Silicon carbide substrate, method of manufacturing silicon carbide substrate, and manufacturing apparatus for silicon carbide substrate
AssigneeSumitomo Electric Industries, Ltd.
InventorShunsaku UETA
Life of this patent
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Abstract
A silicon carbide substrate is a silicon carbide substrate having a main surface and doped with vanadium. The main surface is constituted of an outer edge, an outer peripheral region that is a region within 5 mm from the outer edge, and a central region surrounded by the outer peripheral region. When the central region is divided into a plurality of square regions each having each side with a length of 5 mm, an electrical resistivity in each of the plurality of square regions is 1×1011 Ωcm or more. An area density of micro-pipes in the central region is 1 cm2 or less.
Claims16
A silicon carbide substrate having a main surface and doped with vanadium,
- wherein the main surface is constituted of an outer edge, an outer peripheral region that is a region within 5 mm from the outer edge, and a central region surround by the outer peripheral region,
- when the central region is divided into a plurality of square regions each having each side with a length of 5 mm, an electrical resistivity in each of the plurality of square regions is 1×1011 Ωcm or more, and
- an area density of micropipes in the central region is 1 cm−2 or less.
A method of manufacturing a silicon carbide substrate, the method comprising:
- preparing a first crucible in which silicon carbide powder and a silicon carbide seed crystal are disposed and a second crucible in which powder containing vanadium is disposed and which is connected to the first crucible through a connection member;
- and
- heating each of the first crucible and the second crucible,
- wherein in the heating each of the first crucible and the second crucible, the powder containing vanadium is sublimated and introduced into the first crucible through the connection member, and the silicon carbide powder is sublimated and recrystallized on the silicon carbide seed crystal, so that a silicon carbide single crystal doped with vanadium grows on the silicon carbide seed crystal, and
- in the heating each of the first crucible and the second crucible, a temperature of the powder containing vanadium is lower than a temperature of the silicon carbide powder.
A manufacturing apparatus for a silicon carbide substrate, the manufacturing apparatus comprising:
- a first crucible in which silicon carbide powder and a silicon carbide seed crystal are disposed;
- a second crucible in which powder containing vanadium is disposed and which is connected to the first crucible;
- and
- a heater configured to heat each of the first crucible and the second crucible such that a temperature of the powder containing vanadium is lower than a temperature of the silicon carbide powder.
Dependencies are inferred from the claim text.