A silicon carbide single crystal manufacturing apparatus includes a crucible constituted by a crucible body and a crucible lid and a base having a crucible lid side surface supported by the lower surface of the crucible lid, and a seed crystal mounting surface on which the seed crystal is mounted and which is a surface on the opposite side of the crucible lid side surface, wherein the base is made of graphite material, the area of the seed crystal mounting surface is larger than the area of the crucible lid side surface, and the base has at least of a portion in which the cross-sectional area orthogonal to the vertical direction connecting the crucible lid side surface and the seed crystal mounting surface is gradually reduced, and a portion that is getting smaller gradually, from the surface of the seed crystal mounting surface toward the crucible lid side surface.

A crystal growing system can include a spool-balanced seed lift assembly for rotating and lifting a seed crystal supported by a cable. The seed crystal is supported along and rotated about a lift axis. The spool-balanced seed lift assembly includes a spool that rotates on, and has a center of gravity along, an axis that intersects the lift axis. As the spool rotates, it moves axially along its axis to avoid displacing the cable from the lift axis. A guide pulley positioned below the spool is used to direct the cable between the lift axis and a spool-tangent axis to minimize displacement of the cable as it is raised and rotated.

The present invention provides an optical ZnS material and a preparation method thereof, wherein the preparation method comprises: charging zinc and sulfur into a first crucible and a feeding device of a chemical vapor deposition furnace, respectively; heating the first crucible, the second crucible and a deposition chamber, and charging sulfur into the second crucible through the feeding device; introducing an inert carrier gas into the first crucible, and introducing an inert carrier gas and hydrogen into the second crucible, flowing the carrier gas containing zinc vapor and sulfur vapor respectively into the deposition chamber through pipelines to deposit ZnS, and supplying the second crucible with sulfur regularly and quantitatively through the feeding device during the deposition process to maintain a saturated vapor pressure of sulfur in a range of 0.8 to 1.8 KPa. The preparation method of the present invention does not generate H.sub.2S; thus it can avoid the formation of hydrogen-zinc complexes by H ions produced from the decomposition of H.sub.2S and Zn vapor, which would otherwise affect the transmittance and emissivity of ZnS material. (FIG. 4B)

In a state in which a SiC container (3) of a material including polycrystalline SiC is housed in a TaC container (2) of a material including TaC and in which an underlying substrate (40) is housed in the SiC container (3), the TaC container (2) is heated in an environment where a temperature gradient occurs in such a manner that inside of the TaC container (2) is at a Si vapor pressure. Consequently, C atoms sublimated by etching of the inner surface of the SiC container (3) are bonded to Si atoms in an atmosphere so that an epitaxial layer (41) of single crystalline 3C-SiC thereby grows on the underlying substrate (40).

A method for preparing a SiC ingot includes preparing a crucible assembly comprising a crucible body having an internal space, loading a raw material into the internal space of the crucible body and placing a plurality of SiC seed in the internal space of the crucible body at regular intervals spaced apart from the raw material, and growing the SiC ingot from the plurality of SiC seed by adjusting the internal space of the crucible body to a crystal growth atmosphere such that the raw material is vapor-transported and deposited to the plurality of SiC seed. A density of the crucible body may be 1.70 to 1.92 g/cm.sup.3.

Ingot puller apparatus for preparing a single crystal silicon ingot by the Czochralski method are disclosed. The ingot puller apparatus includes a heat shield. The heat shield has a leg segment that includes a void (i.e., an open space without insulation) disposed in the leg segment. The heat shield may also include insulation partially within the heat shield.

A die for growing a single crystal by an Edge-defined Film-fed Growth (EFG) technique includes a first outer die plate; a second outer die plate; and at least one central die plate positioned between the first outer die plate and the second outer die plate such that at least two capillaries are formed between the first outer die plate and the second outer die plate. First ends of the first outer die plate and the second outer die plate have a slope extending away from at least one of the at least two capillaries to form a growth interface at a top of the die. Second ends of the first outer die plate and the second outer die plate are immersed in a raw material melt provided in a crucible. The raw material melt is configured to travel to the growth interface by capillary flow of the raw material melt through the at least two capillaries.

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 CZ crucible for growing a single crystal silicon ingot by a CZ method, where the CZ crucible includes a closed-end cylindrical graphite crucible and a closed-end cylindrical quartz glass crucible disposed inside the graphite crucible, and the CZ crucible includes a gap between an inner surface of a bottom portion of the graphite crucible and an outer surface of a bottom portion of the quartz glass crucible on a central axis of the CZ crucible, the gap keeping the inner surface of the bottom portion of the graphite crucible and the outer surface of the bottom portion of the quartz glass crucible contactless with each other. This provides a CZ crucible that ensures that a closed-end cylindrical quartz glass crucible for growing a single crystal silicon ingot by a CZ method can be stable and self-supporting when disposed inside a closed-end cylindrical graphite crucible.

A quartz glass crucible for growing a single crystal silicon ingot by a CZ method, where the crucible has a closed-end cylindrical shape including a cylindrical straight body portion, a first curved portion continuous with a lower end of the straight body portion and having a first curvature R1, a second curved portion continuous with the first and having a second curvature R2, and a bottom portion continuous with the second curved portion, R1 and R2 have a relationship of R1<R2, and an outer surface of the bottom portion forms a flat surface perpendicular to a central axis of the crucible or a concave surface concave with respect to the flat surface. This provides a closed-end cylindrical quartz glass crucible for growing a single crystal silicon ingot by a CZ method that can be stable and self-supporting when it is disposed inside a closed-end cylindrical graphite crucible.