Abstract: An 8-inch SiC single crystal substrate of an embodiment has a diameter in a range of 195 mm to 205 mm, a thickness in a range of 300 ?m to 650 ?m, a SORI of 50 ?m or less, and an in-plane variation of the thickness of the substrate, which is the difference between the maximum and minimum substrate thickness at the center of the substrate and four points on the circumference of a circle having a radius half the radius of the substrate, is 1.5 ?m or less.

Abstract: An 8 inch n-type SiC single crystal substrate of an embodiment has a diameter in the range of 195 to 205 mm, a thickness in the range of 300 ?m to 650 ?m, thicknesses of work-affected layers on both the front and back sides are 0.1 nm or less, and the dopant concentration is 2×1018/cm3 or more and 6×1019/cm3 or less at least five arbitrarily selected points in the plane within 5% of the thickness of the substrate in the depth direction from the main surface of the substrate.

Abstract: An 8-inch SiC single crystal substrate of an embodiment has a diameter in a range of 195 mm to 205 mm, a thickness in a range of 300 ?m to 650 ?m, a SORT of 50 ?m or less, and an in-plane variation of the thickness of the substrate, which is the difference between the maximum and minimum substrate thickness at the center of the substrate and four points on the circumference of a circle having a radius half the radius of the substrate, is 1.5 ?m or less.

Abstract: A SiC single crystal substrate of an embodiment is a SiC single crystal substrate wherein the main plane of the SiC single crystal substrate has an off angle of 0° to 6° to the (0001) plane in the <11-20> direction and an off angle of 0° to 0.5° to the (0001) plane in the <1-100> direction, and includes non-MP defects wherein when the Si surface is etched in molten KOH at 500° C. for 15 minutes, the non-MP defects that appear by etching are hexagonal and have no core, the area of the observed etch pit of the non-MP defect is more than 10% larger than that of the observed etch pit of the TSD and is less than 110% of that of the observed etch pit of the micropipe (MP), and a transmission X-ray topography image of the non-MP defect is distinguishable from the transmission X-ray topography image of the micropipe (MP), wherein etch pits, which are identified as the non-MP defects, appear in the range of 0.1/cm2 to 50/cm2.

Abstract: A SiC single crystal, including: a seed crystal; a first growth portion formed in a direction that is substantially orthogonal to a <0001> direction; a second growth portion formed in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction in which the first growth portion is formed; a third growth portion that is formed on a surface of the seed crystal opposite the first growth portion; and a fourth growth portion that is formed on a surface of the seed crystal opposite the second growth portion.

Abstract: A crystal growing apparatus includes: a crucible which includes a main body portion, and a first portion having a radiation rate different from that of the main body portion, and is capable of controlling a temperature of a specific region inside during heating to a higher or lower temperature than that of the other regions; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the first portion is at a position where the crucible and a line segment connecting a heating center of the heating unit and the specific region intersect with each other.

Abstract: A crystal growing apparatus includes: a crucible including a main body portion and a low radiation portion having a radiation rate lower than that of the main body portion; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the low radiation portion is provided on an outer surface of a first point which is a heating center, in a case where the crucible does not include the low radiation portion.

Abstract: A SiC single crystal growth apparatus of an embodiment includes a seed crystal installation part in which a seed crystal is installable at a position thereof which faces a raw material; a guide member which extends from a periphery of the seed crystal installation part toward the raw material and guides crystal growth performed inside the guide member; and a heat-insulating material which is movable along an extension direction of the guide member on the outside of the guide member.

Abstract: A SiC single crystal, including: a seed crystal; a first growth portion formed in a direction that is substantially orthogonal to a <0001> direction; a second growth portion formed in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction in which the first growth portion is formed; a third growth portion that is formed on a surface of the seed crystal opposite the first growth portion; and a fourth growth portion that is formed on a surface of the seed crystal opposite the second growth portion.

Abstract: This method for producing a SiC single crystal includes a first growth step of growing a crystal from a seed crystal in a direction that is substantially orthogonal to the <0001> direction, a second growth step of growing the crystal in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction of crystal growth in the first growth step, a third growth step of growing the crystal along the direction of crystal growth in the first growth step but in the opposite orientation to the orientation of crystal growth in the first growth step, and a fourth growth step of growing the crystal along the direction of crystal growth in the second growth step but in the opposite orientation to the orientation of crystal growth in the second growth step.

Abstract: A crystal growing apparatus includes: a crucible which includes a main body portion, and a first portion having a radiation rate different from that of the main body portion, and is capable of controlling a temperature of a specific region inside during heating to a higher or lower temperature than that of the other regions; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the first portion is at a position where the crucible and a line segment connecting a heating center of the heating unit and the specific region intersect with each other.

Abstract: A crystal growing apparatus includes: a crucible including a main body portion and a low radiation portion having a radiation rate lower than that of the main body portion; and a heating unit which is positioned on the outside of the crucible and is configured to heat the crucible by radiant heat, and the low radiation portion is provided on an outer surface of a first point which is a heating center, in a case where the crucible does not include the low radiation portion.

Abstract: A SiC single crystal growth apparatus of an embodiment includes a seed crystal installation part in which a seed crystal is installable at a position thereof which faces a raw material; a guide member which extends from a periphery of the seed crystal installation part toward the raw material and guides crystal growth performed inside the guide member; and a heat-insulating material which is movable along an extension direction of the guide member on the outside of the guide member.

Abstract: A SiC single crystal seed of the present invention has a main surface with an offset angle of at least 2° but not more than 20° relative to the {0001} plane, and at least one sub-growth surface, wherein the sub-growth surface includes an initial facet formation surface that is on the offset upstream side of the main surface and has an inclination angle ? relative to the {0001} plane with an absolute value of less than 2° in any direction, and the initial facet formation surface has a screw dislocation starting point.

Abstract: This method for producing a SiC single crystal includes a first growth step of growing a crystal from a seed crystal in a direction that is substantially orthogonal to the <0001> direction, a second growth step of growing the crystal in a direction that is substantially orthogonal to the <0001> direction and substantially orthogonal to the direction of crystal growth in the first growth step, a third growth step of growing the crystal along the direction of crystal growth in the first growth step but in the opposite orientation to the orientation of crystal growth in the first growth step, and a fourth growth step of growing the crystal along the direction of crystal growth in the second growth step but in the opposite orientation to the orientation of crystal growth in the second growth step.

Abstract: A SiC single crystal seed of the present invention has a main surface with an offset angle of at least 2° but not more than 20° relative to the {0001} plane, and at least one sub-growth surface, wherein the sub-growth surface includes an initial facet formation surface that is on the offset upstream side of the main surface and has an inclination angle ? relative to the {0001} plane with an absolute value of less than 2° in any direction, and the initial facet formation surface has a screw dislocation starting point.

Abstract: A method for producing a sapphire single crystal, which includes: performing a sapphire single crystal growth step wherein a sapphire ingot, which is an ingot of sapphire single crystal, is produced (step 101); performing a subsequent ingot heating step wherein the sapphire ingot obtained in the sapphire single crystal growth step is heated (step 102); and performing a subsequent ingot processing step wherein the heated sapphire ingot is machined (step 103). In the ingot heating step, the sapphire ingot is heated in an atmosphere in which the oxygen concentration is increased to be equal to or higher than that in the air. Consequently, crystal defects in the ingot of sapphire single crystal produced by crystal growth are removed and the occurrence of cracks in the sapphire ingot during machining of the sapphire ingot is suppressed, thereby improving the yield of sapphire products obtained from the ingot.

Abstract: Following steps are implemented: a melting step in which aluminum oxide within a crucible is melted to obtain an aluminum melt; a shoulder-portion formation step in which a seed crystal brought into contact with the aluminum melt is pulled up to thereby form a shoulder portion below the seed crystal; a body-portion formation step in which single-crystal sapphire is pulled up from the melt to form a body portion; and a tail-portion formation step in which a mixed gas including oxygen and an inert gas and having an oxygen concentration set at not less than 1.0 vol % nor more than 5.0 vol % is supplied while the single-crystal sapphire is pulled away from the melt to form a tail portion. Thus, when single-crystal sapphire is obtained by growth from a melt of aluminum oxide, formation of a protrusion in the tail portion of the single-crystal sapphire is more effectively inhibited.

Abstract: Following steps are implemented: a melting step in which aluminum oxide within a crucible placed in a chamber is melted to obtain an aluminum melt; a shoulder-portion formation step in which a seed crystal brought into contact with the aluminum melt is pulled up to thereby form a shoulder portion below the seed crystal; and a body-portion formation step in which a mixed gas including oxygen and an inert gas and having an oxygen concentration set at not less than 0.6 vol % nor more than 3.0 vol % is supplied to the inside of the chamber while single-crystal sapphire is pulled up from the melt, thereby forming a body portion. Thus, when single-crystal sapphire is obtained by crystal growth from a melt of aluminum oxide, air bubbles are more effectively inhibited from coming into the single-crystal sapphire.

Abstract: A method for producing an SiC single crystal comprises providing a low temperature region and a high temperature region in a crystal growth crucible (6); disposing a seed crystal substrate formed of an SiC single crystal in the low temperature region of the crystal growth crucible; disposing an SiC raw material in the high temperature region; and depositing a sublimation gas that sublimes from the SiC raw material on the seed crystal substrate to grow the SiC single crystal. A material used in the crucible member where the seed crystal is disposed is a material having a room-temperature linear expansion coefficient that differs from that of SiC by 1.0×10?6/K or less, and the crucible member where the seed crystal is disposed is made of Sic.