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.

Provided is a method of enhancing silicon carbide monocrystalline growth yield, including the steps of: (A) filling a bottom of a graphite crucible with a silicon carbide raw material selected; (B) performing configuration modification on a graphite seed crystal platform; (C) fastening a silicon carbide seed crystal to the modified graphite seed crystal platform with a graphite clamping accessory; (D) placing the graphite crucible containing the silicon carbide raw material and the silicon carbide seed crystal in an inductive high-temperature furnace; (E) performing silicon carbide crystal growth process by physical vapor transport; and (F) obtaining silicon carbide monocrystalline crystals. The geometric configuration of the surface of the graphite seed crystal platform is modified to eradicate development of peripheral grain boundary.

A shielding member placed between a SiC source loading portion and a crystal installation portion in an apparatus for single crystal growth, including a crystal growth container including the loading portion which accommodates a SiC source in an inner bottom portion; a crystal installation portion facing the loading portion, and a heating unit configured to heat the crystal growth container. The device grows a single crystal of the SiC source on a crystal installed on the crystal installation portion by sublimating the SiC source from the loading portion. The shielding member includes a plurality of shielding plates, wherein each area of the plurality of shielding plates is 40% or less of a base area of the crystal growth container. When the SiC source loading portion is filled with a SiC source, a shielding ratio provided by a projection surface of the plurality of shielding plates is 0.5 or more.

A vacuum system for silicon crystal growth includes a silicon crystal growth chamber, a first vacuum pipe, a second vacuum pipe, and an oxides container. The first vacuum pipe is coupled to the chamber and has within a first brush that is movable in a first direction for removing internal oxides. The second vacuum pipe is coupled to the first vacuum pipe for receiving the internal oxides via the first brush and has within a second brush that is movable in a second direction different from the first direction. The second brush transports the received internal oxides away from the first vacuum pipe. The oxides container is coupled to the second vacuum pipe for receiving the internal oxides via the second brush.

A vacuum system for silicon crystal growth includes a silicon crystal growth chamber, a first vacuum pipe, a second vacuum pipe, and an oxides container. The first vacuum pipe is coupled to the chamber and has within a first brush that is movable in a first direction for removing internal oxides. The second vacuum pipe is coupled to the first vacuum pipe for receiving the internal oxides via the first brush and has within a second brush that is movable in a second direction different from the first direction. The second brush transports the received internal oxides away from the first vacuum pipe. The oxides container is coupled to the second vacuum pipe for receiving the internal oxides via the second brush.

A thermal shielding system for thermally shielding a batch space of high-temperature furnaces includes at least one shielding element. The shielding element has an encasing wall formed of refractory metal sheet(s) and a ceramic material accommodated in the wall. The ceramic material is present in a particulate and/or fibrous structure and it is based on zirconium oxide (ZrO.sub.2)

An object of this invention is to provide a crucible for growing a sapphire single crystal, which is optimized for providing a sapphire single crystal and is reusable. A crucible for growing a sapphire single crystal of this invention includes: a base material (3) containing molybdenum as a main component and having a crucible shape; and a coating layer (5) with which only an inner periphery of the base material (3) is coated and which is formed of tungsten and inevitable impurities, in which the coating layer (5) has a surface roughness Ra of 5 μm or more and 20 μm or less.

A chemical vapor deposition (CVD) reactor includes a resonating cavity configured to receive microwaves. A microwave transparent window positioned in the resonating cavity separates the resonating cavity into an upper zone and a plasma zone. Microwaves entering the upper zone propagate through the microwave transparent window into the plasma zone. A substrate is disposed proximate a bottom of the plasma zone opposite the microwave transparent window. A ring structure, positioned around a perimeter of the substrate in the plasma zone, includes a lower section that extends from the bottom of the resonating cavity toward the microwave transparent window and an upper section on a side of the lower section opposite the bottom of the resonating cavity. The upper section extends radially toward a central axis of the ring structure. A method of microwave plasma CVD growth of a diamond film on the substrate is also disclosed.

A roller guide assembly for use in lifting a seed coupled to a cable includes a mounting plate, a shaft, and a roller guide. The mounting plate has a throughhole. The shaft is coupled to the mounting plate such that the shaft is movable relative to the mounting plate in a direction that is generally perpendicular to a central axis of the shaft. The roller guide is rotationally coupled about the shaft and generally positioned within the throughhole of the mounting plate such that at least a portion of the roller guide extends out of the throughhole.

A vapor conduit for use in an apparatus for bulk vapor phase crystal growth, an apparatus for bulk vapor phase crystal growth, and a process for bulk vapor phase crystal growth are described. The vapor conduit is a flow conduit defining a passage means adapted for transport of vapor from a source volume to a growth volume, wherein a flow restrictor is provided in the passage means between the source volume and the growth volume and wherein the flow conduit further comprises a flow director structured to direct vapor flow downstream of the flow restrictor away from a longitudinal center line of the conduit and for example towards an edge of the conduit.