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US 11,459,669 B2Granted
SiC ingot and method of manufacturing SiC ingot
AssigneeShowa Denko K.K.
InventorsRimpei Kindaichi, Yohei Fujikawa, Yoshishige Okuno
Life of this patent
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Abstract
A SiC ingot includes a core portion; and a surface layer that is formed on a plane of the core portion in a growing direction, and a coefficient of linear thermal expansion of the surface layer is smaller than a coefficient of linear thermal expansion of the core portion.
Claims20
A SiC ingot consisting of:
- a core portion;
- and
- a surface layer that is formed on a plane of the core portion in a growing direction,
- wherein the SiC ingot consists of the core portion and the surface layer immediately after crystal growth,
- wherein a coefficient of linear thermal expansion of the surface layer is smaller than a coefficient of linear thermal expansion of the core portion,
- the surface layer is the topmost layer of the SiC ingot,
- the surface layer has a concentration of dopant, which is 1.5 times or more as high as a concentration of dopant of the core portion, and
- a thickness of the surface layer is 0.3 mm or more and is smaller than that of the core portion.
5 more elements
A method of manufacturing a SiC ingot comprising:
- a first step of causing a single crystal that becomes a core portion to grow in one plane of a seed crystal;
- a second step of causing a surface layer to grow in a plane of the core portion on a side opposite to the seed crystal in an atmosphere with higher concentration of dopant gas than that in the first step;
- and
- a third step of cooling a produced SiC ingot after the second step,
- wherein the surface layer is the topmost layer of the SiC ingot,
- the surface layer has a concentration of dopant, which is 1.5 times or more as high as a concentration of dopant of the core portion, and
- the first step, the second step and the third steps are performed one and not more than one time respectively.
4 more elements
Dependencies are inferred from the claim text.