Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. In a direction parallel to a central region, a ratio of a standard deviation of a carrier concentration of the silicon carbide layer to an average value of the carrier concentration of the silicon carbide layer is less than 5%. The average value of the carrier concentration is more than or equal to 1×1014 cm?3 and less than or equal to 5×1016 cm?3. In the direction parallel to the central region, a ratio of a standard deviation of a thickness of the silicon carbide layer to an average value of the thickness of the silicon carbide layer is less than 5%. The central region has an arithmetic mean roughness (Sa) of less than or equal to 1 nm. The central region has a haze of less than or equal to 50.

Abstract: A method of manufacturing a silicon carbide epitaxial substrate includes: preparing a silicon carbide single-crystal substrate having a polytype of 4H and having a principal surface inclined at an angle ? from a {0001} plane in a <11-20> direction; growing a silicon carbide epitaxial layer on the principal surface having a basal plane dislocation, the basal plane dislocation having a portion extending in a <1-100> direction and a portion extending in a <11-20> direction; and irradiating the silicon carbide epitaxial layer with an ultraviolet light having a predetermined power and a predetermined wavelength for a predetermined period of time to stabilize the basal plane dislocation. After the irradiating, the basal plane dislocation does not move even when the basal plane dislocation is irradiated with an ultraviolet light having a power of 270 mW and a wavelength of 313 nm for 10 seconds.

Abstract: A silicon carbide epitaxial wafer includes a single crystal silicon carbide substrate of 4H polytype having a major surface thereof inclined at an angle ? to a {0001} plane toward a <11-20> direction, and a silicon carbide epitaxial layer of a thickness t formed on the major surface, wherein a diameter of the single crystal silicon carbide substrate is greater than or equal to 150 mm, wherein the angle ? exceeds 0°, and is less than or equal to 6°, wherein one or more pairs of a screw dislocation pit and a diagonal line defect situated at a distance of t/tan? from the pit are present in a surface of the silicon carbide epitaxial layer, and wherein a density of the pairs of a pit and a diagonal line defect is less than or equal to 2 pairs/cm2.

Abstract: A silicon carbide epitaxial layer includes a first silicon carbide layer, a second silicon carbide layer, a third silicon carbide layer, and a fourth silicon carbide layer. A nitrogen concentration of the second silicon carbide layer is increased from the first silicon carbide layer toward the third silicon carbide layer. A value obtained by dividing, by a thickness of the second silicon carbide layer, a value obtained by subtracting a nitrogen concentration of the first silicon carbide layer from a nitrogen concentration of the third silicon carbide layer is less than or equal to 6×1023 cm?4. Assuming that the nitrogen concentration of the third silicon carbide layer is N cm?3; and a thickness of the third silicon carbide layer is X ?m, X and N satisfy a Formula 1.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide substrate, a first silicon carbide epitaxial layer, and a second silicon carbide epitaxial layer. The silicon carbide substrate has a first main surface and a second main surface opposite to the first main surface. The first silicon carbide epitaxial layer is in contact with a whole of the first main surface. The second silicon carbide epitaxial layer is in contact with a whole of the second main surface. A carrier concentration of the silicon carbide substrate is higher than a carrier concentration of each of the first silicon carbide epitaxial layer and the second silicon carbide epitaxial layer.

Abstract: When a value obtained by dividing the number of the one or more second regions by a total of the number of the one or more first regions and the number of the one or more second regions is defined as a first defect free area ratio, a value obtained by dividing the number of the one or more fourth regions by a total of the number of the one or more third regions and the number of the one or more fourth regions is defined as a second defect free area ratio, and a value obtained by dividing the number of the one or more macroscopic defects by an area of the central region is defined as X cm?2, A is smaller than B, B is less than or equal to 4, X is more than 0 and less than 4, and a Formula 1 is satisfied.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. In a direction parallel to a central region, a ratio of a standard deviation of a carrier concentration of the silicon carbide layer to an average value of the carrier concentration of the silicon carbide layer is less than 5%. The average value of the carrier concentration is more than or equal to 1×1014 cm?3 and less than or equal to 5×1016 cm?3. In the direction parallel to the central region, a ratio of a standard deviation of a thickness of the silicon carbide layer to an average value of the thickness of the silicon carbide layer is less than 5%. The central region has an arithmetic mean roughness (Sa) of less than or equal to 1 nm. The central region has a haze of less than or equal to 50.

Abstract: The composite defect includes an extended defect and a basal plane dislocation. The extended defect includes a first region extending in a <11-20> direction from an origin located at a boundary between the silicon carbide substrate and the silicon carbide epitaxial film, and a second region extending along a <1-100> direction. The first region has a width in the <1-100> direction that increases from the origin toward the second region. The basal plane dislocation includes a third region continuous to the origin and extending along the <1-100> direction, and a fourth region extending along a direction intersecting the <1-100> direction. When an area of the main surface is a first area, and an area of a quadrangle circumscribed around the composite defect is a second area, a value obtained by dividing the second area by the first area is not more than 0.001.

Abstract: A crystal growth apparatus includes: a chamber including a gas inlet, a gas outlet, a welded portion, and a water-cooling portion configured to water-cool a portion at least including the welded portion; an exhaust pump connected to the gas outlet; a dew point instrument disposed between the gas outlet and the exhaust pump, the dew point instrument being configured to measure a dew point of gas passing through the gas outlet.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. In a direction parallel to a central region, a ratio of a standard deviation of a carrier concentration of the silicon carbide layer to an average value of the carrier concentration of the silicon carbide layer is less than 5%. The average value of the carrier concentration is more than or equal to 1×1014 cm?3 and less than or equal to 5×1016 cm?3. In the direction parallel to the central region, a ratio of a standard deviation of a thickness of the silicon carbide layer to an average value of the thickness of the silicon carbide layer is less than 5%. The central region has an arithmetic mean roughness (Sa) of less than or equal to 1 nm. The central region has a haze of less than or equal to 50.

Abstract: A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 ?m.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. A first ratio of an absolute value of a difference between a dopant density in a first end region and a dopant density in a central region to an average value of the dopant density in the first end region and the dopant density in the central region is not more than 40%. A second ratio of an absolute value of a difference between a dopant density in a second end region and the dopant density in the central region to an average value of the dopant density in the second end region and the dopant density in the central region is not more than 40%.

Abstract: A silicon carbide epitaxial wafer includes a single crystal silicon carbide substrate of 4H polytype having a major surface thereof inclined at an angle ? to a {0001} plane toward a <11-20> direction, and a silicon carbide epitaxial layer of a thickness t formed on the major surface, wherein a diameter of the single crystal silicon carbide substrate is greater than or equal to 150 mm, wherein the angle ? exceeds 0°, and is less than or equal to 6°, wherein one or more pairs of a screw dislocation pit and a diagonal line defect situated at a distance of t/tan? from the pit are present in a surface of the silicon carbide epitaxial layer, and wherein a density of the pairs of a pit and a diagonal line defect is less than or equal to 2 pairs/cm2.

Abstract: Assuming that one or more defects satisfying relations of Formula 1 and Formula 2 are first defects, and one or more defects satisfying relations of Formula 3 and Formula 2 are second defects, where an off angle is ?°, the thickness of a silicon carbide layer in a direction perpendicular to a second main surface is W ?m, the width of each of the one or more defects in a direction obtained by projecting a direction parallel to an off direction onto the second main surface is L ?m, and the width of each of the one or more defects in a direction perpendicular to the off direction and parallel to the second main surface is Y ?m, a value obtained by dividing the number of the second defects by the sum of the number of the first defects and the number of the second defects is greater than 0.5.

Abstract: It is assumed that a defect satisfying relations of Formula 1 and Formula 2 is a first defect, where an off angle is ?. It is assumed that a defect having an elongated shape when viewed in a direction perpendicular to the second main surface, and satisfying relations of Formula 3 and Formula 4 is a second defect. A value obtained by dividing the number of the second defect by the sum of the number of the first defect and the number of the second defect is greater than 0.5.

Abstract: A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 ?m.

Abstract: A device of manufacturing a silicon carbide single crystal includes a crucible, a first resistive heater, a second resistive heater, and a first support portion. The crucible has 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. The first resistive heater is disposed to face the bottom surface. The second resistive heater is provided to surround the side surface. The first support portion supports the crucible such that the bottom surface is separated from the first resistive heater, and the side surface is separated from the second resistive heater. The first support portion is in contact with at least one of the top surface and the side surface.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single-crystal substrate having a diameter of 100 mm or larger and including a principal surface inclined at an angle of more than 0 degrees and not less than 8 degrees with respect to a {0001} plane, a silicon carbide epitaxial layer formed on the principal surface and having a thickness of 20 ?m or thicker, and a basal plane dislocation contained in the silicon carbide epitaxial layer and having one end coupled to a threading screw dislocation contained in the silicon carbide epitaxial layer and the other end present in a surface of the silicon carbide epitaxial layer. The basal plane dislocation extends in a direction having a slope of 20 degrees or more and 80 degrees or less with respect to a <11-20> direction in a {0001} basal plane. Density of the basal plane dislocation is 0.05/cm2 or less.

Abstract: A silicon carbide epitaxial substrate includes: a silicon carbide single-crystal substrate having a polytype of 4H and having a principal surface inclined at an angle ? from a {0001} plane in a <11-20> direction; and a silicon carbide epitaxial layer provided on the principal surface and having a basal plane dislocation, wherein even when the basal plane dislocation is irradiated with an ultraviolet light having a power of 270 mW and a wavelength of 313 nm for 10 seconds, the basal plane dislocation does not move.

Abstract: A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 ?m.