Light emitting device including second conductive type semiconductor layer and method of manufacturing the light emitting device

• US 8,698,125 B2
• Filed: 11/01/2010
• Issued: 04/15/2014
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Son, Hyo Kun
• Primary Examiner(s): Cao, Phat X
• Application Number:
  US12/916,740
• Publication Number:
  US 20110101340A1
• Time in Patent Office: 1,261 Days
• Field of Search: 257/14, 257/43, 257/E33.007, 257/E33.008
• US Class Current: 257/14
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Provided is a light emitting device, which includes a first conductive type semiconductor layer, an active layer, a roughness pattern, and a second conductive type semiconductor layer. The active layer is disposed on the first conductive type semiconductor layer. The roughness pattern is disposed on the active layer. The second conductive type semiconductor layer is disposed on the roughness pattern and the active layer, and includes a metal oxide.

Claims

1. A light emitting device comprising:

a first conductive type semiconductor layer including an n-type dopant;

an active layer on the first conductive type semiconductor layer;

a roughness pattern disposed on the active layer, a first portion of the active layer exposed by the roughness pattern and a second portion of the active layer covered by the roughness pattern; and

a second conductive type semiconductor layer including a p-type dopant on the roughness pattern and the active layer, the second conductive type semiconductor layer including a metal oxide semiconductor,

wherein a first portion of the second conductive type semiconductor layer contacts an upper surface of the roughness pattern,

wherein a second portion of the second conductive type semiconductor layer contacts the first portion of the active layer exposed by the roughness pattern,

wherein an entire region of the roughness pattern is located at a position higher than an entire region of the active layer,

wherein the active layer includes a nitride-based material different from the second conductive type semiconductor layer, and

wherein the roughness pattern contacts a top surface of the active layer.

2. The light emitting device according to claim 1, wherein the metal oxide semiconductor is formed of a zinc oxide (ZnO).

3. The light emitting device according to claim 1, wherein the p-type dopant of the second conductive type semiconductor layer comprises at least one of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and cadmium (Cd).

4. The light emitting device according to claim 1, wherein the second conductive type semiconductor layer comprises a concave-convex pattern.

5. The light emitting device according to claim 1, wherein the roughness pattern has a composition formula of In_xAl_yGa_1-x-yN, where 0≦

x≦

1, 0≦

y≦

1, and 0≦

x+y≦

1.

6. The light emitting device according to claim 5, wherein the roughness pattern comprises a p-type dopant including at least one of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and cadmium (Cd).

7. The light emitting device according to claim 1, wherein the active layer is formed by stacking a barrier layer and a well layer.

8. The light emitting device according to claim 7, wherein the barrier layer is provided in plurality,

the active layer comprises the barrier layers, and

a first barrier layer having a thickness ranging from about 150% to about 250% of a thickness of the other barrier layers is disposed on an uppermost part of the barrier layers.

9. The light emitting device according to claim 8, wherein an upper portion of the first barrier layer comprises a p-type dopant including at least one of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and cadmium (Cd).

10. The light emitting device according to claim 9, wherein the upper portion of the first barrier layer including the p-type dopant has a thickness ranging from about 20% to about 30% of an entire thickness of the first barrier layer.

11. The light emitting device according to claim 1, wherein an electrode is disposed on the second conductive type semiconductor layer.

12. The light emitting device according to claim 1, further comprising a conductive support member on the second conductive type semiconductor layer and a reflective layer between the conductive support member and the second conductive type semiconductor layer.

13. The light emitting device according to claim 1, wherein the first portion of the second conductive type semiconductor layer is disposed on the second portion of the active layer.

14. The light emitting device according to claim 1, wherein a lowermost surface of the second conductive type semiconductor layer contacts an uppermost surface of the active layer, and

wherein the second portion of the second conductive type semiconductor layer is disposed in porous regions of the roughness pattern.

15. The light emitting device according to claim 1, wherein the active layer includes a plurality of barrier layers and a plurality of well layers,

wherein the plurality of barrier layer includes a first barrier layer having a thickness greater than a thickness of the other barrier layers,

wherein the first barrier layer is disposed to be closer to the second conductive type semiconductor layer than to all of the plurality of well layers, and

wherein the roughness pattern contacts a top surface of the first barrier layer.

16. The light emitting device according to claim 15, wherein the roughness pattern includes a nitride-based material different from the second conductive type semiconductor layer, and

wherein the roughness pattern has a thickness less than a thickness of the second conductive type semiconductor layer in a vertical direction.

17. The light emitting device according to claim 1, wherein the roughness pattern is formed of a p-type nitride-based semiconductor, and

wherein the roughness pattern is disposed between the active layer and the second conductive type semiconductor layer.

18. The light emitting device according to claim 17, wherein the roughness pattern has porous regions, and

wherein the porous regions are regularly distributed on an entire region of the top surface of the first barrier layer.

19. A light emitting device package comprising:

a body having a cavity;

a plurality of electrodes exposed within the cavity and separated from each other;

a light emitting device within the cavity, the light emitting device being connected to the electrode; and

a resin filling the cavity,

wherein the light emitting device includes a first conductive type semiconductor layer including an n-type dopant, an active layer on the first conductive type semiconductor layer, a roughness pattern on the active layer, and a second conductive type semiconductor layer including a p-type dopant on the roughness pattern and the active layer, the second conductive type semiconductor layer including a metal oxide semiconductor,

wherein a first portion of the active layer is exposed by the roughness pattern and a second portion of the active layer is covered by the roughness pattern,

wherein a first portion of the second conductive type semiconductor layer contacts an upper surface of the roughness pattern,

wherein a second portion of the second conductive type semiconductor layer contacts the first portion of the active layer exposed by the roughness pattern,

wherein an entire region of the roughness pattern is located at a higher position than that of an entire region of the active layer,

wherein the active layer includes a nitride-based material different from the second conductive type semiconductor layer,

wherein the roughness pattern contacts a top surface of the active layer, and

wherein the roughness pattern is disposed between the active layer and the second conductive type semiconductor layer.

20. The light emitting device according to claim 19, wherein the roughness pattern includes a p-type nitride-based semiconductor different from the second conductive type semiconductor layer.