Silicon carbide on diamond substrates and related devices and methods
AssigneeCree, Inc.
InventorAdam Saxler
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Abstract
A high power, wide-bandgap device is disclosed that exhibits reduced junction temperature and higher power density during operation and improved reliability at a rated power density. The device includes a diamond substrate for providing a heat sink with a thermal conductivity greater than silicon carbide, a single crystal silicon carbide layer on the diamond substrate for providing a supporting crystal lattice match for wide-bandgap material structures that is better than the crystal lattice match of diamond, and a Group III nitride heterostructure on the single crystal silicon carbide layer for providing device characteristics.
Claims40
A high power, wide-bandgap device that exhibits reduced junction temperature and higher power density during operation and improved reliability at a rated power density, said device comprising:
- a diamond substrate for providing a heat sink with a thermal conductivity greater than silicon carbide;
- a single crystal silicon carbide layer on said diamond substrate for providing a supporting crystal lattice match for wide-bandgap material structures that is better than the crystal lattice match of diamond;
- and
- a Group III nitride heterostructure on said single crystal silicon carbide layer for providing device characteristics.
A wide-bandgap high electron mobility transistor (HEMT) comprising:
- a diamond substrate for providing a heat sink with a thermal conductivity greater than silicon carbide;
- a semi-insulating single crystal silicon carbide layer on said diamond substrate for providing a favorable crystal growth surface for Group III nitride epilayers;
- a buffer layer on said silicon carbide layer for providing an enhanced crystal transition between silicon carbide and a Group III nitride;
- a first epitaxial layer of a first Group III nitride on said buffer layer;
- a second epitaxial layer of a different Group III nitride on said first epitaxial layer for forming a heterojunction with said first epilayer, and with said Group III nitride of said second epilayer having a wider bandgap than said first Group III nitride of said first epilayer for generating a two-dimensional electron gas in the first epilayer at the interface of said first and second epilayers;
- and
- respective source, gate, and drain contacts to said second epitaxial Group III nitride layer for providing a flow of electrons between the source and drain that is controlled by a voltage applied to the gate.
A wide-bandgap high electron mobility transistor (HEMT) comprising:
- a diamond substrate for providing a heat sink with a thermal conductivity greater than silicon carbide;
- a semi insulating single crystal silicon carbide layer on said diamond substrate for providing a favorable crystal growth surface for Group III nitride epilayers;
- a Group III nitride buffer layer on said silicon carbide substrate;
- an epitaxial layer of gallium nitride on said buffer layer;
- an epitaxial layer of aluminum gallium nitride on said gallium nitride epitaxial layer for forming a heterojunction with said gallium nitride epilayer with said aluminum gallium nitride having a wider bandgap than said gallium nitride epitaxial layer for generating a two-dimensional electron gas in said gallium nitride epilayer at the interface of said gallium nitride and aluminum gallium nitride epilayers;
- and
- respective source, gate, and drain contacts to the aluminum gallium nitride layer for providing a flow of electrons between the source and drain that is controlled by a voltage applied to the gate.
A wafer precursor for semiconductor devices comprising:
- a substrate of single crystal silicon carbide that is at least two inches in diameter;
- and
- a layer of diamond on a first face of said silicon carbide substrate;
- wherein the opposite face of said silicon carbide substrate is prepared for Group III nitride epitaxial growth thereon.
A semiconductor laser comprising:
- a diamond substrate;
- a single crystal silicon carbide layer on said diamond substrate;
- at least a first cladding layer on said silicon carbide layer;
- a Group III nitride active portion on said at least one cladding layer;
- and
- at least a second cladding layer on said active portion.
Dependencies are inferred from the claim text.