59 results about "Polycrystalline aluminum" patented technology

Methods of preparing polycrystalline aluminum nitride materials that have high density, high purity, and favorable surface morphology are disclosed. The methods generally comprises pressing aluminum nitride powders to form a slug, sintering the slug to form a sintered, polycrystalline aluminum nitride boule, and optionally shaping the boule and/or polishing at least a portion of the boule to provide a finished substrate. The sintered, polycrystalline aluminum nitride materials beneficially are prepared without the use of any sintering aid or binder, and the formed materials exhibit excellent density, AlN purity, and surface morphology.

Disclosed are methods and materials useful in the preparation of semiconductor devices. In particular embodiments, disclosed are methods for engineering polycrystalline aluminum nitride substrates that are thermally matched to further materials that can be combined therewith. For example, the polycrystalline aluminum nitride substrates can be engineered to have a coefficient of thermal expansion (CTE) that is closely matched to the CTE of a semiconductor material and/or to a material that can be used as a growth substrate for a semiconductor material. The invention also encompasses devices incorporating such thermally engineered substrates and semiconductor materials grown using such thermally engineered substrates. The thermally engineered substrates are advantageous for overcoming problems caused by damage arising from CTE mismatch between component layers in semiconductor preparation methods and materials.

There is provided a polycrystalline aluminum nitride base material having a linear expansion coefficient similar to GaN. The polycrystalline aluminum nitride base material as a substrate material for crystal growth of GaN-base semiconductors has a mean linear expansion coefficient of 4.9×10⁻⁶/K to 6.1×10⁻⁶/K between 20° C. and 600° C. and 5.5×10⁻⁶/K to 6.6×10⁻⁶/K between 20° C. and 1100° C.

A ceramic metal halide lamp is provided wherein the ceramic discharge vessel is comprised of dysprosium oxide. The lamp has a warm-up time that is less than about 50%, and preferably less than about one-third, of the warm-up time of a similarly constructed and operated lamp having a ceramic discharge vessel made of polycrystalline aluminum oxide.

A method of making high purity crystalline AlON bodies by synthesizing and calcining AlON powders having less than 80 ppm Si, Mg, Ca, Na, and K impurities. The AION powders are milled to reduce the particle size of the AlON powders using a high purity milling media. An AlON body is formed from the milled AlON powders. Such AlON bodies are particularly suitable for semiconductor process chamber components.

Disclosed is a method for preparing polycrystalline aluminum oxynitride having enhanced transparency, and preparing polycrystalline aluminum oxynitride by sintering a powder mixture of Al₂O₃ and AlN under atmospheric pressure, wherein the content of AlN is set to 17 to 26 mol %, a first sintering is performed at 1,575° C. to 1,675° C. so as to enable raw-material powders to have a relative density of 95% or higher, and a second sintering is performed so as to enable the raw-material powders to have a higher relative density.

The invention discloses a method for producing a sapphire surface acoustic wave transducer, belongs to the technical field of manufacture of surface acoustic wave devices. The method comprises the following steps of: firstly lithographing and developing a graph of the surface acoustic wave transducer on the surface of a sapphire, and then adopting the ion injection method to inject metal aluminum or copper element; then depositing a polycrystalline aluminum nitride piezoelectric thin film on the surface of the sapphire after ion injection; and finally removing a photoresist and obtaining the graph of the surface acoustic wave transducer. The method greatly reduces the surface resistivity of the sapphire by injecting the ions and greatly enhances the electric conductivity, thereby replacing the original deposition of a conductive thin film. The method does not need to deposit an Al or Au thin film and does not need the etching process either. Therefore, the operation is greatly simplified, and the anti-power bearing force of the device is also greatly enhanced.

An incandescent lamp that emits infrared light and a method of making the lamp includes a filament assembly inside a polycrystalline aluminum oxide (PCA) envelope, where the filament assembly preferably has a coiled tungsten filament, solid metal ends of tungsten or molybdenum attached to the coiled tungsten filament, and leads at distal ends of the solid metal ends. End caps are attached to ends of the envelope and have openings through which a respective one of the leads extends, where the leads are each made of an electrically conductive material having a coefficient of thermal expansion compatible with the end caps, such as niobium. The leads are attached to the end caps with glass-ceramic sealing frits. The end caps and sealing frits seal a suitable gas inside the envelope.

The present invention relates to a method of manufacturing a transparent polycrystalline aluminum oxynitride. Aluminum oxynitride manufactured by prior art methods has a great number of porosities therein and thus has low transparency. The present invention is directed to solving such a problem. In the method of manufacturing aluminum oxynitride of the present invention, a sintering additive added to a source powder includes less than 0.5 wt. % MgO. Further, the source powder is presintered at 1550° C. to 1750° C. so that a relative density becomes 95% or more and is then resintered at 1900° C. or more so that a relative density higher than that of presintering can be accomplished. According to the present invention, a cubic-phased polycrystalline aluminum oxynitride ceramic can be obtained, wherein porosities therein are nearly eliminated and its substantial transparency becomes 95% or more.

The invention provides high polymer molecule modified waterproof and anticorrosive resin mortar and a preparation method thereof, and relates to the field of resin mortar materials. The composition comprises the following components in parts by weight: 60-80 parts of POSS modified epoxy resin; 5-10 parts of liquid chloroprene rubber, 5-10 parts of liquid polysulfide rubber, 5-10 parts of carboxyl-terminated polybutadiene, 10-15 parts of talcum powder, 10-15 parts of modified clay, 1-5 parts of N550 carbon black, 4-8 parts of expanded and vitrified micro bubbles, 4-8 parts of expanded polyphenyl particles, 5-10 parts of polycrystalline aluminum oxide fibers, 1-3 parts of 2, 4, 6-tri (dimethylaminomethyl) phenol, 1-3 parts of polypropylene glycol diglycidyl ether, 0.1-1 part of aminosilane,0.1-1 part of vinyltriethoxysilane, 3-6 parts of polyethylene wax, 1-3 parts of hydroxyethyl cellulose, 1-3 parts of a thixotropic agent, 5-10 parts of a binding agent, 5-10 parts of a diluent and 1-2parts of a curing agent. The high polymer molecule modified waterproof and anticorrosive resin mortar has excellent mechanical properties and excellent crack resistance, impermeability, compression resistance, alkali resistance, acid resistance and salt corrosion resistance, and all the properties meet the use requirements.

The invention discloses a preparation method of a high-quality aluminum nitride piezoelectric film, and the method comprises the following steps: (1) taking a substrate, cleaning, spin-drying, and growing a single crystal aluminum nitride film on the substrate by using MOCVD equipment; (2) performing magnetron sputtering on the single crystal aluminum nitride thin film obtained in the step (1) byadopting PVD equipment to generate a polycrystalline aluminum nitride thin film. The method combines MOCVD and PVD two-step growth methods, is simple and easy to operate, significantly improves the crystal quality of the sputtered aluminum nitride film, and realizes the controllability of the thickness and stress of the grown aluminum nitride material. The invention further discloses a high-quality aluminum nitride piezoelectric film which is prepared by the method, the single crystal aluminum nitride film is arranged as a buffer layer, the crystal quality of the aluminum nitride film is high,and the overall performance of the aluminum nitride piezoelectric film is excellent. The invention further discloses an application of the aluminum nitride piezoelectric film to an FBAR filter, and the overall performance of an FBAR filter can be improved.

A method of forming a composite polycrystalline aluminum containing grit can include forming a dispersion of alumina and gelling the dispersion of alumina to form a gel. A nitride abrasive particle can be added to either the dispersion of alumina or the gel. After the nitride abrasive particle has been added, the gel can be processed to form a composite polycrystalline alumina nitride grit.

The invention discloses a microencapsulated composite phase change material as well as production and application thereof. A core material of the microencapsulated composite phase change material is apolycrystalline aluminum nitride-capric acid compound, and a capsule material of the microencapsulated composite phase change material is polyvinyl alcohol. The preparation method comprises the following steps: preparing polycrystalline aluminum nitride-capric acid compound latex particles, coating with polyvinyl alcohol, and carrying out secondary coating. The application method comprises the step of preparing polypropylene fiber cotton by using the microencapsulated composite phase change material. The phase change material has high phase change latent heat and heat exchange capacity, and the phase change temperature of the phase change material is 31.5 DEG C, which is in the most comfortable temperature range of a human body. The prepared intelligent temperature-adjusting polypropylenefiber cotton has a good temperature-adjusting effect and good mechanical properties.

The present invention provides a nitride semiconductor substrate suitable for a high frequency device. The nitride semiconductor substrate has a substrate, a buffer layer made of group 13 nitride semiconductors, and an active layer made of group 13 nitride semiconductors in this order, wherein the substrate is composed of a first substrate made of polycrystalline aluminum nitride, and a second substrate made of Si single crystal having a specific resistance of 100 Ω·cm or more, formed on the first substrate, the average particle size of AlN constituting the first substrate is 3 to 9 μm, and preferably, the second substrate grown by the MCZ method has an oxygen concentration of 1E+18 to 9E+18 atoms/cm³ and a specific resistance of 100 to 1000 Ω·cm.

An LED epitaxial structure includes the first layer thin film and the second layer thin film. The first layer thin film and the second layer thin film are polycrystalline aluminum nitride and single crystal aluminum nitride respectively, which have good thermal conductivity, insulation, mechanical intensity, and chemistry stability. Based on the substrate mentioned above, growing a single crystal gallium nitride on the second layer thin film as the third layer thin film allows the single crystal aluminum nitride and gallium nitride to have good lattice and thermal expansion match, resulting in the promotion of light emitting and thermal conduction efficiency.

The invention relates to a heat preservation device for microwave sintering of a titanium carbonitride-based metal ceramic material. The heat preservation device comprises a large-size crucible, a small-size crucible, polycrystalline aluminum oxide high-temperature fibers, first polycrystalline aluminum oxide fiber cotton and a polycrystalline mullite fiber board. The small-size crucible is arranged on the inner side of the large-size crucible, the polycrystalline alumina high-temperature fiber is arranged between the small-size crucible and the large-size crucible, the first polycrystalline alumina fiber cotton is annularly arranged on the outer side of the large-size crucible, and the bottom of the large crucible is arranged on the polycrystalline mullite fiber board. The problems that heat insulation cotton is softened at high temperature, so that the position of a crucible deviates, heat loss is accelerated, and the sintering quality is reduced are solved.

The present invention provides a substrate for a semiconductor device and a semiconductor device using the same. The substrate for a semiconductor device comprises a ceramic supporting base plate formed by a polycrystalline aluminum nitride (AlN) sintered body; at least one silicon oxide layer formed on the base plate by a sol-gel method wherein the at least one silicon oxide layer has an average roughness less than the base plate to block polycrystalline orientation of the base plate and has a total thickness in a range of 10˜5000 nm, the silicon oxide layer is only formed from the sol-gel method and are not single crystalline; a first buffer layer comprising aluminum nitride (AlN) on the at least one silicon oxide layer with a thickness of 0.1˜10 μm; and a gallium nitride layer formed on the first buffer layer and having a single-crystal crystalline structure.