LED having vertical structure and method for fabricating the same

• US 20070164298A1
• Filed: 12/15/2006
• Published: 07/19/2007
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Kim, Jong Wook, Cho, Hyun Kyong, Choi, Jae Wan, Na, Jong Ho, Jang, Jun
• Granted Patent: US 7,812,357 B2
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

A light emitting diode (LED) having a vertical structure and a method for fabricating the same. The light emitting diode (LED) having a vertical structure includes a support layer; a first electrode formed on the support layer; a plurality of semiconductor layers formed on the first electrode; a conductive semiconductor layer formed on the plurality of semiconductor layer and provided with an outer surface having a tilt angel of a designated degree; and a second electrode formed on the conductive semiconductor layer.

Claims

1. A method for fabricating a light emitting diode (LED), comprising:

forming a mask layer on a substrate;

forming a conductive semiconductor layer on the mask layer;

forming a plurality of semiconductor layers on the conductive semiconductor layer;

forming a first electrode on the plurality of semiconductor layers;

forming a support layer on the first electrode;

separating the substrate; and

forming a second electrode on the surface of the conductive semiconductor layer, exposed by the separation of the substrate.

2. The method according to claim 1, wherein the mask layer is formed on a buffer layer formed on the substrate in the formation of the mask layer.

3. The method according to claim 2, wherein the buffer layer is a gallium nitride-based semiconductor (Al_xIn_yGa_1-x-yN:

0≦

(x,y)≦

1) layer.

4. The method according to claim 1, wherein the formation of the mask layer includes:

forming a dielectric layer on the substrate; and

patterning the dielectric layer into a circular or polygonal shape.

5. The method according to claim 4, wherein the horizontal sectional shape of the conductive semiconductor layer is substantially the same as the circular or polygonal shape of the dielectric layer.

6. The method according to claim 4, wherein the horizontal sectional shape of the conductive semiconductor layer has more sides than the polygonal shape of the dielectric layer.

7. The method according to claim 1, wherein the dielectric layer is made of silicon oxide or silicon nitride.

8. The method according to claim 1, wherein the conductive semiconductor layer is a conductive GaN layer having a thickness of 1˜

300 μ

m.

9. The method according to claim 1, wherein the conductive semiconductor layer is formed by a hydride vapor phase epitaxy (HVPE) method.

10. The method according to claim 1, wherein the formation of the plurality of semiconductor layers includes:

forming an n-type semiconductor layer on the conductive semiconductor layer;

forming a light emitting layer on the n-type semiconductor layer; and

forming a p-type semiconductor layer on the light emitting layer.

11. The method according to claim 1, wherein the substrate is a GaN substrate formed by a hydride vapor phase epitaxy (HVPE) method.

12. The method according to claim 1, wherein the plurality of semiconductor layers are formed by a metal organic chemical vapor deposition (MOCVD) method.

13. The method according to claim 1, wherein the substrate is removed by a laser lift-off process or a wet etching process.

14. A light emitting diode (LED) having a vertical structure comprising:

a support layer;

a first electrode formed on the support layer;

a plurality of semiconductor layers formed on the first electrode;

a conductive semiconductor layer formed on the plurality of semiconductor layers, and provided with an outer surface having a tilt angle of a designated degree; and

a second electrode formed on the conductive semiconductor layer.

15. The LED according to claim 14, wherein the tilt angle of the outer surface of the conductive semiconductor layer is an angle between an upper surface and a side surface of the conductive semiconductor layer, which is in the range of 35˜

65°

.

16. The LED according to claim 14, wherein the conductive semiconductor layer is a conductive GaN layer having a thickness of 1˜

300 μ

m.

17. The LED according to claim 14, wherein at least one of the support layer, the first electrode, the plurality of semiconductor layers, the conductive semiconductor layer, and the second electrode has a horizontal sectional shape of a polygon, which is more than a rectangle.

18. The LED according to claim 14, wherein the first electrode includes:

a reflective electrode; and

an ohmic electrode formed on the reflective electrode.

19. The LED according to claim 14, wherein the first electrode is a reflective ohmic electrode.

20. The LED according to claim 14, wherein the substrate is one selected from the group consisting of a sapphire (Al₂O₃) substrate, a silicon (Si) substrate, a silicon carbide (SiC) substrate, a sapphire substrate, on which a nitride-based semiconductor layer is formed, a silicon substrate, on which a nitride-based semiconductor layer is formed, and a silicon carbide substrate, on which a nitride-based semiconductor layer is formed.

21. The LED according to claim 14, wherein the support layer is one selected from the group consisting of a silicon (Si) substrate, a gallium arsenide (GaAs) substrate, a germanium (Ge) substrate, a metal substrate, and a substrate including metal.

22. The LED according to claim 14, wherein the support layer is made of nickel (Ni) or copper (Cu).