1374results about "Under a protective fluid" patented technology

A method may produce a resonant cavity light emitting device. A seed gallium nitride crystal and a source material in a nitrogen-containing superheated fluid may provide a medium for mass transport of gallium nitride precursors therebetween. A seed crystal surface may be prepared by applying a first thermal profile between the seed gallium nitride crystal and the source material. Gallium nitride material may be grown on the prepared surface of the seed gallium nitride crystal by applying a second thermal profile between the seed gallium nitride crystal and the source material while the seed gallium nitride crystal and the source material are in the nitrogen-containing superheated fluid. A stack of group III-nitride layers may be deposited on the single-crystal gallium nitride substrate. The stack may include a first mirror sub-stack and an active region adaptable for fabrication into one or more resonant cavity light emitting devices.

A method of manufacturing a single crystal ingot, and a single crystal ingot and a wafer manufactured thereby are provided. The method of manufacturing a single crystal ingot according to an embodiment includes forming a silicon melt in a crucible inside a chamber, preparing a seed crystal on the silicon melt, and growing a single crystal ingot from the silicon melt, and pressure of the chamber may be controlled in a range of 90 Torr to 500 Torr.

The invention is related to nuclear physics, medicine and oil industry, namely to the measurement of x-ray, gamma and alpha radiation; control for trans uranium nuclides in the habitat of a man; non destructive control for the structure of heavy bodies; three dimensional positron-electron computer tomography, etc.The essence of the invention is in additional ingredients in a chemical composition of a scintillating material based on crystals of oxyorthosilicates, including cerium Ce and crystallized in a structural type Lu2SiO5.The result of the invention is the increase of the light output of the luminescence, decrease of the time of luminescence of the ions Ce3+, increase of the reproducibility of grown crystals properties, decrease of the cost of the source melting stock for growing scintillator crystals, containing a large amount of Lu2O3, the raise of the effectiveness of the introduction of SCintillating crystal luminescent radiation into a glass waveguide fibre, prevention of cracking of crystals during the production of elements, creation of waveguide properties in scintillating elements, exclusion of expensive mechanical polishing of their lateral surface.

The present invention relates to a process for the preparation of doped organic semiconductor materials having an increased charge carrier density and effective charge carrier mobility, by doping with a dopant, a process in which after mixing the dopant into the organic semiconductor material, hydrogen, carbon monoxide, nitrogen or hydroxyl radicals are split off and at least one electron is transferred to the semiconductor material or from the semiconductor material. The process is distinguished by the fact that an uncharged organic compound is used as dopant. Doped organic semiconductor materials are obtainable by one of the processes. The semiconductor materials are distinguished by the fact that the doped layer contains cations of at least one organic compound, the uncharged form of the organic compound being unstable in air.

Apparatus and methods are described for fabricating a compound nitride semiconductor structure. Group-III and nitrogen precursors are flowed into a first processing chamber to deposit a first layer over a substrate with a thermal chemical-vapor-deposition process. The substrate is transferred from the first processing chamber to a second processing chamber. Group-III and nitrogen precursors are flowed into the second processing chamber to deposit a second layer over the first layer with a thermal chemical-vapor-deposition process. The first and second group-III precursors have different group-III elements.

A method for determining crystallization conditions for a material, the method comprising: taking a microfluidic device comprising one or more lumens having microvolume dimensions and a plurality of different crystallization samples within the one or more lumens, the plurality of crystallization samples comprising a material to be crystallized and crystallization conditions that vary among the plurality of crystallization samples; transporting the plurality of different crystallization samples within the lumens; and identifying a precipitate or crystal formed in the one or more lumens.

A capsule for containing at least one reactant and a supercritical fluid in a substantially air-free environment under high pressure, high temperature processing conditions. The capsule includes a closed end, at least one wall adjoining the closed end and extending from the closed end; and a sealed end adjoining the at least one wall opposite the closed end. The at least one wall, closed end, and sealed end define a chamber therein for containing the reactant and a solvent that becomes a supercritical fluid at high temperatures and high pressures. The capsule is formed from a deformable material and is fluid impermeable and chemically inert with respect to the reactant and the supercritical fluid under processing conditions, which are generally above 5 kbar and 550° C. and, preferably, at pressures between 5 kbar and 80 kbar and temperatures between 550° C. and about 1500° C. The invention also includes methods of filling the capsule with the solvent and sealing the capsule, as well as an apparatus for sealing the capsule.

A method for growing a nitride crystal and a crystalline composition selected from one of AlN, InGaN, AlGaInN, InGaN, and AlGaNInN is provided. The composition comprises a true single crystal, grown from a single nucleus, at least 1 mm in diameter, free of lateral strain and tilt boundaries, with a dislocation density less than about 104 cm−2.

A silicon casting apparatus for producing polycrystal silicon ingot by heating a silicon melt (8) held in a mold (4) from above by a heater (3) and cooling it from below while changing the heat exchange area of a heat exchange region (HE), defined between a pedestal (5) having the mold (4) placed thereon and a bottom cooling member (6), in such a manner as to keep pace with the rise of the solid-liquid interface of the silicon melt (8), thereby causing unidirectional solidification upward along the mold (4); and a method of producing polycrystal silicon ingot using such apparatus. According to this production method, the temperature gradient given to the silicon melt (8) can be maintained at constant by adjusting the heat exchange area, so that polycrystal silicon ingot having good characteristics can be produced with good reproducibility.

Method capable of preparing silicon having purity of about 6N applied to a solar cell efficiently at a low cost. Raw silicon containing boron and a slag are melted and a shaft is rotated by a rotating / driving mechanism for stirring the molten silicon. The molten slag is dispersed in the molten silicon, thereby accelerating the boron removal reaction. It is further effective to use a slag containing at least 45 percent by mass of silicon oxide or to blow gas mixed with water vapor into the molten silicon for refining reaction.

There is provided a group III nitride crystal growth method capable of obtaining a material which is a GaN substrate of low defect density capable of being used as a power semiconductor substrate and in which characteristics of n-type and p-type requested for formation of transistor or the like. A growth method of group III nitride crystals includes: forming a mixed melt containing at least group III element and a flux formed of at least one selected from the group consisting of-alkaline metal and alkaline earth metal, in a reaction vessel; and growing group III nitride crystals from the mixed melt and a substance containing at least nitrogen, wherein after immersing a plurality of seed crystal substrates placed in an upper part of the reaction vessel in which the mixed melt is formed, into the mixed melt to cause crystal growth, the plurality of seed crystal substrates are pulled up above the mixed melt.

A silicon semiconductor substrate is obtained by deriving a silicon semiconductor substrate from a silicon single crystal grown by the Czochralski method from a molten silicon containing not less than 1x1016 atoms / cm3 and not more than 1.5x1019 atoms / cm3 of nitrogen and heat-treating the silicon semiconductor substrate at a temperature of not less than 1000° C. and not more than 1300° C. for not less than one hour and is characterized by the fact that the density of crystal defects measuring not less than 0.1 mum as reduced to diameter is not more than 104 pieces / cm3 at least in the region reaching a depth of 1 mum from the surface of the substrate and the nitrogen content at the center of thickness of the silicon semiconductor substrate is not less than 1x1013 atoms / cm3 and not more than 1x1016 atoms / cm3.

Inventions relate to scintillation substances and they may be utilized in nuclear physics, medicine and oil industry for recording and measurements of X-ray, gamma-ray and alpha-ray, nondestructive testing of solid states structure, three-dimensional positron-emission tomography and X-ray computer tomography and fluorography. Substances based on silicate comprising lutetium and cerium characterised in that compositions of substances are represented by chemical formulae CexLu2+2y−xSi1−yO5+y, CexLiq+pLu2−p+2y−x−zAzSi1−yO5+y−p, CexLiq+pLu9.33−x−p−z□0.67AzSi6O26−p, where A is at least one element selected from group consisting of Gd, Sc, Y, La, Eu, Tb, x is value between 1×10−4 f.units and 0.02 f.units., y is value between 0.024 f.units and 0.09 f.units, z is value does not exceeding 0.05 f.units, q is value does not exceeding 0.2 f.units, p is value does not exceeding 0.05 f.units. Achievable technical result is the scintillating substance having high density, high light yield, low afterglow, and low percentage loss during fabrication of scintillating elements.

A method of producing high-quality and large-diameter single crystals by the Czochralski method is disclosed which can provide wafers with a minimized number of such grown-in defects as dislocation clusters and laser scattering tomography defects. Specifically, it is a method of producing silicon single crystals which comprises carrying out the crystal pulling while maintaining the solid-melt interface during pulling in the shape of an upward convex with the central portion of the interface being higher by at least 5 mm than the peripheral region thereof and while applying a magnetic field, and optionally in addition to the above, while maintaining the temperature gradient in the direction of axis of pulling in the peripheral region at a level lower than that in the central portion in the range of from the melting point to 1,200° C. In this case, it is desirable that the portion of the single crystal surface lying at least 50 mm above the melt surface be shielded from direct radiant heat from the heater and / or crucible wall, that a horizontal magnetic field of 0.08 to 0.3 T be applied in parallel with the melt surface or a cusped magnetic field showing an intensity of 0.02 to 0.07 T at a crucible wall site on the melt surface be applied and that the crucible be rotated at a speed of not more than 5 min-1 and the single crystal at a speed of not less than 13 min-1.

A weir is extended vertically to define an optimal annular gap between the top of the weir and the underside of a super-adjacent heat shield. The annular gap provides a high velocity stream of argon gas to be directed from the growth region to the melt region to substantially eliminate the transport of airborne particles from the melt region to the growth region. The tall weir may be configured as a modular, reusable weir extension supportably engaged with an outer (and / or inner) weir.

A method of making a single crystal GaN boule, comprising contacting a GaN seed wafer with a GaN source environment under process conditions including a thermal gradient in the GaN source environment producing growth of gallium nitride on the GaN seed wafer, thereby forming the GaN boule. The GaN source environment in various implementations includes gallium melt in an ambient atmosphere of nitrogen or ammonia, or alternatively, supercritical ammonia containing solubilized GaN. The method produces single crystal GaN boules >10 millimeters in diameter, of device quality suitable for production of GaN wafers useful in the fabrication of microelectronic, optoelectronic and microelectromechanical devices and device precursor structures therefor.

A novel method for growing semiconductor material including GaN is disclosed. The method involves placing a first substance into a growth reactor, supplying a second gaseous substance into the grouth reactor, and applying electrical field to the second gaseous substance to produce the cry stalline compound material.

The present invention is directed to the method and apparatus for the robotic harvesting of solids from liquids as exemplified by harvesting protein crystals. Further, the present invention is directed to a fluid / solid management system in a chamber that automates the task of solid harvesting. The fluid / solid management system includes two supporting structures for at least one pipette on one structure and a second pipette on the other structure, the two pipettes in tip-to-tip alignment. The pipettes each having a drop of liquid at the end thereof are moved apart to form a liquid bridge in which the solid crystal is isolated. A robotic arm has a device on the end thereof for the harvesting of the solid at the working point between the tips of the pipettes. The system has a flash freezing system in the chamber for the safe storage of the harvested solid.

An improved system based on the Czochralski process for continuous growth of a single crystal ingot comprises a low aspect ratio, large diameter, and substantially flat crucible, including an optional weir surrounding the crystal. The low aspect ratio crucible substantially eliminates convection currents and reduces oxygen content in a finished single crystal silicon ingot. A separate level controlled silicon pre-melting chamber provides a continuous source of molten silicon to the growth crucible advantageously eliminating the need for vertical travel and a crucible raising system during the crystal pulling process. A plurality of heaters beneath the crucible establish corresponding thermal zones across the melt. Thermal output of the heaters is individually controlled for providing an optimal thermal distribution across the melt and at the crystal / melt interface for improved crystal growth. Multiple crystal pulling chambers are provided for continuous processing and high throughput.

A crucible is provided that is thermally stable at high temperatures and is suitable for use in the growth of large, bulk AlN, AlxGa1-xN or other nitride single crystals. The crucible is comprised of specially treated tantalum. During the initial treatment, the walls of the crucible are carburized, thus achieving a crucible that can be subjected to high temperatures without deformation. Once the carburization of the tantalum is complete, the crucible undergoes further treatment to protect the surfaces that are expected to come into contact with nitride vapors during crystal growth with a layer of TaN. If the crucible is to be used with a graphite furnace, only the inner surfaces of the crucible are converted to TaN, thus keeping TaC surfaces adjacent to the graphite furnace elements. If the crucible is to be used with a non-graphite furnace, both the inner and outer surfaces of the crucible are converted to TaN.

A method for producing a single crystal ingot includes steps of providing a first amount of polycrystalline material and a first amount of dopant material to form a first mixture having a first dopant concentration in a process furnace, increasing a temperature of the first mixture to provide a molten first mixture, providing a seed material to the molten first mixture, withdrawing the seed from the molten first mixture by a first distance to form a boule having a first length, providing a second amount of the polycrystalline material and a second amount of the dopant material to the molten first mixture to provide a molten second mixture having the first dopant concentration, withdrawing the first length of the boule from the molten second mixture by a second distance to form the boule having a second length, and removing the boule from the molten second mixture to form the single crystal ingot of uniform axial resistivity.

A quartz crucible having reduced / controlled bubble content is disclosed, comprising an outer layer and an inner layer doped with elements and compounds that: a) react with oxygen and nitrogen at or near the fusion temperature of quartz; and b) form compounds that are thermally stable at temperatures of above 1400° C. and chemically stable in a SiO2 environment. A method to make a crucible having controlled bubble content is also disclosed, the method comprises the step of forming a crucible having an inner layer doped with a material that reacts with residual gases in the bubble such as nitrogen and oxygen and thus consume the gases in the bubbles and empty them in the fusion process.

A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

A scintillator composition of a halide perovskite material of at least one ABX3 type halide perovskite, at least one activator for the matrix material and optionally at least one charge compensator to assist the incorporation of the activator in the perovskite lattice and any reaction products thereof. Radiation detectors that use the scintillators are also described, as are related methods for detecting high-energy radiation and method of producing an activated halide-perovskite based scintillator crystal.

A method and apparatus for growing silicon carbide crystals is provided. The apparatus includes a sublimation chamber with a plurality of spaced apart dividers that can direct the direction of silicon carbide crystal growth into passages between the dividers to form a plurality of silicon carbide crystal plates. The silicon carbide crystal plates can be used as seed crystals in subsequent sublimation steps in a manner that promotes the growth of silicon carbide crystals in different crystallographic directions to thereby terminate defect formation.

A silica glass crucible includes a thin barium-doped inner layer, a stable, bubble-free intermediate layer, and a stable opaque outer layer. The fusion process of the present invention controls the dynamic gas balance at the fusion front where formed grain is melted to dense fused silica. The crucible demonstrates reduced bubble growth during a Czochralski process. As a result of the thin barium-doped layer and the reduced bubble growth, the inner surface of the crucible is uniformly minimally textured during a CZ process. The present crucible is especially suited for intense CZ processes for manufacturing silicon ingots used for solar cells or with silicon that is heavily doped with antimony, boron, or arsenic.

A vitreous silica member of the present invention is characterized by being formed of vitreous silica exhibiting the easily crystallizable property in the absence of a crystallization accelerator. The vitreous silica having the easily crystallizable property is obtained preferably by heating and melting crystalline quartz at a temperature in the range of 1,710° C. or more to 1,780° C. or less for vitrification, and controlling the fictive temperature of the glass to be in the range of 1,100° C. or more to 1,400° C. or less. The invention also includes a vitreous silica crucible and a method of pulling single-crystal silicon using this vitreous silica crucible.

A high-quality crystal sheet is provided. An apparatus for use in producing a crystal sheet includes a substrate having a main surface on which a crystal sheet is formed, a crucible holding a melt therein, a movable member holding the substrate to move it to bring its main surface into contact with the melt and then move the substrate away from the melt, and cooling means for cooling the movable member.