Abstract: A production apparatus is used for a solution growth method. The production apparatus includes a seed shaft and a crucible. The seed shaft has a lower end surface to which an SiC seed crystal is attached. The crucible contains an SiC solution. The crucible includes a cylindrical portion, a bottom portion, and an inner lid. The bottom portion is disposed at a lower end of the cylindrical portion. The inner lid is disposed in the cylindrical portion. The inner lid has a through hole and is positioned below a liquid surface of the SiC solution when the SiC solution is contained in the crucible.

Abstract: Provided is a process for preparing graphene on a SiC substrate, based on metal film-assisted annealing, comprising the following steps: subjecting a SiC substrate to a standard cleaning process; placing the cleaned SiC substrate into a quartz tube and heating the quartz tube up to a temperature of 750 to 1150° C.; introducing CCl4vapor into the quartz tube to react with SiC for a period of 20 to 100 minutes so as to generate a double-layered carbon film, wherein the CCl4 vapor is carried by Ar gas; forming a metal film with a thickness of 350 to 600 nm on a Si substrate by electron beam deposition; placing the obtained double-layered carbon film sample onto the metal film; subsequently annealing them in an Ar atmosphere at a temperature of 900 to 1100° C. for 10-30 minutes so as to reconstitute the double-layered carbon film into double-layered graphene; and removing the metal film from the double-layered graphene, thereby obtaining double-layered graphene.

Abstract: A UV photoexcited red light-emitting material comprising a fluoride single crystal represented by the chemical formula: M1?xRExF2+x?w, wherein M is at least one metal element belonging to Group 2 of the Periodic Table selected from the group consisting of Be, Mg, Ca, Sr, and Ba, RE is a rare earth element, and the relationships: 0<x?0.4 and 0?w?0.5 are satisfied.

Abstract: The invention is directed to calcium fluoride crystal optics with improved laser durability that can be used for the transmission of below 250 nanometer (nm) electromagnetic radiation. The optics consists of CaF2 as the major component and Mg in an amount in the range of 13 ppm to 20 ppm while Ce and Mn are <0.5 ppm. The doped crystal and optics made therefrom have a ratio of 515/380 nm transmission loss of less than 0.3 after exposure to greater than 2.8 MRads of ?-radiation. Further, the doped crystal and optics made therefrom exhibit a greatly improved lifetime as shown by ALDT testing to at least 1 billion pulses.

Abstract: A method for large-scale manufacturing of gallium nitride boules. Large-area single crystal seed plates are suspended in a rack, placed in a large diameter autoclave or internally-heated high pressure apparatus along with ammonia and a mineralizer, and grown ammonothermally. The seed orientation and mounting geometry are chosen to provide efficient utilization of the seed plates and of the volume inside the autoclave or high pressure apparatus. The method is scalable up to very large volumes and is cost effective.

Abstract: An apparatus for growth of uniform multi-component single crystals is provided. The single crystal material has at least three elements and has a diameter of at least 50 mm, a dislocation density of less than 100 cm?2 and a radial compositional variation of less than 1%.

Abstract: Equipment for crystal growth by a vertical boat method includes a crucible enclosing a raw material, an ampoule encapsulating the crucible, and a crystal growth heater provided around the ampoule to heat the raw material. The raw material is melted into a raw material melt by the crystal growth heater, and a temperature of the raw material melt is controlled such that a crystal grows in the crucible from a bottom toward a top thereof. The crucible encloses GaAs as the raw material and Si as a dopant. The ampoule includes an additional B2O3 as an additional raw material at a position separated from the raw material, and a B2O3 adding-heater to heat the additional B2O3 separately from the raw material. A temperature of the additional B2O3 is controlled by the B2O3 adding-heater during growth of the crystal such that at least a portion of the additional B2O3 is melted and supplied into the crucible.

Abstract: In a method for growing a silicon carbide single crystal on a silicon carbide single crystal substrate by contacting the substrate with a solution containing C prepared by dissolving C into the melt that contains Cr and X, which consists of at least one element of Ce and Nd, such that a proportion of Cr in a whole composition of the melt is in a range of 30 to 70 at. %, and a proportion of X in the whole composition of the melt is in a range of 0.5 at. % to 20 at. % in the case where X is Ce, or in a range of 1 at. % to 25 at. % in the case where X is Nd, and the silicon carbide single crystal is grown from the solution.

Abstract: A method for growing high-resistivity single crystals includes placing a raw material in a vacuum-sealable ampoule, heating the raw material in the vacuum-sealable ampoule to vaporize the moisture in the raw material, exhausting the vaporized moisture from the vacuum-sealable ampoule, vacuum-sealing the vacuum-sealable ampoule, heating the raw material in the vacuum-sealable ampoule to vaporize the oxide compounds in the raw material, cooling a bulb in a cap on the vacuum-sealable ampoule to produce condensed oxide compounds on an inner surface of the bulb, removing the bulb and the condensed oxide compounds from the vacuum-sealable ampoule, wherein the raw material in the vacuum-sealable ampoule comprises carbon as an impurity, and placing the vacuum-sealable ampoule comprising the raw material in a crystal growth apparatus to grow a high-resistivity crystal from the raw material.

Abstract: A raw material mixture containing an easily oxidizable material is weighed. The raw material mixture is melted and then solidified within a reaction vessel 1 set in a non-oxidizing atmosphere to thereby produce a solidified matter 19. The reaction vessel 1 and the solidified matter 19 are heated in a non-oxidizing atmosphere within a crystal growth apparatus to melt the solidified matter to thereby produce a solution. A single crystal is grown from the solution.

Abstract: A method for growing II-VI semiconductor crystals and II-VI semiconductor layers as well as crystals and layers of their ternary or quaternary compounds from the liquid or gas phase is proposed. To this end, the solid starting materials are introduced into a growing chamber for the growing of crystals. Inside the growing chamber, carbon monoxide is supplied by way of reducing agent. At least certain zones of the growing chamber are heated to a temperature at which a first-order phase transition of the starting materials takes place and the starting materials pass into the liquid or gas phase. The starting materials are then cooled down accompanied by the formation of a semiconductor crystal or semiconductor layer, again with a first-order phase transition taking place. The oxygen present in the growing chamber is bound by the carbon monoxide and the formation of an oxide layer at the phase boundary of the growing semiconductor crystal or semiconductor layer is prevented.

Abstract: An oxide single crystal having a composition represented by RExSi6O1.5x+12 (RE: La, Ce, Pr, Nd, or Sm, x: 8 to 10) is grown by using the Czochralski method such that the crystal growth orientation coincides with the c-axis direction. The solidification rate (the weight of the grown crystal÷the weight of the charged raw material) in the crystal growth is less than 45%.

Abstract: A method for purifying silicon includes placing silicon to be purified and an aluminum-silicon alloy ingot, made from high purity aluminum in close contact in a closed environment to be subjected to heating under vacuum, such that the aluminum-silicon alloy ingot is melted into an aluminum-silicon melt. The temperatures are kept constant when the temperature M the interface of the silicon and the aluminum-silicon melt and the temperature at a free end of the aluminum-silicon melt reach 900° C. and 800° C. respectively. As the purified silicon begins to segregate and the interface, the heating apparatus is moved in step with the growth rate of the segregated silicon toward the silicon to be purified to maintain the temperatures at both ends of the aluminum-silicon melt. The segregated pure silicon is cut off upon the completion of dissolution of purified silicon and after cooling and air pressure recovery.

Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.

Abstract: In a method for growing a silicon carbide single crystal on a silicon carbide single crystal substrate by contacting the substrate with a solution containing C by dissolving C into the melt that contains Si, Cr and X, which consists of at least one element of Sn, In and Ga, such that the proportion of Cr in the whole composition of the melt is in a range of 30 to 70 at. %, and the proportion of X is in a range of 1 to 25 at. %, and the silicon carbide crystal is grown from the solution.

Abstract: The invention is directed to calcium fluoride crystal optics with improved laser durability that can be used for the transmission of below 250 nanometer (nm) electromagnetic radiation. The optics consist of CaF2 as the major component and, in one embodiment, at least one dopant/amount selected >0.3-1200 ppm Mg, >0.3-200 ppm Sr, >0.3-200 ppm Ba, while Ce and Mn are <0.5 ppm. The doped crystal and optics made therefrom have a ratio of 515/380 nm transmission loss of less than 0.3 after exposure to greater than 2.8 MRads of ?-radiation.

Abstract: A process for producing fluoride crystals, in particular calcium fluoride crystals, having high radiation resistance to ultraviolet radiation, which includes: provisioning of a crystal powder (6) containing alkali metal fluoride or alkaline earth metal fluoride to form a raw crystal mass, melting of the raw crystal mass in a crystal growing unit (11) and solidifiying of the molten raw crystal mass by cooling. In the process, an ammonium salt (7) of a complex fluoro acid and an aliphatic alcohol (8) are added to the crystal powder (6) or to the raw crystal mass, to decrease oxidic impurities. A fluoride crystal produced by the process and also an optical component formed from such a fluoride crystal are also disclosed.

Abstract: A method for producing thin silicon rods using a floating zone crystallization process includes supplying high frequency (HF) current to a flat induction coil having a central opening, a plurality of draw openings and a plate with a slot as a current supply of the HF current so as to provide a circumfluent current to the central opening. An upper end of a raw silicon rod is heated by induction using the flat induction coil so as to form a melt pool. A thin silicon rod is drawn upwards through each of the plurality of draw openings in the flat induction coil from the melt pool without drawing a thin silicon rod through the central opening having the circumfluent current.

Abstract: Silicon raw material is filled into a graphite crucible (10), the graphite crucible (10) is heated to form molten silicon (M), at least one rare earth element and at least one of Sn, Al, and Ge are added to molten silicon (M), and a temperature gradient is maintained in the molten silicon in which the temperature decreases from within the molten silicon toward the surface while growing an silicon carbide single crystal starting from an silicon carbide seed crystal (14) held immediately below the surface of the molten liquid.

Abstract: In accordance with various embodiments, crystalline structures are formed by providing, at a growth temperature, a liquid comprising AlN and having a quality factor greater than approximately 0.14 and forming solid AlN from the liquid, the growth temperature being lower than the melting point of AlN.

Abstract: Disclosed are a method of fabricating a quasi-substrate wafer with a subcarrier wafer and a growth layer, and a semiconductor body fabricated using such a quasi-substrate wafer. In the method of fabricating a quasi-substrate wafer, a growth substrate water is fabricated that is provided with a separation zone and comprises the desired material of the growth layer. The growth substrate wafer is provided with a stress that counteracts a stress generated by the formation of the separation zone, and/or the stress generated by the formation of the separation zone is distributed, by structuring a first main race of the growth substrate water and/or the separation zone, to a plurality of subregions along the first main face. The growth substrate wafer with separation zone exhibits no or only slight bowing.

Abstract: A method for purifying silicon bearing materials for photovoltaic applications includes providing metallurgical silicon into a crucible apparatus. The metallurgical silicon is subjected to at least a thermal process to cause the metallurgical silicon to change in state from a first state to a second state, the second stage being a molten state not exceeding 1500 Degrees Celsius. At least a first portion of impurities is caused to be removed from the metallurgical silicon in the molten state. The molten metallurgical silicon is cooled from a lower region to an upper region to cause the lower region to solidify while a second portion of impurities segregate and accumulate in a liquid state region. The liquid state region is solidified to form a resulting silicon structure having a purified region and an impurity region. The purified region is characterized by a purity of greater than 99.9999%.

Abstract: A method of growing a group III nitride crystal grows a group III nitride crystal from a solution in which an alkaline metal, a group III metal and nitrogen are dissolved, and includes, in the solution, a material which increases solubility of the nitrogen into the solution.

Abstract: A process for obtaining bulk mono-crystalline gallium-containing nitride, liminating impurities from the obtained crystal and manufacturing substrates made of bulk mono-crystalline gallium-containing nitride has been now proposed.

Abstract: A process is provided to produce bulk quantities of nanowires in a variety of semiconductor materials. Thin films and droplets of low-melting metals such as gallium, indium, bismuth, and aluminum are used to dissolve and to produce nanowires. The dissolution of solutes can be achieved by using a solid source of solute and low-melting metal, or using a vapor phase source of solute and low-melting metal. The resulting nanowires range in size from 1 nanometer up to 1 micron in diameter and lengths ranging from 1 nanometer to several hundred nanometers or microns. This process does not require the use of metals such as gold and iron in the form of clusters whose size determines the resulting nanowire size. In addition, the process allows for a lower growth temperature, better control over size and size distribution, and better control over the composition and purity of the nanowire produced therefrom.

Abstract: It is an object of the present invention to provide a magnetic garnet single crystal at a reduced Pb content, and a method for producing the same and an optical element using the same. The object is attained with a magnetic garnet single crystal represented by the chemical formula Bi?Na?M13-?-?Fe5-?M2?O12 (M1 is at least one element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and M2 is at least one element selected from Si, Ge and Ti, provided that 0.5<??2.0, 0<??0.8, 0.2?3????<2.5, and 0<??1.6).

Abstract: A method for producing a Group III element nitride single crystal, which comprises reacting at least one Group III element selected from the group consisting of gallium(Ga), aluminum(Al) and indium(In) with nitrogen(N) in a mixed flux of sodium(Na) and at least one of an alkali metal (except Na) and an alkaline earth metal. The method allows the production, with a good yield, of the single crystal of a group III element nitride which is transparent, is reduced in the density of dislocation, has a bulk form, and is large. In particular, a gallium nitride single crystal produced by the method has high quality and takes a large and transparent bulk form, and thus has a high practical value.

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: An improved mineralizer used for a process for obtaining bulk mono-crystalline gallium-containing nitride of a general formula of AlxGa1-xN, where 0?×<1 in an environment of supercritical ammonia-containing solution has been now proposed. According to the invention growth rate and quality of the product obtained can be controlled by suitable selection of mineralizer, so as to ensure presence of ions of Group I element (IUPAC 1989), preferably sodium in combination with other components selected from the group consisting of Group I elements (IUPAC 1989), ions of Group II elements (IUPAC 1989), one or more substances containing oxygen-free species causing some weakening of the ammono-basic nature of the supereritical solvent, optionally in combination with Group II elements (JUPAC 1989), preferably calcium or magnesium.

Abstract: In a diamond manufacturing method, a melt of carbon and blue kimberlite is contained in a vessel at 1000° C. The vessel is pressurized by a gas of predominantly hydrogen to 200 atmospheres. A crystallization seed is drawn from the melt to generate a piece of diamond material.

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: A method of forming at least one single crystal of a Group III metal nitride. The method includes the steps of: providing a flux material and a source material comprising at least one Group III metal selected from the group consisting of aluminum, indium, and gallium, to a reaction vessel; sealing the reaction vessel; heating the reaction vessel to a predetermined temperature and applying a predetermined pressure to the vessel. The pressure is sufficient to suppress decomposition of the Group III metal nitride at the temperature. Group III metal nitrides, as well as electronic devices having a Group III metal nitride substrate formed by the method are also disclosed.

Abstract: A method of making a fluoride crystal suitable for use as an optical element is disclosed. The method includes a mixing step for mixing a prepared raw fluoride material with a scavenger to yield a fluoride mixture. In a preliminary step, the fluoride mixture is formed into a fluoride disk. A grown fluoride crystal is formed by melting and then gradually cooling the fluoride disk in a cylindrical crucible. The grown fluoride crystal is then annealed.

Abstract: The object of the present invention is a process of preparing an optical fluoride crystal containing barium fluoride, which comprises: loading a crucible with a barium fluoride starting material crystal feedstock which contains at least one oxide as impurity, and an effective and non-excess amount of at least one fluorinating agent which is solid at ambient temperature, melting said mixture within said crucible, growing the crystal, by controlled cooling of the molten mixture, controlled cooling of said crystal to ambient temperature, recovering said crystal; and which is characterized in that the oxide(s) resulting from the reaction between said fluorinating agent(s) and said oxide(s), the impurity or impurities, can be discharged from said crucible, in view of the intrinsic permeability of the material constituting it. Said process is particularly adapted for preparing 157 nm transmitting lithography excimer laser optical fluoride crystals in graphite crucibles.

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: A method for producing a silicon single crystal in accordance with CZ method, characterized in that before producing the crystal having a predetermined kind and concentration of impurity, another silicon single crystal having the same kind and concentration of impurity as the crystal to be produced is grown to thereby determine an agglomeration temperature zone of grown-in defects thereof, and then based on the temperature, growth condition of the crystal to be produced or temperature distribution within a furnace of a pulling apparatus is set such that a cooling rate of the crystal for passing through the agglomeration temperature zone is a desired rate to thereby produce the silicon single crystal. A silicon single crystal produced in accordance with the above method, characterized in that a density of LSTD before subjecting to heat treatment is 500 number/cm2 or more and the average defect size is 70 nm or less.

Abstract: A method of preparing a compound semiconductor crystal is able to dope the crystal with carbon with high reproducibility. The method includes the steps of sealing a carbon oxide gas of a predetermined partial pressure and a compound semiconductor material in a gas-impermeable airtight vessel, increasing the temperature of the vessel to melt the compound semiconductor material sealed in the vessel, and then decreasing the temperature of the vessel to solidify the melted compound semiconductor material to grow a compound semiconductor crystal containing a predetermined amount of carbon. With this method, a compound semiconductor crystal with a carbon concentration of 0.1×1015cm−3 to 20×1015cm−3 is prepared with high reproducibility.

Abstract: A process for producing nitrogen-doped semiconductor wafers has the nitrogen being derived from a dopant gas which contains NH3. The process includes pulling a single crystal from a melt of molten semiconductor material, feeding the dopant gas to the semiconductor material, and cutting the nitrogen-doped semiconductor wafers off the pulled single crystal. The dopant gas is fed to the semiconductor material at most until pulling begins for that part of the single crystal from which the semiconductor wafers are cut.

Abstract: A method of preparing a compound semiconductor crystal is able to dope the crystal with carbon with high reproducibility. The method includes the steps of sealing a carbon oxide gas of a predetermined partial pressure and a compound semiconductor material in a gas-impermeable airtight vessel, increasing the temperature of the vessel to melt the compound semiconductor material sealed in the vessel, and then decreasing the temperature of the vessel to solidify the melted compound semiconductor material to grow a compound semiconductor crystal containing a predetermined amount of carbon. With this method, a compound semiconductor crystal with a carbon concentration of 0.1×1015 cm−3 to 20×1015 cm−3 is prepared with high reproducibility.

Abstract: An object of the present invention is to provide a fluoride crystal having a high transmittance with respect to an excimer laser and an excellent resistance with respect to a high output laser, and a production method therefore. The fluoride crystal of the present invention contains at least one kind of atom selected from the group consisting of Zn, Cd, Pb, Li, Bi and Na with a content of 10 ppm or less, and has an internal transmittance of 70% or more with respect to 135 nm wavelength light. The method of the present invention of producing a fluoride crystal comprises conducting a refining step of adding a scavenger to a calcium fluoride raw material and refining the raw material at least once, and a crystal growth step of further adding the scavenger to the refined raw material and growing a crystal by using a crucible lowering method, wherein the amount of the scavenger to be added in the first refining step is 0.04 to 0.

Abstract: It is an object of the present invention to provide a calcium fluoride crystal in which the light transparency does not deteriorate with consecutive irradiation by high output short wavelength light over long time periods. A calcium fluoride crystal in accordance with the present invention has an internal transmittance of 70% or more for light of 135-nm wavelength or over. A calcium fluoride crystal contains any one of strontium, aluminum, silicon and magnesium, with the strontium content ranging from 1 ppm to 600 ppm, the aluminum content ranging from 1 ppm to 50 ppm, the silicon content ranging from 1 ppm to 50 ppm, or the magnesium content ranging from 1 ppm to 10 ppm. A calcium fluoride crystal has an internal transmittance of 70% or more for light of 135-nm wavelength or over and contains 1 ppm or less of La and 10 ppm or less of Y. An optical system for an excimer laser in accordance with the present invention comprises a lens comprising any calcium fluoride crystal set forth above.

Abstract: An annealing method for a single crystal of fluoride is provided. The method includes the steps of removing at least one of attached objects and absorbed objects from the surface of the single crystal of fluoride to clean the surface, thereafter annealing the single crystal of fluoride, including heating the single crystal of fluoride and gradually cooling the heated single crystal of fluoride, and removing a deteriorated layer which is formed on the surface of the single crystal of fluoride during the annealing step.

Abstract: There is disclosed a method of producing, in large volume and at low cost, titanium carbide, nitride and carbonitride whiskers, with preferably submicron diameters, to be used as reinforcing material. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Titanium oxide, hydroxide or alkali compounds thereof are mixed with a carbon source with a volatile part which volatiles at temperatures exceeding 500.degree. C. and in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for titanium as well as a catalyst able to dissolve Ti plus C and/or N, such as Ni or Co. The reactant powders are blended in some typical manner, e.g., by using a high speed blender so as to intimately mix them.

Abstract: An apparatus and a method for producing single crystal semiconductor particulate in near spherical shape and the particulate product so formed is accomplished by producing uniform, monosized, near spherical droplets; identifying the position of an undercooled droplet in a nucleation zone; and seeding the identified droplet in the nucleation zone to initiate single crystal growth in the droplet.

Abstract: A process for producing silicon wafers with low defect density is one wherein a) a silicon single crystal having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 is produced by molten material being solidified to form a single crystal and is then cooled, and the holding time of the single crystal during cooling in the temperature range of from 850.degree. C. to 1100.degree. C. is less than 80 minutes; b) the single crystal is processed to form silicon wafers; and c) the silicon wafers are annealed at a temperature of at least 1000.degree. C. for at least one hour. Also, it is possible to prepare a silicon single crystal based upon having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 and a nitrogen doping concentration of at least 1*10.sup.14 /cm.sup.3 for (a) above.

Abstract: There is disclosed a method of producing whiskers in large volumes and at low cost to be used as reinforcing material. The whiskers are solid solutions between two or more transition metal carbides, nitrides and carbonitrides, (Me.sub.1-X-Y.sub.Me'.sub.X+Y)C.sub.1-Z N.sub.Z, having preferably submicron diameters, where Me' is one or more transition metals other than Me. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Transition metal oxides, hydroxides or alkali compounds thereof are mixed with carbon powder. The carbon source is added in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for the transition metals and a catalyst such as Ni or Co that is able to dissolve transition metals plus C and/or N. The reactant powders are blended so as to intimately mix them.

Abstract: A method of preparing a compound semiconductor crystal is able to dope the crystal with carbon with high reproducibility. The method includes the steps of sealing a carbon oxide gas of a predetermined partial pressure and a compound semiconductor material in a gas-impermeable airtight vessel, increasing the temperature of the vessel to melt the compound semiconductor material sealed in the vessel, and then decreasing the temperature of the vessel to solidify the melted compound semiconductor material to grow a compound semiconductor crystal containing a predetermined amount of carbon. With this method, a compound semiconductor crystal with a carbon concentration of 0.1×1015cm?3 to 20×1015cm?3 is prepared with high reproducibility.

Abstract: A method of preparing a compound semiconductor crystal is able to dope the crystal with carbon with high reproducibility. The method includes the steps of sealing a carbon oxide gas of a predetermined partial pressure and a compound semiconductor material in a gas-impermeable airtight vessel, increasing the temperature of the vessel to melt the compound semiconductor material sealed in the vessel, and then decreasing the temperature of the vessel to solidify the melted compound semiconductor material to grow a compound semiconductor crystal containing a predetermined amount of carbon. With this method, a compound semiconductor crystal with a carbon concentration of 0.1×1015cm?3 to 20×1015cm?3 is prepared with high reproducibility.