1034results about "From condensed vapors" patented technology

Crystal growth systems with a baffle are provided. In one example, a crystal growth system for growing crystalline material, the crystalline material including silicon carbide, includes a seed holder configured to hold a silicon carbide seed crystal. The seed crystal provides a growth surface for growth of the silicon carbide crystalline material. The system includes a crucible at least partially defining a crystal growth chamber. The system includes a source material. The system includes one or more baffles within the crystal growth chamber and spaced apart from the source material. The one or more baffles include one or more apertures defined through the one or more baffles. The baffle includes a long dimension that is non-perpendicular to the growth surface of the seed crystal.

A silicon carbide source material structure for use in a sublimation system for growing single crystal silicon carbide is provided. The silicon carbide source material structure may comprise a first layer and a second layer, the first layer being different from the second layer in at least one property.

The invention provides an anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice film with high energy storage density as well as a preparation method and application thereof. The anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice film with high energy storage density comprises a substrate layer, a bottom electrode layer and a plurality of stacked relaxation ferroelectric layers, wherein the bottom electrode layer and the multiple stacked relaxation ferroelectric layers are sequentially arranged on the substrate layer; each relaxor ferroelectric layer sequentially comprises a first functional layer, a second functional layer and a third functional layer from bottom to top; the first functional layer comprises LaFeO3, the second functional layer comprises BiFeO3, and the third functional layer comprises SrTiO3. The anti-ferroelectric lanthanum ferrite, bismuth ferrite and strontium titanate superlattice thin film with the high energy storage density has small electric leakage performance and high polarization value, and more excellent energy storage performance is achieved.

A silicon carbide source material structure for use in a sublimation system for growing crystalline silicon carbide is provided. The silicon carbide source material structure includes a composite shaped solid. The composite shaped solid may be made by casting, extrusion, 3D printing, graphite conversion, or other suitable process.

An object of the present invention is to provide a novel technique capable of manufacturing a large-diameter AlN substrate.The present invention is a method for manufacturing an AlN substrate, including a crystal growth step S30 of forming an AlN layer 20 on a SiC underlying substrate 10 having through holes 11. In addition, the present invention is a method for forming an AlN layer including the through hole formation step S20 of forming the through holes 11 in the SiC underlying substrate 10 before forming the AlN layer 20 on the SiC underlying substrate 10.

The invention discloses a silicon carbide crystal growth container and silicon carbide crystal growth equipment with the same. The silicon carbide crystal growth container comprises a container main body, the heating device is positioned outside the container main body; the inner cylinder is arranged in the container main body, an inner containing space is formed in the inner cylinder, an outer containing space is formed between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the container main body, and silicon carbide powder is contained in the inner containing space and the outer containing space; the heights of the silicon carbide powder in the inner accommodating space and the outer accommodating space are different; the filtering part is arranged in the container main body and is positioned above the silicon carbide powder. The silicon carbide crystal growth container provided by the embodiment of the invention has the advantages of uniform crystal growth rate, high yield and the like.

The invention belongs to the technical field of SiC crystal growth, and particularly relates to a thermal field component for SiC crystal growth and a preparation method of the thermal field component. The thermal field component comprises a thermal field component body, and the thermal field component body is made of a porous tantalum carbide material. The thermal field component can efficiently filter carbon particles, has corrosion resistance and long service life, and can remarkably reduce the production cost.

The utility model relates to a shutter device and molecular beam epitaxy equipment. Comprising a baffle plate configured to swing between a first position and a second position; when the baffle plate is in the first position, a beam injection track between the source furnace and the film growth area is blocked by the baffle plate, the baffle plate and the beam injection track are obliquely intersected, and a free falling body track formed at any position on the baffle plate is outside the source furnace; when the baffle is in the second position, the beam injection track between the source furnace and the thin film growth area does not intersect with the baffle, and the baffle is located below the source furnace; the first end of the support is connected with the baffle, and the second end extends away from the baffle; the bracket can swing to drive the baffle to swing between a first position and a second position; the power assembly is configured to drive the support to swing, and the power assembly is connected with the second end of the support. According to the technical scheme, blockage of the injection orifice of the source furnace can be reduced, and the film growth quality can be improved.

Crystal growth systems for growing crystalline material comprising silicon carbide are provided. In one example, the crystal growth system includes a crucible at least partially defining a crystal growth chamber. The crystal growth chamber has a plurality of zones, each zone associated with a different processing profile. The system includes a silicon carbide crystal. The system includes a source material.

The invention discloses a silicon carbide growth feeding device which comprises a feeding box and a conveying mechanism installed in the feeding box, a crucible capable of moving up and down is arranged on the conveying mechanism, a uniform feeding assembly is arranged in the feeding box and comprises a guide disc, a feeding pipe is arranged on the guide disc in a sliding mode, a sliding pipe is rotationally arranged on the feeding pipe, and the sliding pipe is connected with the feeding box. A trowelling frame and a stirring frame are rotatably arranged at the bottom of the guide disc, a lifting assembly is arranged in the feeding box and comprises a plurality of lifting sliding rails fixedly connected to the interior of the feeding box, lifting threaded sliding blocks capable of moving up and down are slidably arranged in the lifting sliding rails, and vibrating bars and clamping blocks are installed on the lifting threaded sliding blocks; the uniform feeding assembly helps materials to be uniformly distributed and leveled, the lifting assembly achieves crucible lifting and material compaction, manual participation is not needed in the feeding process, the influence of human factors is reduced, the growth shape of silicon carbide crystals is regular, and waste of follow-up machining is reduced.

The invention discloses a single crystal boron nitride wafer batch preparation method based on a copper-nickel single crystal film and application, and belongs to the technical field of two-dimensional material preparation and nano electronic device manufacturing. The method comprises the following steps: forming a Cu80Ni20 (111) single crystal film on a c-plane sapphire substrate through magnetron sputtering and high-temperature annealing to serve as a growth substrate; carrying out thermal conversion treatment on the ammonia borane precursor to form a supply source system capable of stably releasing a borazine gas phase precursor; a porous structure quartz sleeve is adopted to regulate and control the release behavior of a precursor, and multi-wafer airflow homogenization control is realized in a CVD system through a quartz staggered wafer carrier; and carrying out epitaxial growth, and synchronously preparing more than 10 single crystal boron nitride wafers which are consistent in crystal orientation, smooth in surface and free of crystal boundaries in a single batch. According to the method, efficient, uniform and repeatable batch preparation of the high-quality monocrystal h-BN is realized, and the obtained wafer has atomic-scale flatness and excellent insulating property and is suitable for high-performance two-dimensional electronic devices, deep ultraviolet photoelectric devices and quantum device platforms.

The invention provides a seed crystal bonding method for inhibiting back sublimation of SiC, and belongs to the technical field of silicon carbide crystal growth treatment. A laser annealing mode is adopted, laser is used as a heat source, after the laser passes through a transmission system, a laser beam with uniform energy distribution can be generated and is projected to the surface of the silicon carbide seed crystal, silicon carbide on the surface layer absorbs the energy of the laser to be melted and then decomposed into carbon and silicon, the melting point of the silicon is low, and the silicon escapes after being melted and gasified; and the left carbon can form a compact carbon film on the surface layer of the silicon carbide. The production cost is reduced, the production efficiency is improved, meanwhile, the problem of back sublimation during SiC growth is solved, and the success rate of seed crystal bonding and the SiC crystal quality are both improved.

Systems and methods for defect mitigation in silicon carbide crystal growth systems are provided. In an aspect, an example method includes providing a crystalline material in a first zone of the crystal growth chamber. In some implementations, the example method includes providing a silicon carbide vapor source material in a second zone of the crystal growth chamber. The example method includes providing an etching agent in the crystal growth chamber. The example method includes controlling a temperature gradient in the crystal growth chamber such that a first temperature in the first zone is greater than a second temperature in the second zone to implement an etching process on the crystalline material in the crystal growth chamber.

An example seed structure, systems, and methods for conducting crystal growth processes are provided. In one example, the present disclosure provides an example seed structure for a silicon carbide crystal growth system. The seed structure includes a carrier layer. The carrier layer is silicon carbide. The seed structure includes a seed layer bonded to the carrier layer with a bond. The seed layer is crystalline silicon carbide. The seed layer provides a growth surface for growing a crystalline silicon carbide structure in a silicon carbide crystal growth process.

The invention relates to a silicon nitride crystal based on high static nitrogen pressure and active nitrogen regulation and a growth method thereof. The silicon nitride crystal is prepared by the growth method, and the method adopts a physical gas phase transmission process and specifically comprises the following steps: introducing high static pressure nitrogen (1-3 bar) and trace NH3 / N2 mixed gas into source powder formed by mixing high-purity beta-Si3N4 and polycrystalline silicon, and dynamically maintaining the gas phase N / Si molar ratio to be (1.33 + / -0.1): 1, thereby inhibiting the decomposition of the source powder and stabilizing the crystal growth; carrying out spray granulation on the source powder, carrying out compression molding, placing the obtained product in a graphite crucible with the inner wall coated with TaC, and carrying out ordered epitaxial growth by controlling the temperature difference of a temperature zone at 1800-2000 DEG C and the axial temperature gradient; according to the method, the dislocation density and the carbon impurity content of the silicon nitride crystal can be remarkably reduced, then the high-purity silicon nitride crystal with a complete structure and a smooth surface is obtained, and the method is suitable for the fields of high-temperature electronic devices and deep ultraviolet light electronics.

A semiconductor crystal control system for modifying a crystal growth process of silicon carbide is provided. The system can obtain one or more crystal growth parameters associated with growing a semiconductor crystal in a crystal growth assembly. The system can determine, based on the one or more crystal growth parameters, a predicted growth condition. The system can modify a crystal growth process based at least in part on the predicted growth condition.

The invention relates to a method for fabricating a two-dimensional (2D) heterostructure comprising depositing graphene on a substrate in an ultrahigh vacuum (UHV) chamber at a first temperature and a first chamber pressure to form sub-monolayer graphene on the substrate; and subsequently depositing borophene onto the sub-monolayer graphene on the substrate in the UHV chamber at a second temperature and a second chamber pressure so as to couple the borophene with the graphene on the substrate to form a 2D borophene-graphene heterostructure comprising lateral and / or vertical heterostructures.

The utility model provides a silicon carbide crystal growth device for improving the spiral dislocation defect. The silicon carbide crystal growth device comprises a crucible body and a plurality of graphite partition plates arranged in the crucible, and the graphite partition plates are arranged at the bottom of a raw material area of the crucible at equal intervals; the graphite clapboards are inserted into the silicon carbide powder at intervals, the heights of the graphite clapboards are in an arithmetic progression, so that the heights of the silicon carbide powder are also in an arithmetic progression, and the heights of the graphite clapboards and the silicon carbide powder in the corresponding areas are gradually reduced in the direction from the small surface area of the seed crystal to the direction far away from the small surface area. In the single crystal growth process, the silicon carbide powder in the graphite partition interlayer is heated to sublimate, and the distance between the surface of the silicon carbide powder and the growth surface of the seed crystal is reduced due to the height advantage of the silicon carbide powder in the graphite partition area with higher height, so that the growth component forms the component density advantage at the surface of the seed crystal in the area; the conversion and movement processes of screw dislocation in the crystal are effectively promoted, and the crystal quality is improved.

The utility model discloses a wafer taking and placing structure of a multi-wafer epitaxial furnace. The wafer taking and placing structure comprises a process cavity, a carrying manipulator, a manipulator cavity, a transmission cavity, a tray base, a rotary lifting mechanism and a tray horizontal conveying mechanism. The graphite tray conveying device is reasonable in structural design, a plurality of graphite trays with substrates are placed on the tray base one by one through the carrying manipulator, the rotary lifting mechanism descends to place the tray base on the tray horizontal conveying mechanism, and the tray base is conveyed into a process cavity through the tray horizontal conveying mechanism; during discharging, the tray horizontal conveying mechanism takes out the tray base in the process cavity and moves the tray base to the position above the rotary lifting platform, the rotary lifting platform ascends to jack the tray base up to the working area of the carrying mechanical arm, and then the carrying mechanical arm takes away all graphite trays on the tray base one by one. The purpose of simultaneously carrying out process growth on a plurality of substrates at one time is achieved, and the production efficiency is remarkably improved.

The invention provides a method for in-situ measurement of an internal stress state of an ultrathin film surface by using RHEED, and relates to the technical field of condensed state substance structure detection, and the method comprises the following steps: epitaxially growing an ultrathin film on a substrate by using film growth equipment; irradiating the ultrathin film by using an RHEED electron beam to obtain a diffraction pattern, and obtaining characteristic parameters of the diffraction pattern; obtaining the lattice constant of the ultrathin film through the characteristic parameters of the diffraction pattern; based on the lattice constant of the ultrathin film, the stress type and strain borne by the ultrathin film are determined. According to the method, the distance between diffraction fringes in a diffraction pattern is accurately extracted from a simple RHEED image, the lattice constant from the diffraction pattern is calculated, the stress state of the ultrathin film is accurately judged by comparing lattice constants in a stress-free state, existing equipment does not need to be greatly modified, and the method is simple and convenient to operate. The method can be realized only by using the existing RHEED electron beam and image processing software.

An organometallic compound is provided which includes a central metal atom; and organic ligands capable of forming polydentate bonds to the central metal atom. Related methods and articles having a metal carbide coating are also provided.

An epitaxial structure of a nonpolar AlGaN-based deep-ultraviolet (DUV) photoelectric detector and a preparation method thereof are provided. The epitaxial structure of the nonpolar AlGaN-based DUV photoelectric detector includes a nonpolar AlN buffer layer, a nonpolar Al0.15Ga0.85N buffer layer, and a nonpolar Al0.7Ga0.3N epitaxial layer that are sequentially grown on a LaAlO3 substrate. The LaAlO3 substrate takes a (100) plane as an epitaxial plane, and AlN[11-20] as an epitaxial growth direction. With the LaAlO3 substrate, the epitaxial structure reduces dislocations and stresses between the substrate and the epitaxial buffer layer. By designing two AlGaN epitaxial buffer layers with different components, the epitaxial structure reduces a dislocation density and a surface roughness of the nonpolar AlGaN epitaxial layer, further accelerates photoresponse and detectivity of the detector, and enhances overall performance of the nonpolar AlGaN-based DUV photoelectric detector.

Described herein is a method of fabricating a ferroelectric material, comprising the steps of: providing a semiconductor substrate; treating the semiconductor substrate with an oxidant to form an oxidized surface; depositing a metal on top of the oxidized surface to provide a film; and annealing the film at a temperature between 700°C and 900°C, thereby forming a metal oxide layer on top of the semiconductor substrate, wherein the interface between the semiconductor substrate and the metal oxide layer does not contain any remnant oxidized surface, and a ferroelectric material and a ferroelectric transistor or capacitor comprising said ferroelectric material.

The invention discloses an aluminum nitride composite substrate, a preparation method thereof and a semiconductor device. The preparation method comprises the following steps: sequentially forming a sacrificial layer and an aluminum nitride epitaxial layer on a heterogeneous substrate; temporarily bonding a supporting substrate on the aluminum nitride epitaxial layer through bonding glue to obtain a first bonding structure; dissociating the sacrificial layer to separate the heterogeneous substrate of the first bonding structure from the aluminum nitride epitaxial layer to obtain a second bonding structure exposing a first separation surface of the aluminum nitride epitaxial layer; bonding a polycrystalline aluminum nitride ceramic substrate on the first separation surface of the aluminum nitride epitaxial layer to obtain a third bonding structure; dissociating the bonding glue to separate the supporting substrate and the aluminum nitride epitaxial layer in the third bonding structure to obtain a fourth bonding structure exposing a second separation surface of the aluminum nitride epitaxial layer; and growing an aluminum nitride single crystal wafer on the second separation surface of the aluminum nitride epitaxial layer to obtain the aluminum nitride composite substrate. By adopting the scheme, the high-quality aluminum nitride composite substrate can be prepared.

The application relates to a ferroelectric monolayer vanadium trichloride film and a preparation method thereof. The method comprises the following steps: evaporating and depositing VCl3 powder on the surface of a NbSe2 substrate under an ultrahigh vacuum atmosphere, and performing annealing treatment, so that the ferroelectric monolayer vanadium trichloride film is obtained. The sample preparation strategy of molecular beam epitaxy under an ultrahigh vacuum environment is used, high-purity VCl3 powder is evaporated and deposited on a NbSe2 substrate, an atomically flat monolayer VCl3 sample is obtained through annealing treatment, in-situ scanning tunneling microscope technology and scanning tunneling spectrum technology are combined, and it is determined that the monolayer VCl3 is a semiconductor material with ferroelectricity. The method provides a new method and idea for introducing ferroelectricity in the family of transition metal trichlorides, has high application potential and scientific research value, meanwhile, the successful introduction of ferroelectricity in the system also provides a new platform for carrying out multi-state regulation and research.

The invention belongs to the technical field of silicon carbide single crystal materials, and particularly relates to a device for growing silicon carbide single crystals through a PVT method and a silicon carbide single crystal growing method.The device for growing the silicon carbide single crystals through the PVT method comprises a crucible, a heat preservation layer wrapping the crucible and an external heating system, the top of the heat preservation layer is provided with a center heat dissipation area and at least three auxiliary heat dissipation areas distributed in the circumferential direction. And the heat conduction efficiency of the auxiliary heat dissipation area is lower than that of the central heat dissipation area. Through the heat conduction efficiency difference design of the center heat dissipation area and the auxiliary heat dissipation area at the top of the heat preservation layer and in cooperation with the segmented pressure regulation and control technology, a stable radial heat barrier is constructed in the initial stage of crystal growth to restrain edge polycrystalline defects (deeply compressed to the submillimeter level), meanwhile, axial temperature gradient driving high-speed growth is strengthened, and the crystal growth efficiency is improved. And the crystal thickness breaks through the industry bottleneck of 18mm, and the dislocation density is reduced by one order of magnitude, so that the breakthrough of'low-defect thick growth 'of the large-size silicon carbide single crystal is finally realized.

The invention provides a method for reducing silicon inclusion defects in silicon carbide single crystals, which comprises the following steps of: A) carrying out microwave sintering on silicon carbide powder under a vacuum condition and a protective atmosphere before the silicon carbide powder grows silicon carbide crystals; the microwave sintering comprises a first stage, a second stage and a third stage; in the first stage, the silicon carbide powder is heated to the temperature T1 from the room temperature with the microwave power P1, and heat preservation is conducted for t1 time at the temperature T1; in the second stage, the silicon carbide powder is heated from the temperature T1 to the temperature T2 at the microwave power P2; in the third stage, the temperature T2 is kept constant at the microwave power P3, and heat preservation is conducted for t2; p2 > P1, and P3 < = P2; t1 ranges from 300 DEG C to 600 DEG C, and T2 ranges from 1400 DEG C to 1800 DEG C; and B) washing and drying the silicon carbide powder subjected to microwave sintering. The method provided by the invention effectively improves the defect of silicon wrappage directly generated due to rich Si in a gas phase in the growth process.

The embodiment of the invention discloses a hafnium oxide-based ferroelectric film doped in a calcium gap position and a preparation method. The method comprises the following steps: preparing a target material: mixing hafnium oxide and calcium oxide according to a set ratio, and grinding to obtain mixed raw material powder; calcining the mixed raw material powder for the first time; grinding the mixed raw material powder calcined for the first time, and performing compression molding to obtain a target material biscuit; calcining the target material biscuit for the second time to obtain the hafnium oxide-based ceramic target material doped in the calcium gap position; a commercial bottom electrode La0. 7Sr0. 3MnO3 target material is used as a first sputtering target, sputtering is carried out under a first set condition, and an LSMO bottom electrode thin film is obtained; taking the calcium gap position doped hafnium oxide-based ceramic target material as a second sputtering target, sputtering under a second set condition, and epitaxially growing on the LSMO bottom electrode film to form a calcium gap position doped hafnium oxide-based ferroelectric film; the chemical composition of the hafnium oxide-based ferroelectric film doped in the calcium gap position is CaxHf (1-x) O (2-x), x is 0.01-0.05, and calcium ions occupy the gap position of a hafnium oxide crystal lattice.

A silicon carbide substrate having high crystal quality, belonging to the technical field of silicon carbide production and processing. The silicon carbide substrate comprises a first main surface and a second main surface; the first main surface has a central area and an annular area surrounding the central area, the width of the annular area extending inward from an edge of the substrate being 5-30 mm; the central area is divided into square areas, each having a side length of 5 mm, the internal stress of each square area being less than the internal stress of the annular area, and the internal stress being the stress value detected at least 30 μm vertically extending from the first main surface or the second main surface into the silicon carbide substrate. The internal stress in the central area of the silicon carbide substrate is relatively low.