LIGHT EMITTING DIODE AND LASER DIODE USING N-FACE GaN, InN, AND AlN AND THEIR ALLOYS

• US 20080111144A1
• Filed: 11/15/2007
• Published: 05/15/2008
• Est. Priority Date: 11/15/2006
• Status: Abandoned Application

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Keller, Stacia, Mishra, Umesh K., Fichtenbaum, Nicholas A.
• Application Number:
  US11/940,856
• Publication Number:
  US 20080111144A1
• Time in Patent Office: Days
• US Class Current: 257/96
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

The present invention allows the growth of InGaN with greater compositions of Indium than traditionally available now, which pushes LED and LD wavelengths into the yellow and red portions of the color spectrum. The ability to grow with Indium at higher temperatures leads to a higher quality AlInGaN. This also allows for novel polarization-based band structure designs to create more efficient devices. Additionally, it allows the fabrication of p-GaN layers with increased conductivity, which improves device performance.

Claims

1. A light emitting device, comprising:

(a) a p-type group-ITT nitride;

(b) an n-type group-III nitride; and

(c) a group-III-nitride active region growth along a [000-1] crystal direction resulting in a top surface which is a nitrogen face, wherein

(1) a first grown layer of the group-III-nitride active region growth is a group III atom layer and a last grown layer of the group-III-nitride active region growth is a nitrogen layer, such that a spontaneous polarization points towards a growth surface of the III-nitride active region; and

(2) the group-III-nitride active region growth is light emitting and between the n-type nitride and the p-type nitride.

2. The light emitting device of claim 1, wherein the group-III-nitride active region growth is from a nitrogen face.

3. The light emitting device of claim 2, wherein the group-III-nitride active region growth is from a group-III-nitride layer.

4. The light emitting device of claim 1, wherein the group-III-nitride active region is on a misoriented and nitridized substrate.

5. The light emitting device of claim 1, wherein the group-III-nitride active region growth is a growth from the n-type nitride.

6. The light emitting device of claim 1, wherein the n-type nitride is a growth along a [000-1] direction resulting in a top surface of the n-type nitride which is an N-face.

7. The light emitting device of claim 1, wherein the p-type nitride is a growth from the N-face of the group-III-nitride active region.

8. The light emitting device of claim 7, wherein the p-type nitride has a magnesium doping greater than 3×

10²⁰.

9. The light emitting device of claim 1, wherein the active region contains indium.

10. The light emitting device of claim 9, wherein the group-III-nitride active region growth contains more indium than an active region which is a growth along a [0001] direction resulting in a top surface which is a gallium face.

11. The light emitting device of claim 1, wherein the group-III-nitride active region is made from a material selected from the group comprising Nitrogen (N) face Gallium Nitride (GaN), N-face Indium Nitride (InN), and N-face Aluminum Nitride (AlN) and their alloys.

12. A method for growing a light emitting device, comprising

growing a light emitting III-nitride active region along a [000-1] crystal direction, resulting in a top surface of the III-nitride active region which is nitrogen-face (N-face).

13. The method of claim 12, wherein the light emitting III-nitride active region contains indium and is grown at a higher temperature and has an improved surface quality compared to an active region grown along a [0001] direction.

14. The method of claim 12, further comprising:

(a) growing an n-type nitride along a [000-1] direction and terminating on an N-face of the n-type nitride layer,

(b) growing the light emitting III-nitride active region on the N-face of the n-type nitride layer; and

(c) growing a p-type nitride layer along a [000-1] direction on the N-face of the light emitting III-nitride active region and terminating on an N-face of the p-type nitride layer,

15. The method of claim 12, further comprising:

(a) growing an n-type N-face GaN buffer layer on a misoriented and nitridized substrate;

(b) growing the light emitting III-nitride active region on the n-type N-face GaN buffer layer, the light emitting III-nitride active region comprising a multiple quantum well region;

(c) growing a p-type N-face GaN cap layer on the light emitting III-nitride active region;

(d) applying a metal to contact the p-type N-face GaN cap layer;

(e) forming one or more light emitting diode mesas by etching the layers obtained in steps (a)-(e); and

(f) applying a second metal to contact the n-type N-face GaN buffer layer.

16. The method of claim 12, further comprising:

(a) growing an n-type N-face AlGaN buffer and confinement layer;

(b) growing an n-type N-face GaN layer on the AlGaN buffer and confinement layer;

(c) growing the light emitting III-nitride active region on the n-type N-face GaN layer, the light emitting III-nitride active region comprising multiple quantum wells of InGaN active material;

(d) growing a p-type N-face GaN layer on the light emitting III-nitride active region;

(e) growing a p-type AlGaN cladding layer on the p-type N-face GaN layer;

(f) applying a metal to contact the p-type AlGaN cladding layer;

(g) etching a laser diode stripe structure and forming mirror facets into the layers obtained from steps (a)-(g); and

(h) applying a second metal to contact the n-type N-face GaN layer.

17. A III-nitride film, comprising:

a growth of III-nitride resulting in a top surface which is a nitrogen face.

18. The III-nitride film of claim 17, wherein a first grown layer of the growth is a group III atom layer and a last grown layer of the growth is a nitrogen layer, such that a spontaneous polarization points towards a growth surface of the III-nitride film.

19. The III-nitride film of claim 17, wherein the growth is from a misoriented and nitridized surface of a substrate.

20. The III-nitride film of claim 17, wherein the III-nitride film emits light.