Abstract: A method of making a bulk crystal substrate of a GaN single crystal includes the steps of forming a molten flux of an alkali metal in a reaction vessel and causing a growth of a GaN single crystal from the molten flux, wherein the growth is continued while replenishing a compound containing N from a source outside the reaction vessel.

Abstract: An apparatus and method of providing a large semiconductor crystal at a low cost are provided. The apparatus of producing a semiconductor crystal includes a reactor tube having an open end at least one end side, formed of any one material selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, and aluminum oxide, or of a composite material with any one material selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, boron nitride, aluminum oxide, magnesium oxide, mullite, and carbon as a base, and having an oxidation-proof or airtight film formed on the surface of the base, a kanthal heater arranged around the reactor tube in the atmosphere, a flange attached at the open end to seal the reactor tube, and a crucible mounted in the reactor tube to store material of a semiconductor crystal. The material stored in the crucible is heated and melted to form material melt. The material melt is solidified to grow a semiconductor crystal.

Abstract: A crystal growth apparatus comprising a heating furnace capable of controlling uniformly the temperature distribution in the same horizontal plane, and a method for producing a single crystal by using the crystal growth apparatus are provided. In the crystal growth apparatus comprising a cylindrical heating furnace (110) having plural heaters (101, 102, 103 and 104) laminated in multi-stage in an axial direction (Z), each heater is disposed for the terminal portions of the adjacent heaters not to be overlapped in the same position, but to be in a mutually separated position, seeing from the axial direction of the heating furnace. Concretely, in case of N (n is a positive integer of three or more) heaters, each heater (101, 102, 103 and 104) is disposed for the terminal portions (110a, 102a, 103a and 104a) of the heaters to be located at each apex of a regular n-gon (n is an integer satisfying 3≦n≦N), seeing from the axial direction Z of the heating furnace.

Abstract: An apparatus for and method of producing a large semiconductor crystal at a low cost are provided. The apparatus for producing a semiconductor crystal includes a reactor (1) having an open end at both ends thereof, that is formed of any material selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, and aluminum oxide, or of a composite material including a base material selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, boron nitride, aluminum oxide, magnesium oxide, mullite, and carbon as a base, and including an oxidation-proof or airtight film formed on the surface of the base. The apparatus further includes a resistance heater (3) arranged around the reactor (1) in the atmosphere, a flange (9) attached at the open end to seal the reactor (1), and a crucible (2) mounted in the reactor (1) to store material of a semiconductor crystal. The material stored in the crucible (2) is heated and melted to form a material melt (60).

Abstract: A method and apparatus for hydrothermally growing crystals in a pressure vessel containing feed crystals immersed in a mineralizing solution. The apparatus is disposed in the pressure vessel, above the mineralizing solution. The apparatus includes an enclosure having opposing major walls with passages extending therethrough. The enclosure completely surrounds a seed plate having opposing major faces. A restraining structure holds the seed plate within the enclosure such that the major faces of the seed plate are spaced inwardly from the major walls.

Abstract: A process and an apparatus for producing a polycrystalline semiconductor including charging a raw semiconductor material into a crucible, heating to melt the raw semiconductor material in the crucible by heating means, solidifying the melted material while depriving the bottom of the crucible of heat, and then cooling the crucible to cool the solidified semiconductor, in an atmosphere inert to the semiconductor throughout, characterized by alternately subjecting the semiconductor crystal to growth and annealing in the solidification step while periodically varying the amount of heat liberated from the raw semiconductor material.

Abstract: Transition metals of Group VIII (Co, Rh and Ir) have been prepared as semiconductor compounds with the general formula TSb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using vertical gradient freezing techniques and/or liquid phase sintering techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities (up to 1200 cm.sup.2.V.sup.-1.s.sup.-1) and good Seebeck coefficients (up to 150 .mu.VK.sup.-1 between 300.degree. C. and 700.degree. C.).

Abstract: A seal apparatus is disclosed for sealing an outlet of a pressurized chamber from fluid loss from the chamber and contamination to the chamber. The apparatus includes certain combinations of (a) a chamber outlet structure; (b) a removable cover; (c) means for reversibly connecting the cover to the chamber outlet structure; and (d) a compressible self-energizing ring having a surface which consists essentially of a material selected from the group consisting of noble metals, noble metal alloys and polytetrafluoroethylene, which has a hardness selected to substantially avoid deformation when the cover is sealed to the chamber outlet structure.Also disclosed are certain pressure vessels for hydrothermal crystal growth using a crystal growth media, which comprise (a) a vessel base and (b) a removable vessel cover.

Abstract: The present invention is a filtering flow guide for hydrothermal reaction vessels--such as crystal growth apparatus--which improves crystal production efficiency and crystal quality without significantly slowing down flow velocities or crystal growth times. One embodiment of the flow guide fits inside a conventional hydrothermal autoclave for crystal growth, and includes at least one central inlet conduit by which crystal nutrient solution flows from the autoclave's dissolving zone into its growth chamber. A plurality of funnels encircle the inlet conduit, the funnels contiguous with each other along their lateral edges and with the inlet conduit's intake opening at the funnels' innermost edges. Each funnel may be substantially shaped as a hollow, inverted triangular pyramid with a nadir instead of an apex, the nadir opening into a filter-containing outlet.

Abstract: Crystal growing cell including first and second casings. The first casing has a first solution chamber for containing a first solution therein. The first solution chamber has an opening. The second casing has a closing member placed therein for movement in a first direction and in a second direction opposite to the first direction. The second casing has a third casing placed therein. The third casing is fixed to the first casing around the opening to form a second solution chamber for containing a second solution therein. The closing member is moved in the first direction to close the opening so as to separate the first solution chamber from the second solution chamber. The closing member is moved in the second direction to open the opening so as to connect the first solution chamber to the second solution chamber.

Abstract: An apparatus (10) and method are provided for directly viewing, through a viewport assembly (26), the process for forming a layer of mercury cadmium telluride of a predetermined composition on a surface of a wafer (not shown). According to the invention, a molten melt (20) comprising mercury, cadmium and tellurium is provided in a vertically oriented crystal growth chamber (14), which, in turn, is housed in a reactor tube (12). A wafer (not shown) is contacted with the crystal growth melt while cooling the melt below its liquidus temperature at a predetermined rate sufficient to cause a crystal growth layer of mercury cadmium telluride to form on the wafer (not shown). Viewports (26, 48) located approximately radially adjacent to the melt (22) provide direct see through capability to visually monitor the crystal growth process.

Abstract: In order to obtain large, high-quality crystals or crystal layers of a me orthophosphate, in particular, GaPO.sub.4 or AlPO.sub.4, from a nutrient solution with the use of a seed plate, the proposal is put forward that in the initial phase of the growth process a seed plate of alpha-quartz (.alpha.-SiO.sub.2) be introduced into the nutrient solution, and that fluoride ions (F.sup.-) be added to this solution, at least for formation of the primary crystal layer on the quartz seed plate.

Abstract: A direct contact cryogenic crystallizer having a vertically oriented draft tube into which cryogenic fluid is injected at a high velocity along with warm gas and through which a crystal slurry is drawn for subsequent cooling and agitation for the production of crystals.