Light emitting diode with displaced P-type doping

Patent metadata

Field	Value
Publication number	US-10490691-B2
Application number	US-201615746486-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Jul 31, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Light emitting diodes re described. In an embodiment, an LED includes a graded p-side spacer layer on a p-type confinement layer, and the graded p-side spacer layer graded from an initial band gap adjacent the p-type confinement layer to a lower band gap. For example, the graded band gap may be achieved by a graded Aluminum concentration.

First claim

What is claimed is:

1. An LED comprising:
a p-type confinement layer;
a graded p-side spacer layer on the p-type confinement layer, the graded p-side spacer layer graded from an initial band gap adjacent the p-type confinement layer to a lower band gap;
an active region on the graded p-side spacer layer;
an n-side spacer layer on the active region; and
an n-type confinement layer on the n-side spacer layer;
wherein a diffusion profile of a p-dopant from the p-type confinement layer extends into a region of the graded p-side spacer layer that is otherwise undoped.

2. The LED of claim 1 , wherein the graded p-side spacer layer extends from the p-type confinement layer to the active region.

3. The LED of claim 1 , further comprising an intermediate p-side spacer layer between the graded p-side spacer layer and the active region, wherein the intermediate p-side spacer layer is not graded.

4. The LED of claim 1 , wherein the intentionally doped region is 200-500 nm from the active region.

5. The LED of claim 4 , wherein the graded p-side spacer layer is about 100-500 nm thick.

6. The LED of claim 4 , wherein the graded p-side spacer layer is about 50-150 nm thick.

7. The LED of claim 4 , wherein the LED does not include a graded n-side spacer layer.

8. The LED of claim 4 , wherein the set back region is 100-200 nm thick, and the set back region and the intentionally doped region are formed of a same semiconductor composition.

9. An LED comprising:
a p-type confinement layer comprising an intentionally doped region and a set back region on the intentionally doped region, wherein the intentionally doped region is doped with a p-type dopant concentration;
a graded p-side spacer layer on the set back region of the p-type confinement layer, wherein the graded p-side spacer layer is graded from an initial band gap adjacent the set back region to a lower band gap;
an active region on the graded p-side spacer layer;
an n-side spacer layer on the active region; and
an n-type confinement layer on the n-side spacer layer;
wherein a diffusion profile of the p-type dopant extends from the intentionally doped region, through set back region, and into the graded p-side spacer layer.

10. The LED of claim 9 , wherein the p-type dopant concentration is substantially uniform in the intentionally doped region.

11. An LED comprising:
a p-type confinement layer;
a graded p-side spacer layer on the p-type confinement layer and, the graded p-side spacer layer graded from (Al x Ga 1-x ) y In 1-y P (0.6≤x≤1.0) (0.4≤y≤0.6) adjacent the p-type confinement layer to (Al x Ga 1-x ) y In 1-y P (0.2≤x≤0.8) (0.4≤y≤0.6);
an active region on the graded p-side spacer layer;
an n-side spacer layer on the active region; and
an n-type confinement layer on the n-side spacer layer.

12. The LED of claim 11 , wherein the graded p-side spacer layer comprises a diffusion profile of a p-type dopant from the p-type confinement layer.

13. The LED of claim 11 , wherein the p-type confinement layer comprises a p-type dopant selected from the group consisting of Mg and Zn.

14. The LED of claim 13 , wherein the p-type dopant is Mg.

15. The LED of claim 14 , wherein a Mg dopant concentration in the p-type confinement layer is set back about 200-500 nm from the active region.

16. The LED of claim 15 , wherein the graded layer is about 100-500 nm thick.

17. The LED of claim 15 , wherein the graded layer is about 50-150 nm thick.

18. The LED of claim 15 , wherein the Mg dopant concentration is set back about 100-200 nm into the p-type confinement layer away from the graded p-side spacer layer.

19. The LED of claim 15 , wherein the p-type confinement layer comprises AlInP.

20. The LED of claim 15 , wherein the graded spacer layer includes an Aluminum gradient of Δx ≥0.3.

21. The LED of claim 20 , wherein y is equal to about 0.5.

22. The LED of claim 21 , wherein an initial Aluminum content adjacent the p-type confinement layer is (Al x Ga 1-x ) 0.5 In 0.5 P, x=1.0.

23. The LED of claim 22 , wherein the graded p-side spacer layer is graded to (Al x Ga 1-x ) 0.5 In 0.5 P (0.2≤x≤0.7).

24. The LED of claim 21 , wherein an initial Aluminum content adjacent the p-type confinement layer is (Al x Ga 1-x ) 0.5 In 0.5 P, x=0.7.

25. The LED of claim 24 , wherein the graded p-side spacer layer is graded to (Al x Ga 1-x ) 0.5 In 0.5 P (0.2≤x≤0.5).

26. The LED of claim 15 , wherein the Mg dopant concentration in the p-type confinement layer is about 5×10 17 cm −3 -1.5×10 18 cm −3 .

27. The LED of claim 26 , wherein the LED does not include a graded n-side side spacer layer.

Assignees

• Apple Inc

Inventors

• Bour David P
• Sizov Dmitry S

Classifications

• H01L33/0025 Primary

  Electricity · mapped topic

• H01L33/06

  Electricity · mapped topic

• H01L33/305

  Electricity · mapped topic

• H01L33/02

  Electricity · mapped topic

• H01L33/14

  Electricity · mapped topic