Abstract: The invention relates to new improvements in a process for crystal growth in the environment of supercritical ammonia-containing solution, which are based on use of specific azide mineralizers and result in the improved bulk Group XIII element nitride monocrystals, in particular balk monocrystalline gallium-containing nitride, intended mainly for variety of nitride-based semiconductor products such as various opto-electronic devices. The invention further relates to a mineralizer used for supercritical ammonia-containing solution which comprises at least one compound selected from the group consisting of LiN3, NaN3, KN3, and CsN3.

Abstract: The present invention relates to a nitride semiconductor laser device provided with a window layer on a light-emitting end face of the resonator which comprises an active layer of nitride semiconductor between the n-type nitride semiconductor layers and the p-type nitride semiconductor layers, in which at least the radiation-emitting end face of said resonator is covered by said window layer comprising monocrystalline nitride of general formula AlxGa1?x?yINyN, where 0?x+y?1, 0?x?1 and 0?y<1, having a wider energy gap than that of the active layer and being formed at a low temperature so as not to damage said active layer.

Abstract: The present invention provides a process for forming a bulk monocrystalline aluminum nitride by using a supercritical ammonia. The process comprises the steps of forming a supercritical solvent containing ions of an alkali metal in an autoclave; and dissolving a feedstock in this supercritical solvent to form a supercritical solution, and simultaneously or separately crystallizing aluminum nitride on the face of a crystallization seed. This process is carried out in the autoclave (1) which is provided with a convection-controller (2) arranged therein and which is to produce a supercritical solvent. The autoclave is set in a furnace unit (4) equipped with a heater (5) and/or a cooler (6).

Abstract: The invention relates to a substrate for epitaxy, especially for preparation of nitride semiconductor layers. Invention covers a bulk nitride mono-crystal characterized in that it is a mono-crystal of gallium nitride and its cross-section in a plane perpendicular to c-axis of hexagonal lattice of gallium nitride has a surface area greater than 100 mm2, it is more than 1.0 &mgr;m thick and its C-plane surface dislocation density is less than 106/cm2, while its volume is sufficient to produce at least one further-processable non-polar A-plane or M-plane plate having a surface area at least 100 mm2. More generally, the present invention covers a bulk nitride mono-crystal which is characterized in that it is a mono-crystal of gallium-containing nitride and its cross-section in a plane perpendicular to c-axis of hexagonal lattice of gallium-containing nitride has a surface area greater than 100 mm2, it is more 1.0 &mgr;m thick and its surface dislocation density is less than 106/cm2.

Abstract: The present invention provides a process for forming a bulk monocrystalline gallium-containing nitride, i.e. GaN etc., on the surface of heterogeneous substrate, i.e. SiC etc., comprising the steps of forming a supercritical ammonia solvent containing ion or ions of alkali metals in an autoclave, dissolving a gallium-containing feedstock in the supercritical ammonia solvent to form a supercritical solution in which the feedstock is dissolved, and crystallizing gallium-containing nitride on the face of a seed which contains no element of oxygen and has a lattice constant of 2.8 to 3.6 with respect to ao-axis from the supercritical solution, under a condition of a higher temperature and/or a lower pressure than the temperature and/or the pressure where the gallium-containing feedstock is dissolved in the supercritical solvent. Therefore nitride gallium system compound semiconductor device can be formed on a conductive substrate.

Abstract: The object of this invention is to provide a high-output type nitride light emitting device.

Abstract: The present invention provides a process for forming a bulk monocrystalline gallium nitride by using supercritical ammonia. The process comprises the steps of forming a supercritical solvent containing ion or ions of alkali metals in an autoclave; and dissolving a monocrystalline gallium nitride prepared by flux methods as a feedstock in this supercritical solvent to form a supercritical solution, and simultaneously or separately recrystallizing gallium nitride on the face of a seed.

Abstract: The object of this invention is to provide a high-output type nitride semiconductor laser device comprising a pair of end faces of a resonator.

Abstract: The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality.

Abstract: The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality.

Abstract: The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality.

Abstract: The present invention relates to a phase-change optical information recording medium comprising a recording layer which reversibly phase-changes between the crystalline phase and the amorphous phase by irradiation of a light having a recording wavelength of 390 to 430 nm, and a light transmittance thermally controllable layer showing a light transmittance varying according to temperature, in which the light transmittance increases at a rate of 0.2 to 0.7% /10° C.

Abstract: The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality.

Abstract: The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality.