The present invention relates to a silicon carbide (SiC) substrate with improved mechanical and electrical characteristics. Furthermore, the invention relates to a method for producing a bulk SiC crystal in a physical vapor transport growth system. The silicon carbide substrate comprises an inner region (102) which constitutes at least 30% of a total surface area of said substrate (100), a ring shaped peripheral region (104) radially surrounding the inner region (102), wherein a mean concentration of a dopant in the inner region (102) differs by at maximum 5.Math.10.sup.18 cm.sup.−3, preferably 1.Math.10.sup.18 cm.sup.−3, from the mean concentration of this dopant in the peripheral region (104).

The present invention relates to a silicon carbide (SiC) substrate with improved mechanical and electrical characteristics. Furthermore, the invention relates to a method for producing a bulk SiC crystal in a physical vapor transport growth system. The silicon carbide substrate comprises an inner region (102) which constitutes at least 30% of a total surface area of said substrate (100), a ring shaped peripheral region (104) radially surrounding the inner region (102), wherein a mean concentration of a dopant in the inner region (102) differs by at maximum 5.Math.10.sup.18 cm.sup.−3, preferably 1.Math.10.sup.18 cm.sup.−3, from the mean concentration of this dopant in the peripheral region (104).

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.

Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density≦100 cm.sup.−2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density≦100 cm.sup.−2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

A silicon carbide powder which, when used as a raw material in a sublimation recrystallization method, enables improvement in productivity of a silicon carbide single crystal by exhibiting a high sublimation rate and allowing a small amount of silicon carbide to remain without being sublimated, and enables an increase in size of the silicon carbide single crystal (for example, a single crystal wafer). The silicon carbide powder has a Blaine specific surface area of from 250 cm.sup.2/g to 1,000 cm.sup.2/g and a ratio of a silicon carbide powder having a particle size of more than 0.70 mm and 3.00 mm or less of 50 vol % or more with respect to a total amount of the silicon carbide powder. When a silicon carbide powder accommodated in a crucible is heated to be sublimated, a silicon carbide single crystal is formed on a seed crystal provided on an undersurface of a lid.

A silicon carbide powder which, when used as a raw material in a sublimation recrystallization method, enables improvement in productivity of a silicon carbide single crystal by exhibiting a high sublimation rate and allowing a small amount of silicon carbide to remain without being sublimated, and enables an increase in size of the silicon carbide single crystal (for example, a single crystal wafer). The silicon carbide powder has a Blaine specific surface area of from 250 cm.sup.2/g to 1,000 cm.sup.2/g and a ratio of a silicon carbide powder having a particle size of more than 0.70 mm and 3.00 mm or less of 50 vol % or more with respect to a total amount of the silicon carbide powder. When a silicon carbide powder accommodated in a crucible is heated to be sublimated, a silicon carbide single crystal is formed on a seed crystal provided on an undersurface of a lid.

A deposition device for providing a thin film on a substrate. The device comprises a material source for providing at least one first metallic element which does not re-evaporate substantially from the substrate under particular growth conditions, at least one second metallic element or metal based molecule which does re-evaporate substantially from the substrate under the same growth conditions, and a component suitable for forming an at least one first compound with the at least one first metallic element and an at least one second compound with the at least one second metallic element or metal based molecule. The device comprises a controller configured to control the growth conditions, and the amounts of the at least one first metallic element, the at least one second metallic element or metal based molecule, and the component so as to obtain a substantially stoichiometric thin film.

The present disclosure provides high-purity semi-insulating single-crystal silicon carbide wafer and crystal which include one polytype single crystal. The semi-insulating single-crystal silicon carbide wafer has silicon vacancy inside, wherein the silicon-vacancy concentration is greater than 5E11 cm{circumflex over ( )}-3.

The present disclosure provides semi-insulating single-crystal silicon carbide bulk material and powder which include one polytype single crystal. The semi-insulating single-crystal silicon carbide bulk material has silicon vacancy inside, wherein the silicon-vacancy concentration is greater than 5E11 cm{circumflex over ( )}−3.