Abstract: The frequency and power of ultrasonic waves is adjusted to materialize the relation 0.04f?20.0?P?0.09f?7.5, wherein f (kHz) is the frequency of the ultrasonic waves and P (W/L) is the power per unit fluid volume obtained by dividing the power (W) of the ultrasonic waves by the volume (L) of a cleaning fluid. The discharge condition of the cleaning fluid by a pump is adjusted such that the proportion (C5) of the brightness of the fluid when 5 seconds has passed since the state wherein both an ultrasonic wave irradiation means and a bubble supply means are concurrently operating to the brightness of the fluid when no bubbles exist in the fluid is 0.75 or less. The coalition and crush of bubbles due to the irradiation of ultrasonic waves are suppressed, and the both actions can be utilized for a long period.

Abstract: An underlying film 2 of a group III nitride is formed on a substrate 1 by vapor phase deposition. The substrate 1 and the underlying film 2 are subjected to heat treatment in the present of hydrogen to remove the underlying film 2 so that the surface of the substrate 1 is roughened. A seed crystal film 4 of a group III nitride single crystal is formed on a surface of a substrate 1A by vapor phase deposition. A group III nitride single crystal 5 is grown on the seed crystal film 4 by flux method.

Abstract: It is provided a method of growing gallium nitride single crystal of good quality with a high productivity, in the growth of gallium nitride single crystal by Na-flux method. Gallium nitride single crystal is grown using flux 8 containing at least sodium metal. Gallium nitride single crystal is grown in atmosphere composed of gases mixture “B” containing nitrogen gas at a pressure of 300 atms or higher and 2000 atms or lower. Preferably, the nitrogen partial pressure in the atmosphere is 100 atms or higher and 2000 atms or lower. Preferably, the growth temperature is 1000° C. or higher and 1500° C. or lower.

Abstract: In the assembly-completed state, the Lower Mold, the Outer Mold, the Upper Mold, and the “inner mold (the integral body of the Pin-holder and the Pin)” are stacked and fixed in this order from the bottom, and the Pin is coaxially inserted into the First Hole of the Outer Mold and the Second Hole of the Upper Mold. In the assembly-completed state, the molding space for molding the ceramic molded body is formed between the surface of the Pin and the First Hole, and the annular minute gap is formed between the surface of the Pin and the Second Hole. The ceramic slurry poured into the Slurry Reservoir Pres formed on the upper surface of the Upper Mold falls and flows into the molding space through the annular minute gap by virtue of the action of gravity or the like.

Abstract: A silicon-based thin film depositing apparatus, including a plurality of transparent electrodes disposed to face corresponding counter electrodes with a space therebetween. Subsequently, while injecting a raw material gas from raw material gas injection orifices toward the supporting electrodes and also injecting a barrier gas from barrier gas injection orifices in the same direction as the direction in which the raw material gas is injected, the gases are discharged from a gas outlet, and thereby, the pressure in a chamber is controlled to a pressure of more than 1 kPa. Then, a DC pulse voltage is applied to each counter electrode to deposit a silicon-based thin film. A DC pulse voltage is applied to perform discharge. Therefore, even in a state where the distance between the electrodes is increased, plasma can be generated efficiently, and the in-plane distribution of film thickness can be improved.

Abstract: A silicon-based thin film mass-producing apparatus, including transparent electrodes placed to face in parallel to corresponding counter electrodes with a space therebetween, and silicon-based thin films are deposited on the transparent electrodes by feeding a raw material gas for depositing the silicon-based thin films into the chamber and by applying a DC pulse voltage to the counter electrodes to generate plasma. Unlike methods in which a radio frequency voltage is intermittently applied to perform discharge, a high plasma density distribution does not occur, and in-plane film thickness distribution does not occur. Furthermore, since the DC pulse voltage rises sharply, the ON period can be shortened. As a result, generation of a sheath ceases in the transient state before reaching the steady state, and the thickness of the sheath is small, which allows the space between the counter and transparent electrodes to decrease.

Abstract: An apparatus for producing group III nitride crystals includes a pressure container, a reaction vessel positioned in the pressure container, a supplier for supplying an interior of the pressure container with nitrogen gas and nitrogen mixed gas at 1 to 20 MPa, a heater for heating the reaction vessel in the pressure container to at least 700° C., a power unit, a seed crystal arrangement for holding a plurality of seed crystal substrates, a dry box part disposed outside the pressure container, and raising/lowering and rotational axes disposed outside the pressure container.

Abstract: There is provided a group III nitride crystal growth method capable of obtaining a material which is a GaN substrate of low defect density capable of being used as a power semiconductor substrate and in which characteristics of n-type and p-type requested for formation of transistor or the like. A growth method of group III nitride crystals includes: forming a mixed melt containing at least group III element and a flux formed of at least one selected from the group consisting of-alkaline metal and alkaline earth metal, in a reaction vessel; and growing group III nitride crystals from the mixed melt and a substance containing at least nitrogen, wherein after immersing a plurality of seed crystal substrates placed in an upper part of the reaction vessel in which the mixed melt is formed, into the mixed melt to cause crystal growth, the plurality of seed crystal substrates are pulled up above the mixed melt.

Abstract: The frequency and power of ultrasonic waves is adjusted to materialize the relation 0.04f?20.0?P?0.09f?7.5, wherein f (kHz) is the frequency of the ultrasonic waves and P (W/L) is the power per unit fluid volume obtained by dividing the power (W) of the ultrasonic waves by the volume (L) of a cleaning fluid. The discharge condition of the cleaning fluid by a pump is adjusted such that the proportion (C5) of the brightness of the fluid when 5 seconds has passed since the state wherein both an ultrasonic wave irradiation means and a bubble supply means are concurrently operating to the brightness of the fluid when no bubbles exist in the fluid is 0.75 or less. The coalition and crush of bubbles due to the irradiation of ultrasonic waves are suppressed, and the both actions can be utilized for a long period.

Abstract: In the assembly-completed state, the Lower Mold, the Outer Mold, the Upper Mold, and the “inner mold (the integral body of the Pin-holder and the Pin)” are stacked and fixed in this order from the bottom, and the Pin is coaxially inserted into the First Hole of the Outer Mold and the Second Hole of the Upper Mold. In the assembly-completed state, the molding space for molding the ceramic molded body is formed between the surface of the Pin and the First Hole, and the annular minute gap is formed between the surface of the Pin and the Second Hole. The ceramic slurry poured into the Slurry Reservoir Pres formed on the upper surface of the Upper Mold falls and flows into the molding space through the annular minute gap by virtue of the action of gravity or the like.

Abstract: An underlying film 2 of a group III nitride is formed on a substrate 1 by vapor phase deposition. The substrate 1 and the underlying film 2 are subjected to heat treatment in the present of hydrogen to remove the underlying film 2 so that the surface of the substrate 1 is roughened. A seed crystal film 4 of a group III nitride single crystal is formed on a surface of a substrate 1A by vapor phase deposition. A group III nitride single crystal 5 is grown on the seed crystal film 4 by flux method.

Abstract: A silicon-based thin film depositing apparatus, including a plurality of transparent electrodes disposed to face corresponding counter electrodes with a space therebetween. Subsequently, while injecting a raw material gas from raw material gas injection orifices toward the supporting electrodes and also injecting a barrier gas from barrier gas injection orifices in the same direction as the direction in which the raw material gas is injected, the gases are discharged from a gas outlet, and thereby, the pressure in a chamber is controlled to a pressure of more than 1 kPa. Then, a DC pulse voltage is applied to each counter electrode to deposit a silicon-based thin film. A DC pulse voltage is applied to perform discharge. Therefore, even in a state where the distance between the electrodes is increased, plasma can be generated efficiently, and the in-plane distribution of film thickness can be improved.

Abstract: A silicon-based thin film mass-producing apparatus, including transparent electrodes placed to face in parallel to corresponding counter electrodes with a space therebetween, and silicon-based thin films are deposited on the transparent electrodes by feeding a raw material gas for depositing the silicon-based thin films into the chamber and by applying a DC pulse voltage to the counter electrodes to generate plasma. Unlike methods in which a radio frequency voltage is intermittently applied to perform discharge, a high plasma density distribution does not occur, and in-plane film thickness distribution does not occur. Furthermore, since the DC pulse voltage rises sharply, the ON period can be shortened. As a result, generation of a sheath ceases in the transient state before reaching the steady state, and the thickness of the sheath is small, which allows the space between the counter and transparent electrodes to decrease.

Abstract: An object of the present invention is to produce an oxide film having good surface morphology and crystal quality, by a metal organic chemical vapor deposition using two or more raw material gases of metal organic compounds and oxygen gas. It is used a film forming system having a first supply hole 11A, a second supply hole 11B, a third supply hole 11C and a film forming chamber 7. A first raw material gas “A” containing a first metal organic compound is supplied through the first supply hole 11A into the chamber 7. A second raw material gas “B” containing the second metal organic compound is supplied through the second supply hole 11B into the chamber 7, and oxygen gas “C” is supplied through the third supply hole 11C into the chamber 7. The oxygen gas “D” contacts the first raw material gas “E” before the oxygen gas is mixed with the second raw material gas “F” in the chamber 7.

Abstract: An object of the present invention is to produce an oxide film having good surface morphology and crystal quality, by a metal organic chemical vapor deposition using two or more raw material gases of metal organic compounds and oxygen gas. It is used a film forming system having a first supply hole 11A, a second supply hole 11B, a third supply hole 11C and a film forming chamber 7. A first raw material gas “A” containing al first metal organic compound is supplied through the first supply hole 11A into the chamber 7. A second raw material gas “B” containing the second metal organic compound is supplied through the second supply hole 11B into the chamber 7, and oxygen gas “C” is supplied through the third supply hole 11C into the chamber 7. The oxygen gas “D” contacts the first raw material gas “E” before the oxygen gas is mixed with the second raw material gas “F” in the chamber 7.

Abstract: Major surface of a substrate having an optical waveguide and a modulation electrode is pasted to a base substrate through a thermosetting resin, and then the rear surface of the substrate is machined thus making thin the entirety. Subsequently, the rear surface of the substrate thus rendered thin is subjected to machining or laser machining to form a thin part, which is further subjected to machining or laser machining to form a first thin part at a part, including the optical waveguide, of the thin part and a second thin part thinner than the first thin part contiguously thereto. Thereafter, the rear surface of the substrate is pasted to the major surface of a supporting substrate through a thermosetting resin and the base substrate is stripped thus obtaining an optical modulator.

Abstract: There is provided a group III nitride crystal growth method capable of obtaining a material which is a GaN substrate of low defect density capable of being used as a power semiconductor substrate and in which characteristics of n-type and p-type requested for formation of transistor or the like. A growth method of group III nitride crystals includes: forming a mixed melt containing at least group III element and a flux formed of at least one selected from the group consisting of-alkaline metal and alkaline earth metal, in a reaction vessel; and growing group III nitride crystals from the mixed melt and a substance containing at least nitrogen, wherein after immersing a plurality of seed crystal substrates placed in an upper part of the reaction vessel in which the mixed melt is formed, into the mixed melt to cause crystal growth, the plurality of seed crystal substrates are pulled up above the mixed melt.

Abstract: It is provided a method of growing gallium nitride single crystal of good quality with a high productivity, in the growth of gallium nitride single crystal by Na-flux method. Gallium nitride single crystal is grown using flux 8 containing at least sodium metal. Gallium nitride single crystal is grown in atmosphere composed of gases mixture “B” containing nitrogen gas at a pressure of 300 atms or higher and 2000 atms or lower. Preferably, the nitrogen partial pressure in the atmosphere is 100 atms or higher and 2000 atms or lower. Preferably, the growth temperature is 1000° C. or higher and 1500° C. or lower.

Abstract: An optical waveguide device has a substrate composed of a nonlinear optical material and a periodically domain-inverted structure having the same composition as the nonlinear optical material, where the domain-inverted structure has a refractive index distribution relying on the domain-inverted structure.

Abstract: An optical waveguide device includes a waveguide layer that converts a wavelength of incident light and emits converted light. In the waveguide layer, a ridge waveguide and slab waveguides are provided, the slab waveguides being formed on both sides of the ridge waveguide with recess portions intervening therebetween. The waveguide layer satisfies a multi-mode condition for the incident light, and light propagating through the ridge waveguide is in a single mode.