LIGHT-EMITTING DEVICE

• US 20050072968A1
• Filed: 10/06/2003
• Published: 04/07/2005
• Est. Priority Date: 10/06/2003
• Status: Abandoned Application

• Current Assignee: United Epitaxy Company, Ltd. (Ennostar, Inc.)
• Original Assignee: United Epitaxy Company, Ltd. (Ennostar, Inc.)
• Inventors: Chang, Chih-Sung, Chen, Tzer-Perng, Chien, Wei-En, Tsai, Tzong-Liang
• Application Number:
  US10/605,539
• Publication Number:
  US 20050072968A1
• Time in Patent Office: Days
• US Class Current: 257/10
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

The present invention discloses a light-emitting device that has a substrate, an n-type electrode, an active layer, a p-type semiconductor layer, a reflective layer, and a p-type electrode. The n-type electrode is located on the bottom surface of the substrate and the active layer is located on a top surface of the substrate. The p-type semiconductor layer covers the active layer. The reflective layer is located on the p-type semiconductor layer, and the p-type electrode covers the reflective layer. The reflective layer is a conductive layer with high reflectivity, and is formed under the p-type electrode to avoid light of the light-emitting device being absorbed by the metal electrode.

Claims

1. A semiconductor light-emitting device comprising:

a substrate;

an n-type electrode located on a bottom surface of the substrate;

an active layer located on a top surface of the substrate;

a p-type semiconductor layer covering the active layer;

a reflective layer located on the p-type semiconductor layer; and

a p-type electrode covering the reflective layer.

2. The semiconductor light-emitting device of claim 1 wherein the substrate is a conductive material.

3. The semiconductor light-emitting device of claim 1 wherein the p-type semiconductor layer comprises a plurality of p-type III-V compound layers.

4. The semiconductor light-emitting device of claim 1 wherein the reflective layer is a conductive layer with predetermined reflectivity, the reflective layer reflects light from the active layer to avoid light being absorbed by the p-type electrode.

5. The semiconductor light-emitting device of claim 4 wherein the reflective layer is a single-layer structure.

6. The semiconductor light-emitting device of claim 4 wherein the reflective layer is a multi-layer structure.

7. The semiconductor light-emitting device of claim 4 wherein the reflective layer comprises silver (Ag), aluminum (Al), gold (Au), chromium (Cr), platinum (Pt), or rhodium (Rh).

8. The semiconductor light-emitting device of claim 1 wherein the reflective layer is a conductive layer with predetermined scattering rate, the reflective layer partially reflects light from the active layer to reduce light being absorbed by the p-type electrode.

9. The semiconductor light-emitting device of claim 1 wherein the reflective layer and the p-type semiconductor layer contact at a rough surface, the rough surface having an incline or a curved structure with a specific reflective angle to enhance the reflective layer.

10. The semiconductor light-emitting device of claim 1 further comprising a distributed Bragg reflector (DBR) located between the substrate and the active layer.

11. A semiconductor light-emitting device comprising:

a substrate;

an n-type semiconductor layer covering the substrate;

an active layer and an n-type electrode separately covering portions of the n-type semiconductor layer;

a p-type semiconductor layer covering the active layer;

a first reflective layer located on the p-type semiconductor layer; and

a p-type electrode covering the first reflective layer.

12. The semiconductor light-emitting device of claim 11 wherein the substrate is a nonconductive material.

13. The semiconductor light-emitting device of claim 11 wherein the n-type semiconductor layer comprises a plurality of n-type III-V compound layers and the p-type semiconductor layer comprises a plurality of p-type III-V compound layers.

14. The semiconductor light-emitting device of claim 11 further comprising a second reflective layer located between the n-type semiconductor layer and the n-type electrode.

15. The semiconductor light-emitting device of claim 14 wherein the first reflective layer and the second reflective layer are both a conductive layer with predetermined reflectivity, the first reflective layer and the second reflective layer reflect light from the active layer to avoid light being absorbed by the p-type electrode and the n-type electrode.

16. The semiconductor light-emitting device of claim 15 wherein the second reflective layer and the n-type semiconductor layer contact at a rough surface, the rough surface having an incline or a curved structure with a specific reflective angle to enhance the second reflective layer.

17. The semiconductor light-emitting device of claim 15 wherein the first reflective layer and the second reflective layer are both a single-layer structure.

18. The semiconductor light-emitting device of claim 15 wherein the first reflective layer and the second reflective layer are both a multi-layer structure.

19. The semiconductor light-emitting device of claim 15 wherein the first reflective layer and the second reflective layer comprise silver (Ag), aluminum (Al), gold (Au), chromium (Cr), platinum (Pt), or rhodium (Rh).

20. The semiconductor light-emitting device of claim 14 wherein the first reflective layer and the second reflective layer are both a conductive layer with predetermined scattering rate, the first reflective layer and the second reflective layer partially reflect light from the active layer to reduce light being absorbed by the p-type electrode and the n-type electrode.

21. The semiconductor light-emitting device of claim 11 wherein the first reflective layer and the p-type semiconductor layer contact at a rough surface, the rough surface having an incline or a curved structure with a specific reflective angle to enhance the first reflective layer.

22. The semiconductor light-emitting device of claim 11 further comprising a distributed Bragg reflector (DBR) located between the substrate and the n-type semiconductor layer.