep wide trenches; (c) applying resin glass (polysiloxane) to the planar surface of said semiconductor substrate and within said deep wide trenches; (d) spinning off at least a portion of the resin glass on the planar surface of the substrate; (e) baking the substrate at a low temperature; (f) exposing the resin glass contained within the deep wide trenches of substrate to the energy of an E-beam; (g) developing the resin glass contained on said substrate in a solvent; (h) heating said substrate in oxygen to convert said resin glass contained within said deep wide trenches to silicon dioxide; (i) depositing a layer of silicon dioxide to provide a planar silicon dioxide surface on the exposed the surface of said substrate; and (j) planarize exposed silicon dioxide surface to silicon of substrate. A planar deep oxide isolation process for providing deep wide silicon dioxide filled trenches in the planar surface of a silicon semiconductor substrate as recited in the preceding paragraph, wherein the following steps are performed in lieu of step i of claim 1, said steps comprising: (i-1) apply a second thin layer of resin glass; and (i-2) convert said resin glass to silicon dioxide.

Spray‐deposited high‐efficiency SnO2/n‐Si solar cells

Abstract: SnO2/n‐Si solar cells (area=1 and 4 cm2) having AM1 efficiencies of 12.3% on single‐crystal silicon and 10.1% on polycrystalline silicon have been fabricated. The tin oxide is deposited by spraying a SnCl4 mixture onto heated silicon substrates. Using this low‐cost process, large‐area (20‐cm2) single‐crystal cells having 10% efficiency have also been made. The smaller diffusion length and higher resistivity in the polycrystalline silicon (Wacker) accounts for its lower efficiency as compared to single‐crystal cells.

Semiconductor absolute pressure transducer assembly and method

Abstract: A semiconductor pressure transducer assembly comprising a silicon diaphragm assembly and a glass covering member. The silicon diaphragm assembly has a circular diaphragm portion of thin silicon which is formed using etching, and a thick supporting portion therearound. Piezoresistive elements of a piezoresistive bridge circuit and conducting paths for electrically connection thereof are formed on the silicon diaphragm assembly. On a surface of the silicon diaphragm assembly, a passivating layer of silicon dioxide are formed in uniform thickness, and further on a surface of the passivating layer is formed a layer of polysilicon on the supporting portion of the silicon diaphragm assembly. In the passivating layer, a contacting window is formed, through which the polysilicon layer is electrically connected to the silicon diaphragm assembly. The covering member of borosilicate glass having a circular well is mounted and bonded onto the silicon diaphragm assembly in contact with the polysilicon layer using Anodic Bonding method. And the processed silicon diaphragm assembly has a flat surface thereof, on which the piezoresistive elements and the conducting paths are constructed using Ion Implantation method, or reforming a silicon dioxide layer thereon after removing another silicon dioxide layer used as mask in diffusing process.

Low pressure chemical vapor deposition of silicon dioxide with oxygen enhancement of the chlorosilane-nitrous oxide reaction

Abstract: A method is described for forming a silicon dioxide layer on a semiconductor substrate in a furnace heated reaction zone of a chemical vapor deposition reactor having an input end for gaseous reactants wherein the silicon dioxide layer is not subject to degradation during subsequent oxidation cycles. A gaseous chlorosilane is mixed with nitrous oxide gas in the reactor. Oxygen gas is added, between about 0.25% to 10% by volume of total reactive gas mixture, to the chlorosilane and nitrous oxide gases in the reaction zone where the temperature is between about 800° C. to 1200° C. in a pressure of less than about 5 torr to deposit the silicon dioxide layer onto the substrate.

Physicochemical characterization of the interaction between cobalt molybdenum oxide and silicon dioxide--2. Influence of the amount of oxide phase

Abstract: Catalysts containing 2.8-20.6Vertical Bar3< molybdenum on silica or 3.7-27.6Vertical Bar3< of a mixed cobalt-molybdenum oxide containing 36Vertical Bar3< cobalt were studied by hydrogen reduction, pore size distribution, X-ray analysis, diffuse reflectance spectroscopy, and analytical electron microscopy. The results suggested that the differences between the molybdenum and cobalt-molybdenum hydrodesulfurization catalysts are only quantitative and that their activity differences depend mainly on their dispersion in the sulfided form, which in turn depends on the dispersion of the oxide precursors.

Aqueous heat-storage compositions containing fumed silicon dioxide and having prolonged heat-storage efficiencies

Abstract: Aqueous heat-storage compositions useful in space heating applications are disclosed which contain a phase-change material which absorbs and stores heat as it is heated above its phase-change temperature and releases stored heat as it is cooled below its phase-change temperature. These compositions include fumed silicon dioxide which acts as a stabilizing agent and provides dramatically prolonged heat-storage efficiency for these compositions as they undergo repetitive cycling through their phase-change temperature. Articles containing such compositions and methods of forming such compositions are additionally disclosed.

Method of manufacture of optical fiber

Abstract: A process is disclosed for manufacturing an optical fiber comprising a silica cladding and multi-component glass core wherein a tube made of the cladding material serves as a crucible in which the core glass is melted and fined. The core glass includes silicon dioxide, boron oxide, barium oxide or lead oxide (or a combination of both, and an alkali oxide). The materials are selected to provide a high numerical aperture, rapid melting and stability at the high temperatures required to draw the fiber. In accordance with a further feature of the invention, the batch material for the core is actually melted as it is falling to the bottom of the silica tube, thereby increasing the speed of melting and further facilitating outgassing of effluents.

Method for surface treatment of phosphor particles

Abstract: Disclosed is a method for surface treatment of phosphor particles which comprises forming a continuous film of silicon dioxide on the surface of each phosphor particle by treating the phosphor particle with a solution containing an aqueous solution of organic alkali and silicon dioxide dissolved therein.

Silicon—silicon dioxide as an electrode for electrical and ellipsometric measurements of adsorbed organic molecules

Abstract: The use of silicon covered by silicon dioxide as a substrate for thin organic layers studied by a combination of electrical impedance measurements and ellipsometric measurements is described. This substrate is inert and the silicon-dioxide surface may be made hydrophobic or hydrophilic at will. Adsorption of organic molecules can be studied both electrically and optically. With doubleelectrode systems coverage and capacitance of the adsorbed monolayers may be measured separately. Surface potential may be measured provided the adsorbed layers are sufficiently insulating. Lipid monolayers may be established on the surface and their insulating properties measured. Further adsorption on the lipid monolayers may be studied as for example the influence of different drugs. Measurements on protein, peptide, and lipid monomolecular layers are presented.

A method of etching a surface

Abstract: The invention relates to a method of etching surfaces such as silicon dioxide, silicon nitride and silicon carbide by exposing the surface simultaneously to a noble gas halide such as fluorinated xenon compound and radiation such as electron beam radiation. The etch rate of silicon dioxide achieved by the present invention, as illustrated in Figure 1, is about 200 angstroms per minute.

Methods of making composite conductive structures in integrated circuits

Abstract: A method of making a composite conductive structure is described. The structure includes an insulating substrate on which is provided a conductor of a refractory metal substantially nonreactive with silicon dioxide covered by a layer of a silicide of the refractory metal and a layer of silicon dioxide. The method includes depositing a layer of polycrystalline silicon over the conductor and the insulating substrate, reacting the layer of polycrystalline silicon with the conductor to form a refractory metal silicide, removing the unreacted portion of the layer of polycrystalline silicon, and then oxidizing the exposed surface of the refractory metal silicide into a layer of silicon dioxide.

Cementitious compositions with early high strength development and methods for controlling setting rate

Abstract: A composition is supplied for filling pot holes and other types of structural deterioration The composition consist of hydraulic cement and an alkali metal silicate The silicate includes a molar ratio of silican dioxide to alkali metal oxide from 04 to 40 The silicate is in a concentration ranging from 02 to 20 percent by weight of the cement A method is also provided which comprises repairing a deteriorating structure by inserting therein a cementitious composition and controlling the rate of setting of the composition by the inclusion therein of sodium silicate in the molar ratio of silicon dioxide to sodium oxide of from 04 to 40

Room temperature two color infrared detector

Abstract: An amorphous film (44) of a photoresponsive semi-conducting material such germanium-telluride deposited upon a thick silicon dioxide layer (40) formed on a silicon chip substrate (38). The silicon chip (38) underlying the central region of the amorphous film (44) is etched through to the silicon dioxide layer (40) to define a trough (48) thermally isolating the central region of the silicon dioxide layer (40).

Process for doping semiconductor crystals

Abstract: Semiconductor crystals, especially silicon semiconductor crystals, are doped using a solution to which there are added a silicon dioxide film forming material, a p or n doping material and organic solvent, by applying this solution to the surface of the semiconductor crystals drying and calcining while forming a cohesive, adhering coating layer, and diffusing the doping material into the semiconductor crystals in the calcining. The improvement is using as the silicon dioxide film forming components acidified solutions of partially hydrolyzed alkyl and/or polysilicates, the solutions having a pH between 2 and 6.

Sequentially annealed oxidation of silicon to fill trenches with silicon dioxide

Abstract: A process for making dielectrically isolated silicon integrated circuits which use silicon oxide filled trenches to provide isolation is described. To minimize damage to the silicon, the trenches are filled by sequentially annealed oxidation process which involves alternately growing some oxide and then annealing to relieve stresses before growing more oxide.

Process for the preparation of 1,4-diazabicyclo-(2,2,2)-octane

Abstract: A process for the preparation of 1,4-diazobicyclo-(2,2,2)-octane by contacting piperazine with a catalyst at an elevated temperature, the catalyst containing silicon dioxide

Compositions containing silicon dioxide

Abstract: The present invention relates to the use of amorphous, dust-like silicon dioxide emission products from electro-thermic manufacture of ferrosilicon and/or silicon as fillers in refractory compositions. The advantages obtained from the use of the products include improvement in mechanical abrasion resistance, heat stability, and electrical, thermal and sound insulation.

Apparatus for producing and casting liquid silicon

Abstract: The method and apparatus for producing liquid silicon of high purity and for casting silicon. Hydrogen and a hydrogenated silane in gaseous state are mixed, preferably with a source of a small amount of oxygen, in a heated chamber producing the liquid silicon, with the exhaust gases bubbling out of the melt under a baffle. The chamber for the melt of liquid silicon preferably is lined with silicon dioxide. The liquid silicon may be used in making high purity vitreous silica and may be used in making castings of silicon. In making castings, the liquid silicon is accumulated in a second chamber and is periodically drawn from the second chamber into a third chamber which contains the mold for the casting.

Planar epitaxial refill using liquid phase epitaxy

Abstract: Planar silicon device structures are fabricated by refilling grooves etched in an oxide-coated silicon substrate using liquid phase epitaxial growth from a tin melt. Since tin does not wet silicon dioxide, silicon nucleation on the oxide-covered areas of the substrate is precluded. Consequently, epitaxial growth selectively occurs in the grooves, without undesirable silicon growth over the oxide. This avoids the short-circuits and surface nonplanarity resulting from the growth of polycrystalline silicon on the oxide layer covering the unetched areas when vapor phase epitaxial growth is employed.

Method for increasing the bulk weight of silicon dioxide

Abstract: A method for increasing the bulk weight of silicon dioxide with a surface of at least 50m2 /g by means of sub-atmospheric pressure applied at a filter face, wherein the silicon dioxide is moved by means of a conveyor screw, whose longitudinal axis is arranged parallel with respect to the filter face and which preferably has a decreasing thread pitch in feeding direction. Furthermore, the invention relates to the use of the treated silicon dioxide as a filler material for polymeric masses, especially diorganopolysiloxane, which is storeable in the absence of water and when admixed with water at room temperature results in a hardened elastomer mass.

Aluminum metaphosphate optical fibers

Abstract: Aluminum metaphosphate optical fibers are disclosed. In a specific embodiment, aluminum metaphosphate, doped with from 10 to 30 mole percent of diboron trioxide, is found to yield an optical fiber which combines the desirable properties of both high numerical aperture and low material dispersion. The fiber is nonhygroscopic and has a high melting temperature. The index of refraction of the glass may be lowered by doping with silicon dioxide. Consequently, a graded fiber may be made by increasing the concentration of silicon oxide from the core to the cladding.

Multilevel interconnect system for high density silicon gate field effect transistors

Abstract: A metal oxide semiconductor device having at least one level of polycrystalline silicon interconnects and novel insulation layers for multilevel interconnects. In one embodiment a layer of arsenic doped glass replaces the conventional phosphorus doped glass insulation layer. In other embodiments a layer of arsenic doped glass upon an undoped layer of silicon dioxide provides the insulation layer. Slow diffusing source-drain impurities along with these insulation layers provide minimum lateral source-drain diffusion.

Preparation of plastic antireflection film

Abstract: PURPOSE: To obtain an antireflection film having improved adhesion, resistance to boiling water and scuffing, by evaporating silicon monoxide and zirconium in the presence of oxygen, and by forming an oxide layer of higher degree than said compound on a plastic base board. CONSTITUTION: A gas containing oxygen is introduced to evaporate silicon monoxide (which may contain a high-degree silicon oxide) and zirconium or its monoxide in a vacuum system. The vapor is then deposited on a plastic base board, if necessary ion bombarded, by radiofrequency ion plating or vacuum deposition in combination, to form a film of higher degree than said compound. A combination of the compounds provides an antireflection film comprising, e.g. films of silicon oxide of refractive index (RI) about 1.7, zirconium oxide of RI 1.2, and silicon dioxide of RI l.5 on the base film of silicon dioxide. COPYRIGHT: (C)1980,JPO&Japio

Semiconductor component mfg. process - radiating silicon di:oxide passivation layer containing phosphor with long wave laser light to cause depletion near surface

Abstract: A silicon dioxide layer containing phosphor is used as the passivation or covering layer. The phosphor content is 5% max. The mounting is carried out by intensive radiation of long-wave laser light in the micron region. The wavelength is chosen so that it falls within the max. absorption range of the silicon dioxide layer. The duration and intensity of the phosphor in the zone near the surface. The Thosphor-doped layer begins to melt, under the influence of the absorbed light, at a temp. well below that of the silicon substrate, oxide layer and silicon layer. The doping profile remains since the laser light is not absorbed by the silicon structure.

Production of semiconductor device

Abstract: PURPOSE:To control impurity concentration of diffused layer by implanting impurity ions through ion implantation into the insulation film of a semiconductor substrate and performing diffusion in the semiconductor with this insulation film as a diffusion source. CONSTITUTION:Silicon dioxide 2 is grown on monocrystalline silicon 1 and a pattern for obtaining diffused layers is formed through photo resist 3. Next, boron B ions 4 are doped into the silicon dixode 2 through ion implantaion to convert the silicon dixode to borosilicate glass 5. Next, the photo resist 3 is removed, after which drive-in is performed in an inert gas atmosphere, whereby a P type diffused layer 6 is obtaind. As a result, the P type diffused layer 6 having been formed has less variations in impurity concentration owing to the controlled doping through ion implantation and since the silicon dioxide is thick, the out-diffusion of the impurity from the inside of the silicon substrate is less.