Abstract: A single crystal heat treatment method having a step of heating a single crystal of a specific cerium-doped silicate compound in an oxygen-poor atmosphere at a temperature T1 (units: ° C.) that satisfies the conditions represented by formula (3) below 800?T1<(Tm1?550)??(3) (wherein Tm1 (units: ° C.) represents the melting point of the single crystal).

Abstract: A method of forming monodisperse metal chalcogenide nanocrystals without precursor injection, comprising the steps of: combining a metal source, a chalcogen oxide or a chalcogen oxide equivalent, and a fluid comprising a reducing agent in a reaction pot at a first temperature to form a liquid comprising assembly; increasing the temperature of the assembly to a sufficient-temperature to initiate nucleation to form a plurality of metal chalcogenide nanocrystals; and growing the plurality of metal chalcogenide nanocrystals without injection of either the metal source or the chalcogen oxide at a temperature equal to or greater than the sufficient-temperature, wherein crystal growth proceeds substantially without nucleation to form a plurality of monodisperse metal chalcogenide nanocrystals. Well controlled monodispersed CdSe nanocrystals of various sizes can be prepared by choice of the metal source and solvent system.

Abstract: A scintillator single crystal of a specific cerium-doped silicate compound that contains 0.00005 to 0.1 wt % of one or more types of element selected from the group consisting of elements belonging to group 2 of the periodic table based on the total weight of the single crystal.

Abstract: The present invention provides a single crystal heat treatment method, having a step of heating a single crystal of a cerium-doped silicate compound represented by any of general formulas (1) to (4) below in an oxygen-containing atmosphere Y2?(x+y)LnxCeySiO5??(1) (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, x represents a numerical value from 0 to 2, and y represents a numerical value greater than 0 but less than or equal to 0.2) Gd2?(z+w)LnzCewSiO5??(2) (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, z represents a numerical value greater than 0 but less than or equal to 2, and w represents a numerical value greater than 0 but less than or equal to 0.

Abstract: Provided is an excellent p-type nitride type 3-5 group compound semiconductor having escellent electrical properties such as a low contact resistance to an electrode metal, a low ohmic property, etc., by heat-treating a nitride type 3-5 group compound semiconductor doped with p-type dopant in an hydrogen-containing gas atmosphere of a specific concentration.

Abstract: The invention herein relates to controlling the nitrogen content in silicon carbide crystals and in particular relates to reducing the incorporation of nitrogen during sublimation growth of silicon carbide. The invention controls nitrogen concentration in a growing silicon carbide crystal by providing an ambient atmosphere of hydrogen in the growth chamber. The hydrogen atoms, in effect, block, reduce, or otherwise hinder the incorporation of nitrogen atoms at the surface of the growing crystal.

Abstract: When a SiC substrate is heated up to around 1800°C., sublimation of SiC occurs from the SiC substrate. Moreover, temperature of the front surface of the SiC substrate is lower than that of the back surface of the SiC substrate. Therefore, sublimation gas sublimed from a back-surface vicinity of the substrate, where temperature is high, moves to a front-surface vicinity of the substrate, where temperature is low, through the hollow micro-pipe defect. Epitaxial growth proceeds on the front surface of the substrate while the sublimation gas is recrystallized at the front-surface vicinity of the substrate, so that the micro-pipe defect is occluded.

Abstract: A manufacturing method for a single crystal of calcium fluoride by which it is possible to obtain a single crystal of calcium fluoride with adequately small double refraction, which can be used in optical systems for photolithography, and in particular, a single crystal of calcium fluoride with a large diameter (ø200 mm or larger) having superior optical properties, which can be used for photolithography with a wavelength of 250 nm or less.

Abstract: Silicon single crystal wafers for semiconductor devices of high quality are obtained with high productivity by effectively reducing or eliminating grown-in defects in surface layers of silicon single crystal wafers produced by the CZ method. The present invention provides a method for producing a silicon single crystal wafer, which comprises growing a silicon single crystal ingot by the Czochralski method, slicing the single crystal ingot into a wafer, subjecting the wafer to a heat treatment at a temperature of 1100-1300° C. for 1 minute or more under a non-oxidative atmosphere, and successively subjecting the wafer to a heat treatment at a temperature of 700-1300° C. for 1 minute or more under an oxidative atmosphere without cooling the wafer to a temperature lower than 700° C. The present invention also provides a CZ silicon single crystal wafer, wherein density of COPs having a size of 0.09 &mgr;m or more in a surface layer having a thickness of up to 5 &mgr;m from a surface is 1.

Abstract: An apparatus comprises an Si-disposing section in which solid Si is disposed; a seed-crystal-disposing section in which a seed crystal of SiC is disposed; a synthesis vessel adapted to accommodate the Si-disposing section, the seed-crystal-disposing section, and carbon; heating means adapted to heat the Si-disposing section and the seed-crystal-disposing section; and a control section for transmitting to the heating means a command for heating the Si to an evaporation temperature of Si or higher and heating the seed crystal to a temperature higher than that of Si; wherein the Si evaporated by the heating means is adapted to reach the seed-crystal-disposing section.

Abstract: A process for growing single crystal silicon ingots which are substantially free of agglomerated intrinsic point defects. An ingot is grown generally in accordance with the Czochralski method. No portion of the ingot cools to a temperature which is less than a temperature TA at which agglomeration of intrinsic point defects in the ingot occurs during the time the ingot is being grown. The achievement of defect free ingots is thus substantially decoupled from process parameters, such as pull rate, and system parameters, such as axial temperature gradient in the ingot.

Abstract: A process and apparatus for regulating the concentration and distribution of oxygen in a single crystal silicon rod pulled from a silicon melt, optionally doped with antimony or arsenic, in accordance with the Czochralski method wherein an atmosphere is maintained over the melt. In batch embodiments of the process, the gas pressure of the atmosphere over the melt is progressively increased to a value in excess of 100 torr as the fraction of silicon melt solidified increases. In continuous embodiments of the process, the gas pressure of the atmosphere over the melt is maintained at or near a constant value in excess of 100 torr. The process and apparatus are further characterized in that a controlled flow of inert gas is used to remove vapors and particulate away from the surface of the rod and melt, resulting in the production of a single crystal silicon rod having zero dislocations.

Abstract: In producing an optical single crystal epitaxial film from a melt containing a transition metal on a single crystal substrate by a liquid phase epitaxial method, this process contains the steps of: annealing the film at a predetermined temperature in an ozonic atmosphere; and temperature-increasing and -decreasing to and from the predetermined temperature, wherein at least one of temperature-increasing and -decreasing steps, the film is exposed to a substantially ozone-free atmosphere.

Abstract: A method for fabricating composite articles with an epitaxial layer is described. The method can be performed under conditions of relatively high pressure and low substrate surface temperature. The resulting epitaxial layers can demonstrate various advantageous properties, such as low pore density and/or inclusions with small average particle size diameter.

Abstract: The present invention provides a method of manufacturing a semiconductor wafer whereby (1) deterioration of a micro-roughness in a low temperature range in hydrogen atmospheric treatment and increase of resistivity due to outward diffusion of an electrically active impurity in a high temperature range are prevented; (2) in the heat treatment in a hydrogen gas atmosphere, the concentration of gas molecules in the atmosphere, such as water, oxygen and the like, are brought to 5 ppm or less in water molecule conversion; and a reaction is suppressed in which a substrate surface is oxidized unequally and the micro-roughness deteriorates; and (3) the same kind of impurity as the electrically active impurity contained in a Si substrate is mixed into the atmosphere and the outward diffusion of the impurity in the vicinity of the Si substrate surface is prevented to prevent variation of the resistivity.