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.

A group 13 element source, a flux comprising at least one of an alkali metal and an alkaline earth metal, and an additive being liquid at an ambient temperature are placed in a crystal growing vessel. The crystal growing vessel is heated and pressurized under a nitrogen atom-containing gas atmosphere to form a melt containing the group 13 element source, the flux and the additive. Evaporation of the additive is prevented until the flux is melted. The crystal of the nitride of the group 13 element is then grown in the melt.

A substrate mounting member according to the present invention is a member for mounting a SiC substrate for epitaxial growth, which includes a wafer plate including a SiC polycrystal, and a supporting plate configured to be placed on the wafer plate, include no SiC polycrystal and have a surface serving as a SiC substrate placing surface, the surface being on the side opposite to a surface in contact with the wafer plate, and in which a thickness h [mm] of the supporting plate satisfies an expression h.sup.4≦3pa.sup.4(1−v.sup.2){(5+v)/(1+v)}16E when a force applied to a unit area of the supporting plate by a self-weight of the supporting plate and by the SiC substrate is represented as p [N/mm.sup.2], a radius of the supporting plate as a [mm], a Poisson's ratio as v and a Young's modulus as E [MPa].

A method of forming an epitaxial layer on a substrate such as a sapphire wafer that does not readily absorb thermal radiation. The method includes coating a first side surface of the substrate with an energy-absorbing opaque material. The opaque material forms a thermally absorptive coating on the substrate. The coated substrate may be heated to remove contaminants from the thermally absorptive coating. The coated substrate is positioned in a vacuum deposition chamber and heated by directing radiative energy onto the thermally absorptive coating. An epitaxial layer such as GaN or SiGe is formed on a second side surface of the substrate opposite the thermally absorptive coating.

An MBE system is disclosed for eliminating the excess flux in an MBE growth chamber before growth, during growth or growth interruption, and/or after growth by evaporating getter material from an effusion evaporator to the cold panel. The cold panel can be the cryopanel of the MBE growth chamber or a cold panel in an attached chamber. Said MBE system includes the cyropanel in the MBE growth chamber or a cold panel in the chamber attached to the MBE growth chamber. With a proper process such as cooling the cold panel, loading a substrate for the MBE process, providing necessary flux for the MBE growth, heating the effusion evaporator and opening the shutter for the evaporator to get the getter material flux onto the said panel, the excess flux will be eliminated. The cross contamination of the grown layer is then avoided.

An MBE system is disclosed for eliminating the excess flux in an MBE growth chamber before growth, during growth or growth interruption, and/or after growth by evaporating getter material from an effusion evaporator to the cold panel. The cold panel can be the cryopanel of the MBE growth chamber or a cold panel in an attached chamber. Said MBE system includes the cyropanel in the MBE growth chamber or a cold panel in the chamber attached to the MBE growth chamber. With a proper process such as cooling the cold panel, loading a substrate for the MBE process, providing necessary flux for the MBE growth, heating the effusion evaporator and opening the shutter for the evaporator to get the getter material flux onto the said panel, the excess flux will be eliminated. The cross contamination of the grown layer is then avoided.

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 silicon carbide wafer is provided, wherein within a range area of 5 mm from an edge of the silicon carbide wafer, there are no low angle grain boundaries formed by clustering of basal plane dislocation defects, and the silicon carbide wafer has a bowing of less than 15 μm.

A silicon carbide wafer is provided, wherein within a range area of 5 mm from an edge of the silicon carbide wafer, there are no low angle grain boundaries formed by clustering of basal plane dislocation defects, and the silicon carbide wafer has a bowing of less than 15 μm.

A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm.sup.−2, a threading screw dislocation density of not more than 1×10.sup.4 cm.sup.−2, a threading edge dislocation density of not more than 1×10.sup.4 cm.sup.−2, a basal plane dislocation density of not more than 1×10.sup.4 cm.sup.−2, a stacking fault density of not more than 0.1 cm.sup.−1, a conductive impurity concentration of not less than 1×10.sup.18 cm.sup.−3, a residual impurity concentration of not more than 1×10.sup.16 cm.sup.−3, and a secondary phase inclusion density of not more than 1 cm.sup.−3.