Ube Industries, Inc.

Ngk Insulators, Inc.

National Institute of Advanced Industrial Science and Technology

Tetsuo Yamada

Takeshi Yamao

Shin-ichi Sakata

Keigo Nagao

Chisen Hashimoto

Takashi Kawahito

Tadashi Iwai

Tetsuo Nakayasu

Keiichiro Watanabe

Morito Akiyama

Naohiro Ueno

Hiroshi Tateyama

Kosuke Nishimura

Yasuhiko Kohtoku

Takuji Takahashi

Shin-Ichi Sakata

Koji Shibata

Hiroshi Yanagisawa

Eiji Masui

Youky Bessyo

Tetsuro Kunisawa

Atsuhiko Tanaka

Tadayuki Mitani

Hideo Nakamura

Yasukazu Kondo

Yoshinori Himukashi

An oxynitride phosphor includes an &#x3b1;-sialon as the main component, which is represented by the formula: MSiAlON:Ln(wherein 0.3&#x2266;x+y&#x3c;1.5, 0&#x3c;y&#x3c;0.7, 0.3&#x2266;m&#x3c;4.5, 0&#x3c;n&#x3c;2.25, and assuming that the atomic valence of the metal M is a and the atomic valence of the lanthanide metal Ln is b, m=ax+by) and in which the aggregation index, A=D/D&#x2266;3.0 or the aggregation index A=D/D&#x2266;3.0; and a production method and usage of the phosphor.

Sialon-based oxynitride phosphor and production method thereof

To provide sialon phosphor particles or a powder exhibiting high emission intensity in the region from ultraviolet to blue and not requiring a strong pulverization operation for pulverizing a sintered body or a large aggregated lump, and a production method thereof. Sialon phosphor particles represented by the formula: MLnSiAlON(wherein M is at least one metal selected from the group consisting of Li, Ca, Mg and Y, Ln is a lanthanide metal containing at least Eu, and assuming that the valence of the metal M is a and the valence of the lanthanide metal Ln is b, ax+by=m, x is 0&#x3c;x, y&#x2266;2.0, 0.3&#x2266;m&#x3c;4.5 and 0.5&#x2266;n&#x3c;2.5), wherein in the surface analysis by X-ray photoelectron spectroscopy, the ratio between the peak area of 3dspectrum of europium and the peak area of 2p spectrum of Si is 0.5 or less.

Sialon phosphor particles and production method thereof

A red phosphor where the crystal phase constituting the phosphor is monoclinic Eu-activated CaAlSiN. A red phosphor which is Eu-activated CaAlSiNpowder having an average particle diameter of 10 &#x3bc;m or less as measured in the non-pulverized state by the laser scattering particle size distribution analysis. A light-emitting device comprising a blue light-emitting element, a yellow phosphor capable of converting the blue light emitted from the blue light-emitting element into yellow light, and the above-described red phosphor capable of converting the blue light emitted from the blue light-emitting element into red light. A method for producing Eu-activated CaAlSiN, comprising firing a raw material powder comprising CaN, AlN, SiNand EuN at 1,400 to 2,000&#xb0; C. in a nitrogen-containing atmosphere, the CaN, AlN and SiNgiving a composition falling in the region surrounded by a straight line connecting the following four points A to D in the composition diagram of FIG., and EuN being contained in an amount of 0.01 to 10 parts by weight as Eu per 100 parts by weight in total of CaN, AlN and SiN.

Red nitride phosphor and production method thereof

A piezoelectric thin film resonator has a substrate and a piezoelectric layered structure including a lower electrode, piezoelectric aluminum nitride thin film with c-axis orientation and upper electrode formed on the substrate in this order. The lower electrode are made of a metal thin film including a layer containing ruthenium as a major component having a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of ruthenium of 3.0&#xb0; or less. The piezoelectric aluminum nitride thin film formed on the lower electrode has a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of 2.0&#xb0; or less.

Aluminum nitride thin film, composite film containing the same and piezoelectric thin film resonator using the same

A thin film piezoelectric device includes a substrate () having via holes () and a piezoelectric laminated structure () consisting of a lower electrode (), a piezoelectric film (), and an upper electrode () formed on the substrate () via an insulation layer (). A plurality of thin film piezoelectric resonators () are formed for the via holes (). The piezoelectric laminated structure () includes diaphragms () located to face the via holes () and a support area other than those. The thin film piezoelectric resonators () are electrically connected by the lower electrode (). When the straight line in the substrate plane passing through the centers () of the diaphragms () of the thin film piezoelectric resonators () has the length Dof the segment passing through the support area and the distance between the centers of the diaphragms of the thin film piezoelectric resonators () is Dthe ratio D/Dis 0.1 to 0.5. The via hole () is fabricated by the deep graving type reactive ion etching method.

Thin film piezoelectric resonator, thin film piezoelectric device, and manufacturing method thereof

To provide a sialon-based phosphor capable of forming a thin film by mixing it with a resin, and giving a uniform photoluminescent light with high light emission intensity, and to provide a method for producing a sialon-based phosphor not having excessively large agglomerated particles and a wide particle size distribution, there is provided a method for producing an &#x3b1;-sialon based phosphor represented by the formula:MLnSiAlONwherein M is at least one metal selected from Ca, Mg, Y and Li, Ln is at least one lanthanide metal selected from Eu, Dy, Er, Tb, Yb and Ce, ax+by=m (assuming that the valence of metal M is a and the valence of lanthanide metal Ln is b), 0&#x3c;x&#x2266;1.5, 0.3&#x2266;m&#x2266;4.5, and 0&#x3c;n&#x3c;2.25), wherein the silicon nitride raw material used as the raw material is a silicon nitride raw material powder comprising amorphous silicon nitride and crystalline silicon nitride.

Production method of sialon-based phosphor, and sialon-based phosphor

Method of producing a piezoelectric thin film device comprises a step of forming an insulating layer () capable of being etched by a specific chemical substance on the upper surface of a substrate (); a step of forming a sacrificial layer () made of a substance having a higher etching rate by the specific chemical substance than the insulating layer on a partial region of the insulating layer; a step of forming a lower electrode () on a region including the sacrificial layer; a step of forming the piezoelectric thin film () on a region including a part of the lower electrode; a step of forming an upper electrode () on a region including a part of the piezoelectric thin film; a step of forming via hole (), which penetrates the piezoelectric thin film and lower electrode, so as to expose a part of the sacrificial layer; and a step of forming a space () for oscillation by etching both the sacrificial layer and the insulating layer with the same specific chemical substance by introducing the specific chemical substance through the via hole.

Method of manufacturing piezoelectric thin film device and piezoelectric thin film device

To provide a Sialon-based phosphor having a high photoluminescent intensity, which can realize a high brightness LED, particularly a white LED using a blue LED as the light source, and a production method of the Sialon-based phosphor. The &#x3b1;-Sialon based phosphor of the present invention is represented by the formula:LiMLnSiAlON&#x2003;&#x2003;(I)wherein M is at least one metal selected from Ca, Mg and Y, Ln is at least one lanthanide metal selected from Eu, Dy, Er, Tb, Yb and Ce, x+ay+bz=m (assuming that the valence of metal M is a and the valence of lanthanide metal Ln is b), 0&#x3c;x&#x2266;0.8, 0&#x3c;y, 0&#x3c;z, 0.3&#x2266;m&#x3c;4.5, and 0&#x3c;n&#x3c;2.25.

Sialon-based phosphor and its production method

A method of producing a thin film bulk acoustic resonator having a piezoelectric layer, a first electrode joined to a first surface of the piezoelectric layer, and a second electrode joined to a second surface of the piezoelectric layer, which is located at the opposite side to the first surface, including the steps of forming a pit on a surface of a substrate; filling the pit with a sacrificial layer; polishing a surface of the sacrificial layer so that the RMS variation of a height of the surface of the sacrificial layer is equal to 25 nm or less; forming the first electrode over a partial area of the surface of the sacrificial layer and a partial area of the surface of the substrate; forming the piezoelectric layer on the first electrode so that RMS variation of a height of the second surface of the piezoelectric layer is equal to 5% or less of a thickness of the piezoelectric layer; forming the second electrode on the piezoelectric layer; and removing the sacrificial layer from the inside of the pit by etching.

Method of producing thin film bulk acoustic resonator

An &#x3b1;-sialon-based oxynitride phosphor characterized in that the content of &#x3b1;-sialon represented by the general formula: MSAlON:Ln(wherein M is at least one metal selected from among Li, Ca, Mg, Y or lanthanide metals excluding La and Ce, Ln is at least one lanthanide metal selected from among Ce, Pr and La or at least one lanthanide metal selected from among Eu, Dy, Er, Tb and Yb, 0.3&#x2266;x+y&#x3c;1.5, 0&#x3c;y&#x3c;0.7, 0.3&#x2266;m&#x3c;4.5, 0&#x3c;n&#x3c;2.25, and m=ax+by, where a is the valence of the metal M and b is the valence of the lanthanide metal Ln), wherein all or a portion of the metal M dissolved in the &#x3b1;-sialon is replaced with the lanthanide metal Ln as the luminescence center, is 75 wt % or greater when the lanthanide metal Ln is at least one lanthanide metal selected from among Ce, Pr and La and 90 wt % or greater when the lanthanide metal Ln is at least one lanthanide metal selected from among Eu, Dy, Er, Tb and Yb, and in that the content of metal impurities other than the metal M, lanthanide metal Ln, silicon, IIIA elements (aluminum, gallium), oxygen and nitrogen, is no greater than 0.01 wt %.

Sialon-based oxynitride phosphor, process for its production, and use thereof

A thin film bulk acoustic resonator comprises a substrate () of a silicon single crystal, a base film () formed on the substrate () and composed of a dielectric film mainly containing silicon oxide, and a piezoelectric stacked structure () formed on the base film (). A vibratory section () composed of a part of the base film () and a part of the piezoelectric stacked structure (). The piezoelectric stacked structure () includes a lower electrode (), a piezoelectric film (), and an upper electrode () formed in this order from below. The substrate () had a via hole () in the region corresponding to the vibratory section (). The via hole forms a space for allowing vibration of the vibratory section (). The piezoelectric film () is an aluminum nitride thin film containing 0.2 to 3.0 atom % of alkaline earth metal and/or a rare earth metal. Thus, the thin film bulk acoustic resonator has a high performance such as a large electromechanical coupling coefficient, an excellent acoustic quality factor (Q) and an excellent frequency-temperature characteristic.

Film bulk acoustic resonator

A pit () is formed in a substrate comprising a silicon wafer () on a surface of which a silicon oxide thin layer () is formed. A sandwich structure () comprising a piezoelectric layer () and lower and upper electrodes () joined to both surfaces of the piezoelectric layer is disposed so as to stride over the pit (). The upper surface of the lower electrode () and the lower surface of the piezoelectric layer () joined to the upper surface of the lower electrode are treated so that the RMS variation of the height thereof is equal to 25 nm or less. The thickness of the lower electrode () is set to 150 nm or less. According to such a structure, there is provided a high-performance thin film bulk acoustic resonator which are excellent in electromechanical coupling coefficient and acoustic quality factor.

Thin film acoustic resonator and method of producing the same

A silicon nitride powder which provides a water-based slurry with a low viscosity and a high powder concentration. The silicon nitride powder has a specific surface area of 6 to 25 m.sup.2 /g, a number of coarse particles of coarse primary particles, agglomerated particles and/or fused particles, and having a size of 3 to 50 .mu.m, of not more than 1000 per 1 cm.sup.3 of the powder, a number of foreign metallic particles, having a size of more than 20 .mu.m, of not more than 3 per 1 cm.sup.3 of the powder, and a number of foreign metallic particles, having a size of 10 to 20 .mu.m, of not more than 15 per 1 cm.sup.3 of the powder.

Silicon nitride powder

A crystalline silicon nitride powder having a high specific surface area and an enhanced sintering property is produced with a high producibility and a large scale, by calcining a silane material comprising at least one nitrogen-containing silane compound in a nitrogen-containing inert gas mixed with 0.1 to 5%, based on the total volume of the mixed gas, of molecular oxygen, preferably at 600.degree. to 1200.degree. C.; baking the resultant amorphous silicon nitride powder in a nitrogen-containing inert gas preferably at 1400.degree. to 1700.degree. C.; and milling the resultant crystalline silicon nitride powder in a mixed gas atmosphere comprising 5 to 40% by volume of molecular oxygen and the balance consisting of an inert gas preferably at 0.degree. to 100.degree. C.

Process for producing a crystalline silicon nitride powder

A silicon nitride powder containing .beta.-phase and .alpha.-phase at a ratio by weight (.beta./.alpha.) of from 0.018 to 0.032, and composed of crystallites 0.2 .mu.m or less in diameter.

Growing community of inventors

Ube, Japan

Tetsuo Yamada