HIGH POWER GALLIUM NITRIDE ELECTRONICS USING MISCUT SUBSTRATES
A method of fabricating an electronic device includes providing 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 method also includes growing a first III-V epitaxial layer coupled to the III-V substrate and growing a second III-V epitaxial layer coupled to the first III-V epitaxial layer. The method further includes forming a first contact in electrical contact with the III-V substrate and forming a second contact in electrical contact with the second III-V epitaxial layer.
1 . A method of fabricating an electronic device, the method comprising:
providing 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°;
growing a first III-V epitaxial layer coupled to the III-V substrate;
growing a second III-V epitaxial layer coupled to the first III-V epitaxial layer;
forming a first contact in electrical contact with the III-V substrate; and
forming a second contact in electrical contact with the second III-V epitaxial layer.
2 . The method of claim 1 wherein the normal to the growth surface is misoriented towards the negative <1 1 00> direction.
3 . The method of claim 2 wherein the misorientation is between 0.4° and 0.5°.
4 . The method 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 method of claim 1 wherein the III-V substrate comprises an n-type GaN substrate.
6 . The method of claim 1 wherein the first III-V epitaxial layer comprises an n-type GaN epitaxial layer having a thickness greater than 3 μm and the second III-V epitaxial layer comprises a p-type GaN epitaxial layer.
7 . The method of claim 6 wherein the n-type GaN epitaxial layer has a thickness greater than 5 μm.
8 . The method of claim 1 wherein the electronic device comprises a PN diode, the first contact comprises a cathode, and the second contact comprises an anode.
9 . The method of claim 1 further comprising forming an isolation region disposed laterally to the second III-V epitaxial layer.
10 . The method of claim 1 further comprising forming 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.