The present application discloses a method and apparatus for synchronous growth of silicon carbide crystals in multiple crucibles comprising a chamber and an insulation layer assembly arranged close to inner walls of the chamber wherein the insulation layer assembly is used to divide the chamber into a plurality of independent growth cavities, and each of the growth cavities is provided with an independent growth assembly; wherein the independent growth assembly comprises a graphite crucible, a seed crystal tray arranged on the top of the graphite crucible and a drive assembly arranged at the bottom the crucible.

A silicon carbide ingot having micropipes in a seed crystal closed and being reduced in the gathering of screw dislocations, a method for manufacturing the silicon carbide ingot, and a method for manufacturing a silicon carbide wafer are provided. The silicon carbide ingot comprises: a seed crystal composed of a silicon carbide single crystal and having micropipes being hollow defects; a buffer layer provided on the seed crystal and composed of silicon carbide; and a bulk crystal growth layer provided on the buffer layer and composed of silicon carbide. The buffer layer and the bulk crystal growth layer have a plurality of screw dislocations continuous with the micropipes closed with the buffer layer, and the plurality of screw dislocations having the micropipe in common in the bulk crystal growth layer are 150 μm or more apart from each other.

A method of forming a film comprises growing, using a deposition system, at least a portion of the film and analyzing, using a RHEED instrument, the at least a portion of the film. Using a computer, data is acquired from the RHEED instrument that is indicative of a stoichiometry of the at least a portion of the film. Using the computer, adjustments to one or more process parameters of the deposition system are calculated to control stoichiometry of the film during subsequent deposition. Using the computer, instructions are transmitted to the deposition system to execute the adjustments of the one or more process parameters. Using the deposition system, the one or more process parameters are adjusted.

In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.

The present disclosure provides a method for growing a seed crystal, including: obtaining a plurality of orthohexagonal seed crystals in a hexagonal crystal system by performing a first cutting on a plurality of seed crystals in the hexagonal crystal system to be expanded, respectively; splicing the plurality of orthohexagonal seed crystals in the hexagonal crystal system; obtaining a seed crystal in the hexagonal crystal system to be grown by performing a second cutting on the plurality of spliced orthohexagonal seed crystals in the hexagonal crystal system; obtaining an intermediate seed crystal in the hexagonal crystal system by performing a gap growth on the seed crystal in the hexagonal crystal system to be grown under a first setting condition; and obtaining a target seed crystal in the hexagonal crystal system by performing an epitaxial growth on the intermediate seed crystal in the hexagonal crystal system under a second setting condition.

The present disclosure provides a device for preparing a crystal and a method for growing a crystal. The device may include a growth chamber configured to execute a crystal growth; and a temperature control system configured to heat the growth chamber to cause that a radial temperature difference in the growth chamber does not exceed a first preset range of an average temperature in the growth chamber during the crystal growth. The method may include placing a seed crystal and a source material in a growth chamber to grow a crystal; and controlling a heating component based on information of a temperature sensing component, to cause that a radial temperature difference in the growth chamber does not exceed a first preset range of an average temperature in the growth chamber during a crystal growth.

Quality of a silicon carbide single crystal is improved. A crucible having first and second sides is prepared. A solid source material for growing silicon carbide with a sublimation method is arranged on the first side. A seed crystal made of silicon carbide is arranged on the second side. The crucible is arranged in a heat insulating container. The heat insulating container has an opening facing the second side. The crucible is heated such that the solid source material sublimes. A temperature on the second side is measured through the opening in the heat insulating container. The opening has a tapered inner surface narrowed toward the outside of the heat insulating container.

According to various implementations of the invention, high quality a-axis XBCO may be grown with low surface roughness. According to various implementations of the invention, low surface roughness may be obtained by: 1) adequate substrate preparation; 2) calibration of flux rates for constituent atoms; and/or 3) appropriate control of temperature during crystal growth. According to various implementations of the invention, a wafer comprises a smoothing layer of c-axis XBCO; a first conducting layer of a-axis XBCO formed on the smoothing layer; an insulating layer formed on the first conducting layer; and a second conducting layer of a-axis XBCO formed on the insulating layer, where, for a same surface roughness, a thickness of the smoothing layer and the first conducting layer combined is greater than a thickness of the first conducting layer without the smoothing layer.

A nanopowder continuous production device for improving nanopowder collection efficiency is proposed. In one aspect, the device includes a reaction chamber evaporating a raw material using a plasma electrode and a crucible, and a raw material supplier connected to a first side of the reaction chamber and supplying the raw material to the reaction chamber. The device may also include a conveying film moving along a closed loop while capturing and conveying evaporated raw material or crystallized nanopowder at an upper portion in the reaction chamber, and a collector connected to a second side of the reaction chamber and collecting the nanopowder conveyed by the conveying film. The collector may include a first capturer having a scrapper disposed at an end of the conveying film and tensioners elastically supporting the scrapper, and a first side of the scrapper is in close contact with the conveying film.

A crystal growth apparatus according to the present embodiment includes a crucible, a heater which is installed on an outward side of the crucible and surrounds the crucible, and a coil which is installed on an outward side of the heater and surrounds the heater, in which an inner surface of the heater on the crucible side includes a first region, and a second region which is further away from an outer side surface of the crucible than the first region is.