Highly uniform group III nitride epitaxial layers on 100 millimeter diameter silicon carbide substrates
AssigneeCree, Inc.
InventorsAdam William Saxler, Edward Lloyd Hutchins
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Abstract
A semiconductor structure is disclosed that includes a silicon carbide wafer having a diameter of at least 100 mm with a Group III nitride heterostructure on the wafer that exhibits high uniformity in a number of characteristics. These include: a standard deviation in sheet resistivity across the wafer less than three percent; a standard deviation in electron mobility across the wafer of less than 1 percent; a standard deviation in carrier density across the wafer of no more than about 3.3 percent; and a standard deviation in conductivity across the wafer of about 2.5 percent.
Claims77
A semiconductor structure comprising:
- a silicon carbide substrate wafer having a diameter of at least 100 mm;
- a Group III nitride heterostructure on said substrate wafer;
- and
- said heterostructure demonstrating a standard deviation in sheet resistivity across said wafer of less than 3%.
A semiconductor structure comprising
- a silicon carbide wafer having a diameter of at least 100 mm;
- a Group III nitride heterostructure on said wafer;
- and
- said wafer and heterostructure demonstrating a standard deviation in electron mobility across said wafer of less than 3 percent.
A semiconductor structure comprising
- a silicon carbide wafer having a diameter of at least 100 mm;
- a Group III nitride heterostructure on said wafer;
- and
- said wafer and heterostructure demonstrating a standard deviation in carrier density across said wafer of less than 3.3%.
A semiconductor structure comprising:
- an epitaxial layer of Group III nitride containing aluminum on a compatible substrate;
- said Group III nitride layer having a diameter of at least 100 millimeters;
- and
- said Group III nitride layer having a ratio of minimum to maximum aluminum content of at least 0.9.
A semiconductor structure comprising:
- a Group III nitride epitaxial layer selected from the group consisting of gallium nitride and aluminum gallium nitride on a compatible substrate;
- said Group III nitride layer having a diameter of at least 100 millimeters;
- and
- said Group III nitride layer having a ratio of minimum to maximum thickness of at least 0.8.
A semiconductor structure comprising:
- a silicon carbide wafer having a diameter of at least about 100 millimeters;
- a Group III nitride layer on said silicon carbide wafer and having a diameter substantially the same as said silicon carbide wafer;
- and
- said wafer and epitaxial layer having a warp less than 100 microns.
A semiconductor structure comprising:
- a silicon carbide wafer having a diameter of at least 100 millimeters;
- a Group III nitride epitaxial layer on said silicon carbide wafer and having substantially the same size as said wafer;
- and
- said wafer and epitaxial layer having a bow of less than 100 microns.
A semiconductor structure comprising:
- an epitaxial layer of Group III nitride containing aluminum on a compatible substrate;
- said Group III nitride layer having a diameter of at least 100 millimeters;
- and
- said Group III nitride layer demonstrating a standard deviation in aluminum content of less than 5 percent.
A plurality of 100 millimeter wafers, each said wafer comprising:
- an epitaxial layer of Group III nitride containing aluminum on a compatible substrate;
- said Group III nitride layer having a diameter of at least 100 millimeters;
- and
- at least 75 percent of said wafers demonstrating a standard deviation in thickness of said Group III nitride layer of less than 7.2 percent.
Dependencies are inferred from the claim text.