Claims
- 1. A light-emitting diode comprising:
a substrate; an n-type layer of III-nitride formed over the substrate; an active region, formed over the n-type layer; a p-type AlxGa(1−x)N (0≦x≦1) layer, formed over the active region; a p-type transition layer of GaN, formed over the p-type AlxGa(1−x)N layer, the p-type transition layer having a resistivity of about 100 Ωcm; and an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type transition layer.
- 2. A light-emitting diode comprising:
a substrate; an n-type layer of III-nitride formed over the substrate; an active region, formed over the n-type layer; a p-type AlxGa(1−x)N (0≦x<1) layer, formed over the active region; a p-type transition layer, formed over the p-type AlxGa(1−x)N layer, the p-type transition layer having a resistivity from about 7 Ωcm to about 250 Ωcm; and an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type transition layer.
- 3. The light emitting diode of claim 2 wherein the p-type transition layer further comprises at least one Group II dopant selected from Be, Mg, Ca, Sr, Zn, Cd, and C.
- 4. The light emitting diode of claim 3 wherein the Group II dopant is Mg and wherein the p-type transition layer further comprises a co-dopant selected from Si, Ge, O, S, Se, and Te.
- 5. The light emitting diode of claim 4 wherein the concentration of Mg exceeds about 5e1019 cm−3 in the p-type transition layer.
- 6. The light emitting diode of claim 2 wherein the p-type transition layer is a III-V material.
- 7. The light emitting diode of claim 2 wherein the p-type transition layer is selected from GaN, AlInGaN, InGaN, GaNAs, GaNP, AlInGaNAsP, and GaNAsP.
- 8. The light emitting diode of claim 2 further comprising a p-type conductivity layer of GaN, formed over the p-type AlxGa(1−x)N layer.
- 9. The light emitting diode of claim 2 wherein a driving voltage of the light emitting diode is less than about 3.5 volts.
- 10. A light-emitting diode comprising:
a substrate; an n-type layer of III-nitride, formed over the substrate; an active region, formed over the n-type layer; a single p-type layer, formed over the active layer, the single p-type layer having a varying composition and a varying concentration of a dopant; an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type layer.
- 11. The light-emitting diode of claim 10, wherein the p-type layer dopant is a Group II dopant selected from Be, Mg, Ca, Sr, Zn, Cd, and C.
- 12. The light-emitting diode of claim 11, wherein the Group II dopant is magnesium and the p-type layer further comprises a co-dopant selected from Si, Ge, O, S, Se, and Te.
- 13. The light-emitting diode of claim 10, wherein the p-type layer comprises a material selected from III-nitride, III-nitride arsenide, III-nitride phosphide, and III-nitride arsenide phosphide.
- 14. The light-emitting diode of claim 10, wherein the p-type layer has a thickness between 5 and 200 nm.
- 15. The light-emitting diode of claim 10, wherein a first concentration of the dopant in a region of the p-type layer adjacent to the active region is less than a second concentration of the dopant in a region of the p-type layer adjacent to the p-type contact.
- 16. The light-emitting diode of claim 15, wherein the dopant is magnesium and the first concentration is about 1e18 cm−3 to about 5e19 cm−3.
- 17. The light-emitting diode of claim 15, wherein the dopant is magnesium and the second concentration is about 5e19 cm−3 to about 1e21 cm−3.
- 18. The light-emitting diode of claim 10 wherein the p-type layer comprises a varying composition of aluminum.
- 19. The light-emitting diode of claim 18 wherein the composition of aluminum varies from about 20% in a region of the p-type layer adjacent to the active region to about 0% in a region of the p-type layer adjacent to the p-type contact.
- 20. The light emitting diode of claim 10 wherein the p-type layer comprises a varying composition of indium.
- 21. The light emitting diode of claim 20 wherein the composition of indium varies from about 0% in a region of the p-type layer adjacent to the active region to about 40% in a region of the p-type layer adjacent to the p-type contact.
- 22. The light emitting diode of claim 10 wherein a driving voltage of the light emitting diode is less than about 3.5 volts.
- 23. A light-emitting diode comprising:
a substrate; an n-type layer of III-nitride formed over the substrate; an active region, formed over the n-type layer; a p-type AlxGa(1−x)N (0≦x≦1) layer, formed over the active region; a p-type transition layer, formed over the p-type AlxGa(1−x)N layer, the p-type transition layer comprising a superlattice, the superlattice further comprising: a first sublayer of doped p-type material; a second sublayer of material, wherein a concentration of dopant in the second sublayer is less than a concentration of dopant in the first sublayer; and an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type transition layer.
- 24. The light-emitting diode of claim 23 wherein the dopant is Mg and the dopant concentration of the first sublayer is about 1e20 cm−3 to about 5e21 cm−3.
- 25. The light-emitting diode of claim 23 wherein the dopant is Mg and the dopant concentration of the second sublayer is undoped to about 1e20 cm−3.
- 26. The light-emitting diode of claim 23 wherein each of the first and second sublayers has a thickness from about 2 to about 20 nm.
- 27. The light emitting diode of claim 23 wherein a driving voltage of the light emitting diode is less than about 3.5 volts.
- 28. A light emitting diode comprising:
a substrate; an n-type layer of III-nitride formed over the substrate; an active region, formed over the n-type layer; a p-type AlxGa(1−x)N (0≦x≦1) layer, formed over the active region; a p-type transition layer, formed over the p-type AlxGa(1−x)N layer, the p-type transition layer comprising a sublayer of a p-type doped material and a sublayer of elemental dopant; and an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type transition layer.
- 29. The light emitting diode of claim 28 wherein the dopant is Mg.
- 30. The light emitting diode of claim 28 further comprising a p-type conductive layer of GaN, formed over the p-type AlxGa(1−x)N layer.
- 31. The light emitting diode of claim 28 wherein a driving voltage of the light emitting diode is less than about 3.5 volts.
- 32. A method of manufacturing a light-emitting diode comprising:
forming an n-type layer of III-nitride over a substrate; forming an active region over the n-type layer; forming a p-type layer over the active layer, the p-type layer having a varying composition and a varying concentration of a dopant; forming an n-type contact and a p-type contact, the n-type contact being connected to the n-type layer, the p-type contact being connected to the p-type layer.
- 33. The method of claim 32, further comprising doping the p-type layer with a Group II dopant selected from Be, Mg, Ca, Sr, Zn, Cd, and C.
- 34. The method of claim 32, wherein the Group II dopant is magnesium, the method further comprising doping the p-type layer with a co-dopant selected from a group consisting of Si, Ge, O, S, Se, and Te.
- 35. The method of claim 32, further comprising:
doping a region of the p-type layer adjacent to the active region to a first concentration; and doping a region of the p-type layer adjacent to the p-type contact to a second concentration, wherein the first concentration is less than the second concentration.
- 36. The method of claim 32 further comprising varying a composition of aluminum from 20% in a region of the p-type layer adjacent to the active region to 0% in a region of the p-type layer adjacent to the p-type contact.
- 37. The method of claim 32 the p-type layer is a superlattice, and wherein forming a p-type layer further comprises:
forming a first sublayer of doped p-type material; and forming a second sublayer of doped p-type material, wherein a concentration of dopant in the second sublayer is less than a concentration of dopant in the first sublayer.
Parent Case Info
[0001] This is a continuation-in-part of application Ser. No. 09/092,065, filed Jun. 5, 1998.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09092065 |
Jun 1998 |
US |
Child |
09755935 |
Jan 2001 |
US |