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US 11,600,538 B2Granted
SiC epitaxial wafer and method for producing SiC epitaxial wafer
AssigneeShowa Denko K.K.
InventorsNaoto Ishibashi, Koichi Murata, Hidekazu Tsuchida
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Abstract
A SiC epitaxial wafer according to an embodiment includes: a SiC substrate; and a SiC epitaxial layer formed on a first surface of the SiC substrate. The in-plane uniformity of a density of Z1/2 centers of the SiC epitaxial layer is 5% or less.
Claims12
A SiC epitaxial wafer, comprising:
- a SiC substrate;
- and
- a SiC epitaxial layer formed on a first surface of the SiC substrate,
- wherein in-plane uniformity of a density of Z1/2 centers of the SiC epitaxial layer is 5% or less,
- a diameter of the SiC epitaxial wafer is 149 mm or more,
- the in-plane uniformity of a density of Z1/2 centers is obtained by dividing a standard deviation at 10 or more measurements points by an average value, and
- wherein the measurement points are arranged in a cross shape at a pitch of 10 mm within a range of a radius of 50 mm from a center of the SiC epitaxial wafer.
4 more elements
A method for producing a SiC epitaxial wafer, comprising:
- a test step;
- and
- a main step,
- wherein the test step includes:
- a first film formation step of forming a SiC epitaxial layer on a first surface of a test SiC substrate;
- a first measurement step of measuring in-plane uniformity of a density of Z1/2 centers of the SiC epitaxial layer;
- and
- a feedback step of performing first feedback for changing at least one of heating conditions in the first film formation step and temperature lowering conditions in the first film formation step on the basis of the result measured in the first measurement step,
- the test step repeatedly performs the first film formation step, the first measurement step, and the feedback step a plurality of times, and
- the main step includes a second film formation step of forming a SiC epitaxial layer on a first surface of a SiC substrate on the basis of the result of the test step,
- the in-plane uniformity of a density of Z1/2 centers is obtained by dividing a standard deviation at 10 or more measurements points by an average value, and
- wherein the measurement points are arranged in a cross shape at a pitch of 10 mm within a range of a radius of 50 mm from a center of the SiC epitaxial wafer.
9 more elements
Dependencies are inferred from the claim text.