1056results about "Liquid-phase epitaxial-layer growth" patented technology

Scanning Laser Epitaxy (SLE) is a layer-by-layer additive manufacturing process that allows for the fabrication of three-dimensional objects with specified microstructure through the controlled melting and re-solidification of a metal powders placed atop a base substrate. SLE can be used to repair single crystal (SX) turbine airfoils, for example, as well as the manufacture functionally graded turbine components. The SLE process is capable of creating equiaxed, directionally solidified, and SX structures. Real-time feedback control schemes based upon an offline model can be used both to create specified defect free microstructures and to improve the repeatability of the process. Control schemes can be used based upon temperature data feedback provided at high frame rate by a thermal imaging camera as well as a melt-pool viewing video microscope. A real-time control scheme can deliver the capability of creating engine ready net shape turbine components from raw powder material.

A high pressure apparatus and related methods for processing supercritical fluids. In a specific embodiment, the present apparatus includes a capsule, a heater, at least one ceramic ring but can be multiple rings, optionally, with one or more scribe marks and / or cracks present. In a specific embodiment, the apparatus optionally has a metal sleeve containing each ceramic ring. The apparatus also has a high-strength enclosure, end flanges with associated insulation, and a power control system. IN a specific embodiment, the apparatus is capable of accessing pressures and temperatures of 0.2-2 GPa and 400-1200° C., respectively.

An improved capsule for processing materials or growing crystals in supercritical fluids. The capsule is scalable up to very large volumes and is cost effective according to a preferred embodiment. In conjunction with suitable high pressure apparatus, the capsule is capable of processing materials at pressures and temperatures of 0.2-8 GPa and 400-1500° C., respectively. Of course, there can be other variations, modifications, and alternatives.

Scanning Laser Epitaxy (SLE) is a layer-by-layer additive manufacturing process that allows for the fabrication of three-dimensional objects with specified microstructure through the controlled melting and re-solidification of a metal powders placed atop a base substrate. SLE can be used to repair single crystal (SX) turbine airfoils, for example, as well as the manufacture functionally graded turbine components. The SLE process is capable of creating equiaxed, directionally solidified, and SX structures. Real-time feedback control schemes based upon an offline model can be used both to create specified defect free microstructures and to improve the repeatability of the process. Control schemes can be used based upon temperature data feedback provided at high frame rate by a thermal imaging camera as well as a melt-pool viewing video microscope. A real-time control scheme can deliver the capability of creating engine ready net shape turbine components from raw powder material.

Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.

A single crystal substrate and method of fabricating the same are provided. The single crystal substrate includes an insulator having a window exposing a portion of a substrate, a selective epitaxial growth layer formed on the portion of the substrate exposed through the window and a single crystalline layer formed on the insulator and the selective epitaxial growth layer using the selective epitaxial growth layer as an epitaxial seed layer.

An improved high pressure apparatus and related methods for processing supercritical fluids. In a specific embodiment, the present apparatus includes a capsule, a release sleeve, a heater, at least one ceramic segment or ring but can be multiple segments or rings, optionally, with one or more scribe marks and / or cracks present. In a specific embodiment, the apparatus optionally has a metal sleeve containing each ceramic ring. The apparatus also has a high-strength enclosure, end flanges with associated insulation, and a power control system. In a specific embodiment, the apparatus is capable of accessing pressures and temperatures of 0.2-2 GPa and 400-1200° C., respectively. Following a run, the release sleeve may be at least partially dissolved or etched to facilitate removal of the capsule from the apparatus.

Porous films with straight pores oriented normal to the plane of the films are produced through solution processing techniques. The production takes advantage of inorganic-surfactant or inorganic-polymer co-assembly and a patterned substrate. The patterned substrate, which is also produced via solution phase self-assembly, forces vertical orientation in a hexagonal cylinder system with no practical limits in substrate size or type. This provides a route to vertically oriented inorganic pores with a pitch ranging from 3 nm to over 15 nm and pore sizes ranging from 2 nm to over 12 nm. The size is tuned by choice the choice of organic templating agents and the deposition conditions. The pores can be produced with or without a capping layer which can be used to seal the nanopores.

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 method for fabricating a Light Emitting Diode (LED) with increased light extraction efficiency, comprising providing a III-Nitride based LED structure comprising a light emitting active layer between a p-type layer and an n-type layer; growing a Zinc Oxide (ZnO) layer epitaxially on the p-type layer by submerging a surface of the p-type layer in a low temperature aqueous solution, wherein the ZnO layer is a transparent current spreading layer; and depositing a p-type contact on the ZnO layer. The increase in efficiency may be more than 93% with very little or no increase in cost.

Provided are a graphene pattern and a process of preparing the same. Graphene is patterned in a predetermined shape on a substrate to form the graphene pattern. The graphene pattern can be formed by forming a graphitizing catalyst pattern on a substrate, contacting a carbonaceous material with the graphitizing catalyst and heat-treating the resultant.

A method of forming an epitaxially grown layer, preferably by providing a region of weakness in a support substrate and transferring a nucleation portion to the support substrate by bonding. A remainder portion of the support substrate is detached at the region of weakness and an epitaxial layer is grown on the nucleation portion. The remainder portion is separated or otherwise removed from the support portion.

The present invention provides nanoparticle film and methods of making such films. The nanoparticle film comprises a three dimensional cross-linked array of nanoparticles and linker molecules. The nanoparticle film is coherent, robust and self supporting. The film may be produced by adding linker molecules to a suspension of nanoparticles. The linker molecules form cross-links between the nanoparticles. Prior to completion of the cross-linking reaction the cross-linked nanoparticles are separated from the suspension.

The present III-nitride crystal manufacturing method, a method of manufacturing a III-nitride crystal (20) having a major surface (20m) of plane orientation other than {0001}, designated by choice, includes: a step of slicing III-nitride bulk crystal (1) into a plurality of III-nitride crystal substrates (10p), (10q) having major surfaces (10pm), (10qm) of the designated plane orientation; a step of disposing the substrates (10p), (10q) adjoining each other sideways in such a way that the major surfaces (10pm), (10qm) of the substrates (10p), (10q) parallel each other and so that the [0001] directions in the substrates (10p), (10q) are oriented in the same way; and a step of growing III-nitride crystal (20) onto the major surfaces (10pm), (10qm) of the substrates (10p), (10q).

A method of manufacturing a potassium niobate (KNbO3) single crystal thin film, includes the steps of maintaining the substrate under a predetermined oxygen partial pressure; maintaining the substrate within a temperature region which is equal to or higher than an eutectic temperature of KNbO3 and 3K2O.Nb2O5 and is equal to or lower than complete melting temperature of KNbO3 and 3K2O.Nb2O5 so that a solid phase of KNbO3 and a liquid phase can coexist on the substrate; depositing a vapor phase material on the substrate in a state in which a solid phase and a liquid phase coexist; and precipitating KNbO3 on the substrate from the liquid phase as a solid phase to grow a KNbO3 single crystal thin film. The composition of a starting material to be vaporized to generate the vapor phase material is from K2O.Nb2O5=50:50 to K2O.Nb2O5=65:35.

There are provided methods of purifying a material, comprising melting solid material to form liquefied material, directionally solidifying a portion of the liquefied material; and removing a liquid remainder from the purified solidified material. Preferably, the purified solidified material is melted to form re-liquefied purified material, and re-liquefied purified material is removed. Preferably, the material is positioned in a container as it is being purified. The method is particularly useful for purifying elemental material, e.g., semiconductor material such as silicon and / or germanium, such as recycle scrap silicon and / or metallurgical grade silicon. There are also provided systems for carrying out such methods.

A method for producing a nitride semiconductor crystal comprising a step (a) for forming fine crystal particles made of a nitride semiconductor on a substrate; a step (b) for forming a nitride semiconductor island structure having a plurality of facets inclined relative to a surface of the substrate with the fine crystal particles as nuclei; and a step (c) for causing the nitride semiconductor island structure to grow in a direction parallel with a surface of the substrate to merge a plurality of the nitride semiconductor island structures with each other, thereby forming a nitride semiconductor crystal layer having a flat surface; the steps (a)-(c) being continuously conducted in the same growing apparatus.

A crystal growth apparatus comprises a reaction vessel holding a melt mixture containing an alkali metal and a group III metal, a gas supplying apparatus supplying a nitrogen source gas to a vessel space exposed to the melt mixture inside the reaction vessel, a heating unit heating the melt mixture to a crystal growth temperature, and a support unit supporting a seed crystal of a group III nitride crystal inside the melt mixture.

The present invention is a method suitable for heat treatment, or a heat treatment method for growing single crystal silicon carbide by a liquid phase epitaxial method, wherein a monocrystal silicon carbide substrate as a seed crystal and a polycrystal silicon carbide substrate are piled up, placed inside a closed container, and subjected to high-temperature heat treatment, by which very thin metallic silicon melt layer is interposed between the monocrystal silicon carbide substrate and the polycrystal silicon carbide substrate during heat treatment, and single crystal silicon carbide is liquid-phase epitaxially grown on the monocrystal silicon carbide substrate. The closed container is in advance heated to a temperature exceeding approximately 800° C. in an preheating chamber kept at a pressure of approximately 10−5 Pa or lower, the closed container is reduced in pressure to approximately 10−5 Pa or lower, and the container is transported and placed in the heat chamber, which is in advance heated to a prescribed temperature in a range from approximately 1400° C. to 2300° C., in a vacuum at a pressure of approximately 10−2 Pa or lower or in an inert gas atmosphere at a prescribed reduced pressure, by which the monocrystal silicon carbide substrate and the polycrystal silicon carbide substrate are heated in a short time to a prescribed temperature in a range from approximately 1400° C. to 2300° C. to produce single crystal silicon carbide which is free of fine grain boundaries and approximately 1 / cm2 or lower in density of micropipe defects on the surface. Further, the present invention is heat treatment equipment used in carrying out the heat treatment method.

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.

This disclosure relates to methods that include depositing a first component and a second component to form a film including a plurality of nanostructures, and coating the nanostructures with a hydrophobic layer to render the film superhydrophobic. The first component and the second component can be immiscible and phase-separated during the depositing step. The first component and the second component can be independently selected from the group consisting of a metal oxide, a metal nitride, a metal oxynitride, a metal, and combinations thereof. The films can have a thickness greater than or equal to 5 nm; an average surface roughness (Ra) of from 90 to 120 nm, as measured on a 5 μm×5 μm area; a surface area of at least 20 m2 / g; a contact angle with a drop of water of at least 120 degrees; and can maintain the contact angle when exposed to harsh conditions.

The present invention provides a method of surface passivation of colloidal nanocrystalline materials using a ligand exchange process in which quantum nanoparticles of pre-selected size and shape has polymer multidentate ligands bound at the surface of the nanocrystals for stabilizing quantum size-dependent properties of nanocrystals and providing colloidal stability of the nanoparticles in solvents. The method includes preparing a colloidal dispersion of nanoparticles, preparing a suitable polymer multidentate ligand and dissolving said suitable polymer multidentate ligand in a fluid, the polymer multidentate ligand having first portions which can bind to a surface of the nanoparticles and a second portion which does not bind to the surface of the nanoparticles, and mixing the fluid containing the suitable polymer with the colloidal dispersion of nanoparticles under conditions suitable to induce binding of at least some of the first portions of the polymer multidentate ligand onto the surface of the nanoparticles, the suitable polymer multidentate ligand being selected so that the at least some of the first portions which bind to the surface to stabilize quantum size-dependent properties of the nanocrystals, and the second portion which does not bind to the surface provides colloidal stability of the nanoparticles in a desired fluid.

Present embodiments include an additive manufacturing tool configured to receive a metallic material and to supply a plurality of droplets to a part at a work region of the part, wherein each droplet of the plurality of droplets comprises the metallic material and a heating system comprising a primary laser system configured to generate a primary laser beam to heat a molten zone of a substrate of the part and a secondary laser system configured to generate a secondary laser beam to heat a transition zone of the substrate of the part, wherein the molten zone and the work region are colocated, and wherein the transition zone is disposed about the molten zone.

The present invention provides a Group III nitride crystal substrate whose surface has concavities and convexities reduced in size. The surfaces with concavities and convexities, such as hillocks, pits and facets, of Group III nitride crystals are brought into contact with a melt and thereby the surfaces are subjected to meltback etching or mechanochemical polishing. The melt includes at least one of alkali metal and alkaline-earth metal. Thus a Group III nitride crystal substrate that has reduced strain and a reduced number of defects, which are caused through the processing, and is excellent in surface flatness is manufactured. Furthermore, by the use of the Group III nitride crystal substrate of the present invention, for instance, semiconductor devices of high performance can be obtained.

Affords III-nitride crystals having a major surface whose variance in crystallographic plane orientation with respect to an {hkil} plane chosen exclusive of the {0001} form is minimal. A method of manufacturing the III-nitride crystal is one of: conditioning a plurality of crystal plates (10) in which the deviation in crystallographic plane orientation in any given point on the major face (10m) of the crystal plates (10), with respect to an {hkil} plane chosen exclusive of the {0001} form, is not greater than 0.5°; arranging the plurality of crystal plates (10) in a manner such that the plane-orientation deviation, with respect to the {hkil} plane, in any given point on the major-face (10m) collective surface (10a) of the plurality of crystal plates (10) will be not greater than 0.5°, and such that at least a portion of the major face (10m) of the crystal plates (10) is exposed; and growing second III-nitride crystal (20) onto the exposed areas of the major faces (10m) of the plurality of crystal plates (10).

A method for producing a Group III element nitride single crystal, which comprises reacting at least one Group III element selected from the group consisting of gallium(Ga), aluminum(Al) and indium(In) with nitrogen(N) in a mixed flux of sodium(Na) and at least one of an alkali metal (except Na) and an alkaline earth metal. The method allows the production, with a good yield, of the single crystal of a group III element nitride which is transparent, is reduced in the density of dislocation, has a bulk form, and is large. In particular, a gallium nitride single crystal produced by the method has high quality and takes a large and transparent bulk form, and thus has a high practical value.

Methods for large-scale manufacturing of semipolar gallium nitride boules are disclosed. The disclosed methods comprise suspending large-area single crystal seed plates in a rack, placing the rack in a large diameter autoclave or internally-heated high pressure apparatus along with ammonia and a mineralizer, and growing crystals ammonothermally. A bi-faceted growth morphology may be maintained to facilitate fabrication of large area semipolar wafers without growing thick boules.

A SiC single crystal is produced by the solution growth method in which a seed crystal attached to a seed shaft is immersed in a solution of SiC dissolved in a melt of Si or a Si alloy and a SiC single crystal is allowed to grow on the seed crystal by gradually cooling the solution or by providing a temperature gradient therein. To this method, accelerated rotation of a crucible is applied by repeatedly accelerating to a prescribed rotational speed and holding at that speed and decelerating to a lower rotational speed or a 0 rotational speed. The rotational direction of the crucible may be reversed each acceleration. The seed shaft may also be rotated synchronously with the rotation of the crucible in the same or opposite rotational as the crucible. A large, good quality single crystal having no inclusions are produced with a high crystal growth rate.