High power gallium nitride electronics using miscut substrates
View Patent ↗An electronic device includes a III-V substrate having a hexagonal crystal structure and a normal to a growth surface characterized by a misorientation from the <0001> direction of between 0.15° and 0.65°. The electronic device also includes a first epitaxial layer coupled to the III-V substrate and a second epitaxial layer coupled to the first epitaxial layer. The electronic device further includes a first contact in electrical contact with the substrate and a second contact in electrical contact with the second epitaxial layer.
1. An electronic device comprising:
a III-V substrate having a hexagonal crystal structure and a normal to a growth surface characterized by a misorientation from the <0001> direction of between 0.15° and 0.65°;
a first III-V epitaxial layer coupled to the III-V substrate;
a second III-V epitaxial layer coupled to the first III-V epitaxial layer;
a first contact in electrical contact with the III-V substrate; and
a second contact in electrical contact with the second III-V epitaxial layer.
2. The electronic device of claim 1 wherein the normal to the growth surface is misoriented towards the negative <1 1 00> direction.
3. The electronic device of claim 1 wherein the misorientation is between 0.4° and 0.5°.
4. The electronic device of claim 1 wherein the normal to the growth surface is characterized by a misorientation towards the <11 2 0> direction of substantially zero degrees.
5. The electronic device of claim 1 wherein the normal to the growth surface is misoriented towards the <1 1 00> direction by an angle ranging between −0.4° and −0.5° and towards the <11 2 0> direction by an angle ranging between −0.1° and −0.2°.
6. The electronic device of claim 1 wherein the III-V substrate comprises an n-type GaN substrate.
7. The electronic device of claim 1 wherein the first III-V epitaxial layer comprises an n-type GaN epitaxial layer and the second III-V epitaxial layer comprises a p-type GaN epitaxial layer.
8. The electronic device of claim 1 wherein the electronic device comprises a PN diode, the first contact comprises a cathode of the PN diode, and the second contact comprises an anode of the PN diode.
9. The electronic device of claim 1 further comprising an isolation region disposed laterally to the second III-V epitaxial layer.
10. The electronic device of claim 1 further comprising a third III-V epitaxial layer disposed between the second III-V epitaxial layer and the second contact, wherein a doping density of the third III-V epitaxial layer is higher than a doping density of the second III-V epitaxial layer.