An aluminum nitride film includes a polycrystalline aluminum nitride. A withstand voltage of the aluminum nitride film is 100 kV/mm or more.

Embodiments of a layered-substrate comprising a substrate and a layer disposed thereon, wherein the layered-substrate is able to withstand fracture when assembled with a device that is dropped from a height of at least 100 cm onto a drop surface, are disclosed. The layered-substrate may exhibit a hardness of at least about 10 GPa or at least about 20 GPa. The substrate may include an amorphous substrate or a crystalline substrate. Examples of amorphous substrates include glass, which is optionally chemically strengthened. Examples of crystalline substrates include single crystal substrates (e.g. sapphire) and glass ceramics. Articles and/or devices including such layered-substrate and methods for making such devices are also disclosed.

Embodiments of a layered-substrate comprising a substrate and a layer disposed thereon, wherein the layered-substrate is able to withstand fracture when assembled with a device that is dropped from a height of at least 100 cm onto a drop surface, are disclosed. The layered-substrate may exhibit a hardness of at least about 10 GPa or at least about 20 GPa. The substrate may include an amorphous substrate or a crystalline substrate. Examples of amorphous substrates include glass, which is optionally chemically strengthened. Examples of crystalline substrates include single crystal substrates (e.g. sapphire) and glass ceramics. Articles and/or devices including such layered-substrate and methods for making such devices are also disclosed.

A method for forming an aluminum nitride layer (310, 320) comprises the provision of a substrate (100) and the forming of a patterned metal nitride layer (110). A bottom electrode metal layer (210) is formed on the exposed portions (101) of the substrate. An aluminum nitride layer portion (320) grown above the exposed portion (101) of the substrate (100) exhibits piezoelectric properties. An aluminum nitride layer portion (310) grown above the patterned metal nitride layer (110) exhibits no piezoelectric properties (310). Both aluminum nitride layer portions (320, 310) are grown simultaneously.

According to the present invention, there are provided a resin composition containing a surface-modified inorganic substance, which is obtained by performing surface modification on an inorganic nitride or an inorganic oxide by using a boronic acid compound, and an epoxy compound, a thermally conductive material including a cured substance of the resin composition, and a device including the thermally conductive material. The boronic acid compound has, for example, an amino group, a thiol group, a hydroxyl group, an isocyanate group, a carboxyl group, or a carboxylic acid anhydride group. By using the resin composition of the present invention, it is possible to provide a thermally conductive material having excellent thermal conductivity and a device having high durability.

A carbon-coated thermal conductive material includes a coating layer comprising amorphous carbon on a surface of a thermal conductive material, wherein the thermal conductive material comprises a metal oxide, a metal nitride, a metal material, or a carbon-based material having a thermal conductivity of 10 W/mK or greater, the amorphous carbon is derived from carbon contained in an oxazine resin, a ratio of a peak intensity of a G band to a peak intensity of a D band is 1.0 or greater when the amorphous carbon is measured by Raman spectroscopy, an average film thickness of the coating layer is 500 nm or less, and a coefficient of variation (CV value) of a film thickness of the coating layer is 15% or less.

A carbon-coated thermal conductive material includes a coating layer comprising amorphous carbon on a surface of a thermal conductive material, wherein the thermal conductive material comprises a metal oxide, a metal nitride, a metal material, or a carbon-based material having a thermal conductivity of 10 W/mK or greater, the amorphous carbon is derived from carbon contained in an oxazine resin, a ratio of a peak intensity of a G band to a peak intensity of a D band is 1.0 or greater when the amorphous carbon is measured by Raman spectroscopy, an average film thickness of the coating layer is 500 nm or less, and a coefficient of variation (CV value) of a film thickness of the coating layer is 15% or less.

A method for producing aluminum nitride is to disclose, which includes injecting a nitrogen-containing gas and a pure aluminum material into a high-temperature jet mill. In the high-temperature jet mill, the injected pure aluminum material reacts with the nitrogen and forms aluminum nitride on the surface. The aluminum nitride is continuously to pulverize in the high-temperature jet mill to form fine aluminum nitride powder. According to the present disclosure, unnecessary cost and complicated processes in elevated-temperature agglomeration is to avoid.

A molten iron-assisted method for producing aluminum nitride (AlN) and a device thereof are disclosed. Pure aluminum is introduced into a vacuumed molten iron bath continuously for producing a molten iron bath having the aluminum, then nitrogen is introduced into the molten iron bath having the aluminum. Production of AIN is controlled by having the concentration of aluminum in the molten iron bath having the aluminum controlled. At the time AIN is formed continuously in the molten iron bath having the aluminum, AIN floats to the surface of the molten iron bath having the aluminum. Ar and N.sub.2 may be blown and dust is removed by static electrons thereafter, such that pure aluminum nitride powder can be collected. Finally, the used gas is recycled and reused.

A method for producing aluminum nitride is to disclose, which includes injecting a nitrogen-containing gas and a pure aluminum material into a high-temperature jet mill. In the high-temperature jet mill, the injected pure aluminum material reacts with the nitrogen and forms aluminum nitride on the surface. The aluminum nitride is continuously to pulverize in the high-temperature jet mill to form fine aluminum nitride powder. According to the present disclosure, unnecessary cost and complicated processes in elevated-temperature agglomeration is to avoid.