Semiconductor light-emitting device

• US 8,227,820 B2
• Filed: 02/09/2005
• Issued: 07/24/2012
• Est. Priority Date: 02/09/2005
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Sharma, Rajat, Pattison, Paul Morgan, Kaeding, John Francis, Nakamura, Shuji
• Primary Examiner(s): Jackson, Jr., Jerome
• Application Number:
  US11/054,271
• Publication Number:
  US 20060175624A1
• Time in Patent Office: 2,722 Days
• Field of Search: 257/95
• US Class Current: 257/95
• 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 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01S 5/0207 Substrates having a special shape
• CPC Class Codes: H01S 5/10 Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region H01S5/20 takes precedence
• CPC Class Codes: H01S 5/1053 Comprising an active region having a varying composition or cross-section in a specific direction
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A semiconductor light-emitting diode, and method of fabricating same, wherein an indium (In)-containing light-emitting layer, as well as subsequent device layers, is deposited on a textured surface. The resulting device is a phosphor-free white light source.

Claims

1. A method of fabricating a semiconductor light emitting device, comprising:

depositing one or more indium-containing light emitting (Al, In, Ga)N active or passive layers directly on a textured surface of an n-type layer, wherein the indium-containing light emitting (Al, In, Ga)N active or passive layers incorporate varying fractions of indium depending on a position on the textured surface, with a higher incorporation of indium at a top of a pillar on the textured surface as compared to a lower incorporation of indium in a valley between pillars on the textured surface, thereby resulting in a spatial variation in the incorporation of indium in the indium-containing light-emitting (Al, In, Ga)N active or passive layers, such that the device comprises a phosphor-free white light source.

2. The method of claim 1, wherein the step of depositing comprises:

(1) depositing one or more first GaN layers on a substrate;

(2) etching the deposited first GaN layers to create the textured surface;

(3) re-growing one or more second GaN layers on the textured surface; and

(4) depositing the indium-containing light-emitting active or passive layers on the re-grown second GaN layers.

3. The method of claim 2, wherein the step (4) of depositing the indium-containing light-emitting active or passive layers on the re-grown second GaN layers further comprises:

(i) depositing a quantum well layer of (Al, In, Ga)N on the re-grown second GaN layers; and

(ii) depositing a barrier layer of (Al, In, Ga)N on the quantum well layer of (Al, In, Ga)N.

4. The method of claim 3, further comprising repeating the steps of depositing (i) and depositing (ii) to obtain a plurality of quantum well and barrier layers.

5. The method of claim 1, further comprising selectively texturing the surface.

6. The method of claim 5, wherein the textured surface is a partially textured surface.

7. The method of claim 5, further comprising controlling a ratio of a textured area of the surface to a non-textured area of the surface.

8. The method of claim 5, further comprising controlling the textured surface'"'"'s pattern.

9. The method of claim 5, further comprising controlling the textured surface'"'"'s dimensions.

10. The method of claim 5, wherein different patterns and depths of the textured surface produce different emission results.

11. A device manufactured according to the method of claim 1.

22. The method of claim 1, wherein varying fractions of Indium are incorporated into the light emitting (Al, In, Ga)N active or passive layers depending on the position on the textured surface, with an intermediate incorporation of Indium in the light emitting (Al, In, Ga)N active or passive layers at a sidewall of a pillar on the textured surface.

23. The method of claim 10, wherein depths of the textured surface are at least 500 nm.

27. The method of claim 1, wherein the spatial variation in the incorporation of indium in the indium-containing light-emitting (Al, In, Ga)N active or passive layers results in multi-wavelength emission from the indium-containing light-emitting (Al, In, Ga)N active or passive layers.

12. A semiconductor light emitting device, comprising:

one or more Indium-containing light emitting (Al, In, Ga)N active or passive layers deposited directly on a textured surface of an n-type layer, wherein the Indium-containing light emitting (Al, In, Ga)N active or passive layers incorporate varying fractions of Indium depending on a position on the textured surface, with a higher incorporation of Indium at a top of a pillar on the textured surface as compared to a lower incorporation of Indium in a valley between pillars on the textured surface, thereby resulting in a spatial variation in the incorporation of Indium in the Indium-containing light-emitting (Al, In, Ga)N active or passive layers, such that the device comprises a phosphor-free white light source.

13. The device of claim 12, further comprising:

(1) one or more first GaN layers deposited on a substrate;

(2) the textured surface created by etching the deposited first GaN layers;

(3) one or more second GaN layers re-grown on the textured surface; and

(4) the indium-containing light-emitting active or passive layers deposited on the re-grown second GaN layers.

14. The device of claim 13, wherein the indium-containing light-emitting active or passive layers deposited on the re-grown second GaN layers further comprise:

(i) a quantum well layer of (Al, In, Ga)N deposited on the re-grown second GaN layers; and

(ii) a barrier layer of (Al, In, Ga)N deposited on the quantum well layer of (Al, In, Ga)N.

15. The device of claim 14, further comprising a plurality of quantum well and barrier layers.

16. The device of claim 12, wherein the surface is selectively textured.

17. The device of claim 16, wherein the textured surface is a partially textured surface.

18. The device of claim 16, wherein a ratio of a textured area of the surface to a non-textured area of the surface is controlled.

19. The device of claim 16, wherein the textured surface'"'"'s pattern is controlled.

20. The device of claim 16, wherein the textured surface'"'"'s dimensions are controlled.

21. The device of claim 16, wherein the textured surface includes different patterns and depths that produce different emission results.

24. The device of claim 12, wherein varying fractions of Indium are incorporated into the light emitting (Al, In, Ga)N active or passive layers depending on the position on the textured surface, with an intermediate incorporation of Indium in the light emitting (Al, In, Ga)N active or passive layers at a sidewall of a pillar on the textured surface.

25. The device of claim 21, wherein depths of the textured surface are at least 500 nm.

26. The device of claim 12, wherein the spatial variation in the incorporation of indium in the indium-containing light-emitting (Al, In, Ga)N active or passive layers results in multi-wavelength emission from the indium-containing light-emitting (Al, In, Ga)N active or passive layers.