SiC SUBSTRATE AND SiC SINGLE CRYSTAL MANUFACTURING METHOD
A SiC substrate contains tantalum or niobium of which the content is equal to or more than 3×10 14 cm −3 and equal to or less than 1×10 15 cm −3 , and nitrogen of which the content is equal to or more than 1×10 16 cm −3 and equal to or less than 1×10 20 cm −3 .
1 . A SiC substrate comprising:
tantalum or niobium of which a content is equal to or more than 3×10 14 cm −3 and equal to or less than 1×10 15 cm −3 ; and
nitrogen of which a content is equal to or more than 1×10 16 cm −3 and equal to or less than 1×10 20 cm −3 .
2 . The SiC substrate according to claim 1 , wherein
a content of aluminum is less than 1×10 16 cm −3 .
3 . The SiC substrate according to claim 1 , wherein
a content of boron is less than 1×10 16 cm −3 .
4 . The SiC substrate according to claim 1 , wherein
a content of a heavy metal element is less than 1×10 14 cm −3 .
5 . The SiC substrate according to claim 1 , wherein
content ratio of tantalum or niobium differ between those on a first surface and a second surface perpendicular to a thickness direction.
6 . The SiC substrate according to claim 1 , further comprising:
a first surface and a second surface perpendicular to a thickness direction,
wherein a content ratio of tantalum or niobium decreases toward the second surface from the first surface.
7 . A SiC single crystal manufacturing method using a sublimation method in which a single crystal is grown by recrystallizing a gas sublimated from a raw material on a surface of a seed crystal, wherein
the raw material contains tantalum or niobium.
8 . The SiC single crystal manufacturing method according to claim 7 , wherein
a concentration of tantalum or niobium in the raw material is substantially constant.
9 . The SiC single crystal manufacturing method according to claim 7 , wherein
a concentration of tantalum or niobium on a surface of the raw material which faces the seed crystal is lower than a concentration of tantalum or niobium inside the raw material.
10 . The SiC single crystal manufacturing method according to claim 7 , wherein
the tantalum or niobium is deposited on a surface of a SiC raw material.
11 . The SiC single crystal manufacturing method according to claim 7 , wherein
a concentration of tantalum or niobium on a surface of the raw material which faces the seed crystal is higher than a concentration of tantalum or niobium inside the raw material.
12 . The SiC single crystal manufacturing method according to claim 7 , wherein
a concentration of tantalum or niobium at the center is higher than a concentration of tantalum or niobium in the outer side when the raw material is seen in a plan view.
13 . The SiC single crystal manufacturing method according to claim 7 , wherein
an amount of the tantalum or niobium added is equal to or more than 1 wt % and equal to or less than 8 wt %.
14 . A SiC single crystal manufacturing method using a sublimation method in which a single crystal is grown by recrystallizing a gas sublimated from a raw material on a surface of a seed crystal, wherein
the raw material is sublimated on the environment in which powder or plate-like tantalum or niobium is positioned between the raw material and the seed crystal.
15 . The SiC single crystal manufacturing method according to claim 14 , wherein
the SiC single crystal manufacturing method is a SiC single crystal manufacturing method using a crucible including a protrusion portion that protrudes toward an axial center of the crucible from an inner surface, and
the raw material is sublimated on the environment in which the powder or plate-like tantalum or niobium is positioned on the protrusion portion.