Light emitting diode with tunnel junction
A light emitting diode (LED) is manufactured using a process in which hydrogen diffuses out of a p-doped semiconductor layer via an exposed side wall of the p-doped semiconductor layer. The process includes forming a light generation layer on a base semiconductor layer and forming the p-doped semiconductor layer on the light generation layer. A tunnel junction layer is formed on the p-doped semiconductor layer and a contact layer is formed on the junction layer. The process also includes etching through at least the contact layer, the tunnel junction layer, and the p-doped semiconductor layer to expose the side wall of the p-doped semiconductor layer and enabling hydrogen to diffuse out of the p-doped semiconductor layer at least partially through the exposed side wall.
1. A method of manufacturing a light emitting diode (LED), comprising:
forming a light generation layer on a base semiconductor layer;
forming a p-doped semiconductor layer on the light generation layer;
forming a tunnel junction layer on the p-doped semiconductor layer;
forming a contact layer on the junction layer;
etching through at least the contact layer, the tunnel junction layer, and the p-doped semiconductor layer to expose a side wall of the p-doped semiconductor layer; and
enabling hydrogen to diffuse out of the p-doped semiconductor layer at least partially through the exposed side wall of the p-doped semiconductor layer.
2. The method of claim 1 , wherein enabling hydrogen to diffuse out of the p-doped semiconductor layer comprises placing the etched contact layer, the etched tunnel junction layer, and the etched p-doped semiconductor layer in a nitrogen environment.
3. The method of claim 2 , wherein placing the etched contact layer, the etched tunnel junction layer, and the etched p-doped semiconductor layer in a nitrogen environment is part of an annealing process that activates p-doped gallium nitride (p-GaN) in the p-doped semiconductor layer.
4. The method of claim 1 , wherein a regrowth operation is not performed after forming the tunnel junction layer.
5. The method of claim 1 , wherein the light generation layer comprises multiple quantum wells.
6. The method of claim 1 , wherein the base semiconductor layer comprises n-doped gallium nitride (n-GaN).
7. The method of claim 1 , wherein the p-doped semiconductor layer comprises p-doped gallium nitride.
8. The method of claim 1 , wherein the tunnel junction layer comprises a heavily p-doped gallium nitride (p++GaN) layer and a heavily n-doped gallium nitride (n++GaN) layer, the heavily p-doped gallium nitride layer disposed on the p-doped semiconductor layer and the heavily n-doped gallium nitride layer disposed on the heavily p-doped gallium nitride layer.
9. The method of claim 1 , wherein the layers are formed using metal-organic chemical vapor deposition.
10. The method of claim 1 , wherein the etching forms a mesa having a longest cross-sectional axis in a range from 0.2 μm to 10 μm.
11. A non-transitory computer-readable medium configured to store instructions that, when executed by a fabrication device, cause the fabrication device to perform operations including:
forming a light generation layer on a base semiconductor layer;
forming a p-doped semiconductor layer on the light generation layer;
forming a tunnel junction layer on the p-doped semiconductor layer;
forming a contact layer on the junction layer;
etching through at least the contact layer, the tunnel junction layer, and the p-doped semiconductor layer to expose a side wall of the p-doped semiconductor layer; and
enabling hydrogen to diffuse out of the p-doped semiconductor layer at least partially through the exposed side wall of the p-doped semiconductor layer.
12. The non-transitory computer-readable medium of claim 11 , wherein enabling hydrogen to diffuse out of the p-doped semiconductor layer comprises placing the etched contact layer, the etched tunnel junction layer, and the etched p-doped semiconductor layer in a nitrogen environment.
13. The non-transitory computer-readable medium of claim 12 , wherein placing the etched contact layer, the etched tunnel junction layer, and the etched p-doped semiconductor layer in a nitrogen environment is part of an annealing process that activates p-doped gallium nitride (p-GaN) in the p-doped semiconductor layer.
14. The non-transitory computer-readable medium of claim 11 , wherein the operations do not include performing a regrowth operation after forming the tunnel junction layer.
15. The non-transitory computer-readable medium of claim 11 , wherein the light generation layer comprises multiple quantum wells.
16. The non-transitory computer-readable medium of claim 11 , wherein the base semiconductor layer comprises n-doped gallium nitride (n-GaN).
17. The non-transitory computer-readable medium of claim 11 , wherein the p-doped semiconductor layer comprises p-doped gallium nitride.
18. The non-transitory computer-readable medium of claim 11 , wherein the tunnel junction layer comprises a heavily p-doped gallium nitride (p++GaN) layer and a heavily n-doped gallium nitride (n++GaN) layer, the heavily p-doped gallium nitride layer disposed on the p-doped semiconductor layer and the heavily n-doped gallium nitride layer disposed on the heavily p-doped gallium nitride layer.
19. The non-transitory computer-readable medium of claim 11 , wherein the layers are formed using metal-organic chemical vapor deposition.
20. The non-transitory computer-readable medium of claim 11 , wherein the etching forms a mesa having a longest cross-sectional axis in a range from 0.2 μm to 10 μm.