Abstract: A method for producing an aluminum nitride sintered product according to the present invention includes the steps of (a) preparing a powder mixture that contains AlN, 2 to 10 parts by weight of Eu2O3 with respect to 100 parts by weight of AlN, Al2O3 such that a molar ratio of Al2O3 to Eu2O3 is 2 to 10, and TiO2 such that a molar ratio of TiO2 to Al2O3 is 0.05 to 1.2, but not Sm; (b) producing a compact from the powder mixture; and (c) firing the compact by subjecting the compact to hot-press firing in a vacuum or in an inert atmosphere.

Abstract: A manufacturing method of a sintered ceramic body mixes barium silicate with aluminum oxide, a glass material, and an additive oxide to prepare a material mixture, molds the material mixture and fires the molded object. The barium silicate is monoclinic and has an average particle diameter in a range of 0.3 ?m to 1 ?m and a specific surface area in a range of 5 m2/g to 20 m2/g. The aluminum oxide has an average particle diameter in a range of 0.4 ?m to 10 ?m, a specific surface area in a range of 0.8 m2/g to 8 m2/g. A volume ratio of the aluminum oxide to the barium silicate is in a range of 10% by volume to 25% by volume.

Abstract: An electrostatic chuck that is a member for a semiconductor-manufacturing apparatus contains an yttrium oxide material containing first inorganic particles and second inorganic particles. The first inorganic particles form solid solutions in yttrium oxide, can be precipitated from yttrium oxide, and are present in grains of yttrium oxide. The second inorganic particles can form solid solutions in the first inorganic particles, are unlikely to form any solid solution in yttrium oxide, and are present at boundaries between the yttrium oxide grains. The first inorganic particles contain at least one of ZrO2 and HfO2. The second inorganic particles contain at least one selected from the group consisting of MgO, CaO, SrO, and BaO. The yttrium oxide material is produced in such a manner that solid solution particles are prepared by mixing and firing the first and second inorganic particles and are mixed with yttrium oxide and the mixture is fired.

Abstract: A cordierite ceramic is provided, which includes at least zirconium oxide or hafnium oxide, and also includes titanium oxide. The molar ratio of zirconium (Zr), hafnium (Hf) and titanium (Ti) in terms of the moles in the form of the dioxides, respectively which is given by the formula [(ZrO2+HfO2)/TiO2] is in a range of 0.1 to 5. In this cordierite ceramic, the phases of the components are contained mainly as zirconium titanate or hafnium titanate, and no heterogeneity in appearance, caused by change in color and generation of spots occurs. A honeycomb structure made of the cordierite ceramic is also provided.

Abstract: There is provided an yttrium oxide-containing material with excellent mechanical characteristics. The yttrium oxide-containing material becomes strong by adding silicon carbide (SiC) and yttrium fluoride (YF3) to yttrium oxide (Y2O3). Accordingly, the yield, handling and reliability can be improved when this strengthened yttrium oxide-containing material is applied to and used for components of semiconductor manufacturing equipment.

Abstract: A method for manufacturing an alumina sintered body of the present invention comprises: (a) forming a mixed powder containing at least Al2O3 and MgF2 or a mixed powder containing Al2O3, MgF2, and MgO into a compact having a predetermined shape; and (b) performing hot-press sintering of the compact in a vacuum atmosphere or a non-oxidizing atmosphere to form an alumina sintered body, in which when a amount of MgF2 to 100 parts by weight of Al2O3 is represented by X (parts by weight), and a hot-press sintering temperature is represented by Y (° C.), the hot-press sintering temperature is set to satisfy the following equations (1) to (4) 1,120?Y?1,300??(1) 0.15?X?1.89??(2) Y??78.7X+1,349??(3) Y??200X+1,212??(4).

Abstract: The aluminum nitride sintered body includes at least europium, aluminum, and oxygen. It was found that a grain boundary phase having a peak having a X-ray diffraction profile substantially the same as that of an Sr3Al2O6 phase could be three-dimensionally continued in the aluminum nitride sintered body to realize a lower resistance without damaging various properties unique to aluminum nitride.

Abstract: An aluminum oxide sintered body of the invention includes: europium and nitrogen; and plate-like crystals having peaks coinciding with EuAl12O19 in an X-ray diffraction profile dispersed over a whole sintered body. Such an aluminum oxide sintered body can be obtained by: forming a mixed powder containing an alumina powder, a europium compound powder and an aluminum nitride powder into a green body having a predetermined shape; and sintering the green body under a non-oxidizing atmosphere.

Abstract: There is provided a strengthened composite material that is able to improve yield, handling, and reliability when it is applied to members of semiconductor manufacturing apparatus. Five to 60 mol % ZrO2 is contained relative to Y2O3, and temperature after a sintering process is maintained between 1,200° C. to 1,500° C. for 5 minutes or longer or temperature falling speed to reach 1,200° C. is adjusted to 200° C./h or slower, thereby producing the composite material containing, as major crystalline phases, a Y2O3 solid solution in which ZrO2 is dissolved in Y2O3 and a ZrO2 solid solution in which Y2O3 is dissolved in ZrO2.

Abstract: A substrate of an electrostatic chuck, which is a member for use in a semiconductor manufacturing apparatus, is formed of an yttrium oxide material that contains yttrium oxide (Y2O3), silicon carbide (SiC), and a compound that contains a rare-earth element (RE), Si, O, and N. The yttrium oxide material contains RE8Si4N4O14 as a compound that contains a rare-earth element (RE), Si, O, and N, wherein RE may be La or Y. Y8Si4N4O14 is produced during a sintering step of a raw material that contains the main component Y2O3 and an accessory component Si3N4. Y8Si4N4O14 and SiC in the yttrium oxide material improve mechanical strength and volume resistivity.

Abstract: A method for producing an aluminum nitride sintered product according to the present invention includes the steps of (a) preparing a powder mixture that contains AlN, 2 to 10 parts by weight of Eu2O3 with respect to 100 parts by weight of AlN, Al2O3 such that a molar ratio of Al2O3 to Eu2O3 is 2 to 10, and TiO2 such that a molar ratio of TiO2 to Al2O3 is 0.05 to 1.2, but not Sm; (b) producing a compact from the powder mixture; and (c) firing the compact by subjecting the compact to hot-press firing in a vacuum or in an inert atmosphere.

Abstract: The aluminum-nitride-based composite material according to the present invention is an aluminum-nitride-based composite material that is highly pure with the content ratios of transition metals, alkali metals, and boron, respectively as low as 1000 ppm or lower, has AlN and MgO constitutional phases, and additionally contains at least one selected from the group consisting of a rare earth metal oxide, a rare earth metal-aluminum complex oxide, an alkali earth metal-aluminum complex oxide, a rare earth metal oxyfluoride, calcium oxide, and calcium fluoride, wherein the heat conductivity is in the range of 40 to 150 W/mK, the thermal expansion coefficient is in the range of 7.3 to 8.4 ppm/° C., and the volume resistivity is 1×1014 ?·cm or higher.

Abstract: An aluminum oxide sintered product including a layer phase containing a rare-earth element and fluorine among grains of aluminum oxide serving as a main component, or a phase containing a rare-earth element and fluorine along edges of grains of aluminum oxide serving as a main component. The product includes a phase containing a rare-earth element and a fluorine element among grains of aluminum oxide, the phase not being in the form of localized dots but in the form of line segments, when viewed in an SEM image. The product can be readily adjusted to have a volume resistivity in the range of 1×1013 to 1×1016 ?·cm, the volume resistivity being calculated from a current value after the lapse of 1 minute from the application of a voltage of 2 kV/mm to the aluminum oxide sintered product at room temperature.

Abstract: There is provided a method for manufacturing cordierite ceramics by forming and heating a cordierite-forming raw material containing ?-alumina. A degree of orientation [expressed by (I006/(I300+I006) where Ihkl is height of X-ray diffraction intensity of a hkl face of an ?-alumina crystal] by X-ray diffraction measurement of an ?-alumina crystal in a formed article of the raw material for forming cordierite is 0.10 or more. A crystal structure of alumina used as a material for a cordierite-forming raw material was studied. The method can provide cordierite ceramics having improved thermal resistance and thermal shock resistance by the use of an ?-alumina crystal having a specific shape.

Abstract: A method of producing cordierite ceramic where the degree of stacking faults and the particle diameter of kaolinite used as a component of a cordierite-forming raw material are appropriately adjusted so that microcracks having an average width of 0.3 ?m or more are introduced into the resulting cordierite ceramic to produce a high-quality cordierite ceramic that includes a cordierite crystal oriented in a specific direction and has a porosity of 25% or more and a coefficient of thermal expansion of 0.30×10?6/° C. or less.

Abstract: An electrostatic chuck that is a member for a semiconductor-manufacturing apparatus contains an yttrium oxide material containing first inorganic particles and second inorganic particles. The first inorganic particles form solid solutions in yttrium oxide, can be precipitated from yttrium oxide, and are present in grains of yttrium oxide. The second inorganic particles can form solid solutions in the first inorganic particles, are unlikely to form any solid solution in yttrium oxide, and are present at boundaries between the yttrium oxide grains. The first inorganic particles contain at least one of ZrO2 and HfO2. The second inorganic particles contain at least one selected from the group consisting of MgO, CaO, SrO, and BaO. The yttrium oxide material is produced in such a manner that solid solution particles are prepared by mixing and firing the first and second inorganic particles and are mixed with yttrium oxide and the mixture is fired.

Abstract: A substrate of an electrostatic chuck, which is a member for use in a semiconductor manufacturing apparatus, is formed of an yttrium oxide material that contains yttrium oxide (Y2O3), silicon carbide (SiC), and a compound that contains a rare-earth element (RE), Si, O, and N. The yttrium oxide material contains RE8Si4N4O14 as a compound that contains a rare-earth element (RE), Si, O, and N, wherein RE may be La or Y. Y8Si4N4O14 is produced during a sintering step of a raw material that contains the main component Y2O3 and an accessory component Si3N4. Y8Si4N4O14 and SiC in the yttrium oxide material improve mechanical strength and volume resistivity.

Abstract: There is provided a strengthened composite material that is able to improve yield, handling, and reliability when it is applied to members of semiconductor manufacturing apparatus. Five to 60 mol % ZrO2 is contained relative to Y2O3, and temperature after a sintering process is maintained between 1,200° C. to 1,500° C. for 5 minutes or longer or temperature falling speed to reach 1,200° C. is adjusted to 200° C./h or slower, thereby producing the composite material containing, as major crystalline phases, a Y2O3 solid solution in which ZrO2 is dissolved in Y2O3 and a ZrO2 solid solution in which Y2O3 is dissolved in ZrO2.

Abstract: The aluminum nitride sintered body includes at least europium (Eu), aluminum (Al), and oxygen (O). It was found that a grain boundary phase having a peak having a X-ray diffraction profile substantially the same as that of an Sr3Al2O6 phase could be three-dimensionally continued in the aluminum nitride sintered body to realize a lower resistance without damaging various properties unique to aluminum nitride.

Abstract: There is provided an yttrium oxide-containing material with excellent mechanical characteristics. The yttrium oxide-containing material becomes strong by adding silicon carbide (SiC) and yttrium fluoride (YF3) to yttrium oxide (Y2O3), and yield, handling, reliability can be improved accordingly when this strengthened yttrium oxide-containing material is applied to components of semiconductor manufacturing equipment.