Light-emitting diode

• US 20050145873A1
• Filed: 01/03/2004
• Published: 07/07/2005
• Est. Priority Date: 12/24/2003
• Status: Abandoned Application

• Current Assignee: Formosa Epitaxy Incorporated (Epistar Corporation)
• Original Assignee: Formosa Epitaxy Incorporated (Epistar Corporation)
• Inventors: Pan, Shyi-Ming, Chien, Fen-Ren, Chen, Lung-Chien
• Application Number:
  US10/750,784
• Publication Number:
  US 20050145873A1
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A light-emitting diode device is provided with the following manufacturing method: forming an n-GaN layer on a substrate; growing an SiO₂ layer on the n-GaN surface, and using the photo-lithography process to expose the n-GaN within the mesa area; using MOCVD to grow an LED structure in the epitaxy within the mesa area, the formed structure being a p-n coplanar structure due to the selective area characteristic; and finally, forming the electrodes on the structure to complete an LED device. The device can be manufactured without the etching process to form the p-n coplanar structure. In comparison to other conventional manufacturing methods, the method simplifies the manufacturing process, and avoids many problems associated with etching, including non-uniform etching, overly rough surface, etching damages, and current leakage. Furthermore, SiO₂ is used as a scattering layer to prevent emitted light from internally reflected, and therefore, improves the external quantum efficiency.

Claims

1. A light-emitting diode (LED) device, comprising:

a substrate;

a first semiconductor layer, formed on top of the substrate;

an insulating layer, formed on top of the first semiconductor layer;

a mesa area, formed on the insulting layer and exposing the surface of the first semiconductor layer; and

an LED structure formed on the exposed surface of the first semiconductor layer;

where the LED structure being a light-emitting active layer and a p-type GaN III-V group compound layer, the p-type GaN III-V group compound layer being connected to a p-type low-resistance ohm contact, and an n-type GaN III-V group compound layer being connected to an n-type low-resistance ohm contact to provide a forward bias.

2. The LED device as claimed in claim 1, wherein the substrate is selected from the group consisting of sapphire, SiC, Si, GaAs, LiAlO₂, LiGaO₂, AlN.

3. The LED device as claimed in claim 1, wherein the first semiconductor layer is an n-type semiconductor layer.

4. The LED device as claimed in claim 1, wherein the first semiconductor layer is an Al_xGa_(1-x-y)In_yN thick film, with 0≦

x,y<

1, 0≦

x+y<

1.

5. The LED device as claimed in claim 1, wherein the insulating layer at least comprises a material selected from a group consisting of SiO₂, SiN, AlN, TiN, Al₂O₃ and a combination thereof.

6. The LED device as claimed in claim 1, wherein the insulating layer is made of metal, alloy, or their combination.

7. The LED device as claimed in claim 1, wherein the insulating layer is fabricated with an e-gun, sputter, or CVD method.

8. The LED device as claimed in claim 1, wherein the insulating layer has the thickness greater than 0.1 μ

m.

9. The LED device as claimed in claim 1, wherein the mesa area is formed with a photo-lithography process.

10. The LED device as claimed in claim 1, wherein the light-emitting active layer is a P-N junction, DH, SQW, or MQW structure.

11. A light-emitting diode (LED) device, comprising:

a substrate;

a first semiconductor layer, formed on top of the substrate;

a plurality of trenches, formed in a part of area of the first semiconductor layer;

an insulating layer, formed in the trenches; and

an LED structure formed on the exposed surface of the first semiconductor layer;

where the LED structure being a light-emitting active layer and a p-type GaN III-V group compound layer, the p-type GaN III-V group compound layer being connected to a p-type low-resistance ohm contact, and an n-type GaN III-v group compound layer being connected to an n-type low-resistance ohm contact to provide a forward bias.

12. The LED device as claimed in claim 11, wherein the substrate is selected from a group consisting of sapphire, SiC, Si, GaAs, LiAlO₂, LiGaO₂, AlN.

13. The LED device as claimed in claim 11, wherein the first semiconductor layer is an Al_xGa_(1-x-y)In_yN thick film, with 0≦

x,y≦

1, 0≦

x+y<

1.

14. The LED device as claimed in claim 11, wherein the first semiconductor layer has the thickness greater than 0.1 μ

m.

15. The LED device as claimed in claim 11, wherein the method of forming the trenches on the first semiconductor layer comprises at least one of the following methods:

photo-lithography or laser processing.

16. The LED device as claimed in claim 11, wherein the method of forming the trenches on the first semiconductor layer comprises at least one of the following methods:

wet etching or dry etching.

17. The LED device as claimed in claim 11, wherein the depth of the trenches on the first semiconductor layer is less than or equal to the thickness of the first semiconductor layer.

18. The LED device as claimed in claim 11, wherein the depth of the trenches on the first semiconductor layer is greater than the thickness of the first semiconductor layer.

19. The LED device as claimed in claim 11, wherein the shape of the trenches on the first semiconductor layer comprises at least one of the following or their combination:

rectangle, triangle, circle, and polygon.

20. The LED device as claimed in claim 11, wherein the insulating layer is selected from a group consisting of SiO₂, Si₃N₄, AlN, TiN, TiO₂ and a combination thereof.

21. The LED device as claimed in claim 11, wherein the insulating layer is made of metal, alloy, or their combination.

22. The LED device as claimed in claim 11, wherein the insulating layer has the thickness greater than 0.1 μ

m.

23. The LED device as claimed in claim 11, wherein the light-emitting active layer is a P-N junction, DH, SQW, or MQW structure.