Reducing or eliminating nanopipe defects in III-nitride structures
Embodiments of the invention include a III-nitride light emitting layer disposed between an n-type region and a p-type region, a III-nitride layer including a nanopipe defect, and a nanopipe terminating layer disposed between the III-nitride light emitting layer and the III-nitride layer comprising a nanopipe defect. The nanopipe terminates in the nanopipe terminating layer.
1. A device comprising:
a III-nitride light emitting layer disposed between an n-type region and a type region; and
a nanopipe termination structure comprising a first III-nitride layer doped with an acceptor and a second III-nitride layer doped with an acceptor, the first and second III-nitride layers doped with an acceptor having different concentrations of acceptor, the n-type region being disposed between the nanopipe termination structure and the III-nitride light emitting layer.
2. The device of claim 1 wherein the acceptor is magnesium.
3. The device of claim 2 wherein:
the first III-nitride layer doped with an acceptor has a magnesium concentration between zero and 2×10 18 cm −3 ; and
the second III-nitride layer doped with an acceptor has a magnesium concentration between 1×10 17 cm −3 and 1×10 20 cm −3 .
4. The device of claim 1 wherein the second III-nitride layer doped with an acceptor is closer to the III-nitride light emitting layer than the first III-nitride layer doped with an acceptor and the second III-nitride layer doped with an acceptor has a higher dopant concentration than the first III-nitride layer doped with an acceptor.
5. The device of claim 1 wherein the first and second III-nitride layers doped with an acceptor have different compositions.
6. The device of claim 1 wherein the nanopipe termination structure comprises a third III-nitride layer doped with an acceptor having a different concentration of acceptor from the first and second III-nitride layers doped with an acceptor.
7. The device of claim 1 further comprising a layer comprising a nanopipe defect, the nanopipe termination structure being disposed between the layer comprising a nanopipe defect and the light emitting layer, the nanopipe defect terminating in the nanopipe termination structure.
8. The device of claim 1 wherein the first and second III-nitride layer doped with an acceptor each comprise aluminum.
9. The device of claim 1 wherein the first III-nitride layer doped with an acceptor comprises indium.
10. A device comprising:
a III-nitride light emitting layer disposed between an n-type region and a p-type region;
a III-nitride layer comprising a nanopipe defect; and
a nanopipe terminating layer that is not intentionally doped disposed between the III-nitride light emitting layer and the III-nitride layer comprising a nanopipe defect, wherein the nanopipe terminates in the nanopipe terminating layer.
11. The device of claim 10 wherein the nanopipe terminating layer comprises aluminum.
12. The device of claim 10 wherein the nanopipe terminating layer comprises indium.