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 crucible device includes a heating chamber, at least a first crucible in which a first crystal is growable, and at least a second crucible in which a second crystal is growable. The first crucible and the second crucible are arranged within the heating chamber spaced apart from each other along a horizontal and vertical and any orientational direction. The crucible device further comprises a heating system arranged within the heating chamber, wherein the heating system is configured for adjusting a temperature along the horizontal and vertical and any orientational directions.

A crucible having a top surface, a bottom surface opposite to the top surface, and a tubular side surface located between the top surface and the bottom surface, a resistive heater provided outside of the crucible and made of carbon, a source material provided in the crucible, and a seed crystal provided to face the source material in the crucible are prepared. A silicon carbide single crystal is grown on the seed crystal by sublimating the source material with the resistive heater. In the step of growing a silicon carbide single crystal, a value obtained by dividing a value of a current flowing through the resistive heater by a cross-sectional area of the resistive heater perpendicular to a direction in which the current flows is maintained at 5 A/mm.sup.2 or less.

A method of growing a conductive Ga.sub.2O.sub.3-based crystal film by MBE includes producing a Ga vapor and a Si-containing vapor and supplying the vapors as molecular beams onto a surface of a Ga.sub.2O.sub.3-based crystal substrate so as to grow the Ga.sub.2O.sub.3-based crystal film. The Ga.sub.2O.sub.3-based crystal film includes a Si-containing Ga.sub.2O.sub.3-based single crystal film. The Si-containing vapor is produced by heating Si or a Si compound and Ga while allowing the Si or a Si compound to contact with the Ga.

In various embodiments, single-crystal aluminum nitride boules and substrates have low Urbach energies and/or absorption coefficients at deep-ultraviolet wavelengths. The single-crystal aluminum nitride may function as a platform for the fabrication of light-emitting devices such as light-emitting diodes and lasers.

A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.

A method for forming a lithium niobate- or lithium tantalum-based (LN/LT) layer includes providing a silicon-based substrate, forming nucleation layer on the substrate, and forming the LN/LT layer by epitaxy on the nucleation layer. The nucleation layer is chosen based upon a III-N material. The nucleation layer may be used in a surface acoustic wave device.

A method for manufacturing a silicon carbide single crystal includes: packing a silicon carbide source material into a crucible, the silicon carbide source material having a flowability index of not less than 70 and not more than 100; and sublimating the silicon carbide source material by heating the silicon carbide source material.

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 purpose of the present is to provide a modified AlN source for suppressing downfall defects. This manufacturing method of a modified aluminum nitride source involves a heat treatment step for heat treating an aluminum nitride source and generating an aluminum nitride sintered body.